A random access method, a communication device and a communication apparatus

Abstract

The embodiment of the present disclosure provides a random access method, a communication device and a communication equipment. The random access method can be applied to a 5G communication and satellite communication integrated system. The method can comprise: a terminal device receiving DCI sent by a network device, the DCI comprising first indication information, the first indication information being used for instructing the terminal device to perform random access; the terminal device determining to update ephemeris information; and the terminal device performing delayed random access on a PRACH according to a first timing offset and a second timing offset, wherein the first timing offset is a round-trip delay of the terminal device to a predetermined reference point, and the second timing offset is a time length for which the terminal device delays performing random access on the PRACH. In the present disclosure, when determining to update ephemeris information, the terminal device delays random access according to the first timing offset and the second timing offset, thereby improving the reliability of random access.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of wireless communication, and in particular to a random access method, a communication device and a communication equipment. BACKGROUND

[0002] With the development of information technology, more urgent requirements are put forward for efficient, mobile, diverse and other communication. At present, a development focus in the field of communication system is global mobile communication, and an important part of global mobile communication is satellite communication. The 3rd generation partnership project (3GPP) standard organization has released the 5th generation mobile network (5G) technical standard to study space-air-ground integrated communication technology, mainly to integrate the existing 5G standard and satellite communication technology to meet the full coverage in the global range.

[0003] In the communication system integrating 5G communication and satellite communication, how to improve the reliability of random access is a problem to be solved urgently. SUMMARY

[0004] The present disclosure provides a random access method, a communication device and a communication equipment to improve the reliability of random access in the communication system integrating 5G communication and satellite communication.

[0005] According to a first aspect of the present disclosure, a random access method is provided, which can be applied to a terminal device in a communication system integrating ground communication and satellite communication. The communication system can also be referred to as a non-terrestrial network (NTN) communication system. The method can include: receiving, by the terminal device, downlink control information sent by a network device, the downlink control information can include first indication information, the first indication information being used to instruct the terminal device to perform random access; determining, by the terminal device, to update ephemeris information; and performing, by the terminal device, delayed random access on a physical random access channel according to a first timing offset and a second timing offset.

[0006] In the present disclosure, the first timing offset is a round-trip delay of the terminal device to a predetermined reference point, and the second timing offset is a time length of the terminal device delaying random access on the physical random access channel.

[0007] Here, the predetermined reference point can be understood as any point on a wireless communication link in the NTN system, such as any point on a service link between a satellite and a terminal, or any point on a feeder link between a satellite and a ground network device. For example, the predetermined reference point can be any access network device on a service link in the NTN communication system, such as a satellite, an NTN gateway, a ground base station, etc. Alternatively, the predetermined reference point can also be any access network device on a feeder link, such as a satellite, an NTN gateway, a ground base station, etc.

[0008] In some possible implementation manners, the terminal device determines to update the ephemeris information, including: the terminal device determines that a valid timer is expired; and the terminal device determines to update the ephemeris information.

[0009] In some possible implementation manners, the terminal device receives the downlink control information sent by the network device, including: the terminal device receives the downlink control information on an nth time slot in a downlink time domain resource, where n is a positive integer.

[0010] In some possible implementation manners, the terminal device delays access on the physical random access channel according to the first timing offset and the second timing offset, including: the terminal device delays a first time length after the nth time slot in the uplink time domain resource, and then performs random access on a next physical random access channel sending opportunity, where the first time length is a sum of the first timing offset and the second timing offset.

[0011] In some possible implementation manners, the downlink control channel further includes second indication information, and the second indication information is used to indicate the second timing offset.

[0012] In some possible implementation manners, the method further includes: the terminal device receives system information within a second time length corresponding to the second timing offset; the terminal device determines the ephemeris information according to the system information; and the terminal device determines the first timing offset according to the determined ephemeris information.

[0013] According to a second aspect of the present disclosure, a random access method is provided, which can be applied to a network device in a communication system integrating ground communication and satellite communication, which can also be referred to as an NTN communication system. The method includes: the network device determines that a terminal device updates ephemeris information; and the network device sends downlink control information to the terminal device, where the downlink control information includes first indication information, and the first indication information is used to indicate that the terminal device performs random access.

[0014] In some possible implementation manners, the network device determines that the terminal device updates the ephemeris information, including: the network device determines that a valid timer of the terminal device is expired; and the network device determines that the terminal device updates the ephemeris information.

[0015] In some possible implementation manners, the downlink control information further comprises second indication information, the second indication information being used to indicate a second timing offset, the second timing offset being a time length for the terminal device to delay random access on the physical random access channel.

[0016] According to a third aspect of the present disclosure, a communication apparatus is provided, which can be a terminal device in an NTN communication system or a chip or system on chip in a terminal device, and can also be a functional module for implementing the method described in the above embodiments in a terminal device. The communication apparatus can implement the functions of the terminal device in the above embodiments, and these functions can be implemented by hardware or software. The hardware or software includes one or more modules corresponding to the above functions. The apparatus can include a receiving module configured to receive downlink control information transmitted by a network device, the downlink control information comprising first indication information, the first indication information being used to indicate random access by the terminal device; a processing module configured to determine updated ephemeris information; and a sending module configured to perform delayed random access on a physical random access channel according to a first timing offset and a second timing offset, wherein the first timing offset is a round-trip delay of the terminal device to a predetermined reference point, and the second timing offset is a time length for the terminal device to delay random access on the physical random access channel.

[0017] In some possible implementation manners, the processing module is specifically configured to determine that the valid timer is expired; and determine the updated ephemeris information.

[0018] In some possible implementation manners, the receiving module is configured to receive the downlink control information on an nth time slot in a downlink time domain resource, n being a positive integer.

[0019] In some possible implementation manners, the sending module is configured to perform random access on a next physical random access channel transmission opportunity after delaying for a first time length from the nth time slot in the uplink time domain resource, wherein the first time length is a sum of the first timing offset and the second timing offset.

[0020] In some possible implementation manners, the downlink control information further comprises second indication information, the second indication information being used to indicate the second timing offset.

[0021] In some possible implementation manners, the receiving module is further configured to receive system information within a second time length corresponding to the second timing offset; the first processing module is further configured to determine the ephemeris information according to the system information; and determine the first timing offset according to the determined ephemeris information.

