Communication method and communication apparatus

Abstract

The embodiments of the present application relate to the technical field of communications. Disclosed are a communication method and a communication apparatus, which can increase the probability of successful access of an A-IoT device. In the method, when a first apparatus triggers or pages a second apparatus, the first apparatus may group access occasions. If the second apparatus determines, on the basis of a first message received from the first apparatus, that the first message is used for paging or triggering a first access occasion group of the second apparatus, the second apparatus sends a second message to the first apparatus in response to the first message. For example, the first apparatus is a reader, and the second apparatus is an A-IoT device. This is equivalent to grouping A-IoT devices such that a plurality of A-IoT devices can give a response after different R2D messages are allocated thereto, so as to solve the problem of a limited number of time-domain resources for D2R transmission after each R2D message is sent being likely to cause an access failure of an A-IoT device to a reader, thereby increasing the access success rate of the A-IoT device.

Description

A communication method and a communication apparatus

[0001] The present application claims priority to the Chinese Patent Application No. 202411392338.6, filed on September 30, 2024, entitled "A communication method and a communication apparatus", to the Chinese Patent Application No. 202411600902.9, filed on November 08, 2024, entitled "A communication method and a communication apparatus", and to the Chinese Patent Application No. 202510398265.X, filed on March 28, 2025, entitled "A communication method and a communication apparatus", all of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, and in particular to a communication method and a communication apparatus. BACKGROUND

[0003] With the development of communication technology, the Internet of Things technology is introduced, for example, the Internet of Things technology can be ambient Internet of Things (A-IoT) technology. A-IoT is based on cellular network communication infrastructure, including network devices (such as base stations) and passive, semi-passive or active A-IoT devices (A-IoT devices can be terminals in the cellular network, which can be understood as extremely low power consumption and extremely low complexity Internet of Things terminals), and the main services include inventory, positioning, sensing or command, etc.

[0004] In the basic inventory or access process of A-IoT, the network device is a reader, and when the reader acts as a reader, in an implementation manner, the R2D (reader to device) message (a message sent by the reader to the A-IoT device) triggers the sending of the D2R (device to reader) message (a message sent by the A-IoT device to the reader), and the access occasion of the D2R defined by the reader is limited, and multiple A-IoT devices may also select the same access occasion to send messages to the reader, resulting in the problem of multiple message collisions at the reader, which easily leads to A-IoT device access failure. SUMMARY

[0005] Embodiments of the present application provide a communication method and a communication apparatus, which can improve the success probability of A-IoT device access.

[0006] In a first aspect, a communication method is provided. The execution subject of the method can be an A-IoT device, a component or apparatus (e.g., a processor, a chip, or a chip system, etc.) applied to the A-IoT device, or a logic module or software capable of implementing all or part of the functions of the A-IoT device. The method comprises: receiving a first message sent by a first apparatus, the first message being used to trigger an access occasion of the first apparatus and / or being used to page at least one second apparatus; and sending a second message to the first apparatus at an access occasion of a first access occasion set, the second message being used for the second apparatus to access the first apparatus or send data to the first apparatus, the first access occasion set being determined based on the first message, and the first access occasion set comprising at least one access occasion.

[0007] The first apparatus can be a reader in an A-IoT architecture, and the second apparatus can be an A-IoT device. The first message can be, for example, an R2D trigger message, and the second message can be, for example, a random number or a device identifier or uplink data generated by the second apparatus. In this way, in the method, the first apparatus can group the second apparatuses, so as to control the number of second apparatuses accessing the first apparatus in groups, and allow a limited number of second apparatuses to access the first apparatus in different access occasion sets. That is, when the second apparatus determines that the received first message triggers or pages an access occasion set to which the second apparatus belongs, the second apparatus will respond to the first message and send a second message to the first apparatus. In the A-IoT architecture, by grouping the A-IoT devices, a plurality of A-IoT devices can be divided into different groups that respond to R2D trigger messages, so as to solve the problem that the number of time domain resources for D2R transmission is limited after each R2D message is sent, and to improve the access success rate of the A-IoT devices.

[0008] In a possible design, the first message comprises at least one of the following information: a total number of access occasion sets for accessing the first apparatus; and a group number of the first access occasion set. That is, the second apparatus can determine whether the first message triggers or pages an access occasion set of the second apparatus based on the total number of access occasion sets carried by the first message and / or the group number of the first access occasion set carried by the first message. The first access occasion set can be understood as one of a plurality of access occasion sets grouped by the first apparatus.

[0009] In one possible design, the first access occasion group is determined based on the first message includes that the first access occasion group is determined based on the first message and a group number of the second access occasion group, and the group number of the second access occasion group is less than or equal to a total number of groups of access occasion groups. In other words, the second device can determine whether the first message triggers an access occasion group of the second device based on contents of the first message and a group number of a second access occasion group. For example, the group number of the second access occasion group can be randomly generated by the second device.

[0010] In one possible design, the method further includes determining a group number of the second access occasion group, and the first access occasion group is determined based on the first message and the group number of the second access occasion group includes that the first access occasion group is the access occasion group for the second device to send the second message when the group number of the second access occasion group is the same as the group number of the first access occasion group. In this case, the group numbers of the access occasion groups determined by multiple second devices can be different, which can enable the multiple second devices to attempt to access the first device in different access occasion groups and thus achieve group triggering or paging of the second devices by the first device.

[0011] In one possible design, the method further includes determining a group number of the first access occasion group, and the first access occasion group is determined based on the first message and the group number of the second access occasion group includes that the first access occasion group is determined by the second device by decrementing the group number of the first access occasion group each time the first message is received and determining when the group number is decremented to the group number of the second access occasion group. This design is equivalent to the second device randomly selecting a first access occasion group, but the randomly selected first access occasion groups can be different. In this case, the time when the group number is decremented to the group number of the second access occasion group can be different each time the first message is received, which can enable the second device to determine at different times that the first message triggers an access occasion group corresponding to the second device and thus achieve group triggering or paging of the second devices by the first device.

[0012] In one possible design, the first access occasion group is determined based on the first message includes that the first access occasion group is determined based on the first message and an index of the first time resource.

[0013] In one possible design, the first access occasion group is the access occasion group for the second device to send the second message when at least one access occasion included by the first access occasion group is in the first time resource.

[0014] In one possible design, the method further includes determining a group number n of the first access occasion group, where the first access occasion group is determined based on the first message and the index of the first time resource, including that the first access occasion group is determined by the second device decreasing the index of the first time resource by one each time the first message is received, and determining when the index decreases to the first value.

[0015] In one possible design, the first access occasion group is determined by the second device decreasing the index of the first time resource by m each time the first message is received, and determining when the index decreases to the first value, where m is the number of time resources determined by the first message.

[0016] In one possible design, the time resource associated with the access occasion of the first device to which the second device has access is determined based on the first message and the index of the first time resource.

[0017] In one possible design, the time resource associated with the access occasion of the first device to which the second device has access is determined based on the first message and the index of the first time resource, including that the index of the time resource associated with the access occasion of the first device to which the second device has access is determined based on the index of the first time resource decreasing to an absolute value or an opposite number smaller than or equal to the first value.

[0018] In one possible design, the method further includes, if the access to the first device fails, receiving a third message sent by the first device, where the third message is used to trigger an access occasion of the first device and / or is used to page at least one second device, and the third message includes at least one of the following information: a total number of access occasion groups of the first device; a group number of a fourth access occasion group, where the group number of the fourth access occasion group is greater than or equal to the group number of the first access occasion group and smaller than or equal to the total number of access occasion groups, or the group number of the fourth access occasion group is greater than the total number of access occasion groups.

[0019] This design is equivalent to that, if the second device fails to access the first device in the first access occasion group, the second device can continue to access the first device according to a group number after the group number of the first access occasion group. Correspondingly, the first device can continue to trigger an access of an access occasion group with a group number after the group number of the first access occasion group.

[0020] In one possible design, the first access occasion group includes at least one access occasion set, and each access occasion set in the at least one access occasion set includes at least one access occasion. In this design, the method further includes receiving a fourth message, where the fourth message is used to update or indicate a number of access occasion sets in the first access occasion group, and / or the fourth message is used to update or indicate a number of access occasions in at least one access occasion set in the first access occasion group.

[0021] In one possible design, the fourth message is configured to update the number of access occasion sets in the first access occasion group, including that the fourth message is configured to indicate a difference between the number of access occasion sets before the update and the number of access occasion sets after the update.

[0022] In this case, the second device can determine the number of access occasion sets after the update based on the difference indicated by the fourth message and the number before the update. Compared with the fourth message directly indicating the number of access occasion sets after the update, the transmission overhead can be reduced.

[0023] In one possible design, the fourth message is configured to indicate the number of access occasion sets in the first access occasion group, including that the fourth message is configured to indicate the number of access occasion sets in the first access occasion group after the update.

[0024] In this case, the second device can directly obtain the number of access occasion sets after the update based on the fourth message. Compared with the fourth message indicating the number of access occasion sets before the update and the number of access occasion sets after the update, the second device can obtain the number of access occasion sets after the update more quickly, reduce the latency, and save resources.

[0025] In one possible design, the method further includes receiving a fifth message, where the fifth message is configured to indicate to stop triggering the set of access occasions.

[0026] In this way, after receiving the fifth message, the second device can stop listening to the set of access occasions that are triggered based on the fifth message, so as to avoid wasting resources of the second device.

[0027] In one possible design, the set of access occasions that are indicated to stop triggering by the fifth message includes the set of access occasions that have not been triggered in the access occasion group that is currently in the triggered state.

[0028] In one possible design, the fifth message further indicates the number of the set of access occasions that are indicated to stop triggering. In this way, the indication of the set of access occasions that are indicated to stop triggering can be flexibly controlled.

[0029] In one possible design, the method further includes receiving a sixth message, where the sixth message is configured to indicate to trigger a plurality of sets of access occasions in the first set of access occasions. One indication to trigger a plurality of sets of access occasions can reduce the indication overhead.

[0030] In one possible design, the sixth message further indicates the plurality of sets of access occasions that are triggered. For example, the sixth message indicates the number and / or set identifiers of the plurality of sets of access occasions that are triggered.

[0031] In one possible design, the method further includes receiving a fourth message, where the fourth message is configured to update or indicate the total number of groups of access occasion groups that access the first device, and / or the fourth message is configured to update or indicate the number of access occasions in the first access occasion group.

[0032] The fourth message is used to update or indicate the total number of access time group sets of the first device, and / or, in the case that the fourth message is used to update or indicate the number of access times in the first access time group set, in a possible design, the method further includes: receiving a sixth message, the sixth message is used to indicate to stop triggering the first access time group set.

[0033] In a possible design, at least one of the first message, the fourth message, the fifth message and the sixth message carries a service identity.

[0034] In a second aspect, a communication method is provided. An execution subject of the method can be a reader-writer in an A-IoT architecture, a component or device (for example, a processor, a chip, or a chip system, etc.) applied to the reader-writer, or a logic module or software capable of realizing all or part of the functions of the reader-writer. The method includes: sending a first message, the first message being used to trigger an access time of a first device and / or being used to page at least one second device; and receiving a second message sent by the second device, the second message being used for the second device to access the first device or send data to the first device, the second message being sent by the second device at an access time of a first access time group set, the first access time group set being determined based on the first message, and the first access time group set including at least one access time.

[0035] The beneficial effects of the second aspect can be referred to the description of the first aspect.

[0036] In a possible design, the first message includes at least one of the following information: a total number of access time group sets of the first device; and a group number of the first access time group set.

[0037] In a possible design, the first access time group set is determined based on the first message and a group number of a second access time group set includes: the first access time group set is determined based on the first message and the group number of the second access time group set; and the group number of the second access time group set is less than or equal to the total number of the access time group sets.

[0038] In a possible design, the first access time group set is determined based on the first message and a group number of a second access time group set includes: when the group number of the second access time group set is the same as the group number of the first access time group set, the first access time group set is an access time group set in which the second device sends the second message.

[0039] In a possible design, the first access time group set is determined based on the first message and a group number of a second access time group set includes: the first access time group set is determined by the second device in a manner that the group number of the first access time group set is decremented by one each time the first message is received, and the first access time group set is determined when the group number is decremented to the group number of the second access time group set.

[0040] In one possible design, the method further includes sending a third message, the third message being used to trigger the access occasions of the first device and / or being used to page the at least one second device, the third message including at least one of the following: a total number of groups of the access occasion groups of the first device; a group number of a fourth access occasion group; where the group number of the fourth access occasion group is greater than or equal to the group number of the first access occasion group and less than or equal to the total number of groups of the access occasion groups; or the group number of the fourth access occasion group is greater than the total number of groups of the access occasion groups.

[0041] In one possible design, the first access occasion group includes at least one access occasion set, each of the at least one access occasion set including at least one access occasion. The method further includes sending a fourth message, the fourth message being used to update or indicate a number of the access occasion sets in the first access occasion group and / or being used to update or indicate a number of the access occasions in at least one access occasion set in the first access occasion group.

[0042] In one possible design, the fourth message is used to update the number of the access occasion sets in the first access occasion group, and the fourth message includes fourth information used to indicate a difference between a number of the access occasion sets before the update and a number of the access occasion sets after the update.

[0043] This design can reduce the transmission overhead as compared with the fourth message directly indicating the number after the update.

[0044] In one possible design, the fourth message is used to indicate the number of the access occasion sets in the first access occasion group, and the fourth message includes information used to indicate the number of the access occasion sets in the first access occasion group after the update.

[0045] This design can help the second device to obtain the number after the update more quickly as compared with the fourth message indicating the number before the update and the number after the update, and thus reduce the latency and save resources of the second device.

[0046] In one possible design, the method further includes sending a fifth message, the fifth message being used to indicate to stop triggering the access occasion sets.

[0047] This way, the second device can stop listening to the access occasion sets that are stopped from being triggered based on the fifth message after receiving the fifth message, and thus resource waste of the second device can be avoided.

[0048] In one possible design, the fifth message indicates to stop triggering the access occasion sets that are not triggered in the access occasion group currently in the triggered state.

[0049] In one possible design, the fifth message can further indicate a number of the set of access occasions that are triggered to stop. This can flexibly control the indication of the set of access occasions that are triggered to stop.

[0050] In one possible design, the method further includes transmitting a sixth message, the sixth message indicating that a plurality of sets of access occasions in the first set of access occasions are triggered. One indication of triggering a plurality of sets of access occasions can reduce the indication overhead.

[0051] In one possible design, the sixth message can further indicate the plurality of sets of access occasions that are triggered. For example, the sixth message can indicate a number and / or set identifiers of the plurality of sets of access occasions that are triggered.

[0052] In one possible design, the method further includes transmitting a fourth message, the fourth message being used to update or indicate a total number of sets of access occasions for accessing the first apparatus, and / or the fourth message being used to update or indicate a number of access occasions in the first set of access occasions.

[0053] In one possible design, the method further includes transmitting a sixth message, the sixth message being used to indicate that the first set of access occasions is triggered to stop, in a case where the fourth message is used to update or indicate a total number of sets of access occasions for accessing the first apparatus, and / or the fourth message is used to update or indicate a number of access occasions in the first set of access occasions.

[0054] In one possible design, at least one of the first message, the fourth message, the fifth message, and the sixth message carries a service identifier.

[0055] In a third aspect, a communication method is provided. The execution subject of the method can be an A-IoT device, a component or apparatus (e.g., a processor, a chip, or a chip system) applied to an A-IoT device, a logic module or software capable of realizing all or part of the functions of an A-IoT device. The method includes: receiving first indication information transmitted by a first apparatus, the first indication information being used to confirm that a second apparatus successfully accesses the first apparatus, the first indication information including second indication information, the second indication information being used to indicate a first time domain resource location, the first time domain resource location being a time domain resource location selected by the second apparatus from among candidate time domain resource locations; transmitting third indication information to the first apparatus, a first time information at which the third indication information is transmitted being determined based on the second indication information, the third indication information being used to transmit data to the first apparatus.

[0056] The first device can be a reader in the A-IoT architecture, and the second device can be an A-IoT device in the A-IoT architecture. The first indication information can be understood as an R2D message, and the third indication information can be understood as a D2R message. In a case where the second indication information carried in the first indication information indicates a time domain resource position selected by the second device from the candidate time domain resource positions, the time at which the third indication information is sent by the second device to the first device is related to the selected time domain resource position. In this way, when multiple second devices send the third indication information to the first device, the time at which the third indication information is sent by the second device can be associated with the selected time domain resource position, and the time at which the third indication information is sent by the second device can be staggered, so that the probability of collision of the third indication information sent by multiple second devices at the first device is reduced. In other words, the probability of collision of the D2R messages sent by multiple second devices at the first device is reduced.

[0057] In a possible design, before receiving the first indication information, the method further includes: sending, to the first device, fourth indication information, where the fourth indication information is used to indicate a random number generated by the second device when the second device requests to access the first device; the first indication information further includes the fourth indication information; and the first time information is determined based on the second indication information and the fourth indication information. In other words, the time at which the third indication information is sent by the second device to the first device is related to not only the time domain resource position indicated by the second indication information, but also the random number indicated by the fourth indication information. In this way, the probability of collision of the third indication information sent by the second device at the first device can be greatly reduced.

[0058] In a possible design, the start time of sending, by the second device, the fourth indication information is determined according to a time resource for sending the fourth information and a first message triggering the second device to send the fourth indication information.

[0059] In a possible design, before sending the third indication information, the method further includes: determining, based on the second indication information and the fourth indication information, that the second device successfully accesses the first device. In other words, when determining whether to successfully access the first device, the second device determines that the second device successfully accesses the first device only when the second indication information indicating the selected time domain resource position carried in the first indication information and the random number indicated by the fourth indication information both match the determination of the second device, and sends the third indication information to the first device, so as to reduce the probability of collision of the third indication information sent by multiple second devices at the first device.

[0060] In a possible design, the first indication information further includes fifth indication information, and the fifth indication information is used to indicate a frequency domain resource position at which the second device sends the third indication information. In this way, the frequency domain resource position at which the second device sends the third indication information can be related to the time domain resource position selected by the second device. When the time domain resource position selected by the second device is different, the frequency domain resource position at which the third indication information is sent can also be different, which can reduce the probability of collision in the frequency domain when the third indication information is sent by multiple second devices.

[0061] In a fourth aspect, a communication method is provided. An execution subject of the method can be a reader-writer in an A-IoT architecture, can be a component or device (for example, a processor, a chip, or a chip system, etc.) applied to the reader-writer, and can also be a logic module or software capable of realizing all or part of the functions of the reader-writer. The method includes: sending, to a second device, first indication information, where the first indication information is used to confirm that the second device successfully accesses a first device, the first indication information includes second indication information, the second indication information is used to indicate a first time domain resource position, and the first time domain resource position is a time domain resource position selected by the second device from among candidate time domain resource positions; and receiving third indication information sent by the second device, where first time information at which the second device sends the third indication information is determined based on the second indication information, and the third indication information is used to send data to the first device.

[0062] The beneficial effects of the fourth aspect can be referred to the description of the third aspect.

[0063] In a possible design, before the first indication information is sent, the method further includes: receiving fourth indication information sent by the second device, where the fourth indication information is used to indicate a random number generated by the second device when the second device requests to access the first device; the first indication information further includes the fourth indication information; and the first time information is determined based on the second indication information and the fourth indication information.

[0064] In a possible design, the first indication information further includes fifth indication information, and the fifth indication information is used to indicate a frequency domain resource position at which the second device sends the third indication information.

[0065] In a fifth aspect, a communication method is provided. The execution subject of the method can be an A-IoT device, a component or apparatus (e.g., a processor, a chip, or a chip system) applied to the A-IoT device, or a logic module or software capable of implementing all or part of the functions of the A-IoT device. The method includes: sending fourth indication information to a first apparatus, the fourth indication information being used for a second apparatus to request access to the first apparatus; and determining that the second apparatus successfully accesses the first apparatus if first indication information is received within a first time period after the fourth indication information is sent, the first indication information being used to confirm that the second apparatus successfully accesses the first apparatus, and the first time period being related to the number of time domain resources selected by the second apparatus when sending a message to the first apparatus.

[0066] The first apparatus can be a reader in an A-IoT architecture, and the second apparatus can be an A-IoT device in the A-IoT architecture. The fourth indication information can be understood as a D2R message sent by the A-IoT device to the reader, and the first indication information can be understood as a R2D message sent by the reader to the A-IoT device after the D2R message. Considering that the maximum time interval between the R2D message and the D2R message is fixed in the prior art, but the number of access occasions triggered or paged by the reader each time is variable, or in other words, the number of time domain resources selected by the A-IoT device when sending a message is variable, which makes the time when the A-IoT device receives the R2D message uncertain. Therefore, in this application, the time when the second apparatus receives the R2D message from the first apparatus is associated with the number of time domain resources selected by the second apparatus when sending a message, so that the maximum time when the second apparatus receives the R2D message from the first apparatus is flexible and variable, and the success rate of the second apparatus accessing the first apparatus can be improved.

[0067] In a possible design, the first time period is determined according to the number of candidate time domain resources and at least one of the following information: a transmission duration of the fourth indication information; and second time information, the second time information being used to indicate a time interval between receiving a first message by the second apparatus and sending the fourth indication information, the first message being used to trigger an access occasion for accessing the first apparatus and / or being used to page at least one second apparatus.

[0068] That is, in the case that the time when the second apparatus receives the R2D message sent by the first apparatus is affected by the fourth indication information and the second time information, the number of time domain resources selected by the second apparatus when sending a message can also be considered, so that the maximum time when the second apparatus receives the R2D message from the first apparatus is flexible and variable with the number of candidate time domain resources. This design can be applied to the scenario in which the R2D message is a R2D concatenated message.

[0069] In one possible design, the first time period is determined based on the number of time-domain resources of the candidate and at least one of the following: a transmission duration of the fourth indication information, a transmission duration of the first indication information, a transmission duration of the third indication information, or the third time information, where the third indication information is data sent by the second device upon successfully accessing the first device, and the second time information is used to indicate a time interval between when the second device receives the first message and when the second device sends the fourth indication information, where the first message is used to trigger an access occasion for accessing the first device and / or is used to page at least one second device. Similar to the above design, the maximum time interval for the second device to receive the R2D message can be associated with the number of time-domain resources selected by the second device when sending the message, so that the time for the second device to receive the R2D message is flexible and variable. This design can be applied to a scenario where the R2D message is an R2D non-cascaded message.

[0070] In a sixth aspect, a communication device, which can be, for example, an A-IoT device, is provided. The communication device includes a receiving unit configured to receive a first message sent by a first device, where the first message is used to trigger an access occasion for accessing the first device and / or is used to page at least one second device, and a sending unit configured to send a second message to the first device at an access occasion of a first access occasion group, where the second message is used for the second device to access the first device or send data to the first device, and the first access occasion group is determined based on the first message, and the first access occasion group includes at least one access occasion.

[0071] In one possible design, the first message includes at least one of the following: a total number of groups of the first access occasion group, and a group number of the first access occasion group.

[0072] In one possible design, the first access occasion group is determined based on the first message and a group number of a second access occasion group, where the group number of the second access occasion group is less than or equal to the total number of groups of the access occasion group.

[0073] In one possible design, the communication device further includes a processing unit configured to determine the group number of the second access occasion group, and the first access occasion group is determined based on the first message and the group number of the second access occasion group, where the group number of the second access occasion group is the same as the group number of the first access occasion group, and the first access occasion group is the access occasion group for the second device to send the second message.

[0074] In one possible design, the processing unit is further configured to determine a group number of the first access occasion group, and the first access occasion group is determined based on the first message and the group number of the second access occasion group, including that the first access occasion group is determined by the second device decrementing the group number of the first access occasion group each time the first message is received and determining the group number of the first access occasion group when the group number is decremented to the group number of the second access occasion group.

[0075] In one possible design, the receiving unit is further configured to receive a third message transmitted by the first device if the access to the first device fails, the third message being used to trigger an access occasion for accessing the first device and / or being used to page the at least one second device, and the third message includes at least one of the following: a total number of groups of the access occasion groups for accessing the first device; a group number of a fourth access occasion group, the group number of the fourth access occasion group being greater than or equal to the group number of the first access occasion group and less than or equal to the total number of groups of the access occasion groups, or the group number of the fourth access occasion group being greater than the total number of groups of the access occasion groups.

[0076] In a seventh aspect, a communication device, e.g., a reader in an A-IoT architecture, is provided. The communication device includes a transmitting unit configured to transmit a first message, the first message being used to trigger an access occasion for accessing a first device and / or being used to page at least one second device, and a receiving unit configured to receive a second message transmitted by the second device, the second message being used for the second device to access the first device or to transmit data to the first device, the second message being transmitted by the second device at an access occasion in a first access occasion group, the first access occasion group being determined based on the first message, and the first access occasion group including at least one access occasion.

[0077] In one possible design, the first message includes at least one of the following: a total number of groups of the access occasion groups for accessing the first device; a group number of the first access occasion group.

[0078] In one possible design, the first access occasion group is determined based on the first message and a group number of a second access occasion group, including that the group number of the second access occasion group is less than or equal to a total number of groups of the access occasion groups.

[0079] In one possible design, the first access occasion group is determined based on the first message and a group number of a second access occasion group, including that the group number of the second access occasion group is the same as the group number of the first access occasion group, and the first access occasion group is the access occasion group for the second device to transmit the second message.

[0080] In one possible design, the first set of access occasions is determined based on the first message and a group number of the second set of access occasions, including that the first set of access occasions is determined by the second device decrementing the group number of the first set of access occasions each time the first message is received and determining the group number of the first set of access occasions when the group number is decremented to the group number of the second set of access occasions.

[0081] In one possible design, the sending unit is further configured to send a third message, the third message being used to trigger the second device to access the access occasion of the first device and / or being used to page the at least one second device, the third message including at least one of the following information: a total number of sets of the access occasion of the first device; a group number of a fourth set of access occasions; where the group number of the fourth set of access occasions is greater than or equal to the group number of the first set of access occasions and less than or equal to the total number of sets of the access occasion; or the group number of the fourth set of access occasions is greater than the total number of sets of the access occasion.

[0082] In an eighth aspect, a communication device, which can be an A-IoT device, is provided. The communication device includes a receiving unit configured to receive first indication information sent by a first device, the first indication information being used to confirm that a second device successfully accesses the first device, the first indication information including second indication information, the second indication information being used to indicate a first time domain resource location, the first time domain resource location being a time domain resource location selected by the second device from among candidate time domain resource locations; and a sending unit configured to send third indication information to the first device, a first time information at which the third indication information is sent being determined based on the second indication information, the third indication information being used to send data to the first device.

[0083] In one possible design, the sending unit is further configured to send, to the first device, fourth indication information before receiving the first indication information, the fourth indication information being used to indicate a random number generated by the second device when the second device requests to access the first device; the first indication information further includes the fourth indication information; and the first time information is determined based on the second indication information and the fourth indication information.

[0084] In one possible design, the communication device further includes a determining unit configured to determine, before sending the third indication information, that the second device successfully accesses the first device based on the second indication information and the fourth indication information.

[0085] In one possible design, the first indication information further includes fifth indication information, the fifth indication information being used to indicate a frequency domain resource location at which the third indication information is sent by the second device.

[0086] In a ninth aspect, a communication apparatus, which can be a reader / writer in an A-IoT architecture, is provided. The communication apparatus includes: a sending unit, configured to send first indication information to a second apparatus, the first indication information being used to confirm that the second apparatus successfully accesses the first apparatus, the first indication information including second indication information, the second indication information being used to indicate a first time domain resource position, the first time domain resource position being one time domain resource position selected by the second apparatus from candidate time domain resource positions; and a receiving unit, configured to receive third indication information sent by the second apparatus, the first time information at which the second apparatus sends the third indication information being determined based on the second indication information, the third indication information being used to send data to the first apparatus.

[0087] In a possible design, before the sending of the first indication information, the receiving unit is further configured to receive fourth indication information sent by the second apparatus, the fourth indication information being used to indicate a random number generated by the second apparatus when the second apparatus requests to access the first apparatus; the first indication information further includes the fourth indication information; and the first time information is determined based on the second indication information and the fourth indication information.

[0088] In a possible design, the first indication information further includes fifth indication information, the fifth indication information being used to indicate a frequency domain resource position at which the second apparatus sends the third indication information.

[0089] In a tenth aspect, a communication apparatus, which can be an A-IoT device, is provided. The communication apparatus includes: a sending unit, configured to send fourth indication information to a first apparatus, the fourth indication information being used to request, by a second apparatus, to access the first apparatus; and a processing unit, configured to determine that the second apparatus successfully accesses the first apparatus if first indication information is received within a first time period after the sending of the fourth indication information, the first indication information being used to confirm that the second apparatus successfully accesses the first apparatus, the first time period being related to a number of time domain resources selected by the second apparatus when the second apparatus sends a message to the first apparatus.

[0090] In a possible design, the first time period is determined according to the number of candidate time domain resources and at least one of the following information: a transmission duration of the fourth indication information; and second time information, the second time information being used to indicate a time interval between when the second apparatus receives a first message and when the second apparatus sends the fourth indication information, the first message being used to trigger an access occasion for accessing the first apparatus and / or being used to page at least one second apparatus.

[0091] In a possible design, the first time period is determined according to the number of candidate time domain resources and at least one of the following: a transmission duration of the fourth indication information, a transmission duration of the first indication information, a transmission duration of the third indication information, or the third time information, wherein the third indication information is data sent by the second device when successfully accessing the first device, and the second time information is used to indicate a time interval between receiving, by the second device, the first message and sending the fourth indication information, the first message is used to trigger an access occasion of accessing the first device, and / or is used to page at least one second device.

[0092] In a eleventh aspect, a communication method is provided, including: receiving a fourth message, the fourth message being used to update or indicate a number of access occasion sets in a first access occasion group, and / or being used to update or indicate a number of access occasions in a first access occasion set, the first access occasion group containing at least one access occasion set, each access occasion set in the at least one access occasion set containing at least one access occasion, and the first access occasion set containing at least one access occasion; and determining an access occasion according to the fourth message.

[0093] In some implementations, the method further includes: receiving a fifth message, the fifth message being used to indicate to stop triggering an access occasion set.

[0094] In a twelfth aspect, a communication method is provided, including: determining a fourth message, the fourth message being used to update or indicate a number of access occasion sets in a first access occasion group, and / or being used to update or indicate a number of access occasions in a first access occasion set, the first access occasion group containing at least one access occasion set, each access occasion set in the at least one access occasion set containing at least one access occasion, and the first access occasion set containing at least one access occasion; and sending the fourth message.

[0095] In a thirteenth aspect, a communication method is provided, including: receiving a seventh message, the seventh message being used to trigger an access occasion of accessing a first device, and / or being used to page at least one second device, the seventh message carrying ninth indication information, the ninth indication information being used to indicate a transport block size and / or whether to respond quickly, when the ninth indication information indicates the transport block size as a first transport block size and / or indicates to respond quickly, sending acknowledgement information of the seventh message, when the ninth indication information indicates the transport block size as a second transport block size and / or does not indicate to respond quickly, sending first information, the first information being used to indicate an identity of a second device, and the second transport block size being greater than the first transport block size.

[0096] In the communication method, the second device feeds back the acknowledgement message when the ninth indication information indicates the indicated transport block size is the first transport block size and / or indicates the fast response, which can save the signaling overhead compared with feeding back the identity of the second device.

[0097] In a possible design, the resource used for transmitting the acknowledgement information is associated with the identity of the second device. In this way, the identity of the second device can be indicated with less signaling overhead.

[0098] In a possible design, the seventh message carries the service identity.

[0099] In a fourteenth aspect, a communication method is provided. The communication method includes: sending a seventh message, the seventh message being used for triggering an access occasion of a first device and / or being used for paging at least one second device, the seventh message carrying ninth indication information, the ninth indication information being used for indicating a transport block size and / or indicating whether a fast response is needed; receiving acknowledgement information of the seventh message when the ninth indication information indicates that the transport block size is a first transport block size and / or the ninth indication indicates the fast response is needed; and receiving first information when the ninth indication information indicates that the transport block size is a second transport block size and / or the ninth indication information does not indicate the fast response is needed, the first information being used for indicating an identity of the second device, the second transport block size being greater than the first transport block size.

[0100] In the communication method, the second device feeds back the acknowledgement message when the ninth indication information indicates the indicated transport block size is the first transport block size and / or indicates the fast response, which can save the signaling overhead compared with feeding back the identity of the second device.

[0101] In a possible design, the resource used for transmitting the acknowledgement information is associated with the identity of the second device. In this way, the identity of the second device can be indicated with less signaling overhead.

[0102] In a possible design, the seventh message carries the service identity.

[0103] In a fifteenth aspect, a communication device is provided. The communication device includes various modules for implementing the method in any of the eleventh aspect to the fourteenth aspect.

[0104] It can be understood that any of the modules can be implemented by using software and / or hardware.

[0105] In a sixteenth aspect, a communication apparatus is provided, comprising a processor and an interface circuit, the interface circuit being configured to receive signals from other communication apparatuses and transmit signals to the processor or send signals from the processor to other communication apparatuses, the processor being configured to implement a method in at least one of the following aspects by logic or by executing code instructions: the method in the first aspect and any possible design of the first aspect, the method in the second aspect and any possible design of the second aspect, the method in the third aspect and any possible design of the third aspect, the method in the fourth aspect and any possible design of the fourth aspect, the method in the fifth aspect and any possible design of the fifth aspect, the method in the eleventh aspect and any possible design of the eleventh aspect, the method in the twelfth aspect and any possible design of the twelfth aspect, the method in the thirteenth aspect and any possible design of the thirteenth aspect, or the method in the fourteenth aspect and any possible design of the fourteenth aspect.

[0106] In a seventeenth aspect, a chip is provided, coupled with a memory, configured to read and execute program instructions stored in the memory to implement a method in at least one of the following aspects: the method in the first aspect and any possible design of the first aspect, the method in the second aspect and any possible design of the second aspect, the method in the third aspect and any possible design of the third aspect, the method in the fourth aspect and any possible design of the fourth aspect, the method in the fifth aspect and any possible design of the fifth aspect, the method in the eleventh aspect and any possible design of the eleventh aspect, the method in the twelfth aspect and any possible design of the twelfth aspect, the method in the thirteenth aspect and any possible design of the thirteenth aspect, or the method in the fourteenth aspect and any possible design of the fourteenth aspect.

[0107] The chip can also be replaced by a chip system.

[0108] In an eighteenth aspect, a communication system is provided, comprising a first communication apparatus and a second communication apparatus. The first communication apparatus can be configured to implement a method in at least one of the following aspects: the method in the first aspect and any possible design of the first aspect, the method in the third aspect and any possible design of the third aspect, the method in the fifth aspect and any possible design of the fifth aspect; the second communication apparatus can be configured to implement a method in at least one of the following aspects: the method in the second aspect and any possible design of the second aspect, the method in the fourth aspect and any possible design of the fourth aspect.

[0109] In a nineteenth aspect, a computer-readable storage medium is provided, which stores computer instructions. When the computer instructions are run on a communication device, the computer instructions cause the communication device to perform the method in at least one of the following aspects: the method of the first aspect and any possible design of the first aspect, the method of the second aspect and any possible design of the second aspect, the method of the third aspect and any possible design of the third aspect, the method of the fourth aspect and any possible design of the fourth aspect, the method of the fifth aspect and any possible design of the fifth aspect, the method of the eleventh aspect and any possible design of the eleventh aspect, the method of the twelfth aspect and any possible design of the twelfth aspect, the method of the thirteenth aspect and any possible design of the thirteenth aspect, or the method of the fourteenth aspect and any possible design of the fourteenth aspect.

[0110] In a twentieth aspect, a computer program product is provided, which includes computer instructions. When the computer instructions are run on a communication device, the computer instructions cause the communication device to perform the method in at least one of the following aspects: the method of the first aspect and any possible design of the first aspect, the method of the second aspect and any possible design of the second aspect, the method of the third aspect and any possible design of the third aspect, the method of the fourth aspect and any possible design of the fourth aspect, the method of the fifth aspect and any possible design of the fifth aspect, the method of the eleventh aspect and any possible design of the eleventh aspect, the method of the twelfth aspect and any possible design of the twelfth aspect, the method of the thirteenth aspect and any possible design of the thirteenth aspect, or the method of the fourteenth aspect and any possible design of the fourteenth aspect. BRIEF DESCRIPTION OF DRAWINGS

[0111] FIG. 1 is a schematic diagram of an overall workflow of an RFID according to an embodiment of the present application;

[0112] FIG. 2 is a schematic diagram of various A-IoT network architectures according to an embodiment of the present application;

[0113] FIG. 3 is a schematic diagram of R2D and D2R transmission between a reader / writer and an A-IoT device according to an embodiment of the present application;

[0114] FIG. 4 is a schematic diagram of a communication method according to an embodiment of the present application;

[0115] FIG. 5 is a schematic diagram of another communication method according to an embodiment of the present application;

[0116] FIG. 6 is a signaling timing diagram of R2D message and D2R message interaction between a reader and a plurality of A-IoT devices according to an embodiment of the present application;

[0117] FIG. 7 is a format diagram of a R2D cascaded message according to an embodiment of the present application;

[0118] FIG. 8 is a flow diagram of a R2D trigger message as a paging message according to an embodiment of the present application;

[0119] FIG. 9 is a flow diagram of another communication method according to an embodiment of the present application;

[0120] FIG. 10 is a signaling timing diagram of message transmission between a reader and an A-IoT device in a non-cascaded R2D message according to an embodiment of the present application;

[0121] FIG. 11 is a signaling interaction diagram between a base station and an A-IoT device in a non-cascaded R2D message according to an embodiment of the present application;

[0122] FIG. 12 is a signaling timing diagram of message transmission between a reader and an A-IoT device in a non-cascaded R2D message according to an embodiment of the present application;

[0123] FIG. 13 is a flow diagram of carrying a bias time of A-IoT device uplink data transmission in downlink data according to an embodiment of the present application;

[0124] FIG. 14 is a diagram of adjusting an access occasion set according to an embodiment of the present application;

[0125] FIG. 15 is a diagram of adjusting an access occasion according to an embodiment of the present application;

[0126] FIG. 16 and FIG. 17 are flow diagrams of a communication method according to an embodiment of the present application;

[0127] FIG. 18 is a structural diagram of a communication apparatus according to an embodiment of the present application;

[0128] FIG. 19 is a structural diagram of another communication apparatus according to an embodiment of the present application. DETAILED DESCRIPTION

[0129] For ease of understanding, some of the example embodiments of the present application are described below with reference to the following concepts. As shown below.

[0130] 1. Radio-frequency identification (RFID) technology.

[0131] RFID technology can be used to identify targets. An RFID system generally includes an interrogator and a tag device. The interrogator can interact with the tag device to manage the tag device. The interrogator can read information in the tag device or write information required to be stored in the tag device into the tag device. The interrogator and the tag device perform non-contact data communication. The tag device has a simple function and needs to rely on the excitation of the interrogator to send information, that is, the tag device converts the wireless signal sent by the interrogator into energy to drive itself to work. The tag supports micro-watt or hundred-micro-watt power consumption and cannot support complex design.