[0022] According to a fourth aspect of the present disclosure, a communication apparatus is provided. The communication apparatus can be a network device in an NTN communication system, or a chip or system-on-chip in the network device. The communication apparatus can also be a functional module in the network device for implementing the method described in the above embodiments. The communication apparatus can implement the functions of the network device described in the above embodiments. These functions can be implemented by hardware or software. The hardware or software includes one or more modules corresponding to the above functions. The apparatus can include a processing module configured to determine that a terminal device updates ephemeris information, and a sending module configured to send, to the terminal device, downlink control information including first indication information, the first indication information being used to instruct the terminal device to perform random access.

[0023] In some possible implementation manners, the processing module is specifically configured to determine that the effective timer of the terminal device is expired, and determine that the terminal device updates ephemeris information.

[0024] In some possible implementation manners, the downlink control information further includes second indication information, the second indication information being used to indicate a second timing offset, and the second timing offset being a time length for the terminal device to delay performing random access on the physical random access channel.

[0025] According to a fifth aspect of the present disclosure, a terminal device is provided. The terminal device includes a memory and a processor. The processor is connected with the memory and is configured to implement the random access method described in the first aspect and any possible implementation manner of the first aspect by executing computer-executable instructions stored in the memory.

[0026] According to a sixth aspect of the present disclosure, a network device is provided. The network device includes a memory and a processor. The processor is connected with the memory and is configured to implement the random access method described in the second aspect and any possible implementation manner of the second aspect by executing computer-executable instructions stored in the memory.

[0027] According to a seventh aspect of the present disclosure, a computer-readable storage medium is provided. The computer-readable storage medium stores instructions. When the instructions are executed on a computer, the instructions are used to perform the random access method described in the first aspect to the second aspect and any possible implementation manner of the first aspect to the second aspect.

[0028] According to an eighth aspect of the present disclosure, a computer program or a computer program product is provided. When the computer program product is executed on a computer, the computer program product causes the computer to implement the random access method described in the first aspect to the second aspect and any possible implementation manner of the first aspect to the second aspect.

[0029] In the present disclosure, when determining to update ephemeris information, the terminal device delays random access according to the first timing offset and the second timing offset, which can well compensate the uplink and downlink frame timing of the terminal device, thereby ensuring reliable transmission of the preamble sequence, and further improving the reliability of random access. Further, it can also reduce the blind detection of the network device without comparison.

[0030] It should be understood that the third to eighth aspects of the present application are consistent with the technical solutions of the first to second aspects of the present application, and the beneficial effects obtained by each aspect and the corresponding feasible implementation manner are similar, which will not be repeated. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a schematic diagram of an NTN communication system in an embodiment of the present disclosure;

[0032] Figure 2 is a schematic diagram of another NTN communication system in an embodiment of the present disclosure;

[0033] Figure 3 is a schematic diagram of a scenario of uplink and downlink alignment on the base station side in an embodiment of the present disclosure;

[0034] Figure 4 is a schematic diagram of a scenario of uplink and downlink misalignment on the base station side in an embodiment of the present disclosure;

[0035] Figure 5 is a schematic diagram of the implementation process of the first random access method in an embodiment of the present disclosure;

[0036] Figure 6 is a schematic diagram of the implementation process of the second random access method in an embodiment of the present disclosure;

[0037] Figure 7 is a schematic diagram of the implementation process of the third random access method in an embodiment of the present disclosure;

[0038] Figure 8 is a schematic diagram of the implementation process of the fourth random access method in an embodiment of the present disclosure;

[0039] Figure 9 is a schematic diagram of the implementation process of the fifth random access method in an embodiment of the present disclosure;

[0040] Figure 10 is a schematic diagram of the implementation process of the sixth random access method in an embodiment of the present disclosure;

[0041] Figure 11 is a schematic diagram of the implementation process of the seventh random access method in an embodiment of the present disclosure;

[0042] Figure 12FIG. 1 is a schematic diagram of a structure of a communication device according to an embodiment of the present disclosure;

[0043] Figure 13 FIG. 2 is a schematic diagram of a structure of another communication device according to an embodiment of the present disclosure;

[0044] Figure 14 FIG. 3 is a schematic diagram of a structure of a communication device according to an embodiment of the present disclosure;

[0045] Figure 15 FIG. 4 is a schematic diagram of a structure of a terminal device according to an embodiment of the present disclosure;

[0046] Figure 16 FIG. 5 is a schematic diagram of a structure of a network device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0047] The exemplary embodiments are described herein with reference to the accompanying drawings, in which examples are shown. The description of the exemplary embodiments is not meant to represent all embodiments in accordance with the present disclosure. Rather, they are merely examples in accordance with some aspects of the present disclosure as detailed in the appended claims.

[0048] The terminology used in the present disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used in the present disclosure and the appended claims, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0049] It will be understood that, although the terms "first," "second," "third," etc. can be used herein to describe various information, the information should not be limited by these terms. These terms are only used to distinguish one piece of information from another. For example, a "first information" can also be termed as a "second information," and similarly, a "second information" can also be termed as a "first information" without departing from the scope of the present disclosure. The word "if' as used herein means "when" or "upon" or "in response to the determination" depending on the context.

[0050] The technical solutions of the embodiments of the present disclosure are applicable to a communication system integrating ground communication and satellite communication. The communication system can also be referred to as a non-terrestrial network (NTN) communication system. For example, the ground communication system can be a long term evolution (LTE) system, a universal mobile telecommunication system (UMTS), a 5G communication system or a new radio (NR) system, a future next-generation mobile communication system, and the like, and the embodiments of the present disclosure do not make specific limitations. Optionally, in the embodiments of the present disclosure, the NTN communication system is taken as an example to integrate 5G communication and satellite communication.

[0051] In wireless communication technology, satellite communication is considered as an important aspect of future wireless communication technology development. Satellite communication refers to communication of radio communication equipment on the ground using satellites as relays. The satellite communication system is composed of a satellite part and a ground part. The characteristics of satellite communication are: large communication range; as long as the range covered by the satellite transmission wave, communication can be carried out between any two points; not easy to be affected by land disasters, high reliability.

[0052] As a supplement to the ground communication system, satellite communication has the following characteristics: 1, extended coverage: for areas that cannot be covered by the cellular communication system or have high coverage costs, such as oceans, deserts and remote mountainous areas, satellite communication can be used to solve the communication problem. 2, emergency communication: in the case of extreme conditions caused by disasters (such as earthquakes, etc.) that make the infrastructure of cellular communication unavailable, satellite communication can quickly establish a communication connection. 3, provide industry applications: for example, for long-distance transmission of time-sensitive services, satellite communication can be used to reduce the transmission delay of services.

[0053] Satellite communication can be communication between radio communication stations on the ground using communication satellites as relay stations to forward radio waves. The communication function of the communication satellite can include: receiving signals, changing the frequency of the signals, amplifying the signals, forwarding the signals, and positioning, etc.