[0132] If RFID is applied to a mobile communication system, for example, a 5th-generation mobile communication technology (5G) system, a base station can serve as an interrogator to implement the function of the interrogator.

[0133] The main application scenario of RFID is identity recognition, and further can be used for data reading and writing.

[0134] The tag device has the following characteristics: the tag design is simple, and the application layer and air interface signaling are designed together; the tag supports micro-watt or hundred-micro-watt power consumption and cannot support complex design and complex measurement; when multiple tags communicate, time division multiplexing is used, and multiple tags use serial reading. It does not support frequency domain and code domain differentiation, and has poor parallel performance.

[0135] RFID tags have low power consumption characteristics, and the power consumption of different types of tags is introduced as follows.

[0136] Passive tag: about 1 μW power consumption. The passive tag itself has no energy storage capability, and the energy for receiving and transmitting signals is entirely derived from the radio frequency energy of the interrogator; uplink transmission needs to rely on reflection communication, and the interrogator needs to send a carrier signal to trigger the passive tag to send a reflection signal, and use radio frequency energy to send the uplink signal to the interrogator.

[0137] Semi-passive tag: about 100 μW power consumption. Compared with the passive tag, the semi-passive tag can store a part of energy (such as using a capacitor), so the transmission power consumption can be greater than that of the passive tag, and the communication also relies on reflection communication, but the communication capability is stronger than that of the passive tag (transmission rate, etc.).

[0138] Active tag: about 50 mW power consumption. The active tag itself has a battery and can actively send signals, and does not rely on reflection signals for communication, and has stronger communication capability.

[0139] As shown in Fig. 1 is a schematic diagram of the overall workflow of RFID, including the following processes: 1) the reader sends a trigger (select / paging) message: for selecting a group of tags, carrying inventory session, instructions (action), mask, etc. Receive select matching tags session ID and corresponding flag bit. Assuming the inventory session selects session ID: S0, action = 0, if the mask matches, the tag will set the session S0 flag position to A.

[0140] 2) The reader sends a query: carrying Q value, session ID and flag bit, assuming session ID: S0, flag bit: A, when the tag determines that the session ID and flag bit of the tag match the session ID and flag bit in the received query, the tag generates a 0~2 Q-1 Random number as the initial value of the counter according to the Q value.

[0141] 3) If no tag sends a response, the reader continues to send repeated queries (queryrep), and when the tag receives queryrep, the counter is set to counter-1. If the counter generated by the tag is 0, the tag feeds back the random number (RN); otherwise, the tag does not respond. For example, when RN is RN16, RN16 can be understood as a 16-bit random number, which is used for tag contention resolution. If multiple tags randomly select the same counter value, multiple tags may send RN16 in the same time slot. If the reader does not receive RN16, it sends queryrep.

[0142] 4) If the tag receives (possibly multiple times) queryrep and the counter decreases to 0, the tag feeds back RN16; otherwise, the tag does not respond. Exemplarily, each queryrep corresponds to the beginning or end of an access slot, and the tag can randomly select an access slot to initiate access or send uplink data or receive downlink data in the corresponding access slot.

[0143] 5) When the reader receives RN16, if there is no collision (only one tag sends RN16), it feeds back an acknowledgement (ACK), which means contention resolution. The ACK contains the random number RN16 received by the reader, which is used to indicate that the contention resolution is successful, i.e. access is successful.

[0144] 6) The tag receives the ACK, and determines that the RN16 carried in the ACK matches the RN16 randomly generated by the tag, and the tag feeds back an electronic product code (EPC), otherwise, the tag does not feed back the EPC.

[0145] 7) The tag sends the EPC and receives the queryrep, which indicates that the tag data transmission is successful, and the tag flips the flag bit, i.e., flips to B (inventory success). For example, the flag bit can be used to prevent the tag that has been inventoried from being inventoried repeatedly, because the flag bit carried in the query sent subsequently is A, and the tag with the flipped flag bit will not respond to the reader when receiving the query with the flag bit A.

[0146] The RFID tag is simple to implement and does not support complex measurements. Therefore, the design scheme of the tag should follow the principle of simplicity.

[0147] 2. Ambient Internet of Things (A-IoT)

[0148] With the development of communication technology, the 3rd Generation Partnership Project (3GPP) defines A-IoT technology. The A-IoT in the A-IoT technology includes a reader and a terminal device, or in other words, the communication system based on A-IoT includes a reader and a terminal device. Among them, the terminal device can be a device with A-IoT function, which can also be referred to as an A-IoT device. In this case, the reader and the A-IoT device can both be implemented based on the infrastructure in the cellular network. In other words, the reader and the A-IoT device can both be devices in the cellular network. For example, the function of the reader can be implemented by a network device, such as a base station. The A-IoT device can be implemented by a terminal in the cellular network, such as an extremely low power consumption, extremely low complexity Internet of Things terminal. The network device and the terminal device can perform non-contact data communication, thereby reading information from the terminal device and / or writing information to be stored into the terminal device.

[0149] A-IoT technology can be understood as an extension of RFID in 3GPP, but A-IoT technology and RFID have some same principles, such as similar inventory business process, but more value scenarios are introduced in 3GPP. A-IoT can be understood as based on cellular network communication infrastructure, composed of readers (such as base stations) and passive A-IoT devices, semi-passive A-IoT devices or active A-IoT devices (A-IoT devices are terminals in the cellular network, which are understood as extremely low power consumption, extremely low complexity Internet of Things terminals), the main business includes: inventory, positioning, sensing or command, etc.; typical application scenarios include logistics, warehousing, industrial manufacturing, identity recognition or environmental monitoring, etc.

[0150] Among them, the inventory business is to use the reader (which can be a base station / terminal) to access the A-IoT devices (A-IoT devices) in the coverage range, and the device that successfully accesses needs to send its own unique identifier (which can be identified by the network, such as EPC in RFID) to the reader.

[0151] Positioning can be understood as using some positioning signals to locate the position of the A-IoT device.

[0152] Sensing is that the A-IoT device reports sensing data such as temperature data to the base station.

[0153] The command can be some operation instruction, such as write or lock. The write process can be understood as that the base station sends downlink instruction and data, instructing the A-IoT device to write the data into its own memory. The lock process can be understood as sending downlink instruction to trigger the A-IoT device to lock the position of the specified address of the memory, and the content of the memory segment cannot be changed and / or read.

[0154] When the communication system based on A-IoT includes a reader and a terminal device, the working process between the reader and the terminal device is similar to the working process in RFID technology. For example, when the reader performs inventory on the terminal device, its process can refer to the working process of the tag device and the reader in FIG. 1.

[0155] The present application can be mainly applied to a communication system of 5G NR, and can also be applied to other communication systems. For example, the present application is also applicable to a 3GPP long term evolution (LTE) system, a universal mobile telecommunications system (UMTS) system, a code division multiple access (CDMA) system, a wireless local area network (WLAN) or a future 5G wireless communication system.

[0156] The present application can be applied to various network architectures, which can be an A-IoT network architecture. As shown in FIG. 2, it is a schematic diagram of various A-IoT network architectures of the present application. The A-IoT network architecture can include a reader and an A-IoT device. The function of the reader can be implemented by a radio access network (RAN) node, such as a base station (BS). The A-IoT device can be a terminal device. The A-IoT device can be understood as a device with A-IoT function. The A-IoT device can be implemented by a terminal in a cellular network, such as an ultra-low power consumption, ultra-low complexity Internet of Things terminal. The A-IoT device can be located within the coverage range provided by the reader. When the reader is a terminal device, the communication between the reader and the A-IoT device can be regarded as transmission between terminals.

[0157] For example, as shown in (a) of FIG. 2, the A-IoT network architecture includes a base station 201 sending signals to an A-IoT device 202 and the A-IoT device 202 receiving signals from the base station, that is, there is uplink / downlink data / signaling between the base station 201 and the A-IoT device 202, or in other words, the A-IoT device 202 and the base station 201 directly communicate in both directions. The communication between the base station 201 and the A-IoT device 202 includes A-IoT data and / or signaling. The communication between the base station 201 and the A-IoT device 202 is a Uu interface, that is, air interface communication.

[0158] As shown in (b) of FIG. 2, the A-IoT network architecture includes a base station 201, an intermediate node 203, and an A-IoT device 202. The A-IoT device 202 can communicate with the intermediate node 203 between the A-IoT device 202 and the base station 201 in both directions. In this topology, the intermediate node can be a repeater, an integrated access and backhaul (IAB) node, a user equipment (UE), a repeater, etc., which can enable the environmental IoT. The intermediate node 203 transmits A-IoT data and / or signaling between the base station 201 and the A-IoT device 202. The communication between the base station 201 and the intermediate node 203 is a Uu interface.

[0159] As shown in (c) of FIG. 2, the A-IoT network architecture includes a base station 201, an A-IoT device 202, and an assisting node 204. In this network architecture, the A-IoT device 202 can send data / signaling to the base station 201 and receive data / signaling from the assisting node 204, or the A-IoT device 202 receives data / signaling from the base station 201 and sends data / signaling to the assisting node 204. In this network architecture, the assisting node 204 can be a repeater, an IAB, a UE, a repeater, etc., which can be used to implement the IoT. The communication between the base station 201 and the assisting node 204 is a Uu interface.

[0160] As shown in (d) of FIG. 2, the A-IoT network architecture includes a terminal 205 and an A-IoT device 202. The A-IoT device 202 can communicate with the terminal 205 in both directions. The communication between the terminal 205 and the A-IoT device 202 includes environmental IoT data and / or signaling.

[0161] Optionally, the A-IoT network architecture can also be a split architecture. That is, the A-IoT device has only uplink (or downlink) connection with the reader / writer (such as a base station), and the A-IoT device has only downlink (or uplink) connection with the UE or the helper.

[0162] The RAN node, also referred to as a radio access network device, RAN entity or access node, is configured to facilitate a terminal to access a communication system wirelessly. In one application scenario, the RAN node can be a base station, an evolved Node B (eNodeB), a transmission reception point (TRP), a next generation NodeB (gNB) in a 5th generation (5G) mobile communication system, a base station in a future mobile communication system or an access node in a WiFi system. The RAN node can be a macro base station, a micro base station or an indoor station, and can also be a relay node or a donor node.

[0163] In another application scenario, a terminal can access a communication system wirelessly through cooperation of multiple RAN nodes, and different RAN nodes implement part of functions of a base station. For example, the RAN node can be a central unit (CU), a distributed unit (DU) or a radio unit (RU). The CU here implements functions of a radio resource control protocol and a packet data convergence protocol (PDCP) of a base station, and can also implement a function of a service data adaptation protocol (SDAP). The DU implements functions of a radio link control layer and a medium access control (MAC) layer of a base station, and can also implement part of a physical layer or all of a physical layer. For details of the protocol layers, refer to relevant technical specifications of 3GPP. The RU can be configured to implement functions of transmitting and receiving radio frequency signals. The CU and the DU can be two independent RAN nodes, or can be integrated in the same RAN node, for example, integrated in a baseband unit (BBU). The RU can be included in a radio frequency device, for example, included in a remote radio unit (RRU) or an active antenna unit (AAU). The CU can be further divided into two types of RAN nodes, CU-control plane and CU-user plane.

[0164] In different systems, the RAN node can have different names, for example, in an O-RAN system, the CU can be referred to as an open CU (O-CU), the DU can be referred to as an open DU (O-DU), and the RU can be referred to as an open RU (O-RU). The RAN node in the embodiments of the present application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module, for example, the RAN node can be a server loaded with a corresponding software module. The embodiments of the present application do not limit the specific technology and specific equipment form adopted by the RAN node. For ease of description, a base station is described as an example of the RAN node in the following.

[0165] In A-IoT, A-IoT devices include active A-IoT devices, passive A-IoT devices, and semi-passive A-IoT devices. The passive A-IoT device can also be referred to as a passive IoT, that is, a passive Internet of Things device. Therefore, it can also be regarded as a terminal.

[0166] The reader, that is, a device that reads (and sometimes writes) information of the A-IoT device, can be handheld or fixed. It can also be understood as a device that communicates with the A-IoT device, which can be a terminal, a base station, or a headend, a pRU, a transmission reception point (TRP), or other nodes that transmit signals, or a device with reading and writing functions. The reader can also be an IAB node or a smart repeater or a relay node.

[0167] The helper can be a terminal, a base station, or a small station. The device only has downlink between the A-IoT device and the reader, and has uplink and downlink data transmission between the reader, which can be through the air interface or through a wired connection.

[0168] In the present application, the reader sending signaling and / or data to the A-IoT device can be understood as R2D (reader-to-device), and the A-IoT device sending signaling and / or data to the reader can be understood as D2R (device-to-reader).

[0169] In some aspects, one R2D message can define X candidate time domain resources for D2R message transmission, where X can be greater than or equal to 1. For example, as shown in FIG. 3, an example of R2D and D2R transmission between a reader and an A-IoT device is shown. As shown in FIG. 3, a reader can send an R2D message to an A-IoT device, where the R2D message can be a paging message or an R2D trigger message. One R2D message can trigger multiple occasions for sending D2R messages. For example, a reader can send an R2D trigger message, where the R2D trigger message indicates X candidate time domain resources for D2R message transmission. At least one A-IoT device can send a D2R message to the reader after the R2D trigger message, and each A-IoT device can select one time domain resource x from the X candidate time domain resources for sending the D2R message. For example, the D2R message can be understood as RN16 in the flow shown in FIG. 1, and can be referred to as message 1 (msg1) in this application.

[0170] It can be understood that when the reader sends the R2D trigger message, the R2D trigger message can be understood as a broadcast message or a message similar to a broadcast message sent to the A-IoT device. For example, the R2D trigger message can be transmitted on a reader-to-device physical channel (PR2DCH). The name of the reader-to-device physical channel is not limited in this application.

[0171] According to the description in FIG. 1, when multiple A-IoT devices determine that the session and the flag bit match, the randomly generated counter can be the same, and the multiple A-IoT devices can all feed back RN16 to the reader. That is, the multiple A-IoT devices can all select a time domain resource from the limited X time domain resources to send RN16 to the reader, and the probability of message collision of RN16 sent by the multiple A-IoT devices at the reader is high, which can easily cause the A-IoT device to fail to access the reader.

[0172] Therefore, in the present application, a communication method is provided, in which the reader can group the A-IoT devices to control the number of A-IoT devices accessing the reader in groups, so that a limited number of A-IoT devices access the reader in different groups, and further can access the reader on X (X is greater than or equal to 1) candidate time domain resources. In this way, by grouping the A-IoT devices, the problem that the number of time domain resources for D2R transmission is limited after each R2D message is sent, which easily leads to the failure of A-IoT devices to access the reader, can be solved, and the access success rate of A-IoT devices is improved.

[0173] Based on this, as shown in FIG. 4, a flowchart of a communication method is shown, in which the A-IoT device can determine whether the R2D message triggers the access time group of the A-IoT device when receiving the R2D message, and feed back the D2R message to the reader when it is determined that the access time group of the A-IoT device is triggered. The method can include the following processes.

[0174] 401. The first device sends a first message, the first message being used to trigger an access time of the first device and / or being used to page at least one second device.

[0175] In some embodiments, the first device is a reader, and the second device is an A-IoT device. Accordingly, the second device receives the first message sent by the first device.

[0176] The first message can be an R2D trigger message, which can be understood as a Select message or a paging message in the present application. The R2D trigger message can also be a query (query) or repeated query (queryrep) message. The specific message type can be referred to the description below. The first device sending the first message can be understood as the first message being used to page multiple A-IoT devices or trigger multiple A-IoT devices to access the reader.

[0177] In some embodiments, when the first message is an R2D trigger message, the first message includes identification information (such as a mask, a group identification, an A-IoT device identification, etc.) and the number X of candidate time domain resources of D2R defined by R2D, and can further include indication information of the location of the X candidate time domain resources.

[0178] 402. The second device sends a second message to the first device at an access time of a first access time group, the second message being used for the second device to access the first device or send data to the first device, the first access time group being determined based on the first message, and the first access time group including at least one access time.

[0179] Accordingly, the first device receives a second message sent by the second device at an access occasion of the access occasion group.

[0180] In some embodiments, when the first message is a Select message or a paging message, the second message can include RN16, denoted as msg1, and the second message is used for the second device to request access to the first device. The RN16 or the second message can be understood as random information, identification information, or a random sequence, etc., used for contention resolution. The RN16 can also be replaced by other names.

[0181] The second message can also be a D2R message or uplink data (such as a device ID, sensing / positioning data, a response to a command, or read data, etc.).

[0182] When the R2D trigger message is a query or a queryrep, the second message includes an EPC of the second device.

[0183] In this application, the R2D trigger can also be replaced by other names, such as R2D scheduling or R2D message, etc. The name of the R2D trigger is not limited in this application.

[0184] The access occasion group can be understood as X occasions paged or triggered by the first message, and each occasion is an access occasion. The first access occasion group is one of the multiple access occasion groups triggered by the first device in multiple groups.

[0185] Optionally, the X occasions can be indicated by the R2D trigger or MAC CE configuration information, which can be direct indication or indirect indication. For example, the indirect indication can be to indicate X by indicating Z, that is, X can be determined by Z. For example, X = 2 Z , or X = function (Z), and the function can be any function of Z.

[0186] In some embodiments, when the first access occasion group is determined based on the first message, the first message includes at least one of the following information: the total number of access occasion groups for accessing the first device; and the group number of the first access occasion group.

[0187] When the total number of access occasion groups for accessing the first device is denoted as N, N can also be understood as the total number of rounds, frames, occasion sets, or the total number of processes indicated by the first message for accessing the first device. The total number of access occasion groups is taken as an example for description in this application.

[0188] Optionally, the total number of groups N can be indicated by the configuration information such as R2D trigger or MAC CE, which can be direct indication or indirect indication. For example, the indirect indication can be by indicating R to indicate X, i.e. X can be determined by R. For example, X = 2R, or X = function(R), and the function can be any function of R.

[0189] Optionally, the access occasion group can be replaced by access round, access frame, set or process of access occasion (or opportunity), and the name of the access occasion group is not limited in the application.

[0190] In essence, the second device is divided into one or more groups / rounds / frames / occasion sets / processes by the R2D message (R2D trigger) for access or data transmission, which can also be understood as one R2D message triggering one or more subsequent access opportunities or transmission opportunities.

[0191] The group number of the first access occasion group can be understood as the group number or group identifier of the access occasion group currently triggered by the first device through the first message, which can be denoted as n, i.e. the nth access occasion group in the N access occasion groups currently triggered by the first device, N is an integer greater than or equal to 2, n is an integer greater than or equal to 1 and less than or equal to N.

[0192] Here are the possible cases: if the first message sent by the first device is the first trigger or paging X access occasions, the first message can include the total number of access occasion groups N of the access occasion group of the first device, or include the total number of access occasion groups N of the access occasion group of the first device and the group number n of the first access occasion group.

[0193] If the first message sent by the first device is not the first trigger or paging X access occasions, the first message can include the group number n of the first access occasion group, or include the total number of access occasion groups N of the access occasion group of the first device and the group number n of the first access occasion group.

[0194] In some embodiments, the first access occasion group is determined based on the first message, including: the first access occasion group is determined based on the first message and the group number of the second access occasion group, and the group number of the second access occasion group is less than or equal to the total number of access occasion groups.

[0195] Wherein, the group number of the second access occasion group can be randomly generated by the second device, or preset in the second device.

[0196] In some embodiments, the group number of the second access occasion group can be understood as the group number of the access occasion group selected by the second device.

[0197] Based on this, in some embodiments, before the second device sends the second message, the method further comprises: the second device determining the group number of the second access occasion group. The first access occasion group is determined based on the first message and the group number of the second access occasion group, comprising: when the group number of the second access occasion group is the same as the group number of the first access occasion group, the first access occasion group is the access occasion group for the second device to send the second message.

[0198] For example, the first message comprises the total group number N of the access occasion groups of the first device and the group number n of the first access occasion group. When the second device receives the first message, the second device randomly generates the group number n0 of the second access occasion group according to N, and n0 is less than or equal to N. If the group number n0 of the second access occasion group randomly generated by the second device is the same as the group number n of the first access occasion group carried by the first message, it can be understood that the first device is currently paging or triggering the access occasion group with the group number n or n0, and the second device determines that the access occasion group currently paged or triggered by the first device is the access occasion group to which the second device belongs. The second device can respond to the first message, i.e., the second device can send the second message to the first device, for example, sending msg1, i.e., RN16. Conversely, if the group number n0 of the second access occasion group randomly generated by the second device is different from the group number n of the first access occasion group carried by the first message, the second device does not respond to the first message.

[0199] In some embodiments, before the second device sends the second message, the method further comprises: the second device determining the group number n of the first access occasion group. The first access occasion group is determined based on the first message and the group number of the second access occasion group, comprising: the first access occasion group is determined by the second device by decreasing the group number of the first access occasion group every time the first message is received, and when the group number is decreased to the group number of the second access occasion group.

[0200] For example, the first message includes the total number N of the access opportunity groups of the first device, but does not include the group number n of the first access opportunity group. When the second device receives the first message, it randomly selects a group number n of the first access opportunity group, n is less than or equal to N, and starts a counter with n as the initial value. When the second device receives a first message, such as an R2D trigger message, it decrements the counter by 1. When the counter decreases to the group number of the second access opportunity group, such as the group number 0, the second device can determine, in response to the last received first message, that the current first message triggers the first access opportunity group randomly selected by the second device, with the group number n. Alternatively, the second device can determine, in response to the last received first message, when the counter decreases to less than or equal to 0, that the current first message triggers the first access opportunity group randomly selected by the second device. Similarly, the second device can also determine, in response to the last received first message, when the counter increases by 1 (or m) and increases to the group number of the second access opportunity group, that the current first message triggers the first access opportunity group randomly selected by the second device. The present application is not limited in this regard. The value of m can be determined or indicated by the R2D trigger message.

[0201] As a possible implementation, each access opportunity group includes one time resource. In this case, the total number N of the access opportunity groups of the first device can also be understood as the total number of time resources of the first device; and the group number n of the first access opportunity group determined by the second device before sending the second message can also be understood as the number / index of the time resource of the first device accessed by the second device.

[0202] For example, the first message includes the total number N of the access opportunity groups of the first device (i.e., the total number of time resources of the first device), but does not include the group number n of the first access opportunity group (i.e., the number / index of the time resource of the first device accessed by the second device). When the second device receives the first message, it randomly selects a group number n of the first access opportunity group (i.e., the index / number of the time resource of the first device accessed by the second device), n is less than or equal to N, and starts a counter with n as the initial value. When the second device receives a first message, such as an R2D trigger message, it decrements the counter by m, m is an integer greater than or equal to 1. When the counter decreases to less than or equal to 0, the second device can determine, in response to the last received first message, that the current first message triggers the first access opportunity group randomly selected by the second device, with the group number n (i.e., that the current first message triggers the time resource of the first device accessed by the second device, with the index of the time resource being n).

[0203] Wherein, m is the number of time resources triggered by a first message (such as R2D trigger message, random access trigger message or random access R2D trigger message). m can also be referred to as the number of time resources managed by a first message, the number of time resources associated with a first message, the number of time resources indicated by a first message, the number of time resources triggered after the transmission of a first message, or the number of time resources determined by a first message, etc. without limitation. Optionally, m can be determined or indicated by the R2D trigger message.

[0204] In addition, in the case that the number of time resources included in each access opportunity group is 1, the time resource associated with the access opportunity of the first device accessed by the second device can also be determined based on the first message and the group number of the second access opportunity group.

[0205] For example, the first message includes the total number of access opportunity groups N of the first device, but does not include the group number (i.e. the index / number of the time resource of the first device) n of the first access opportunity group. When the second device receives the first message, it randomly selects a group number (i.e. the index / number of the time resource of the first device) n of the first access opportunity group, n is less than or equal to N, and starts a counter with n as the initial value. In the case that the counter is decremented to W by the second device according to the received first message, W is less than or equal to 0, the second device can determine that the current first message triggers the first access opportunity group randomly selected by the second device in response to the last received first message, and determine the access opportunity of the time resource associated with the current first message as the |W|th or -Wth time unit after the current first message as the access opportunity of the first device accessed by the second device, and send msg1 (or random ID, data upper layer data, etc.) to the first device at the |W|th or -Wth time unit after the current first message to request access to the first device.

[0206] In addition, after the second device randomly selects a group number n of the first access opportunity group when receiving the first message, it can also start a counter with N as the initial value. When the second device receives a first message, it decrements the counter by m. When the counter is decremented to less than or equal to (N-n), the second device can determine that the current first message triggers the first access opportunity group randomly selected by the second device in response to the last received first message, and the group number is n.

[0207] That is, in the process of determining the group number of the first access occasion group according to the first message and the group number of the second access occasion group, the initial value of the counter can be set as n, the group number of the second access occasion group is set as 0, and the group number of the first access occasion group is determined when the counter is decremented to be less than or equal to the group number of the second access occasion group; or the initial value of the counter is set as N, the group number of the second access occasion group is set as (N-n), and the group number of the first access occasion group is determined when the counter is incremented to be greater than or equal to the group number of the second access occasion group.

[0208] Similarly, the second device can also determine the first access occasion group in which the current first message triggers by increasing the group number. After randomly selecting a group number (i.e., the number / index of the time resource in which the second device accesses the first device) n of the first access occasion group, the initial counter is set as 0. When the second device receives each first message, the counter is incremented by m. When the counter is incremented to be greater than or equal to the group number n of the first access occasion group, it is determined that the current first message triggers the first access occasion group randomly selected by the second device. Or, the initial counter is set as (N-n). When the second device receives each first message, the counter is incremented by m. When the counter is incremented to be greater than or equal to N, it is determined that the current first message triggers the first access occasion group randomly selected by the second device. The present application is not limited in this regard.

[0209] In some embodiments, before the second device sends the second message, the method further includes: determining, by the second device, an index k of the first time resource, and determining the first access occasion group based on the first message and the index of the first time resource.

[0210] The index of the first time resource can be randomly generated by the second device, or preset in the second device. The index of the first time resource can also be referred to as the number of the first time resource, the serial number of the first time resource, or the code of the first time resource, and the like, without limitation.

[0211] In some embodiments, the index of the first time resource can be understood as the index of the time resource corresponding to / located in / occupied by the access occasion selected by the second device.

[0212] Based on this, in some embodiments, before the second device sends the second message, the method further includes: determining, by the second device, an index of the first time resource. The first access occasion group is determined based on the first message and the index of the first time resource includes that: when the time resource in which at least one access occasion included in the first access occasion group is located includes the first time resource (or the index of the time resource in which at least one access occasion included in the first access occasion group is located includes the index of the first time resource), the first access occasion group is the access occasion group in which the second device sends the second message.

[0213] For example, the first message comprises the total number of access occasion groups N, the group number n of the first access occasion group, and the index of the time resource where the at least one access occasion of the first access occasion group is located. Upon receiving the first message, the second device randomly generates the index of the first time resource. If the index of the time resource where the at least one access occasion of the group number n of the first access occasion group is located comprises the index of the first time resource, it can be understood that the access occasion group to which the second device belongs is the one currently paged or triggered by the first device. The second device can respond to the first message, i.e., the second device can send a second message to the first device, for example, send msg1, i.e., RN16. Conversely, if the index of the time resource where the at least one access occasion of the group number n of the first access occasion group is located does not comprise the index of the first time resource, the second device does not respond to the first message.

[0214] In some embodiments, before the second device sends the second message, the method further comprises: the second device determining the group number n of the first access occasion group. The first access occasion group is determined based on the first message and the index of the first time resource, comprising: the second device determining the first access occasion group upon receiving the first message each time, decreasing the index of the first time resource each time, and determining when the index is decreased to the first value.

[0215] For example, the first message comprises the total number of time resources K where the access occasion of the first device is located, but does not comprise the index k of the first time resource. Upon receiving the first message, the second device randomly selects an index k of the first time resource, k is less than or equal to K, and starts a counter with k as the initial value. When the second device receives the first message, for example, the R2D trigger message, each time, the counter is decreased by 1. When the counter is decreased to less than or equal to the first value, for example, 0, the second device can respond to the last received first message to determine that the current first message triggers the first access occasion group of the second device to access the first device.

[0216] In addition, the time resource associated with the access occasion of the first device to which the second device accesses can also be determined based on the first message and the index of the first time resource.

[0217] For example, the first message includes the total number K of time resources in which the access occasions of the first device are located, but does not include the index k of the first time resource. When the second device receives the first message, it randomly selects an index k of the first time resource, k is less than or equal to K, and starts a counter with k as the initial value. When the second device receives a first message, for example, an R2D trigger message, each time, the counter is decremented by m. When the counter is decremented to W, W is less than or equal to the first value. The second device can determine, in response to the last received first message, that the current first message triggers a first access occasion group in which the second device accesses the first device, and take the access occasion associated with the time resource |W| time resources or the -W time unit after the current first message as the access occasion in which the second device accesses the first device, and send msg1 (or random ID, data upper layer data, etc.) to the first device on the time resource |W| time resources or the -W time unit after the current first message to request access to the first device.

[0218] In addition, after the second device randomly selects an index k of the first time resource when receiving the first message, it can also start a counter with K as the initial value. When the second device receives a first message each time, the counter is decremented by m. When the counter is decremented by less than or equal to (K-k), the second device can determine, in response to the last received first message, that the current first message triggers a first access occasion group in which the second device accesses the first device.

[0219] Wherein, m is the number of time resources triggered by a first message (such as an R2D trigger message). m can also be referred to as the number of time resources managed by a first message, the number of time resources associated with a first message, the number of time resources indicated by a first message, or the number of time resources determined by a first message, etc., without limitation. Optionally, m can be determined or indicated by an R2D trigger message.

[0220] Similarly, the second device can also increment the group number in the following way: after randomly selecting an index k of the first time resource, set the initial counter to 0. When the second device receives a first message each time, the counter is incremented by m. When the counter is incremented to greater than or equal to the index k of the first time resource, it is determined that the current first message triggers a first access occasion group in which the second device accesses the first device; or, set the initial counter to (K-k). When the second device receives a first message each time, the counter is incremented by m. When the counter is incremented to greater than or equal to K, it is determined that the current first message triggers a first access occasion group in which the second device accesses the first device. The present application is not limited.

[0221] In the present application, when a number such as N, n or m is indicated by a message, it can be indicated in a MAC CE or a MAC header, or indicated in a physical layer sequence such as a calibration sequence, or a preamble, or a postamble, etc.

[0222] Optionally, when the first message is the first time to trigger X access occasions, the first message can carry an indication of whether the R2D trigger is initial or new (the trigger can be replaced by paging / selection). When the second device receives an indication of an initial or new R2D trigger (for example, a display indication), or when the first message does not carry an indication of a non-initial or new R2D trigger, the second device can generate the group number of the second access occasion group according to the total group number N carried in the first message.

[0223] Here it can be understood that there are two kinds of R2D triggers, one is an initial trigger, for example, an initial or new paging message, which can reset or initialize the group number of the selected / triggered access occasion group. The other is a subsequent trigger message, for example, a retransmission paging or other trigger message, which can trigger each subsequent access occasion group through the group number n.

[0224] How to distinguish between initial and subsequent (non-initial or retransmission) R2D triggers can be indicated by a display indication, such as 0 indicating an initial / new R2D trigger and 1 indicating a subsequent transmission / retransmission / non-initial transmission. Alternatively, carrying a display indication is a subsequent transmission / retransmission / non-initial transmission, and not carrying a display indication is a new transmission / initial transmission, or vice versa, carrying a display indication is a new transmission / initial transmission, and not carrying a display indication is a subsequent / retransmission / non-initial transmission. In this way, when the present application is applied to an A-IoT network architecture, the first device is a reader / writer and the second device is an A-IoT device, the reader / writer can page or trigger multiple A-IoT devices through the first message group trigger or paging. When the A-IoT device determines that the reader / writer is paging or triggering the first access occasion group of the A-IoT device, it sends a second message to the reader / writer to access the reader / writer. In this way, by grouping A-IoT devices, multiple A-IoT devices can be divided into different R2D trigger responses, which can solve the problem of limited time domain resource number for D2R transmission after each R2D message is sent, which can easily cause A-IoT device access to the reader / writer to fail, and improve the access success rate of A-IoT devices.

[0225] In the present application, the determination or triggering of the access opportunity of the second device can be similar to the prior art, and each access opportunity can be triggered by a message similar to QueryRep. For example, the second device triggered by the R2D trigger message determines its own access opportunity according to X, such as selecting the access opportunity x, and receiving the access opportunity trigger message (a message similar to QueryRep, such as access occasion trigger) x times can trigger the access opportunity x.

[0226] Alternatively, the present application can also adopt the method of determining whether the first device currently triggers the access opportunity group of the second device according to the group number. For example, when the second device determines that the R2D trigger message currently triggers the access opportunity group of the second device, the second device can determine the access opportunity of the second device in the access opportunity group according to the bias time. For example, the second device determines that the bias time is 10us, and the access opportunity of the second device is 10us after receiving the R2D trigger message, for example, the second device sends the second message to the first device after 10us.

[0227] In some embodiments, the second device needs to be triggered by the R2D trigger message before determining its own access opportunity, or the second device responds to the currently received R2D trigger message. That is, the second device will further wait or enter the process of confirming the access opportunity, for example, the second device sends the RN message, only when it is determined that the R2D trigger message triggers the access opportunity group corresponding to the second device (the paging message may also need to determine the mask matching, etc.). If the second device determines that the R2D trigger message does not trigger the access opportunity group corresponding to the second device, the second device needs to skip the process of confirming the access opportunity and wait to receive the next R2D trigger message.

[0228] In some embodiments, if the first message also carries the session ID, if the session ID carried by the first message is different from the session ID carried by the previous one, it can be understood that the reader wants to end the paging or triggering of the previously selected access opportunity group in advance. For the second device, when the second device determines that the session ID changes, the second device can also randomly generate the group number of the access opportunity group again to determine whether to respond to the first message according to the group number of the regenerated access opportunity group.

[0229] In some embodiments, when the first message is the R2D trigger message, the R2D trigger message can further include sixth indication information, which is used to indicate that all the groups of access occasions that have not been triggered are ended or terminated or stopped from being triggered. For example, the sixth indication information is used to indicate that the n~N groups of access occasions that have not been triggered are ended or terminated or stopped from being triggered. Optionally, the R2D trigger message further includes seventh indication information, which is used to indicate that the R2D trigger message is an initial R2D trigger message.

[0230] In this way, when the second device receives the sixth indication information, the second device can discard the group number of the second group of access occasions, or the second device stops receiving the R2D trigger message and responds to the initial R2D trigger message.

[0231] In this way, the total number of groups of access occasions that are equivalent to the initial group is terminated or adjusted before all the subsequent groups of access occasions are accessed. For example, when the first device determines that the current grouping of the groups of access occasions is too much or too little, resulting in unreasonable grouping, the total number of groups of the current groups of access occasions is terminated or adjusted. In some embodiments, the R2D trigger message can be used to indicate the total number of groups of access occasions after the reset.

[0232] For example, the R2D trigger message includes eighth indication information, which is used to indicate the total number of groups of access occasions that are reset and the new total number of groups of access occasions N'. In this way, when the second device receives the eighth indication information, the second device can discard the group number of the second group of access occasions and determine the group number of the second group of access occasions again according to the total number of groups N' to reattempt to access the first device.

[0233] In some embodiments, when the first device determines that the group of access occasions that are currently triggered / paged and the number of second devices that successfully access the first device is small or no second device successfully accesses the first device, a re-access process can be performed.

[0234] For example, the first device can send the R2D trigger message again. The R2D trigger message includes the serial number of the group of access occasions that are triggered or paged last time, so as to trigger the second device of the group of access occasions that are triggered or paged last time to reaccess or retransmit data.

[0235] Optionally, the second device does not discard the group number of the selected second group of access occasions of the second device before successful access, or before successful data transmission, or before successful service.

[0236] For example, the first device can send again the R2D trigger message, which does not carry the serial number of the access occasion group triggered or paged last time, and the R2D trigger message can be used to indicate whether it is for re-access or re-transmission of data. The second device which fails to access can continue to receive or listen to the R2D trigger message to re-try to access the first device upon receiving the R2D trigger message.

[0237] For the second device which does not try to access or the second device which does not fail to access, there is no need to respond to the R2D trigger message indicating re-access, or in other words, skip / discard the R2D trigger message indicating re-access.

[0238] In addition, for the A-IoT device, if it is determined not to respond to the first message, i.e. fails to access the reader, and considering that the reader is the group-triggered A-IoT device, the A-IoT device can also continue to listen to the R2D trigger message sent by the first device to determine whether to access the reader.

[0239] Therefore, in some embodiments, the method further comprises: if the access to the first device fails, receiving a third message sent by the first device, the third message being used to trigger an access occasion for accessing the first device and / or being used to page at least one second device; the third message comprising at least one of the following information: total group number of the access occasion groups for accessing the first device; group number of a fourth access occasion group. The group number of the fourth access occasion group is greater than or equal to the group number of the first access occasion group and less than or equal to the total group number of the access occasion groups; or the group number of the fourth access occasion group is greater than the total group number of the access occasion groups.

[0240] Correspondingly, for the first device, the first device sends the third message.

[0241] The type of the third message can be similar to that of the first message. That is, when the second device fails to access, the second device can continue to receive the R2D trigger message, and when the received R2D trigger message carries the group number of the triggered access occasion group, the range of the group number can be n~N. Correspondingly, the second device can also select in n~N when randomly generating the group number of the access occasion group, so as to determine whether the first device triggers or pages the access occasion group selected by the second device.

[0242] In this application, the second device which fails to access can also be replaced by the second device which fails to transmit or the second device which fails in service, etc.

[0243] Optionally, the second device determines the access failure, which can be determined when the second device receives a display indication about the access failure of the second device, or can be determined when the second device does not receive (or does not receive within a period of time) an indication associated with the successful access of the second device.

[0244] Alternatively, the first device can additionally indicate M groups other than the N groups of access occasions through the R2D trigger, in which case, the group numbers of the access occasion groups triggered by the first device are equivalent to [N+1, N+M], and M is an integer greater than or equal to 1, for example, M = 5 or 6, etc. Correspondingly, the second device can also select from [N+1, N+M] when randomly generating the group number of the access occasion group, so as to determine whether the access occasion group to which the second device belongs is triggered or paged by the first device.

[0245] Alternatively, for the second device, if the second device determines that the access occasion group to which the second device belongs is not currently triggered or paged by the first message, the second device can also attempt to access by default when receiving the R2D trigger next time, i.e., randomly generating RN16 and sending to the first device in the second message.