[0054] In some possible implementation manners, Figure 1 For a schematic diagram of an NTN communication system in the embodiments of the present disclosure, see Figure 1As shown, the communication system includes a terminal device 10, a satellite 20, an NTN gateway 30 (which can also be referred to as a ground station, a gateway station, or a gateway), a core network device 40, and a data network 50. At this time, the NTN communication network is in a transparent mode. Among them, the satellite 20 carries a payload with the entire access network device function. The terminal device 10 can be connected with the access network device 20 (such as the satellite 20) through a 5G new air interface (such as a Uu interface), the satellite 20 can be connected with the NTN gateway 30 through an interface (such as a satellite radio interface (SRI)), the NTN gateway 30 is connected with the core network device 40 through a wireless link interface (such as an NG interface), and the core network device 40 is connected with the data network 50 through an interface (such as an N6 interface). The access network device establishes a wireless feeder link through the ground NTN gateway and the core network device.

[0055] In some possible embodiments, Figure 2 For another schematic diagram of the NTN communication system in the embodiments of the present disclosure, refer to Figure 2 As shown, when the access network device adopts a centralized unit (CU) and a distributed unit (DU) architecture (i.e., a CU-DU architecture), the DU is carried on the satellite 20 (it can be understood that the payload carried by the satellite 20 is the DU), and the CU is deployed on the ground base station 60 (such as a gNB). The satellite 20 and the NTN gateway 30 constitute a remote radio unit (RRU), and the satellite 20, the NTN gateway 30, and the ground base station 60 constitute a next-generation wireless access network. At this time, the NTN communication network is in a regenerative mode. The terminal device 10 is connected with the satellite 20 through a new air interface (such as a Uu interface), the satellite 20 is connected with the NTN gateway 30 through an interface (such as an SRI), the ground base station 60 is connected with the core network device 40 through a wireless link interface (such as an NG interface), and the core network device 40 is connected with the data network 50 through an interface (such as an N6 interface). In this way, the DU in the air establishes a wireless feeder link through the ground NTN gateway and the CU.

[0056] For example, the above-mentioned satellite 20 can be a geostationary orbit (GSO) satellite, or a medium earth orbit (MEO) satellite or a low earth orbit (LEO) satellite in a non-geostationary orbit (NGSO), or a high altitude platform station (HAPS), etc.

[0057] It should be noted that, Figure 1 and Figure 2 Satellite 20 can be replaced by other airborne platforms with defined operating orbits, such as drones, hot air balloons, or airplanes. Of course, in some possible embodiments, satellite 20 can also be replaced by other ground platforms with defined operating orbits, such as buses or ships with defined trajectories. This disclosure does not specifically limit this.

[0058] In this embodiment of the disclosure, the NTN gateway 30 can be a transport network layer (TNL) node used to realize the transparent transmission of data or signaling; the NTN gateway can also be replaced by a fixed receiving node or a host node.

[0059] It should be understood that Figure 1 and Figure 2 This is merely an example; the technical solutions of this disclosure can also be applied to other NTN communication systems, and this disclosure does not specifically limit them.

[0060] In this embodiment of the disclosure, the terminal device 10 may also be referred to as: user equipment (UE), mobile station (MS), mobile terminal (MT), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, wireless communication equipment, user agent, or user device, etc.

[0061] It can be understood that the terminal device 10 can be a device providing voice / data connectivity to a user, for example, a handheld device with wireless connection function, a vehicle-mounted device, etc. Exemplarily, some examples of the terminal are: a mobile phone, a tablet computer, a notebook computer, a palm computer, a mobile internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a wireless terminal in auto-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a 5G network, or a terminal device in an evolved public land mobile network (PLMN), etc., and the embodiments of the present disclosure do not make specific limitations thereto.

[0062] It can be understood that the network device in the embodiments of the present disclosure can be an access network device for communicating with the terminal device. The network device is mainly used to provide wireless access services for the terminal device, configure wireless resources, provide reliable wireless transmission protocols and data encryption protocols, etc. The network device can also be referred to as an access device or a radio access network device, which can be an evolved node B (eNB or eNodeB) in an LTE system, and can also be a radio controller in a cloud radio access network (CRAN) system; or the network device can also be a relay station, an access point, a vehicle-mounted device, a wearable device, an access network device in a 5G network, or a network device in a future evolved PLMN network, etc. For example, the network device can be an access point (AP) in a wireless local area network (WLAN), and can also be a gNB in an NR system, and the embodiments of the present disclosure do not make specific limitations on this.

[0063] In addition, in the embodiments of the present disclosure, the network device is a device in a radio access network (RAN), or a RAN node for accessing the terminal device to the wireless network. For example, some examples of the network device are: gNB, transmission reception point (TRP), evolved node B (eNB), radio network controller (RNC), node B (NB), base station controller (BSC), base transceiver station (BTS), home evolved node B (HeNB) or home node B (HNB), baseband unit (BBU), wireless fidelity (Wifi) access point (AP), etc. In a network structure, the network device can include a CU, a DU, a RAN device including a CU and a DU, a CU of a control plane (CP) (such as a CU-CP) and a CU of a user plane (UP) (such as a CU-UP), and a RAN device of a DU.

[0064] In embodiments of the present disclosure, the propagation delay in NTN systems is much longer than that in terrestrial mobile systems, ranging from a few milliseconds to hundreds of milliseconds depending on the altitude of the spaceborne or airborne platform and the type of payload in the NTN. Therefore, in NTN systems, the terminal device (e.g., UE) needs to apply a larger timing advance (TA) value, which will cause a large offset in the downlink (DL) and uplink (UL) frame timing of the terminal device. Figure 3 A scenario is shown in which the UE applies a large TA and the DL and UL frame timing of the network device (e.g., gNB) is aligned. Figure 4 Another scenario is shown in which the DL and UL frames of the gNB do not need to be aligned. The UE applies a UE-specific TA so that the DL and UL frame timing is aligned at a predetermined reference point. However, for Figure 4 For the scenario shown, the network device side needs additional complexity to manage the corresponding scheduling timing of the scenario. Thus, various timing relationships need to be enhanced to cope with the large offset in the DL and UL frame timing of the UE.

[0065] In a possible implementation, the above enhancement can be to introduce a first timing offset and apply the first timing offset to compensate for the transmission delay. Here, the first timing offset can be understood as the round trip time (RTT) between the UE and a predetermined reference point, such as Koffset. Here, the predetermined reference point can be understood as any point on the wireless communication link in the NTN system, such as any point on the service link between the satellite and the terminal, or any point on the feeder link between the satellite and the ground network device. For example, the predetermined reference point can be any access network device on the service link in the NTN communication system, such as a satellite, NTN gateway, ground base station, etc. Alternatively, the predetermined reference point can also be any access network device on the feeder link, such as a satellite, NTN gateway, ground base station, etc.