[0246] Alternatively, for the second device, if the second device has not successfully accessed the first device after receiving the R2D trigger message multiple times, the first device can also continue to send the R2D trigger, which includes a re-access identifier. The re-access identifier is used to indicate that the second device can continue to attempt to access when receiving the R2D trigger, i.e., indicating that the second device randomly generates RN16 and sends to the first device. Alternatively, the R2D trigger does not carry the re-access identifier, but indicates the second device in the R2D trigger by not carrying the mask or session ID, which is used for the second device to re-access, so that more second devices access the first device.

[0247] In some embodiments, the number X of candidate time domain resources corresponding to different groups can be the same or different. Different groups can also be associated with Y candidate frequency domain resources, Y being greater than or equal to 1. That is, multiple A-IoT devices can select a frequency domain resource from Y candidate frequency domain resources when sending the D2R message. Wherein, Y can be directly or indirectly indicated in the R2D trigger message. For example, indirect indication can be to indicate one or more frequency domain resources through a transmission parameter to indicate Y candidate frequency domain resources.

[0248] For example, the Y candidate frequency domain resources can be indicated by the parameters included in the frequency resource indication information. For example, the indication can be implemented in various manners as exemplified herein. Manner 1) The parameters included in the frequency resource indication information indicate the frequency information or the frequency domain location or the frequency point location of the Y candidate frequency domain resources. Manner 2) The parameters included in the frequency resource indication information indicate the frequency shift between the Y candidate frequency domain resources and the default frequency domain location (or the preconfigured frequency domain location). Manner 3) The parameters included in the frequency resource indication information can include at least one of the following to indicate the Y candidate frequency domain resources: a time parameter, for example, a time parameter indicating an uplink or downlink or uplink-downlink transmission time unit, or a parameter related to the uplink or downlink or uplink-downlink transmission time unit, etc.; a code length parameter, for example, a code length parameter being a manchester code repetition number or a parameter related to the manchester code repetition number, etc.; a scaling parameter, for example, a scaling parameter being a level repetition number or a parameter related to the level length, etc.

[0249] Therefore, in some embodiments, the first message further includes the number Y of the D2R frequency domain resources defined by the R2D, and can further include indication information of the location of the Y candidate frequency domain resources. For example, the first message can directly or indirectly indicate the location of the Y candidate frequency domain resources. For example, when the above-mentioned manner 1) of indicating the frequency domain resources is adopted, the first message includes the frequency information or the frequency domain location or the frequency point location of each of the Y candidate frequency domain resources.

[0250] Optionally, the first message further includes the indication of the Y candidate frequency domain resources. In this way, the first message indicates X*Y access occasions. When the first message in the above-mentioned step 401 is the R2D trigger message, the R2D trigger message can trigger X or X*Y access occasions.

[0251] In some embodiments, it has been described above that when the first message is the R2D trigger message, the R2D trigger message can be a paging, query, queryrep, etc. message, and the present application does not limit the message name of the R2D trigger message.

[0252] Among them, the select or paging message can be understood as a paging message, which can be used to select one, multiple, a group, or a type of terminal device, or can also be described as a paging message used to trigger one, multiple, a group, or a type of terminal device to access the network, without limitation. It can be determined by a group identifier, a mask, or a terminal identifier (which can be provided by a core network or a server (such as an Internet of Things server) or an access network device).

[0253] In the present application, in the A-IoT network architecture, the paging message can be used to instruct the A-IoT device to access the reader, such as:

[0254] When the reader is a base station / access network device, the paging message can be used to instruct the A-IoT device to access the network;

[0255] When the reader is a terminal device, the paging can be used to instruct the A-IoT device to access the terminal device, and optionally, the A-IoT device can access the network through the terminal device;

[0256] The paging message can also be used to trigger or instruct the A-IoT device to send uplink data, or to trigger, instruct, or request the A-IoT device to perform at least one of the following services: paging service, inventory service, command service (such as read, write, deactivate, lock, etc.), positioning service, sensing service.

[0257] The paging message can also be called (initial) downlink (download, DL) trigger message, which can be triggered by a core network element (such as an authentication management function (AMF), or AIoTMF (ambient IoT management function), AIoTF (ambient IoT function)) and the like), such as the core network element sending a request message or a paging message to the reader for a first service, wherein the first service can be an inventory service, or a command service, or a positioning service, etc.

[0258] The select or paging message can carry a read, write, lock, or sensing indication, specifically, when the A-IoT device receives the indication, it can have different responses when accessing the reader according to the specific indication.

[0259] For example, when the select or paging message carries a read indication, the read indication can include at least one of the following: the storage area location / type of the read data (such as user-defined area, EPC area, etc.), the length of the read data, or the starting byte of the read data. After receiving the read indication, the A-IoT device needs to send the data content to the reader, for example, to the base station, according to the read indication.

[0260] When the select or paging message carries a write indication, the write indication includes at least one of the following: the storage area location or type of the write data, the write data length, the starting byte of the write data, or the write data content. The A-IoT device writes the data content into the storage area according to the write indication, and if the writing is successful, it feeds back a response message to the reader.

[0261] The select or paging message carries a lock indication, which can also be an inactivation indication. After receiving the lock indication, the A-IoT device is deactivated and no longer works and does not respond to any message.

[0262] The select or paging message carries a sensing indication, which is similar to a read indication. After receiving the sensing indication, the A-IoT device can send sensing data to the reader, for example, to the base station.

[0263] When the R2D trigger message is a query message or a queryrep message (or signaling) similar message, the query message or the queryrep message can be used to trigger the A-IoT device to access the network or randomly access the reader. The query message or the queryrep message can be used to allocate random access resources, for example, can include a random access resource configuration (such as a parameter Q, and the A-IoT device randomly selects a number Counter = 0 ~ 2 Q-1 as an access opportunity), and the A-IoT device calculates the maximum number of transmission time slots according to the random access configuration (parameter Q) and randomly selects an access time slot for random access. For example, the configuration of the random access resource can include a maximum access time slot range.

[0264] For example, the query can also be referred to as an access round indication or a trigger, and the name of the query in the present application is not limited. The query is used to trigger or indicate at least one access opportunity, for example, directly or indirectly indicates the total number of access opportunities, and can also be used to trigger the first access opportunity.

[0265] The queyrep can also be referred to as an access occasion indication or a trigger, and the name of the queyrep in the present application is not limited. The queyrep is used to trigger or indicate the next access opportunity, and can also be understood as indicating or associating with the boundary (start or end) of an access opportunity.

[0266] The above-mentioned access opportunity can also be described as an access opportunity, an access time slot, etc. Each access opportunity can allow the second device to send an access (request), and / or a contention resolution, and / or a data transmission, etc.

[0267] Optionally, the query and the select or paging message can be combined into one message, that is, one message carries the contents (or functions) of both, for example, the select or paging message carries the random access resource configuration, or the query message carries the terminal related identifier, the mask, or the group number (identifier) of the access opportunity group, etc.

[0268] In fact, the query message can also correspond to trigger one or more access occasions, each of which allows one or more A-IoT devices to access (which can be staggered in time, or rely on the reader to be able to distinguish one or more of the RNs sent by multiple A-IoT devices).

[0269] The second message, i.e. msg1, when carrying the RN, is used for contention resolution, or for distinguishing different A-IoT devices in the random access or contention resolution process.

[0270] In the A-IoT network architecture, the R2D message triggers the sending of the D2R message in the manner that the R2D message can indicate a sending time of sending the D2R message through control information. For example, the control information is used to indicate a time offset of the D2R message to indicate the sending time of the D2R message. The reader can send to multiple A-IoT devices through one R2D message after concatenating or merging the R2D messages for multiple A-IoT devices. For example, the reader can send an ACK message (denoted as msg2) to multiple A-IoT devices through R2D concatenation. That is, the ACK message can be concatenated or merged for sending. In this case, multiple A-IoT devices can be triggered to send the D2R message, such as sending the EPC, to the reader when receiving the ACK concatenated message. The reader can configure the time offset for multiple A-IoT devices to avoid the collision of the EPC (denoted as msg3) sent by multiple A-IoT devices in time, that is, to avoid the problem of the EPC sent by multiple A-IoT devices colliding at the reader.

[0271] Specifically, the reader can carry the time offset corresponding to the RN randomly generated by the A-IoT device in the R2D concatenated message to indicate the sending time of the A-IoT device when sending the D2R message. In this R2D concatenation manner, for example, when the R2D concatenated message is an ACK concatenated message, the ACK concatenated message will carry the correspondence between the RN randomly generated by multiple A-IoT devices and the time offset. If the RN randomly generated by different A-IoT devices is the same, the situation that the time offset determined by multiple A-IoT devices according to the correspondence in the ACK concatenated message is the same will occur, resulting in the same time of multiple A-IoT devices sending the EPC to the reader, and the problem of multiple D2R messages colliding at the reader.

[0272] Therefore, the embodiment of the present application provides a communication method, which can be used for solving the problem of how the A-IoT device determines the bias time of sending the D2R message for the R2D cascade message. In the method, considering that the A-IoT device will randomly select a time domain resource (access opportunity) x from X time domain resources (or access opportunities) defined in the R2D message to send the D2R message when sending the D2R message, in the present application, when the reader sends the R2D cascade message and indicates the bias time of the D2R message through the control information, the bias time can be related to not only the RN generated by the A-IoT device, but also the time domain resource (or access opportunity) x randomly selected by the A-IoT device. Considering that the probability of the randomly generated RN being the same as the randomly selected x is relatively small, the probability of the corresponding bias time determined by the A-IoT device according to the time domain resource (or access opportunity) x and the RN being the same will be greatly reduced, and the probability of the collision of multiple D2R messages at the reader is also reduced.

[0273] Based on this, as shown in FIG. 5, a flowchart of a communication method is shown, which can carry the indication of the time domain resource (or access opportunity) x randomly selected by the A-IoT device through the R2D cascade message to indicate the bias time of sending the D2R message to the A-IoT device. The method includes the following flows.

[0274] 501. The first device sends first indication information to the second device, the first indication information is used to confirm that the second device successfully accesses the first device, and the first indication information includes second indication information, and the second indication information is used to indicate a first time domain resource position, which is a time domain resource position selected by the second device from candidate time domain resource positions.

[0275] Correspondingly, the second device receives the first indication information sent by the first device.

[0276] The first device and the second device can refer to the description in the step 401.

[0277] In some embodiments, the first indication information is an R2D cascade message, which is used to send the R2D message to multiple A-IoT devices. When the second indication information is used to indicate the first time domain resource position, the second indication information can be understood as the indication of the time domain resource position x selected by the A-IoT device when sending the D2R message.

[0278] 502. The second device sends third indication information to the first device, and the first time information of sending the third indication information is determined based on the second indication information, and the third indication information is used to send data to the first device.

[0279] In some embodiments, the third indication information can be understood as a D2R message, for example, the D2R message is msg3 in the present application, for example, EPC. That is, the A-IoT device can determine the first time information of the A-IoT device sending the D2R message to the reader based on the selected time domain resource position x.

[0280] In combination with steps 501 and 502, an exemplary signaling timing diagram for the interaction between the reader and the plurality of A-IoT devices for R2D messages and D2R messages is shown in FIG. 6. The interaction process includes:

[0281] The reader sends an R2D trigger message (R2D message) to the plurality of A-IoT devices, for example, the R2D trigger is the first message in the present application, and the first message may, for example, include one or more of the candidate number of time domain resources X, the total number of access occasion groups N, the group number n of the current triggered or paged access occasion group, the flag bit mask, or the offset information. The offset information can indicate a plurality of time offsets, or indicate a time offset and the number of time offsets. In the contention-based random access (CBRA) of the A-IoT device, the offset information can be used by the A-IoT device to determine the time of sending the D2R message based on the offset information and the selected time domain resource position x when sending the D2R message. For example, the offset information carried by the R2D trigger indicates that one time offset is T0, the A-IoT device selects the third time domain resource position as the time domain resource position x, and the A-IoT device determines that the time offset of the D2R is 3 times T0. For example, when the D2R message is msg1 shown in FIG. 6, different A-IoT devices select different time domain resource positions x, and different A-IoT devices send msg1 with different time offsets relative to the R2D trigger, for example, two A-IoT devices determine the time offsets of the D2R messages as offset1 (offset 1) and offset2 (offset 2) shown in FIG. 6, respectively.

[0282] The plurality of A-IoT devices send msg1 to the reader based on the time offset, for example, msg1 is a RN randomly generated by the A-IoT device;

[0283] The reader can send a plurality of R2D messages by concatenation or merging, and when sending a plurality of A-IoT devices by one R2D message, the reader can send first indication information to the plurality of A-IoT devices, and the first indication information is an R2D concatenated message, for example, the R2D concatenated message is msg2 shown in FIG. 6. Msg2 includes second indication information indicating the first time domain resource position x corresponding to the plurality of A-IoT devices, respectively.

[0284] Considering that the msg1 sent by the A-IoT device to the reader after receiving the R2D trigger message carries a randomly generated RN, the R2D concatenated message, i.e., msg2, sent by the reader in response also carries the RN to indicate that the A-IoT device has successfully accessed. In this way, when msg2 is used as the R2D concatenated message, it not only carries the RN corresponding to the A-IoT device, but also carries the first time domain resource location x corresponding to multiple A-IoT devices respectively. The offset time carried in msg2 is related not only to the RN corresponding to the A-IoT device, but also to the first time domain resource location x.

[0285] Therefore, in some embodiments, before the second device receives the first indication information, the method further includes: the second device sending fourth indication information to the first device, the fourth indication information being used to indicate the RN generated by the second device when requesting to access the first device. The fourth indication information can be understood as msg1 in the present application. The first indication information further includes the fourth indication information. The first time information is determined based on the second indication information and the fourth indication information.

[0286] In this way, referring to FIG. 6, in the case where the multiple A-IoT devices can determine the offset time of msg3 based on the selected time domain resource location x and RN carried in msg2, if the time domain resource location x and RN of the multiple A-IoT devices are not completely the same, the time when different A-IoT devices send msg3 can be different, avoiding the collision of msg3 sent by the multiple A-IoT devices at the reader.

[0287] In some embodiments, before the second device sends the third indication information, the method further includes: determining that the second device has successfully accessed the first device based on the second indication information and the fourth indication information.

[0288] For example, in the case where the second indication information indicates the time domain resource location x randomly selected by the A-IoT device, and the fourth indication information indicates the RN randomly generated by the A-IoT device, it is equivalent to that the A-IoT device determines that it has successfully accessed the reader based on the R2D concatenated message, and the time domain resource location x and RN carried in the R2D concatenated message are both correct.

[0289] In some embodiments, the first indication information further includes fifth indication information, the fifth indication information being used to indicate the frequency domain resource location where the second device sends the third indication information.

[0290] Exemplarily, as shown in FIG. 7, there is a format diagram of an R2D cascade message. The R2D cascade message includes x(1), RN(1) associated with one A-IoT device, and R2D resource information corresponding to x(1) and RN(1), and further includes x(2), RN(2) associated with another A-IoT device, and R2D resource information corresponding to x(2) and RN(2).

[0291] The R2D resource information can include bias time and frequency domain information. The bias time can be used to indicate time information of msg3 sent by the A-IoT device, and the frequency domain information can be used to indicate frequency domain position of msg3 sent by the A-IoT device.

[0292] Exemplarily, as shown in FIG. 8, there is a flow diagram of an R2D trigger message as a paging message. In the flow, the reader is a base station, the A-IoT device is a UE, the msg1 is an RN, the msg2 is an ACK cascade message, and the msg3 is an EPC or uplink data. The flow includes the following processes. The flow can be understood in combination with the flow shown in FIG. 1.

[0293] The AMF or TMF network element sends an inventory request to the base station to instruct the base station to page the A-IoT device, for example, the A-IoT device includes UE1 and UE2 shown in FIG. 8;

[0294] The base station sends an R2D trigger message (select message or paging message or query message or queryrep message) to UE1 and UE2;

[0295] When the counter corresponding to UE1 is set to 0, UE1 sends RN1 to the base station at the time domain resource position x1;

[0296] When the counter corresponding to UE2 is set to 0, UE2 sends RN2 to the base station at the time domain resource position x2;

[0297] The base station sends an ACK cascade message to UE1 and UE2. The ACK cascade message includes time offset T1 corresponding to x1 and RN1, and time offset T2 corresponding to x2 and RN2, and T2 is greater than T1;

[0298] When UE1 determines that the correct x1 and RN1 are received based on the ACK cascade message, UE1 sends an EPC or uplink data to the AMF or TMF network element based on T1;

[0299] Optionally, the AMF or TMF network element sends downlink data to UE1;

[0300] UE2 determines that the correct x2 and RN2 are received based on the ACK cascade message, and sends the EPC or uplink data to the AMF or TMF network element based on T2.

[0301] The base station can continue to send the queryrep message to page more UEs.

[0302] That is, if UE1 or UE2 parses the RN and time domain resource location x matched by the UE according to the ACK cascade message, it indicates that the UE contention resolution is successful, that is, the access is successful. Alternatively, if T1 or T2 is equal to 0, the UE determines that it does not need to wait for an additional offset time to send uplink data. If the processing delay of the UE for the message is also considered, the UE needs some additional delay t0 when receiving the ACK cascade message. t0 can be understood as the processing delay of the downlink message sent by the reader / writer (which can be several or tens of us, such as 15.625us, and can also be related to the length of the downlink message) and / or the time delay of the UE from the receiving state to the sending state (several only a few tens of us) and / or additional operation delay (such as read / write data or inactivation operation, depending on the content of the downlink message sent by the network). These additional delays can be calculated together in the time offset, such as the ACK cascade message indicating that T1 needs to be greater than the A-IoT terminal processing delay t0, or the actual sending of the corresponding uplink message time interval = max{t0, T1}. It can also not be calculated together in the time offset, and the UE starts a timer after processing is completed, and counts the time offset, such as the ACK cascade message indicating T1, if the self-processing delay t0, then the actual sending time of the uplink data is t0+T1 from the time of receiving the downlink ACK cascade message.

[0303] In this way, when UE1 and UE2 are both paged, the probability that the corresponding offset time determined by UE1 and UE2 according to the time domain resource (or access opportunity) x and RN is the same is low, thereby reducing the probability that multiple EPC or uplink data messages collide at the base station.

[0304] In some embodiments, the first device can also indicate, through the R2D message, that the second device successfully accesses the first device or that the second device fails to access the first device.

[0305] For example, the first device can indicate, through the R2D message, the number of second devices that successfully access the first device, and / or the number of second devices that fail to access the first device.

[0306] For example, the first device can indicate the number of second devices successfully accessing the first device and / or the number of second devices failing to access the first device via an R2D trigger message. For example, the R2D trigger message can be an ACK cascade message.

[0307] For example, the ACK cascade message includes a time domain resource position x selected by a second device successfully accessing the first device, to indicate that the second device selecting the time domain resource position x successfully accesses the first device. Alternatively, the ACK cascade message includes a time domain resource position x selected by a second device failing to access the first device, to indicate that the second device selecting the time domain resource position x fails to access the first device.

[0308] For example, the ACK cascade message includes a frequency domain resource position y selected by a second device successfully accessing the first device, to indicate that the second device selecting the frequency domain resource position y successfully accesses the first device. Alternatively, the ACK cascade message includes a frequency domain resource position y selected by a second device failing to access the first device, to indicate that the second device selecting the frequency domain resource position y fails to access the first device. Wherein, y is less than or equal to Y.

[0309] For example, the ACK cascade message includes a time domain resource position x, an RN and an indication of successful access selected by a second device successfully accessing the first device, to indicate that at least one device sending a D2R message (e.g., msg1 or msg3, etc.) on the xth time domain resource successfully accesses the second device. Alternatively, the ACK cascade message includes a time domain resource position x, an RN and an indication of failed access selected by a second device failing to access the first device, to indicate that at least one device sending a D2R message (e.g., msg1 or msg3, etc.) on the xth time domain resource fails to access the first device.

[0310] Alternatively, the ACK cascade message can also indicate that at least one device sending a D2R message on the yth frequency domain resource corresponding to the xth time domain resource position successfully accesses or fails to access the first device, via the xth time domain resource position, the yth frequency domain resource position and the indication of successful access / failed access selected by the second device.

[0311] In some embodiments, the time interval between the D2R message and the corresponding R2D message satisfies T_D2R_max. For example, the D2R message is an RN message sent by the A-IoT device to the reader, such as RN16, and the R2D message is an ACK message or an ACK cascade message. If the A-IoT device does not receive the ACK message or the ACK cascade message sent by the reader within the maximum time range T_D2R_max after sending the RN message, the A-IoT device confirms that the access to the reader fails, which can be caused by the sending of the RN message by the A-IoT device, the failure to receive the ACK message or the ACK cascade message, or other reasons.

[0312] As shown in FIG. 3, if the msg1 is an RN message and the msg2 is an ACK message, when the ACK message is not sent in cascade, the time interval for the reader to feed back the ACK message to multiple A-IoT devices is different, that is, the time interval between the msg1 and the msg2 of the same A-IoT device can be affected by the R2D message sent by the reader to other A-IoT devices, so that the time for the A-IoT device to receive the msg2 cannot be determined, and the A-IoT device can not receive the msg2. For example, for the second sent msg1 shown in FIG. 3, the time interval T2 between the corresponding msg2 and the second msg1 can be affected by the first msg1 sent by the reader, and can also be affected by the transmission of a msg3, and the time interval T2 is large, even greater than the maximum time range T_D2R_max, which causes the A-IoT device of the second sent msg1 to fail to access.

[0313] Therefore, the present application provides a communication method, which considers that X time domain resources (access opportunities) are defined in the R2D message and can associate the time interval T2 between the D2R message and the R2D message sent by the A-IoT device with X, so that the time interval between the D2R message and the R2D message sent by the A-IoT device to the reader is not fixed but flexible and variable, which makes it easier for the A-IoT device to receive the R2D message under the flexible and variable T2 and improves the access success rate of the A-IoT device.

[0314] If the packet paging or the scheme of triggering the A-IoT device proposed in the present application is combined, the X value carried in the R2D trigger message sent by the reader each time can be variable, so that the value of the time interval T2 of the A-IoT device will be related to the number X of time domain resources triggered by the reader each time, so that the time interval T2 determined by the A-IoT device is flexible and variable.

[0315] As shown in FIG. 9, it is a flowchart of a communication method provided by an embodiment of the present application, which includes the following processes.

[0316] 901. The second device sends fourth indication information to the first device, and the fourth indication information is used for the second device to request access to the first device.

[0317] The descriptions of the first device and the second device can refer to the descriptions in step 401.

[0318] Correspondingly, the first device receives the fourth indication information sent by the second device.

[0319] In some embodiments, the fourth indication information includes an RN randomly generated by the second device, for example, RN16, which corresponds to msg1 in the present application, and is used to request access to the first device.

[0320] In a possible implementation, the start time of the second device sending the fourth indication information is determined according to the time resource of sending the fourth information and the first message triggering the second device to send the fourth indication information.

[0321] For example, in the case that the time resource used by the second device to send the fourth indication information is the first time resource after the first message triggering the second device to send the fourth indication information, the start time of sending the fourth indication information is TX1-start, which belongs to [T-R2D-MIN, T-R2D-MAX]; in the case that the time resource used by the second device to send the fourth indication information is the second time resource after the first message triggering the second device to send the fourth indication information, the start time of sending the fourth indication information is TX2-start, which belongs to [T-R2D-MAX, T-R2D-MAX+T-msg1*(1+2*SFO)]; in the case that the time resource used by the second device to send the fourth indication information is the third time resource after the first message triggering the second device to send the fourth indication information, the start time of sending the fourth indication information is TX3-start, which belongs to [T-R2D-MAX+1*T-msg1*(1+2*SFO), T-R2D-MAX+2*T-msg1+(1+2*SFO)].

[0322] That is, in the case that the time resource employed by the second device to send the fourth indication information is the Lth time resource after the first message triggering the second device to send the fourth indication information, the starting time TXL-start of the second device sending the fourth indication information belongs to [T-R2D-MAX+(L-2)*T-msg1*(1+2*SFO), T-R2D-MAX+(L-1)*T-msg1+(1+2*SFO)].

[0323] wherein TXL-start is the starting time of the second device sending the fourth indication information on the Lth time resource after the first message triggering the second device to send the fourth indication information, T-msg1 is the transmission time length of the fourth indication information, SFO is the sampling frequency offset (SFO), T-R2D-MIN is the minimum time between one R2D transmission and the corresponding D2R transmission, and T-R2D-MAX is the maximum time between one R2D transmission and the corresponding D2R transmission.

[0324] It is worth mentioning that the starting time TXL-start of the second device sending the fourth indication information on the Lth time resource after the first message triggering the second device to send the fourth indication information is not earlier than (1+SFO)*(TX(L-1)-start+T-msg1) / (1-SFO), wherein TX(L-1)-start is the time of sending the fourth indication information on the (L-1)th time resource.

[0325] 902、if the first indication information is received within the first time period after sending the fourth indication information, the second device determines to successfully access the first device, the first indication information is used to confirm that the second device successfully accesses the first device, and the first time period is related to the number of time domain resources selected by the second device when sending the message to the first device.

[0326] In some embodiments, the first indication information includes an ACK message sent by the first device, which corresponds to msg2 in the present application. The ACK message includes an RN randomly generated by the second device. For example, when the ACK message is an ACK concatenated message, the format of the ACK concatenated message can be referred to the example in FIG. 7. If the second device determines to successfully access the first device, it needs to be in the case that the access occasion x and the RN carried in the ACK concatenated message both match the access occasion x selected by the second device and the RN randomly generated by the second device.

[0327] It is worth mentioning that the determination of the access occasion x selected by the second device can be determined according to the group number of the second time group randomly selected by the second device, or according to the index of the first time resource randomly selected by the second device. The specific determination manner can refer to the related description in the foregoing embodiments, and will not be described herein.

[0328] The first time period can be understood as T2 in the present application, as shown in FIG. 6.

[0329] In some embodiments, the first time period T2 is determined according to the number of candidate time domain resources and at least one of the following information:

[0330] The transmission duration of the fourth indication information;

[0331] The second time information, the second time information is used to indicate the time interval between the reception of the first message by the second device and the transmission of the fourth indication information, the first message is used to trigger the access occasion of the access to the first device, and / or is used to page at least one second device.

[0332] In addition to the relationship between the first time period T2 and the number X of candidate time domain resources, the first time period T2 is also related to the transmission duration of the fourth indication information. It is considered that when the reader can analyze the D2R messages sent by multiple A-IoT devices, for example, the RN messages sent by multiple A-IoT devices, the reader can receive the RN messages sent by multiple A-IoT devices, and therefore the time for the reader to send the ACK concatenated message to multiple A-IoT devices is related to the duration of the RN messages sent by multiple A-IoT devices to the reader.

[0333] The first message can be understood as the R2D trigger message in the present application, and the second time information can be understood as the time interval between the reception of the R2D trigger message by the A-IoT device and the transmission of the RN message. Similarly to the above case, the first time period T2 is also related to the time interval indicated by the second time information, and it is also considered that there are multiple A-IoT devices sending RN messages to the reader.

[0334] In some embodiments, the first time period is determined according to the number of candidate time domain resources and the transmission duration of the fourth indication information.

[0335] For example, the first time period T2 = (X-1)·msg1, where X represents the number of candidate time domain resources indicated by the fourth indication information to the second device, and msg1 represents the transmission duration of the fourth indication information. The first time period T2 can be understood as follows: when the number of candidate time domain resources of the D2R message indicated by the R2D trigger message is X, if the A-IoT device determines that the access occasion group triggered or paged by the R2D trigger message is the access occasion group of the A-IoT device, the maximum time for the A-IoT device to wait for the reader to send the ACK cascade message after the A-IoT device sends the msg1 or RN message to the reader is T2. That is, if the A-IoT device receives the ACK cascade message within the range of (X-1)·msg1, the A-IoT device determines that the access to the reader is successful. If the A-IoT device has not received the ACK cascade message within the range of (X-1)·msg1, the A-IoT device determines that the access to the reader fails.

[0336] For example, when X = 10, the first time period T2 = 9·msg1.

[0337] For example, the transmission duration of msg1 can be configured to the A-IoT device, can be estimated by the A-IoT device, or can be indicated by the R2D trigger message. For the A-IoT devices in the same access occasion group, the transmission duration of msg1 can be the same under the same parameter configuration.

[0338] For example, if the transmission duration of msg1 is estimated by the A-IoT device, the A-IoT device can obtain the transmission duration of msg1 by timing, that is, the A-IoT device starts timing when it starts sending msg1, and ends timing when it ends sending msg1, thereby obtaining the transmission duration of msg1.

[0339] In some embodiments, the duration of the first time period T2 also includes the processing delay of each R2D message and / or D2R message. For example, the processing delay of the second device for accepting the R2D message or the processing delay of the first device for the D2R message before sending the D2R message, and the like.

[0340] In some embodiments, the first time period T2 is determined according to the number of candidate time domain resources and the second time information.

[0341] For example, the first time period T2 = (X-1) offset, where X represents the number of candidate time domain resources indicated by the fourth indication information to the second device, and offset represents the second time information. The first time period T2 can be understood as follows: when the first message / R2D trigger message indicates that the number of candidate time domain resources of the D2R message is X, if the A-IoT device determines that the access occasion group triggered or paged by the R2D trigger message is the access occasion group of the A-IoT device, the maximum time for the A-IoT device to wait for the reader to send the ACK cascade message after sending the msg1 or RN message to the reader is T2. That is, if the time offset between the A-IoT device sending the msg1 or RN message to the reader and the first message / R2D trigger message is offset, if the A-IoT device receives the ACK cascade message within the range of (X-1) offset transmission time, the A-IoT device determines that the access to the reader is successful. If the A-IoT device has not received the ACK cascade message within the range of (X-1) offset transmission time, the A-IoT device determines that the access to the reader fails.

[0342] For example, when X = 10, the first time period T2 = 9 offset.

[0343] In some embodiments, if the A-IoT device has not received the msg2 / ACK cascade message within the first time period T2, or even before receiving the next first message / R2D trigger message, the A-IoT device has not received the ACK cascade message matched with the A-IoT device, the A-IoT device determines that the access to the reader fails.

[0344] In some embodiments, if the A-IoT device receives the ACK cascade message matched with the A-IoT device before receiving the next first message / R2D trigger message, where the matched ACK cascade message includes the selected access occasion x of the A-IoT device, the randomly generated RN, and the correct frequency domain resource for sending the RN.

[0345] In some embodiments, in the present application, when the A-IoT device receives the matched ACK cascade message, the A-IoT device can send msg3, for example, msg3 is EPC, to the reader. If the reader determines that the reception of msg3 fails according to the bias time indicated in the ACK cascade message, the reader can send an indication information to the A-IoT device, indicating that the reception of msg3 from the A-IoT device fails. Considering that the reader can indicate that multiple A-IoT devices fail to receive msg3, the indication information carries the selected access occasion x and RN of the A-IoT device for distinction, or the indication information can carry the access stratum identify (AS ID) associated with the A-IoT device for distinction.

[0346] Similarly, in the present application, when the reader sends downlink data or scheduling information to the A-IoT device, the reader can also carry the selected access occasion x and RN of the A-IoT device in the downlink data or scheduling information, or carry the AS ID associated with the A-IoT device.

[0347] In some embodiments, in the present application, when the A-IoT device sends msg3 / EPC, the A-IoT device can enter a sleep state to save the energy consumption of the A-IoT device.

[0348] If the R2D message is a non-cascade message, one R2D message corresponds to multiple A-IoT devices, at this time, it is also required that T_D2R_max between the D2R message and the R2D message is satisfied, and T_D2R_max is large enough, for example, it needs to include the transmission time of one or more of msg1, msg2 and msg3, to realize the time staggered transmission of msg3 of multiple A-IoT devices. However, if T_D2R_max is set too large, it will cause the A-IoT device to need a longer timing. For the A-IoT device with lower power consumption, it will not support accurate timing for a long time, and the frequency offset is large, for example, the timing of 10 ms may be offset by 1 ms. Among them, the A-IoT device with lower power consumption may be a passive A-IoT device or a semi-passive A-IoT device.

[0349] For example, as shown in FIG. 3, if the number X of time domain resources defined in the R2D trigger message is 2, two A-IoT devices send msg1 / RN messages to the reader, and the reader feeds back msg2 / ACK messages to the two A-IoT devices respectively. Among them, for the second A-IoT device receiving the msg2 / ACK message, the time interval between msg2 (R2D message) and msg1 (D2R message) needs to consider the transmission time of 1 msg1, 1 msg2 and 1 msg3, that is, when the time interval is greater than the transmission time of msg1+msg2+msg3, the msg2 / ACK message can be received. The A-IoT device needs to count for a long time.

[0350] Therefore, in step 902, in the case that the R2D message is a non-cascaded message, the second device determines whether the first time period of successfully accessing the first device can be related to the number X of time domain resources defined in the R2D trigger message, so that in the case that the number X of time domain resources changes, the A-IoT device determines that the time interval between msg2 (R2D message) and msg1 (D2R message) is related to X, that is, the larger X is, the larger the time interval between the R2D message and the D2R message can be set, that is, the first time period in step 902 is flexible and variable.

[0351] Therefore, in some embodiments, in the case that the R2D message or msg2 or the first indication information in the application is a non-cascaded message, the first time period T2 is determined according to the candidate number X of time domain resources and at least one of the following information:

[0352] The transmission time of the fourth indication information, the transmission time of the first indication information, the transmission time of the third indication information;

[0353] Among them, the third indication information is the data sent by the second device when successfully accessing the first device, for example, the third indication information can be understood as msg3 in the application, for example, EPC.

[0354] For example, T2=(X-1)·(msg1+msg2+msg3). msg1 represents the transmission time of the fourth indication information, for example, the RN message, msg2 represents the transmission time of the first indication information, for example, the ACK message, and msg3 represents the transmission time of the third indication information, for example, the EPC.

[0355] An exemplary timing diagram of message transmission between a reader and A-IoT devices in a non-cascaded R2D message case is shown in FIG. 10. As shown in FIG. 10, the R2D trigger message sent by the reader can carry an indication of the bias time, indicating that the A-IoT device determines the time of sending msg1 according to the selected time domain resource / access opportunity x and the bias time. In FIG. 10, it is shown that two A-IoT devices send msg1, e.g., RN message, to the reader at different times. Then, the reader feeds back msg2, e.g., ACK message, to the two A-IoT devices respectively. Each msg2 also carries the bias time of the A-IoT device sending msg3, e.g., EPC, to the reader. For the A-IoT device sending msg1 later, the A-IoT device can determine T2 = (2-1) · (msg1+msg2+msg3) = msg1+msg2+msg3 based on the determination method of the first time period T2 for receiving msg2.

[0356] That is, as shown in FIG. 10, the second A-IoT device receiving msg2 needs to set the timer length for receiving msg2 when sending msg1 to the transmission length of msg1+msg2+msg3. That is, if the A-IoT device receives msg2 within the transmission length of msg1+msg2+msg3 after sending msg1, it is determined to successfully access the reader.

[0357] An exemplary signaling interaction diagram between a base station and A-IoT devices (UE1 and UE2) in a non-cascaded R2D message case is shown in FIG. 11, including the following processes.

[0358] The base station sends R2D message (R2D trigger message), query message or repeated query message, e.g., R2D message includes select message or paging message; correspondingly, UE1 and UE2 receive R2D message, query message or repeated query message; the R2D message includes the bias time of the UE1 and UE2 sending RN, and also includes the number X of time domain resources selected by the UE when sending D2R message;

[0359] UE1 sends RN2 to the base station, and UE2 sends RN2 to the base station;

[0360] The base station feeds back ACK1 message to UE1, and the ACK1 message includes the bias time t1 of UE1 sending EPC; the base station feeds back ACK2 message to UE2, and the ACK2 message includes the bias time t2 of UE2 sending EPC;

[0361] UE1 determines that if ACK1 is received within the time length of (X-1) · (RN+ACK+EPC) according to the determination manner of the first time period T2 (for example, ACK1 includes RN1 and the time domain resource position x1 selected by UE1), it can be determined that the access to the base station is successful. Similarly, UE2 also determines that if ACK2 is received within the time length of (X-1) · (RN+ACK+EPC) according to the determination manner of the first time period T2 (for example, ACK2 includes RN2 and the time domain resource position x2 selected by UE2), it can be determined that the access to the base station is successful.

[0362] UE1 sends EPC to the base station according to the offset time t1, and UE1 sends EPC to the base station according to the offset time t2.

[0363] In this way, in the application, in the case of non-cascading ACK message, the UE can send the RN message staggered in time to the base station based on the offset time carried in the R2D message, and the UE can also send the EPC staggered in time to the base station according to the offset time carried in the ACK, and the UE can also associate the maximum time interval between sending the RN message and receiving the ACK message with the number X of candidate time domain resources, and the maximum time interval is flexible and variable, so that the success rate of the UE accessing the base station is improved.

[0364] In some embodiments, in the case of non-cascading R2D message, if the definition of T_D2R_max between D2R message and R2D message is not adopted, the R2D message can be fed back immediately after the D2R message, for example, msg2 can be fed back immediately after msg1 in the application, or it is understood that when the ACK message is fed back immediately after the RN message, the application can indicate the offset time of the corresponding A-IoT device sending msg3 in msg2, or it is understood that the offset time of the corresponding A-IoT device sending EPC in the ACK message, so as to avoid the problem of collision of msg3 sent by multiple A-IoT devices at the reader.

[0365] As shown in FIG. 12, the R2D trigger message sent by the reader carries an indication of the time offset, which indicates the A-IoT device to determine the time of sending msg1 according to the selected time domain resource / access opportunity x and the time offset. As shown in FIG. 10, two A-IoT devices send msg1 (e.g., RN message) to the reader at different times. The first A-IoT device that feeds back msg1 receives msg2 (e.g., ACK message) immediately after feeding back msg1. The second A-IoT device that feeds back msg1 also receives msg2 (e.g., ACK message) immediately after feeding back msg1. To avoid collision of msg3 (e.g., EPC) sent by the two A-IoT devices at the reader, the two msg2s sent to the two A-IoT devices respectively carry an indication of the time offset of the msg3 sent by the A-IoT device. As shown in FIG. 12, the msg3s sent by the two A-IoT devices are staggered in time. In this way, the problem of collision of msg3s sent by multiple A-IoT devices at the reader in the non-cascaded R2D message case can be avoided.

[0366] In this application, the time offset can be directly indicated in the message or indicated by an index. Alternatively, the index can be combined with coverage enhancement (CE) level to indicate the time offset. Different coverage levels correspond to different modulation and coding schemes (MCS). For example, Table 1 shows an example of indicating the time offset by an index, and Table 2 shows an example of indicating the time offset by an index and CE (e.g., CE0 and CE1).

[0367] Table 1

[0368] Table 2

[0369] In this application, the time offset can also take into account the processing delay of the A-IoT device, which is related to the A-IoT terminal capability, and the reference value is, for example, 15.6us.