[0066] It should be noted that the above uplink and downlink timing relationship can include: a transmission timing of physical uplink shared channel (PUSCH) scheduled by downlink control information (DCI), a transmission timing of PUSCH scheduled by a radom access response grant (RAR grant), a transmission timing of a hybrid automatic repeat request acknowledge character (HARQ-ACK) on a physical uplink control channel (PUCCH), an action timing of a medium access control control element (MAC CE), a channel state information (CSI) reference resource timing, a transmission timing of a non-periodic sounding reference symbol (SRS), and the like.

[0067] In the embodiments of the present disclosure, in the process of communication between the network device and the terminal device, if the network device finds that the terminal device is uplink out-of-sync, the network device can send a physical downlink control channel order (PDCCH order) to the terminal device to trigger the terminal device to initiate random access, so as to re-establish uplink synchronization. That is, if the network device judges that the terminal device is uplink out-of-sync, the network device can trigger the transmission of a physical random access channel (PRACH) by sending a DCI (which can also be understood as a PDCCH) to the terminal device.

[0068] However, in the NTN system described above, due to the large difference in the communication distance between the terminal device and the satellite, between the terminal device and the NTN gateway, or between the terminal device and the ground base station due to the running speed and altitude of the satellite, the transmission delay between the terminal device and the satellite, the transmission delay between the terminal device and the NTN gateway, or the transmission delay between the terminal device and the ground base station is large. Then, after the terminal device loses uplink synchronization, if it wants to re-establish uplink synchronization, it needs to determine whether the received ephemeris information is valid. Only in the case where the ephemeris information is valid, the terminal device can determine the accurate first timing offset, and then ensure the reliability of random access. It can be seen that if the first timing offset is delayed for all terminal devices without distinction, the reliable transmission of the preamble sequence cannot be guaranteed, and thus the reliability of random access of the terminal device is affected.

[0069] To solve the above problems, the present embodiment provides a random access method which can be applied to the NTN communication system described in one or more embodiments.

[0070] The random access method provided by the present embodiment will be described below in combination with the NTN communication system.

[0071] In the present embodiment, the network device can be an access network device such as a ground base station (such as gNB), a satellite, etc. in the NTN communication system described above.

[0072] Figure 5 For the implementation flowchart of the first random access method in the present embodiment, see Figure 5 The random access method can include the following steps:

[0073] S501, the network device sends DCI to the terminal device.

[0074] The DCI can include first indication information, and the first indication information is used to instruct the terminal device to initiate random access to re-establish uplink synchronization in the case of uplink synchronization loss.

[0075] For example, the first indication information described above can be PDCCH order.

[0076] S502, the terminal device determines whether to update the ephemeris information in response to the DCI.

[0077] In a possible implementation, in S502, the terminal device can determine whether to update the ephemeris information by judging whether a validation timer set by itself is expired. If the validation timer is expired, it means that the current ephemeris information is invalid, and the terminal device determines to update the ephemeris information and performs S503. Otherwise, if the validation timer is not expired, it means that the current ephemeris information is still valid, and the terminal device determines not to update the ephemeris information and performs S504.

[0078] In S503, the terminal device delays the random access on the PRACH according to the first timing offset and the second timing offset.

[0079] Here, the second timing offset is used to indicate the time length for which the terminal device delays the random access. The time unit of the second timing offset can be an absolute time or a logical time, such as a number of slots.

[0080] It should be understood that after determining to update the ephemeris information, the terminal device can first obtain the first timing offset and the second timing offset. Then, the terminal device delays sending the preamble sequence on the available PRACH according to the sum of the first timing offset and the second timing offset, to achieve the delayed random access. Here, the available PRACH can be understood as the next PRACH sending occasion.

[0081] In a possible implementation, the second timing offset can be determined in the following two ways, but not limited to.

[0082] In a first way, the second timing offset can be specified by a communication protocol.

[0083] The communication protocol can include various versions of the 3rd generation partnership project (3GPP) wireless communication protocol and its evolution versions.

[0084] It can be understood that the communication protocol can specify one or more timing offsets. Then, after receiving the DCI through S501, the terminal device determines the second timing offset from the one or more timing offsets in response to the DCI.

[0085] In a second way, the second timing offset can be indicated by the network device.

[0086] It can be understood that the network device can pre-configure one or more timing offsets, and determine a timing offset for the terminal device as the second timing offset from the one or more timing offsets. The DCI can further include second indication information for indicating the second timing offset. The terminal device can determine the second timing offset according to the second indication information.

[0087] In another embodiment, the second indication information can also be carried by other DCI.

[0088] Exemplarily, a mapping relationship between the second indication information and the second timing offset (which can be denoted as offset 2) can be, but is not limited to, as shown in Table 1.

[0089] Table 1

[0090] Second indication information Offset 2 value 00 1 01 2 10 3 11 4

[0091] Of course, in actual applications, the second indication information and the second timing offset can also have other values, and the embodiments of the present disclosure do not make specific limitations on this.

[0092] Of course, the terminal device can also determine the second timing offset through other manners such as negotiation with the network device, and the embodiments of the present disclosure do not make specific limitations on this.

[0093] In some possible implementation manners, the DCI is provided with an information field for carrying the second indication information. The information field can be located at a pre-configured position in the DCI, or can be located at a fixed position. Further, the length of the information field can be fixed or configurable. In an implementation example, the length of the information field can be determined according to the number of values that the second indication information needs to indicate. For example, offset 2 can have 4 values, and then the length of the information field can be 2 bits. Or, offset 2 can have 8 values, and then the length of the information field can be 3 bits.

[0094] In some possible implementation manners, the terminal device can also obtain the first timing offset in the following manner: the terminal device receives system information within a time length A (i.e., a second time length) corresponding to the second timing offset. Then, the terminal device determines ephemeris information according to the system information to obtain valid ephemeris information. Finally, the terminal device determines the first timing offset according to the determined ephemeris information. The first timing offset thus determined is more accurate. Exemplarily, the system information can be a master information block (MIB), a system information block (SIB), or the like.

[0095] S504, the terminal device delays the random access on the PRACH according to the first timing offset.

[0096] It should be understood that after determining not to update the ephemeris information, the terminal device can first obtain the first timing offset. Then, the preamble sequence is sent on the available PRACH according to the first timing offset, so as to realize the delayed random access.