[0370] In the present application, the time offset can be implicitly indicated. In the case that different uplink data corresponds to different downlink messages, such as ACK corresponding to tag identification (EPC) or uplink data, QueryRep or Query can correspond to access request (RN), and the A-IoT device can determine the time length of the time offset of the uplink data sent by the A-IoT device according to the received downlink message.

[0371] For example, the A-IoT device can determine the order of the A-IoT device sending uplink data according to the order of the downlink message (such as ACK message) received by the A-IoT device, for example, the order of the A-IoT device sending uplink data (such as EPC) is the second one, then the A-IoT device needs to stagger the time of the uplink data corresponding to the first downlink message.

[0372] Alternatively, the A-IoT device can determine to wait for n offset time, n can be randomly generated within 0~M, M is the maximum number, which can be specified by the protocol, or can be indicated in the downlink message. The time of each offset time can be specified by the protocol, or can be related to the received downlink message. For example, this implementation is suitable for the scene that the A-IoT device does not determine the number of RNs to be sent after receiving queryrep, that is, the A-IoT device itself does not determine the order of sending RN.

[0373] In the present application, for the A-IoT device successfully accessing the reader / writer, the reader / writer can also carry the offset time of the A-IoT device sending uplink data in the downlink data when subsequent data transmission is performed.

[0374] As shown in FIG. 13, the present application provides a flowchart of carrying the offset time of the A-IoT device sending uplink data in the downlink data, including the following processes:

[0375] The base station sends an ACK concatenated message to UE1 and UE2, the ACK concatenated message including the offset time of UE1 and UE2 sending EPC, which is related to the candidate resource position and RN selected by UE1 and UE2; for example, the offset time of UE1 sending EPC1 is 0, and the offset time of UE2 sending EPC2 is t1;

[0376] UE 1 sends EPC1 to the base station;

[0377] The base station sends downlink data 1 to UE1, and the downlink data 1 includes offset time t2, which indicates the time of the subsequent uplink data sent by UE1;

[0378] UE2 sends EPC2 to the base station based on the offset time t1;

[0379] UE1 sends uplink data 1 to the base station based on the offset time t2;

[0380] The base station sends a repeated query message.

[0381] In this way, the application can offset the transmission time of uplink data of different UEs by carrying the offset time of uplink data in the downlink data, so as to avoid the problem of uplink data collision at the base station.

[0382] Optionally, in the application, a separate downlink message can also be used to instruct the A-IoT device to reset the offset time, so that the A-IoT device can send uplink data to the reader after resetting the offset time and starting timing again.

[0383] Optionally, in the application, the queryrep message and the ACK message can be combined and sent to trigger the RN and the transmission of uplink data, and the offset time for offsetting the transmission time of the RN and the uplink data can also be carried in the combined message.

[0384] If the method embodiment of the application is used in the O-RAN architecture, the application can dynamically configure the scheduling time parameter based on the RIC, for example, the offset time, wherein the RIC can also infer the current appropriate offset time according to historical data.

[0385] Optionally, the RIC can instruct the CU, RRC entity, DU, and MAC entity to send the offset time parameter carried in the select or paging or other MAC message according to historical data (access efficiency under different configurations).

[0386] Optionally, the RRC layer is in the CU, and the MAC layer is in the DU, so when the paging or select message is an RRC message, the CU can generate and send the message to the DU. The remaining random access messages can be MAC messages, which can be directly generated and sent by the DU.

[0387] In an embodiment of the application, a communication method is provided, which includes: a first device sending a fourth message, the fourth message being used to update or indicate a number of access occasion sets in a first access occasion group, and / or the fourth message being used to update or indicate a number of access occasions in a first access occasion set, the first access occasion group containing at least one access occasion set, each access occasion set in the at least one access occasion set containing at least one access occasion, and the first access occasion set containing at least one access occasion. Correspondingly, a second device receives the fourth message.

[0388] In some implementation manners of the embodiment of the application, the first device triggers one or more access occasion groups in multiple groups, wherein each access occasion group includes at least one access occasion set, and each access occasion set contains one or more access occasions.

[0389] In some implementations, the first set of access occasions is a set of access occasions in the first group of access occasions.

[0390] In some implementations, the access occasion in the embodiments of the present application can be understood as an access opportunity.

[0391] In some implementations, one access occasion has one or more time domain resources, and / or has one or more frequency domain resources.

[0392] It can be understood that the number of sets of access occasions included in different groups of access occasions can be the same or different.

[0393] It can be understood that the number of access occasions included in different sets of access occasions can be the same or different.

[0394] In some implementations, the first message further comprises: the number of sets of access occasions in the first group of access occasions, and / or the number (or index) of sets of access occasions in the first group of access occasions.

[0395] In some implementations, the communication method further comprises: the first device sends a fourth message, and the second device receives the fourth message, the fourth message being used to update or indicate the number of sets of access occasions in the first group of access occasions, and / or the fourth message being used to update or indicate the number of access occasions in at least one set of access occasions in the first group of access occasions.

[0396] Optionally, the fourth message can be an R2D message.

[0397] Optionally, the fourth message is not an initial R2D message, i.e., is not a message for initially triggering access.

[0398] In the present implementation, by updating the number of sets of access occasions in the group of access occasions and / or updating the number of access occasions in the set of access occasions through the fourth message, compared with sending a message for initially triggering access to adjust the number of sets of access occasions in the group of access occasions and / or update the number of access occasions in the set of access occasions, the adjustment of the set of access occasions and / or the access occasion can be more flexible.

[0399] For example, in the case where the number of second devices is relatively large, the number of sets of access occasions and / or the number of access occasions can be increased, so that the probability of collision of access occasions of multiple devices can be reduced, and thus the success rate of access can be improved.

[0400] For example, in the case where the number of second devices is relatively small, the number of sets of access occasions and / or the number of access occasions can be reduced, so that the access delay of the device can be reduced.

[0401] Figure 14 is a diagram illustrating adjusting the number of access occasion sets in an access occasion group. As shown in Figure 14, n access occasion groups are denoted as access occasion group #1 to access occasion group #n, where n is a positive integer.

[0402] Access occasion group #1 is indicated by an initial trigger message, and access occasion group #1 contains M access occasion sets, denoted as access occasion set #1 to access occasion set #M, where M is a positive integer, and each access occasion set contains at least one access occasion.

[0403] After access occasion group #n-1, access occasion group #n is indicated by an initial trigger message, and access occasion group #n contains one or more access occasion sets.

[0404] After access occasion set #1 in access occasion group #n, the fourth message is used to adjust the number of access occasion sets contained in the access occasion group, for example, access occasion group #n contains Q access occasion sets, denoted as access occasion set #1 to access occasion set #Q, where Q is a positive integer, and each access occasion set contains at least one access occasion.

[0405] In some implementations, before the next initial trigger message is received, if the fourth message is not received, the access occasion is determined based on the configuration of the last received initial trigger message; if the fourth message is received, the access occasion is determined based on the configuration indicated by the last received fourth message. In this way, M or Q does not need to be indicated separately each time.

[0406] Figure 15 is a diagram illustrating adjusting the number of access occasions in an access occasion group. As shown in Figure 15, access occasion group #1 is indicated by an initial trigger message, and access occasion group #1 contains access occasion set #1, and access occasion set #1 contains X access occasions, where X is a positive integer.

[0407] After access occasion set #1, the fourth message is used to adjust the number of access occasions contained in the access occasion set. For example, access occasion group #M contains Y access occasion sets, where Y is a positive integer.

[0408] In some implementations, before the next initial trigger message is received, if the fourth message is not received, the access occasion is determined based on the configuration of the last received initial trigger message; if the fourth message is received, the access occasion is determined based on the configuration indicated by the last received fourth message. In this way, X or Y does not need to be indicated separately each time.

[0409] In some implementations, the fourth message is used to update the number of access occasion sets in the first access occasion group, including: the fourth message is used to indicate the difference between the number of access occasion sets before the update and the number of access occasion sets after the update in the first access occasion group.

[0410] In this case, the second device can determine the updated number of access occasion sets based on the difference value indicated by the fourth message and the number before the update. Compared with the fourth message directly indicating the updated number of access occasion sets, the transmission overhead can be reduced.

[0411] In some implementations, the fourth message is used to indicate the number of access occasion sets in the first access occasion group, including: the fourth message is used to indicate the updated number of access occasion sets in the first access occasion group.

[0412] In this case, the second device can directly obtain the updated number of access occasion sets based on the fourth message. Compared with the fourth message indicating the number of access occasion sets before the update and the updated number of access occasion sets, the second device can obtain the updated number of access occasion sets more quickly, reduce the latency and save resources.

[0413] In some implementations, the communication method further includes: the first device sends a fifth message, and the second device receives the fifth message, the fifth message being used to indicate to stop triggering the access occasion sets. In this case, after receiving the fifth message, the second device can no longer listen to the access occasions and wait for the next initial triggering message.

[0414] In some implementations, the fifth message indicates the access occasion sets to stop triggering include the access occasion sets in the currently triggered access occasion group that have not been triggered.

[0415] For example, the currently triggered access occasion group is the first access occasion group, and the first access occasion set and the second access occasion set in the first access occasion group have been triggered, and the fifth message implicitly indicates that the remaining access occasion sets in the first access occasion group are no longer triggered.

[0416] In some implementations, the fifth message further indicates the number of access occasion sets to stop triggering. In this way, the indication of the access occasion sets to stop triggering can be flexibly controlled.

[0417] For example, the fifth message indicates that the number of access occasion sets to stop triggering is 2. Then, it is implicitly indicated that the two access occasion sets after the last triggered access occasion set in the access occasion sets in the currently triggered access occasion group that have not been triggered stop triggering.

[0418] For example, the first access occasion group contains 5 access occasion sets, denoted as Set 1, Set 2, Set 3, Set 4 and Set 5 respectively, the first device has sent a message to trigger the first access occasion group and trigger Set 1, the first device sends a message to trigger Set 2, and then sends a message to indicate to stop triggering the access occasion sets, in a possible design, the first device stops triggering all the access occasion sets that have not been triggered in the first access occasion group, i.e. stops triggering Set 3, Set 4 and Set 5; in a second possible design, the first device stops triggering the first two access occasion sets that have not been triggered in the first access occasion group, i.e. stops triggering Set 3 and Set 4, where the number 2 can be predefined; in a third possible design, the message sent by the first device to indicate to stop triggering the access occasion sets carries a number 2 of the access occasion sets to be stopped triggering, and then the first device stops triggering Set 3 and Set 4.

[0419] In some implementations, the method further includes receiving a sixth message, the sixth message indicating to trigger a plurality of access occasion sets in the first access occasion set. Triggering a plurality of access occasion sets in one indication can reduce the indication overhead.

[0420] In some implementations, the sixth message further indicates the plurality of access occasion sets to be triggered. For example, the number and / or the set identifiers of the access occasion sets to be triggered are indicated.

[0421] For example, the first access occasion group contains 5 access occasion sets, denoted as Set 1, Set 2, Set 3, Set 4 and Set 5 respectively, the first device has sent a message to trigger the first access occasion group and trigger Set 1. The first device determines that the number of the second devices is less than expected, and in the case of a large access set division, the first device can send a message to indicate to trigger a plurality of sets in Set 2, Set 3, Set 4 and Set 5.

[0422] For example, the first device sends a message to indicate to trigger 2 sets, i.e. to indicate to trigger Set 2 and Set 3.

[0423] Optionally, the message can not carry the number 2, and the number 2 can be predefined. In this case, after receiving the message indicating to trigger a plurality of access occasion sets, the second device can determine that the access occasion sets to be triggered are Set 2 and Set 3.

[0424] In some implementations, at least one of the first message, the fourth message, the fifth message and the sixth message carries a service identifier. In this way, after receiving the message, the second device can determine whether it needs to respond to the message based on the service identifier carried in the message. For example, when the second device determines that the service identifier carried in the received message is a service identifier designed by itself, the second device responds to the received message.

[0425] In the embodiments of the present application, the service identifier is used to associate the first service.

[0426] For example, the reader can initiate multiple services, and each device only completes the service associated with the same service identifier once by carrying different service identifiers in the first message. For example, when the inventory service 1 associated with the service identifier is completed, the device no longer responds to the first message associated with the service identifier. Optionally, the device no longer responds to the service associated with the service identifier for a period of time, and can respond to the service associated with the service identifier again after a period of time.

[0427] In some implementations, the communication method further includes that the first device sends indication information indicating that the service identifier is released / reset, indicating that the service associated with the service identifier is ended, or indicating that the reset of the service identifier is completed (such as a successful reset state and / or an unsuccessful reset state).

[0428] One service can correspond to one service request initiated by the core network, and can include one or more paging, random access, and / or data transmission (such as command, sensing, and other service) procedures.

[0429] In some implementations, the service identifier can be referred to as a task identifier (task ID), and the term “task” can be replaced by the following descriptions: service, session, request, transaction, process, procedure, and the like. The present application does not limit the name.

[0430] For example, the inventory service can be replaced by an inventory task, an inventory procedure, an inventory transaction, and the like. It can be understood that the “service” is a service related to a procedure, which includes at least one of the following: an access procedure, a data transmission procedure, and the like, or can be understood as a service that performs a corresponding procedure. The access procedure can be a random access procedure, such as a contention-based random access or a contention-free random access. The access procedure and the data transmission procedure are not strictly distinguished. After the access procedure is completed, the data transmission procedure is performed. Alternatively, in the access procedure, data transmission can be performed. For example, in the access procedure, the device reports uplink data related to the service, such as a device identifier (device ID). For example, in addition to the RN16, the message 1 sent by the device to the reader also includes uplink data related to the service. Alternatively, in the contention-free random access, the device can send D2R / uplink data in the message 1.

[0431] In some implementations, the first device triggers a set of access occasions through the R2D message.

[0432] In some embodiments, the transmission period of the predefined set of access occasions is predefined, for example, a plurality of access occasions in a set of access occasions are contained in every 100 milliseconds. Then the second device can start timing at a specified time, and the access occasions in a set of access occasions are contained in every 100 milliseconds, so that the position of each set of access occasions can be determined, and the triggering of the set of access occasions can be realized.

[0433] In some embodiments, the communication method further comprises: the first device sending a message indicating or updating the time domain resource and / or the frequency domain resource in the set of access occasions.

[0434] For example, the first device sends a message indicating or updating the number and / or position of the time domain resource in the set of access occasions, and / or indicating or updating the number and / or position of the frequency domain resource in the set of access occasions.

[0435] In some embodiments, when the message sent by the first device carries an access stratum identification (AS ID), it is used to indicate that the device associated with the access stratum identification receives the message and can then send data. For example, after the second device receives the message associated with the access stratum R2D, it can send data to the first device, otherwise it accesses the first device.

[0436] In some embodiments, the communication method shown in FIG. 4 further contains the contents in the embodiments.

[0437] FIG. 16 is an exemplary flowchart of a communication method according to an embodiment of the present application. As shown in FIG. 16, the communication method comprises 1602, 1603 and 1604.

[0438] 1602, the first device sends a seventh message, the seventh message is used to trigger an access occasion of the first device, and / or is used to page at least one second device, the seventh message carries ninth indication information, the ninth indication information is used to indicate the size of the transmission block and / or whether to respond quickly.

[0439] In some embodiments, the ninth indication information comprises at least one of the following information: the size of the transmission block, whether to respond quickly, the type of random access, or identification information.

[0440] In some embodiments, whether to respond quickly can be replaced by the way of sending an access message or the type of the access message.

[0441] Exemplarily, the ninth indication information indicates a contention-free resolution access, such as by indicating a random access type, or by indirectly indicating through identification information (such as indicating a complete device ID or AS ID, which can implicitly indicate a random access).

[0442] Exemplarily, the indication information of whether a fast response can be understood as a D2R message (such as a first D2R message, such as a msg1 message) for the device to determine a random access.

[0443] Exemplarily, the indication information of a manner of sending an access message or a type of an access message can indicate whether to send an ACK or a device ID (AS ID).

[0444] As an example, the seventh message is a R2D message.

[0445] As an example, the seventh message is a paging message.

[0446] In some implementations, the seventh message carries service identification.

[0447] 1603、When the ninth indication information indicates a first transport block size and / or the ninth indication information indicates a fast response, the second device sends the confirmation information of the seventh message.

[0448] As an example, after the second device receives the seventh message, the second device determines whether the ninth indication information indicates a first transport block size or a second transport block size, or whether the transport block size is less than a first threshold value, which can be specified by a protocol or indicated by the reader. If the determination result is yes, the second device sends the confirmation information of the seventh message.

[0449] As an example, after the second device receives the seventh message, the second device determines whether the ninth indication information indicates a fast response. If the ninth indication information indicates a fast response, the second device sends the confirmation information of the seventh message.

[0450] As an example, the indication information of a fast response can occupy 1 bit, and of two values of the bit, one value represents a fast response, and the other value represents a non-fast response or a normal response.

[0451] For example, when the bit value is “1”, it represents a fast response; and when the bit value is “0”, it represents a non-fast response or a normal response.

[0452] In some implementations, the ninth indication information indicating a fast response can be understood as indicating a one-step access, i.e., an access is realized through one step or one message.

[0453] In some embodiments, the confirmation information is used to inform the first device of the existence of the second device.

[0454] For example, when the seventh message carries the service identity, the second device feeds back the confirmation information if the second device determines that the service identity carried by the seventh message is associated with the second device.

[0455] For example, the service identity being associated with the second device can include that the service associated with the second device is the service indicated by the service identity.

[0456] For example, one value of the confirmation information is a predefined value, and the value indicates the existence of the device associated with the service identity carried by the seventh message.

[0457] For example, the confirmation information occupies a small number of bits, and the number of bits is less than the number of bits required to indicate the identity of the second device.

[0458] For example, the confirmation information occupies one bit, and the bit takes a predefined value to indicate the existence of the second device. One example of the predefined value is “1”.

[0459] In some embodiments, there is an association relationship between the resource for transmitting the confirmation information and the identity of the second device. In this way, after the first device receives the confirmation information, the first device can learn the identity of the second device based on the resource for transmitting the confirmation information, so as to reduce the overhead while conveying the identity of the second device.

[0460] 1604、When the ninth indication information indicates the transmission block size as the second transmission block size and / or the ninth indication information does not indicate the fast response, the second device sends the first information, the first information is used to indicate the identity of the second device, and the second transmission block size is greater than the first transmission block size.

[0461] For example, after the second device receives the seventh message, the second device determines whether the ninth indication information indicates the transmission block size as the first transmission block size or the second transmission block size, or determines whether the transmission block size is less than the first threshold value, which can be specified by a protocol or indicated by a reader. If the determination result is no, the second device sends the first information.

[0462] After receiving the seventh message, the second device determines whether the ninth indication information indicates the fast response. If the ninth indication information does not indicate the fast response or indicates the non-fast response, the second device sends the first information.

[0463] For example, the first information includes the complete or partial identity information of the second device, or includes the access layer identity (AS ID) of the second device, or includes the identity information calculated or generated by the second device based on the device ID or the AS ID (such as by means of hashing, modulo, remainder, etc.), such as the complete or partial information of the device ID.

[0464] As an example, the indication information of non-fast response can occupy 1 bit, and one of the two values of the bit represents fast response, and the other value represents non-fast response or normal response.

[0465] For example, when the bit value is "1", it represents fast response; and when the bit value is "0", it represents non-fast response or normal response.

[0466] In some implementations, the ninth indication information indicating non-fast response can be understood as indicating multi-step access, that is, access is realized through multiple steps or multiple messages.

[0467] In some implementations, the first information carries the identity of the second device.