[0097] In some possible embodiments, when the terminal device determines not to update the ephemeris information, for example, the validity timer does not expire, the value of the second timing offset can also be 0, null or other invalid values, which are not limited in the embodiments of the present disclosure.

[0098] In some possible embodiments, the terminal device obtaining the first timing offset in S504 can be: the terminal device determines the first timing offset according to the current ephemeris information.

[0099] It can be understood that through S501, the terminal device can receive the DCI on the nth time slot (for example, a downlink slot n) of the downlink time domain resource, and n is a positive integer. Correspondingly, in S503, the terminal device can delay sending the preamble sequence on the next PRACH occasion after a delay duration B (that is, a first duration, for example, the sum of the first timing offset and the second timing offset) from the nth time slot (for example, an uplink slot n) of the uplink time domain resource, and perform random access. For example, the first timing offset is Koffset, and the second timing offset is offset 2. Then, the terminal device can determine that the next PRACH occasion is after the uplink slot n+Koffset+offset 2. Alternatively, in S504, the terminal device can delay sending the preamble sequence on the next PRACH occasion after a delay duration C (that is, a third duration, for example, the first timing offset) from the nth time slot (for example, an uplink slot n) of the uplink time domain resource, and perform random access. For example, the first timing offset is Koffset. Then, the terminal device can determine that the next PRACH occasion is after the uplink slot n+Koffset.

[0100] In the embodiments of the present disclosure, when the terminal device determines to update the ephemeris information, the random access is delayed according to the first timing offset and the second timing offset, which can well compensate the uplink and downlink frame timing of the terminal device, thereby ensuring the reliable transmission of the preamble sequence, and further improving the reliability of the random access. Further, it can also reduce the blind detection of the network device without comparison.

[0101] In some possible embodiments, the embodiments of the present disclosure also provide a random access method. Figure 6This is a schematic diagram illustrating the implementation process of the second random access method in this disclosure embodiment. See [link / reference]. Figure 6 As shown, the random access method may include:

[0102] S601, the network device sends DCI to the terminal device.

[0103] S602, the terminal device confirms the update of ephemeris information.

[0104] In one possible implementation, the terminal device can determine to update the ephemeris information by judging that its own set valid timer has expired, and then execute S603.

[0105] S603, the terminal device performs delayed random access on PRACH according to the first timing offset and the second timing offset.

[0106] It should be noted that the specific implementation process of S601 to S603 above can be found in [reference needed]. Figure 5 The descriptions of S501 to S503 in the embodiments will not be repeated here.

[0107] In some possible embodiments, this disclosure also provides a random access method. Figure 7 This is a schematic diagram illustrating the implementation process of the third random access method in this disclosure embodiment. See [link / reference]. Figure 7 As shown, the random access method may include:

[0108] S701, the network device sends DCI to the terminal device.

[0109] S702, the terminal device has decided not to update the ephemeris information.

[0110] In one possible implementation, the terminal device can determine that it will not update the ephemeris information by judging that its own set valid timer has not expired, and then execute S703.

[0111] S703, the terminal device performs a delayed random access on PRACH based on the first timing offset.

[0112] It should be noted that the specific implementation process of S701 to S703 above can be found in [reference needed]. Figure 5 The descriptions of S501, S502, and S504 in the embodiments will not be repeated here.

[0113] Based on the same inventive concept, this disclosure also provides a random access method. Figure 8 This is a schematic diagram illustrating the implementation process of the fourth random access method in this disclosure. See [link / reference]. Figure 8 As shown, the random access method may include:

[0114] S801, the network device determines that the terminal device is uplink out-of-sync.

[0115] S802, the network device sends DCI to the terminal device.

[0116] The DCI can include first indication information, and the first indication information is used to instruct the terminal device to perform random access.

[0117] For example, the first indication information can be PDCCH order.

[0118] S803, the terminal device delays random access on the PRACH in response to the DCI.

[0119] It should be understood that in S803, the terminal device can specifically perform S501-S504 described above to delay random access on the available PRACH for a time period C or a time period B, which will not be repeated here.

[0120] In some possible implementation manners, Figure 9 For the implementation flowchart of the fifth random access method in the embodiments of the present disclosure, see Figure 9 As shown in the figure, after S801 and before S802, the method can further include S901, the network device determines whether the terminal device updates ephemeris.

[0121] In an embodiment, the network device can obtain the time period of the valid timer of the terminal device, and then the network device can determine whether the terminal device updates ephemeris information by judging whether the valid timer is expired. If the valid timer is expired, it means that the current ephemeris information is invalid, and the terminal device updates the ephemeris information. Otherwise, if the valid timer is not expired, it means that the current ephemeris information is still valid, and the terminal device does not update the ephemeris information.

[0122] Correspondingly, if the network device determines that the terminal device updates ephemeris information, the DCI in S802 can further include second indication information. That is, S802 can be S902, the network device can send DCI carrying the first indication information and the second indication information to the terminal device to instruct the terminal device to initiate random access and indicate the second timing offset to the terminal device. In this way, after receiving the DCI, the terminal device can delay random access on the available PRACH according to the first timing offset and the second timing offset. For example, the mapping relationship between the second indication information and the second timing offset can be seen from Table 1.

[0123] In some possible implementation, if the network device determines that the terminal device updates the ephemeris information, the DCI in S802 can also not carry the second indication information. In this way, the terminal device can delay the access on the available PRACH according to the second timing offset and the first timing offset specified in the communication protocol.

[0124] Conversely, if the network device determines that the terminal device does not update the ephemeris information, the DCI in S802 can only carry the first indication information. That is, S802 can be: S903, the network device can send the DCI carrying the first indication information to the terminal device to instruct the terminal device to initiate the random access. In this way, after receiving the DCI, the terminal device can delay the random access on the available PRACH according to the first timing offset.

[0125] In some possible implementation, if the network device determines that the terminal device does not update the ephemeris information, the DCI in S802 can also carry the second indication information, and at this time, the second indication information can be 0, null or other invalid value. In this way, after receiving the DCI, the terminal device can still delay the random access on the available PRACH according to the first timing offset.

[0126] It should be noted that if the DCI includes the second indication information, an information field is set on the DCI, and the information field is used to carry the second indication information. The length of the information field can be fixed or configurable.

[0127] In the embodiment of the present disclosure, when it is determined that the terminal device updates the ephemeris information, the network device indicates the second timing offset to the terminal device, so that the terminal device can delay the random access according to the first timing offset and the second timing offset, and the uplink and downlink frame timing of the terminal device is well compensated, thereby ensuring the reliable transmission of the preamble sequence, and further improving the reliability of the random access. Further, it can also reduce the blind detection of the network device.

[0128] In some possible embodiments, the embodiment of the present disclosure also provides a random access method. Figure 10 For the implementation flowchart of the sixth random access method in the embodiment of the present disclosure, referring to Figure 10 As shown in the figure, the random access method can include:

[0129] S1001, the network device determines that the terminal device updates the ephemeris information.

[0130] S1002, the network device sends the DCI carrying the first indication information and the second indication information to the terminal device.

[0131] The first indication information is used to instruct the terminal device to perform the random access, and the second indication information is used to indicate the second timing offset.

[0132] It should be noted that the specific implementation process of S1001 to S1002 can be referred to the description of S901 to S902 in the embodiments of the present disclosure, which will not be repeated here. Figure 9 The description of S901 to S902 in the embodiments of the present disclosure will not be repeated here.

[0133] In some possible embodiments, the present disclosure further provides a random access method. Figure 11 For the implementation flowchart of the seventh random access method in the embodiments of the present disclosure, refer to Figure 11 As shown in the figure, the random access method can include:

[0134] S1101, the network device determines that the terminal device does not update ephemeris information.

[0135] S1102, the network device sends DCI carrying only first indication information to the terminal device.

[0136] The first indication information is used to instruct the terminal device to perform random access.

[0137] It should be noted that the specific implementation process of S1101 to S1102 can be referred to the description of S901 to S902 in the embodiments of the present disclosure, which will not be repeated here. Figure 9 The description of S901 to S903 in the embodiments of the present disclosure will not be repeated here.

[0138] Based on the same inventive concept, the embodiments of the present disclosure provide a communication device, which can be a terminal device in an NTN communication system or a chip or a system on chip in a terminal device, and can also be a functional module in a terminal device for implementing the method described in the above embodiments. The communication device can implement the functions performed by the terminal device in the above embodiments, and these functions can be implemented by executing corresponding software through hardware. These hardware or software include one or more modules corresponding to the above functions. Figure 12 For the structure diagram of a communication device in the embodiments of the present disclosure, refer to Figure 12 As shown in the figure, the communication device 1200 can include: a receiving module 1201, configured to receive the DCI sent by the network device, the DCI including first indication information, the first indication information being used to instruct the terminal device to perform random access; a processing module 1202, configured to determine to update ephemeris information; and a sending module 1203, configured to perform delayed random access on the PRACH according to a first timing offset and a second timing offset, wherein the first timing offset is the round-trip delay of the terminal device to a predetermined reference point, and the second timing offset is the time length of the terminal device delaying random access on the PRACH.

[0139] In some possible implementation manners, the processing module 1202 is specifically configured to determine that the valid timer is timed out; and determine to update ephemeris information.

[0140] In some possible implementation, the receiving module 1201 is configured to receive the DCI on the n th time slot in the downlink time domain resource, where n is a positive integer.

[0141] In some possible implementation, the sending module 1203 is configured to perform the random access on the next PRACH occasion after delaying for a first time duration from the n th time slot in the uplink time domain resource, where the first time duration is a sum of the first timing offset and the second timing offset.

[0142] In some possible implementation, the DCI further includes second indication information, where the second indication information is used to indicate the second timing offset.

[0143] In some possible implementation, the receiving module 1201 is further configured to receive system information within a second time duration corresponding to the second timing offset; the processing module 1202 is further configured to determine the ephemeris information according to the system information, and determine the first timing offset according to the determined ephemeris information.

[0144] It should be noted that the specific implementation process of the receiving module 1201, the processing module 1202 and the sending module 1203 can refer to the detailed description of the embodiments of the present disclosure. Figures 5 to 7 For the sake of brevity of the description, the detailed description of the embodiments of the present disclosure will not be repeated here.

[0145] The receiving module 1201 mentioned in the embodiments of the present disclosure can be a receiving interface, a receiving circuit or a receiver, etc.; the sending module 1203 can be a sending interface, a sending circuit or a sender, etc.; and the processing module 1202 can be one or more processors.

[0146] Based on the same inventive concept, the embodiments of the present disclosure provide a communication apparatus, which can be a network device in an NTN communication system or a chip or a system on chip in the network device, and can also be a functional module for implementing the method described in the above embodiments in the network device. The communication apparatus can implement the functions performed by the network device in the above embodiments, and these functions can be implemented by executing corresponding software by hardware. These hardware or software include one or more modules corresponding to the above functions. Figure 13 The structure of another communication apparatus in the embodiments of the present disclosure is shown in FIG. 13. The communication apparatus 1300 can include a processing module 1301 configured to determine that a terminal device updates ephemeris information, and a sending module 1302 configured to send a DCI to the terminal device, where the DCI includes first indication information, and the first indication information is used to instruct the terminal device to perform random access.

[0147] In some possible implementation, the processing module 1301 is specifically configured to determine that a valid timer of the terminal device is expired, and determine that the terminal device updates the ephemeris information. In some possible implementation, the processing module 1301 is specifically configured to determine that a valid timer of the terminal device is expired, and determine that the terminal device updates the ephemeris information.

[0148] In some possible implementation manners, the DCI further includes second indication information, and the second indication information is used to indicate a second timing offset, and the second timing offset is a time length for delaying random access on the PRACH by the terminal device.

[0149] It should be noted that the specific implementation process of the processing module 1301 and the sending module 1302 can refer to Figures 8 to 11 The detailed description of the embodiments is not described here again for the sake of brevity of the description.

[0150] The sending module 1302 mentioned in the embodiments of the present disclosure can be a sending interface, a sending circuit or a transmitter, etc. The processing module 1301 can be one or more processors.

[0151] Based on the same inventive concept, the embodiments of the present disclosure provide a communication device, which can be the terminal device or the network device in the one or more embodiments described above. Figure 14 For the structure diagram of the communication device in the embodiments of the present disclosure, refer to Figure 14 As shown in the figure, the communication device 1400 adopts a general computer hardware, including a processor 1401, a memory 1402, a bus 1403, an input device 1404 and an output device 1405.

[0152] In some possible implementation manners, the memory 1402 can include computer storage media in the form of volatile and / or non-volatile memory, such as read-only memory and / or random access memory. The memory 1402 can store operating systems, application programs, other program modules, executable codes, program data, user data, etc.

[0153] The input device 1404 can be used to input commands and information to the communication device, and the input device 1404 can be a keyboard or a pointing device, such as a mouse, a trackball, a touchpad, a microphone, a joystick, a game pad, a satellite television antenna, a scanner or the like. These input devices can be connected to the processor 1401 through the bus 1403.