[0468] For example, when the seventh message carries the service identity, if the second device judges that the service identity carried by the seventh message is associated with the second device, the first information is fed back, and the first information carries the identity of the second device.

[0469] In some implementations, when the ninth indication information indicates the second transport block size, the sixth message is an R2D trigger message.

[0470] In this embodiment, the method of indicating the existence of the second device by the first information can be applied to the scene of counting devices.

[0471] In some implementations, the communication method of this embodiment can be applied to the scene of contention-based random access (CBRA) or contention-free random access (CFRA).

[0472] In some implementations, the ninth indication information does not carry the first transport block size, the indication information of fast response, and the indication information of 1-step access, nor the second transport block size, which can be understood as that the ninth indication information implicitly indicates the first transport block size, the indication information of fast response, and 1-step access. In this way, the transmission overhead can be reduced.

[0473] In some implementations, as shown in FIG. 17, the communication method further includes:

[0474] 1601. The core network device sends an eighth message, and the eighth message carries device ID type information.

[0475] Optionally, the device ID type information includes one or more device identities and the number of identities.

[0476] Optionally, the eighth message can also carry fast response indication or 1-step access indication.

[0477] When the eighth message carries the fast response indication or the one-step access indication, the ninth indication information can indicate the first transport block size and / or the fast response, or indicate the first transport block size and / or the one-step access.

[0478] In the description of the embodiments of the present application, "information", "signal", "message", "channel", "signaling" can be mixed sometimes, and it should be pointed out that when the distinction is not emphasized, the meanings expressed are matched.

[0479] It can be understood that, in order to realize the functions in the above embodiments, the reader (network device) and the A-IoT terminal include the corresponding hardware structure and / or software module for executing each function. Those skilled in the art should easily realize that, in combination with the units and method steps of each example described in the embodiments disclosed in the present application, the present application can be realized in the form of hardware or a combination of hardware and computer software. Whether a certain function is realized in the form of hardware or computer software driving hardware depends on the specific application scene and design constraints of the technical solution.

[0480] FIG. 18 and FIG. 19 are structural schematic diagrams of possible communication apparatuses provided by the embodiments of the present application. These communication apparatuses can be used to realize the functions of the reader and the A-IoT terminal in the above method embodiments, and thus can also realize the beneficial effects possessed by the above method embodiments. In the embodiments of the present application, the communication apparatus can be the terminal 202 as shown in FIG. 2, or the base station 201 as shown in FIG. 2, or a module (such as a chip) applied to the terminal or the base station.

[0481] As shown in FIG. 18, the communication apparatus 140 includes a processing unit 1410 and a transceiver unit 1420. The communication apparatus 140 is used to realize any of the above method embodiments. For example, the communication apparatus 140 is used to realize the functions of the A-IoT terminal (second apparatus) or the reader (first apparatus) in the above method embodiments shown in FIG. 4, FIG. 5, or FIG. 9, or FIG. 16.

[0482] As an example, the communication apparatus 140 is configured to implement the functions of the A-IoT terminal (second device) in the method embodiments shown in FIG. 4, FIG. 5 and FIG. 9: the transceiver 1420 is configured to receive the first message to trigger the access occasion of the first device, and / or, to page at least one second device; send the second message on the access occasion of the first access occasion group; receive the first indication information, the first indication information is used to confirm that the second device successfully accesses the first device, and the first indication information includes the second indication information, the second indication information is used to indicate the first time domain resource location, and the first time domain resource location is one time domain resource location selected by the second device from the candidate time domain resource locations; send the third indication information, and the first time information of sending the third indication information is determined based on the second indication information, and the third indication information is used to send data to the first device; and send the fourth indication information, and the fourth indication information is used for the second device to request to access the first device.

[0483] The processing unit 1410 is configured to receive the first indication information within the first time period after sending the fourth indication information, determine to successfully access the first device, and the first indication information is used to confirm that the second device successfully accesses the first device, and the first time period is related to the number of time domain resources selected by the second device when sending the message to the first device.

[0484] As an example, the communication apparatus 140 is configured to implement the functions of the A-IoT terminal (second device) in the method embodiments shown in FIG. 4, FIG. 5 and FIG. 9: the transceiver 1420 is configured to receive the first message to trigger the access occasion of the first device, and / or, to page at least one second device; send the second message on the access occasion of the first access occasion group; receive the first indication information, the first indication information is used to confirm that the second device successfully accesses the first device, and the first indication information includes the second indication information, the second indication information is used to indicate the first time domain resource location, and the first time domain resource location is one time domain resource location selected by the second device from the candidate time domain resource locations; send the third indication information, and the first time information of sending the third indication information is determined based on the second indication information, and the third indication information is used to send data to the first device; and send the fourth indication information, and the fourth indication information is used for the second device to request to access the first device.

[0485] The processing unit 1410 is configured to generate the first message, the first indication information, etc., and is also configured to process the third indication information or the fourth indication information, etc. received from the second device.

[0486] For more detailed description of the processing unit 1410 and the transceiver 1420, please refer to the relevant description in any method embodiment.

[0487] As shown in FIG. 19, the communication apparatus 150 includes a processor 1510 and an interface circuit 1520. The processor 1510 and the interface circuit 1520 are coupled to each other. It can be understood that the interface circuit 1520 can be a transceiver or an input / output interface. Optionally, the communication apparatus 150 can further include a memory 1530 for storing instructions executed by the processor 1510 or storing input data required by the processor 1510 to execute instructions or storing data generated after the processor 1510 executes instructions.

[0488] When the communication apparatus 150 is used to implement any of the foregoing methods, the processor 1510 is configured to implement the functions of the processing unit 1410, and the interface circuit 1520 is configured to implement the functions of the transceiver unit 1420.

[0489] When the communication apparatus is a terminal chip, the terminal chip implements the functions of the terminal in the method embodiments. The terminal chip receives information from a base station, which can be understood as the information being received by other modules (such as a radio frequency module or an antenna) in the terminal first, and then being transmitted to the terminal chip by these modules. The terminal chip transmits information to the base station, which can be understood as the information being transmitted to other modules (such as a radio frequency module or an antenna) in the terminal first, and then being transmitted to the base station by these modules.

[0490] When the communication apparatus is a base station chip, the base station chip implements the functions of the base station in the method embodiments. The base station chip receives information from a terminal, which can be understood as the information being received by other modules (such as a radio frequency module or an antenna) in the base station first, and then being transmitted to the base station chip by these modules. The base station chip transmits information to the terminal, which can be understood as the information being transmitted to other modules (such as a radio frequency module or an antenna) in the base station first, and then being transmitted to the terminal by these modules.

[0491] In this application, entity A transmitting information to entity B can be A directly transmitting to B, or A indirectly transmitting to B through other entities. Similarly, entity B receiving information from entity A can be entity B directly receiving the information transmitted by entity A, or entity B indirectly receiving the information transmitted by entity A through other entities. Here, entity A and B can be RAN nodes or terminals, or modules inside RAN nodes or terminals. The transmission and reception of information can be the information interaction between RAN nodes and terminals, for example, the information interaction between a base station and a terminal; the transmission and reception of information can also be the information interaction between two RAN nodes, for example, the information interaction between a CU and a DU; the transmission and reception of information can also be the information interaction between different modules inside one apparatus, for example, the information interaction between a terminal chip and other modules in the terminal, or the information interaction between a base station chip and other modules in the base station.

[0492] It is to be understood that the processor in the embodiments of the present application can be a central processing unit (CPU), and can also be other general-purpose processors, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor can be a microprocessor or any conventional processor.

[0493] The method steps in the embodiments of the present application can be implemented in hardware or in software instructions executable by a processor. The software instructions can be composed of corresponding software modules, and the software modules can be stored in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, a register, a hard disk, a mobile hard disk, a CD-ROM or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor, so that the processor can read information from and write information to the storage medium. The storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a base station or a terminal. The processor and the storage medium can also exist as discrete components in the base station or the terminal.

[0494] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer programs or instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are performed. The computer can be a general purpose computer, a special purpose computer, a computer network, a network device, a user equipment or other programmable apparatus. The computer programs or instructions can be stored in a computer readable storage medium or transferred from one computer readable storage medium to another computer readable storage medium, for example, the computer programs or instructions can be transferred from one website site, computer, server or data center to another website site, computer, server or data center through wired or wireless manner. The computer readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center and the like integrated with one or more available media. The available media can be a magnetic medium, such as a floppy disk, a hard disk, a magnetic tape; or an optical medium, such as a digital video disc; or a semiconductor medium, such as a solid state disk. The computer readable storage medium can be a volatile or non-volatile storage medium, or can include both volatile and non-volatile storage media.

[0495] In various embodiments of the present application, the terms and / or descriptions of different embodiments are consistent and can be referred to each other if there is no special description and logical conflict, and the technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0496] In the present application, "at least one" means one or more, and "multiple" means two or more. The association relationship between the associated objects is described, which means that there can be three relationships, for example, A and / or B, which can represent the following cases: A exists alone, A and B exist together, and B exists alone, where A and B can be singular or plural. In the literal description of the present application, the character " / ", generally represents that the front and rear associated objects are in an "or" relationship. "Including at least one of A, B and C" can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B and C.

[0497] It can be understood that various numbers involved in the embodiments of the present application are only distinguished for convenience of description, and are not used to limit the scope of the embodiments of the present application. The size of the serial number of the above processes does not mean the execution order, and the execution order of the processes should be determined by its function and inherent logic.

Claims

1. A communication method characterized by comprising: The method comprises: receiving a first message sent by a first device, the first message being used for triggering an access occasion of accessing the first device, and / or being used for paging at least one second device; sending a second message to the first device at an access occasion of a first access occasion group, the second message being used for the second device to access the first device or send data to the first device, the first access occasion group being determined based on the first message, and the first access occasion group comprising at least one access occasion.

2. The method of claim 1, wherein the first message comprises at least one of the following information: a total number of groups of access occasion groups of accessing the first device; a group number of the first access occasion group.

3. The method of claim 2, wherein the first access occasion group being determined based on the first message comprises: the first access occasion group being determined based on the first message and a group number of a second access occasion group, the group number of the second access occasion group being less than or equal to the total number of groups of the access occasion groups.

4. The method of claim 3, wherein the method further comprises determining the group number of the second access occasion group; and the first access occasion group being determined based on the first message and the group number of the second access occasion group comprises: when the group number of the second access occasion group is the same as the group number of the first access occasion group, the first access occasion group is the access occasion group for the second device to send the second message.

5. The method of claim 3, wherein the method further comprises determining the group number of the first access occasion group; and the first access occasion group being determined based on the first message and the group number of the second access occasion group comprises:

6. The method according to any one of claims 1 to 5, characterized in that, the first access occasion group being determined by the second device decrementing the group number of the first access occasion group each time the first message is received, and determining the first access occasion group when the group number is decremented to the group number of the second access occasion group. The method further comprises: if the access to the first device fails, receiving a third message sent by the first device, the third message being used for triggering an access occasion of accessing the first device, and / or being used for paging at least one second device; the third message comprising at least one of the following information: a total number of groups of access occasion groups of accessing the first device; a group number of a fourth access occasion group; 7. The method according to any one of claims 1 to 6, characterized in that, wherein the group number of the fourth access occasion group is greater than or equal to the group number of the first access occasion group, and less than or equal to the total number of groups of the access occasion groups; or the group number of the fourth access occasion group is greater than the total number of groups of the access occasion groups. the first access occasion group comprises at least one access occasion set, and each access occasion set in the at least one access occasion set comprises at least one access occasion; wherein the method further comprises:

8. The method according to any one of claims 1 to 6, characterized in that, receiving a fourth message, the fourth message being used for updating or indicating a number of access occasion sets in the first access occasion group, and / or the fourth message being used for updating or indicating a number of access occasions in each access occasion set. the method further comprises: receiving a fourth message, the fourth message being used for updating or indicating a total number of groups of access time slots of the first device, and / or, the fourth message being used for updating or indicating a number of access time slots in the first group of access time slots.

9. A communication method characterized by comprising: The method comprises: sending a first message, the first message being used for triggering access time slots of the first device, and / or, being used for paging at least one second device; receiving a second message sent by the second device, the second message being used for the second device to access the first device or send data to the first device, the second message being sent by the second device on an access time slot of a first group of access time slots, the first group of access time slots being determined based on the first message, the first group of access time slots comprising at least one access time slot.

10. The method of claim 9, wherein, the first message comprises at least one of the following information: a total number of groups of access time slots of the first device; a group number of the first group of access time slots.

11. The method of claim 10, wherein, the first group of access time slots is determined based on the first message comprises: the first group of access time slots is determined based on the first message and a group number of a second group of access time slots; the group number of the second group of access time slots is less than or equal to the total number of groups of access time slots.

12. The method of claim 11, wherein, the first group of access time slots is determined based on the first message and a group number of a second group of access time slots comprises: when the group number of the second group of access time slots is the same as the group number of the first group of access time slots, the first group of access time slots is the group of access time slots for the second device to send the second message.

13. The method of claim 11, wherein, the first group of access time slots is determined based on the first message and a group number of a second group of access time slots comprises: the first group of access time slots is determined by the second device decrementing the group number of the first group of access time slots each time the first message is received, and determining the first group of access time slots when the group number is decremented to the group number of the second group of access time slots.

14. The method according to any one of claims 9 to 13, characterized in that, The method further comprises: sending a third message, the third message being used for triggering access time slots of the first device, and / or, being used for paging at least one second device, the third message comprising at least one of the following information: a total number of groups of access time slots of the first device; a group number of a fourth group of access time slots; wherein the group number of the fourth group of access time slots is greater than or equal to the group number of the first group of access time slots, and less than or equal to the total number of groups of access time slots; or, the group number of the fourth group of access time slots is greater than the total number of groups of access time slots.

15. The method according to any one of claims 9 to 14, characterized in that, the first group of access time slots comprises at least one set of access time slots, each set of access time slots in the at least one set of access time slots comprises at least one access time slot; wherein the method further comprises: sending a fourth message, the fourth message being used to update or indicate a number of access occasion sets in each of the access occasion groups, or the fourth message being used to update or indicate a number of access occasions in each of the access occasion sets.

16. The method of claim 15, wherein, The method further comprises: sending a fourth message, the fourth message being used to update or indicate a total number of access occasion groups of the first device, and / or, the fourth message being used to update or indicate a number of access occasions in the first access occasion group.

17. A method of communication, comprising: comprising: receiving first indication information sent by a first device, the first indication information being used to confirm that a second device successfully accesses the first device, the first indication information comprising second indication information, the second indication information being used to indicate a first time domain resource location, the first time domain resource location being one time domain resource location selected by the second device from among candidate time domain resource locations; sending third indication information to the first device, and first time information at which the third indication information is sent being determined based on the second indication information, the third indication information being used to send data to the first device.

18. The method of claim 17, wherein, Before receiving the first indication information, the method further comprises: sending fourth indication information to the first device, the fourth indication information being used to indicate a random number generated by the second device when the second device requests to access the first device; the first indication information further comprises the fourth indication information; the first time information is determined based on the second indication information and the fourth indication information.

19. The method of claim 18, wherein, Before sending the third indication information, the method further comprises: determining that the second device successfully accesses the first device based on the second indication information and fourth indication information.

20. The method of any of claims 17-19, wherein the first indication information further comprises fifth indication information, the fifth indication information being used to indicate a frequency domain resource location at which the second device sends the third indication information.

21. A method of communication, comprising: comprising: sending first indication information to a second device, the first indication information being used to confirm that the second device successfully accesses a first device, the first indication information comprising second indication information, the second indication information being used to indicate a first time domain resource location, the first time domain resource location being one time domain resource location selected by the second device from among candidate time domain resource locations; receiving third indication information sent by the second device, and first time information at which the second device sends the third indication information being determined based on the second indication information, the third indication information being used to send data to the first device.

22. The method of claim 21, wherein, Before sending the first indication information, the method further comprises: receiving fourth indication information sent by the second device, the fourth indication information being used to indicate a random number generated by the second device when the second device requests to access the first device; the first indication information further comprises the fourth indication information; the first time information is determined based on the second indication information and the fourth indication information.

23. The method of claim 21 or 22, wherein The first indication information further comprises fifth indication information, the fifth indication information being used for indicating a frequency domain resource position at which the second device transmits the third indication information.

24. A method of communication, comprising: Comprise: transmitting fourth indication information to the first device, the fourth indication information being used for the second device to request to access the first device; if first indication information is received within a first time period after the fourth indication information is transmitted, it is determined that the second device successfully accesses the first device, the first indication information being used for confirming that the second device successfully accesses the first device, the first time period being related to a number of time domain resources selected by the second device when the second device transmits a message to the first device.

25. The method of claim 24, wherein the first time period is determined according to the number of candidate time domain resources and at least one of the following information: a transmission duration of the fourth indication information; second time information, the second time information being used for indicating a time interval between when the second device receives a first message and when the second device transmits the fourth indication information, the first message being used for triggering an access occasion of accessing the first device and / or being used for paging at least one second device.

26. The method of claim 24, wherein the first time period is determined according to the number of candidate time domain resources and at least one of the following information: a transmission duration of the fourth indication information, a transmission duration of the first indication information, a transmission duration of third indication information, or third time information; wherein the third indication information is data transmitted by the second device when the second device successfully accesses the first device; second time information, the second time information being used for indicating a time interval between when the second device receives a first message and when the second device transmits the fourth indication information, the first message being used for triggering an access occasion of accessing the first device and / or being used for paging at least one second device.

27. A method of communication, comprising: The communication method comprises: receiving a seventh message, the seventh message being used for triggering an access occasion of accessing the first device and / or being used for paging at least one second device, the seventh message carrying ninth indication information, the ninth indication information being used for indicating a transport block size and / or whether to respond quickly; when the ninth indication information indicates the transport block size as a first transport block size and / or the ninth indication information indicates quick response, transmitting confirmation information of the seventh message; when the ninth indication information indicates the transport block size as a second transport block size and / or the ninth indication information does not indicate quick response, transmitting first information, the first information being used for indicating an identity of the second device, the second transport block size being greater than the first transport block size.

28. The method of claim 27, wherein, There is a correlation between a resource used for transmitting the confirmation information and the identity of the second device.

29. A method of communication, comprising: Comprise: transmitting a seventh message, the seventh message being used for triggering an access occasion of accessing the first device and / or being used for paging at least one second device, the seventh message carrying ninth indication information, the ninth indication information being used for indicating a transport block size and / or whether to respond quickly; The transmission block size indicated by the ninth indication information is a first transmission block size, and / or when the ninth indication information indicates a fast response, receiving acknowledgement information of the seventh message; The transmission block size indicated by the ninth indication information is a second transmission block size, and / or when the ninth indication information does not indicate a fast response, receiving first information, the first information being used to indicate an identity of the second device, the second transmission block size being larger than the first transmission block size.

30. The method of claim 29, wherein, The resource used for transmitting the acknowledgement information has a correlation relationship with the identity of the second device.

31. A communications device, characterized by The communication device comprises a module for performing the method of any one of claims 1-30.

32. A communications device, characterized by The communication device comprises a processor and an interface circuit, the interface circuit being used to receive signals from other communication devices and transmit the signals to the processor or send signals from the processor to other communication devices, the processor being used to implement the method of any one of claims 1-30 through a logic circuit or an execution code instruction.

33. A computer-readable storage medium, comprising: The computer readable storage medium stores computer instructions, when the computer instructions run on the communication device, the communication device executes the method of any one of claims 1-30.

34. A computer program product, characterised in that, The computer readable storage medium stores computer instructions, when the computer instructions run on the communication device, the communication device executes the method of any one of claims 1-30.

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