[0154] The output device 1405 can be used to output information of the communication device, and in addition to the monitor, the output device 1405 can also be other peripheral output devices, such as a speaker and / or a printing device, and these output devices can also be connected to the processor 1401 through the bus 1403.

[0155] The communication device can be connected to a network through an antenna 1406, for example, connected to a local area network (LAN). In a networked environment, the computer stored in the control device can store the execution instructions in a remote storage device, and is not limited to local storage.

[0156] When the processor 1401 in the communication device executes the executable code or application stored in the memory 1402, the communication device executes the communication method on the terminal device side or network device side in the above embodiments. For the specific execution process, please refer to the above embodiments, which will not be repeated here.

[0157] Furthermore, the aforementioned memory 1402 stores information for implementing... Figure 12 The computer executes instructions to perform the functions of the first receiving module 1201, the first processing module 1202, and the first sending module 1203. Figure 12 The functions / implementation processes of the first receiving module 1201, the first processing module 1202, and the first transmitting module 1203 can all be obtained through... Figure 14 The processor 1401 in the memory calls the computer execution instructions stored in the memory 1402 to implement the function. For the specific implementation process and function, please refer to the above-mentioned related embodiments.

[0158] Alternatively, the memory 1402 described above stores information for implementing... Figure 13 The computer executes instructions to perform the functions of the second processing module 1301 and the second sending module 1302. Figure 13 The functions / implementation processes of the second processing module 1301 and the second sending module 1302 can be obtained through Figure 14 The processor 1401 in the memory calls the computer execution instructions stored in the memory 1402 to implement the function. For the specific implementation process and function, please refer to the above-mentioned related embodiments.

[0159] Based on the same inventive concept, this disclosure provides a terminal device that is consistent with the terminal devices in one or more of the above embodiments. Optionally, the terminal device may be a mobile phone, computer, digital broadcasting terminal, messaging device, game console, tablet device, medical device, fitness device, personal digital assistant, etc.

[0160] Figure 15 This is a schematic diagram of the structure of a terminal device according to an embodiment of this disclosure. See also... Figure 15 As shown, the terminal device 1500 may include one or more of the following components: processing component 1501, memory 1502, power supply component 1503, multimedia component 1504, audio component 1505, input / output (I / O) interface 1506, sensor component 1507, and communication component 1508.

[0161] The processing component 1501 generally controls the overall operations of the terminal device 1500, such as operations associated with display, phone calls, data communications, camera operations, and recording operations. The processing component 1501 can include one or more processors 1510 to execute instructions to complete all or part of steps of the methods described above. In addition, the processing component 1501 can include one or more modules to facilitate interaction between the processing component 1501 and other components. For example, the processing component 1501 can include a multimedia module to facilitate the interaction between the multimedia component 1504 and the processing component 1501.

[0162] The memory 1502 is configured to store various types of data to support operations of the terminal device 1500. Examples of these data include instructions for any application or method operating on the terminal device 1500, contact data, phonebook data, messages, pictures, videos, and the like. The memory 1502 can be implemented by any type of volatile or nonvolatile memory, or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disc, or optical disc.

[0163] The power component 1503 provides power to the various components of the terminal device 1500. The power component 1503 can include a power management system, one or more power sources, and other components associated with generating, managing, and distributing power for the terminal device 1500.

[0164] The multimedia component 1504 includes a screen providing an output interface between the terminal device 1500 and a user. In some embodiments, the screen can include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes the touch panel, the screen can be implemented as a touch screen to receive an input signal from a user. The touch panel includes one or more touch sensors to sense a touch, swiping, and gestures on the touch panel. The touch sensor can not only sense a boundary of a touching or swiping action, but also detect duration and pressure related to the touching or swiping action. In some embodiments, the multimedia component 1504 includes a front camera and / or a rear camera. The front and rear cameras can receive external multimedia data when the terminal device 1500 is in an operation mode, such as a shooting mode or a video mode. Each of the front and rear cameras can be a fixed optical lens system or have a focal length and optical zoom capability.

[0165] The audio component 1505 is configured to output and / or input audio signals. For example, the audio component 1505 includes a microphone (MIC) that is configured to receive an external audio signal when the terminal device 1500 is in an operation mode, such as a call mode, a recording mode, and a voice recognition mode. The received audio signal can be further stored in the memory 1502 or transmitted via the communication component 1508. In some embodiments, the audio component 1505 also includes a speaker for outputting audio signals.

[0166] The I / O interface 1506 provides an interface between the processing component 1501 and peripheral interface modules, which can be a keypad, a click wheel, buttons, and the like. The buttons can include, but are not limited to, a home button, a volume button, a start button, and a lock button.

[0167] The sensor component 1507 includes one or more sensors for providing various state assessments for the terminal device 1500. For example, the sensor component 1507 can detect an open / closed state of the terminal device 1500, relative positioning of components, such as a display and a keypad of the terminal device 1500, a change in position of the terminal device 1500 or a component of the terminal device 1500, presence or absence of user contact with the terminal device 1500, an orientation or acceleration / deceleration / g-force and a temperature change of the terminal device 1500. The sensor component 1507 can include a proximity sensor configured to detect presence of a nearby object without any physical touch. The sensor component 1507 can further include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor component 1507 can further include an acceleration sensor, a gyroscope sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

[0168] The communication component 1508 is configured to facilitate wired or wireless communication between the terminal device 1500 and other devices. The terminal device 1500 can access a wireless network based on a communication standard, such as Wi-Fi, 2G, or 3G, or a combination thereof. In an example embodiment, the communication component 1508 receives broadcast signals or broadcast-related information from an external broadcast management system via a broadcast channel. In an example embodiment, the communication component 1508 further includes a Near Field Communication (NFC) module to facilitate short-range communication. For example, the NFC module can be implemented based on Radio Frequency Identification (RFID) technology, infrared data association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology and other technology.

[0169] In an example embodiment, the terminal device 1500 can be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, micro-controllers, microprocessors or other electronic elements, for executing the above-described methods.

[0170] Based on the same inventive concept, the embodiments of the present disclosure provide a network device, which is consistent with the network device in one or more of the above embodiments.

[0171] Figure 16 For a structural schematic diagram of a network device in the embodiments of the present disclosure, refer to Figure 16 As shown, the network device 1600 can include a processing component 1601, which further includes one or more processors, and a memory resource represented by a memory 1602, for storing instructions executable by the processing component 1601, such as an application program. The application program stored in the memory 1602 can include one or more than one module each corresponding to a set of instructions. In addition, the processing component 1601 is configured to execute the instructions to perform any method of the above-described method of the application on the network device.

[0172] The network device 1600 can further include a power supply component 1603 configured to perform power management of the network device 1600, a wired or wireless network interface 1604 configured to connect the network device 1600 to a network, and an input / output (I / O) interface 1605. The network device 1600 can operate based on an operating system stored in the memory 1602, such as Windows Server TM, Mac OS X TM, Unix TM, Linux TM, FreeBSD TM or the like.

[0173] Based on the same inventive concept, the embodiments of the present disclosure further provide a computer readable storage medium, which stores instructions; when the instructions are run on a computer, for performing the communication method of the terminal device side or the network device A side in one or more of the above embodiments.

[0174] Based on the same inventive concept, the embodiments of the present disclosure further provide a computer program or computer program product, which, when executed on a computer, causes the computer to implement the communication method of the terminal device side or the network device A side in one or more of the above embodiments.

[0175] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

[0176] It should be understood that the application is not limited to the precise construction hereinafter described and illustrated in the accompanying drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application is limited only by the claims that follow.

Claims

1. A random access method, characterized in that, include: The terminal device receives downlink control information (DCI) sent by the network device. The DCI includes first indication information, which is used to instruct the terminal device to perform random access. The terminal device determines to update the ephemeris information; The terminal device performs delayed random access on the Physical Random Access Channel (PRACH) according to a first timing offset and a second timing offset, wherein the first timing offset is the round-trip delay from the terminal device to a predetermined reference point, and the second timing offset is the duration for which the terminal device performs delayed random access on the PRACH. The method further includes: The terminal device receives system information within the second duration corresponding to the second timing offset; The terminal device determines the ephemeris information based on the system information; The terminal device determines the first timing offset based on the determined ephemeris information.

2. The method according to claim 1, characterized in that, The terminal device determines to update ephemeris information, including: The terminal device determines that the valid timer has expired; The terminal device determines to update the ephemeris information.

3. The method according to claim 1, characterized in that, The terminal device receiving the DCI sent by the network device includes: the terminal device receiving the DCI in the nth time slot of the downlink time domain resources, where n is a positive integer.

4. The method according to claim 3, characterized in that, The terminal device performs delayed access on the Physical Random Access Channel (PRACH) according to a first timing offset and a second timing offset, including: after delaying for a first duration from the nth time slot in the uplink time domain resources, the terminal device performs random access on the next PRACH transmission opportunity, wherein the first duration is the sum of the first timing offset and the second timing offset.

5. The method according to claim 1, characterized in that, The DCI also includes second indication information, which is used to indicate the second timing offset.

6. A random access method, characterized in that, include: Network devices determine when terminal devices update ephemeris information; The network device sends downlink control information (DCI) to the terminal device. The DCI includes first indication information, which is used to instruct the terminal device to perform random access. The ephemeris information is used to determine a first timing offset. The first timing offset and the second timing offset are used for the terminal device to perform delayed random access on the Physical Random Access Channel (PRACH). The second timing offset is the duration for which the terminal device delays random access on the PRACH. The terminal device receives system information within a second duration corresponding to the second timing offset, determines the ephemeris information based on the system information, and determines the first timing offset based on the determined ephemeris information.

7. The method according to claim 6, characterized in that, The network device determines that the terminal device has updated its ephemeris information, including: The network device determines that the terminal device's valid timer has expired; The network device determines that the terminal device updates the ephemeris information.

8. The method according to claim 6, characterized in that, The DCI also includes second indication information, which is used to indicate a second timing offset, the second timing offset being the duration by which the terminal device delays random access on the Physical Random Access Channel (PRACH).

9. A communication device, characterized in that, include: The receiving module is used to receive downlink control information (DCI) sent by the network device. The DCI includes first indication information, which is used to instruct the terminal device to perform random access. The processing module is used to determine the need to update ephemeris information; The transmitting module is used to perform delayed random access on the Physical Random Access Channel (PRACH) according to a first timing offset and a second timing offset, wherein the first timing offset is the round-trip delay from the terminal device to a predetermined reference point, and the second timing offset is the duration for which the terminal device performs delayed random access on the PRACH. The receiving module is also used to receive system information within a second duration corresponding to the second timing offset; The processing module is further configured to determine the ephemeris information based on the system information; and to determine the first timing offset based on the determined ephemeris information.

10. The apparatus according to claim 9, characterized in that, The processing module is specifically used to determine when a valid timer expires and to determine when to update the ephemeris information.

11. The apparatus according to claim 9, characterized in that, The receiving module is used to receive the DCI in the nth time slot of the downlink time domain resources, where n is a positive integer.

12. The apparatus according to claim 11, characterized in that, The transmitting module is configured to perform random access on the next PRACH transmitting opportunity after a first delay starting from the nth time slot in the uplink time domain resources, wherein the first delay is the sum of the first timing offset and the second timing offset.

13. The apparatus according to claim 9, characterized in that, The DCI also includes second indication information, which is used to indicate the second timing offset.

14. A communication device, characterized in that, include: The processing module is used to determine when the terminal device needs to update its ephemeris information; The sending module is used to send downlink control information (DCI) to the terminal device. The DCI includes first indication information, which is used to instruct the terminal device to perform random access. The processing module is further configured to determine a first timing offset, wherein the first timing offset and the second timing offset are used for the terminal device to perform delayed random access on the Physical Random Access Channel (PRACH), and the second timing offset is the duration for which the terminal device delays random access on the PRACH. The terminal device receives system information within a second duration corresponding to the second timing offset, determines the ephemeris information based on the system information, and determines the first timing offset based on the determined ephemeris information.

15. The apparatus according to claim 14, characterized in that, The processing module is specifically used to determine when the valid timer of the terminal device expires and to determine when the terminal device updates the ephemeris information.

16. The apparatus according to claim 14, characterized in that, The DCI also includes second indication information, which is used to indicate a second timing offset, the second timing offset being the duration by which the terminal device delays random access on the Physical Random Access Channel (PRACH).

17. A terminal device, characterized in that, include: Memory and processor; The processor is connected to the memory and configured to execute computer-executable instructions stored in the memory to implement the random access method as described in any one of claims 1 to 5.

18. A network device, characterized in that, include: Memory and processor; The processor is connected to the memory and configured to execute computer-executable instructions stored in the memory to implement the random access method as described in any one of claims 6 to 8.

19. A computer storage medium storing computer-executable instructions, characterized in that, The computer-executable instructions, when executed by the processor, can implement the random access method as described in any one of claims 1 to 8.

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