Method and terminal device for random access

Abstract

The embodiment of the present application provides a random access method and terminal equipment, the method is suitable for wireless ad hoc network with time slot division, the wireless ad hoc network is configured with periodic access period, which is equivalent to configuring fixed resource for random access, and the terminal equipment is configured with a timer for listening to the channel, when the terminal equipment wants to access the wireless ad hoc network, a first timer is started in the first access period, if the terminal equipment listens to the channel in the period of the first timer and finds that the channel is in idle state, an access request is sent in the first access period and after the first timer expires, so as to successfully send the access request. In this way, the probability of collision of multiple terminal equipments due to simultaneous period sending of access requests can be reduced, so that the success rate of random access is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wireless communication, and more particularly, to a method of random access and a terminal device in the field of communication. BACKGROUND

[0002] In a wireless communication system, due to the characteristics of temporary networking, fast deployment, no control center and strong invulnerability, wireless ad hoc network is rapidly penetrating from military communication into civil communication field. In the wireless ad hoc network, a device to be accessed needs to initiate random access to successfully communicate with the devices in the network. Specifically, the device to be accessed first needs to send an access request to the devices in the wireless ad hoc network, and the devices in the wireless ad hoc network respond after receiving the access request, and then the two devices can continue to interact to complete the random access.

[0003] However, the resources for communication between devices in the wireless ad hoc network are limited, and the resources for random access are even less. If more devices initiate access requests in the same period, collision will occur, resulting in access failure.

[0004] Therefore, how to improve the success rate of random access of devices in the wireless ad hoc network is a problem to be solved at present. SUMMARY

[0005] The present application provides a method of random access, which is suitable for wireless ad hoc network with time slot division, and improves the success rate of random access of terminal devices in limited time domain resources.

[0006] In a first aspect, a method of random access is provided, which is applied to a wireless ad hoc network, and the wireless ad hoc network is configured with a periodic access period. The method comprises: starting a first timer in a first access period in the periodic access period; if it is detected that a channel is in an idle state within a period of the first timer, sending an access request in the first access period and after the first timer expires, the access request is used to request access to the wireless ad hoc network.

[0007] The method for random access provided in the embodiments of the present application is configured with a periodic access period in the wireless ad hoc network, which is equivalent to configuring a fixed resource for random access. The periodic access period is specially used for random access of the terminal device, and a timer for channel listening is configured for the terminal device. When the terminal device wants to access the wireless ad hoc network, a first timer for channel listening is started in a first access period (any access period in the periodic access period). If the terminal device listens to the idle channel in the period of the first timer, it means that the channel is not occupied by other devices in the period of the first timer, that is, even if multiple terminal devices want to access the wireless ad hoc network in the first access period, it means that other terminal devices to be accessed do not occupy the channel to send an access request. Therefore, the access request is sent after the first access period and after the first timer expires, and the access request can be successfully sent with high probability, reducing the probability of collision of multiple terminal devices sending access requests in the same period, thereby improving the success rate of random access.

[0008] In combination with the first aspect, in some implementations of the first aspect, the access request is carried in an access request frame, and a length of the first access period is greater than a length of the access request frame.

[0009] The method for random access provided in the embodiments of the present application limits the length of the first access period to be greater than the length of the access request frame. In this way, as long as the first timer is properly set, the first terminal device sends the access request frame after the first timer expires, and the access request frame can be successfully sent in the first access period, thereby not affecting the transmission of other information after the first access period, especially in the case where the response period for transmitting each response information is pre-configured by the system, the normal transmission of subsequent response information can be ensured as much as possible.

[0010] In combination with the first aspect, in some implementations of the first aspect, a length of the first access period is less than or equal to a total length of two access request frames.

[0011] The method for random access provided in the embodiments of the present application limits the length of the first access period to be less than or equal to the total length of two access request frames. Therefore, in the case of ensuring the success of random access as much as possible, unnecessary resource waste can be reduced.

[0012] In combination with the first aspect, in some implementations of the first aspect, a length of the first timer is greater than 0 and less than or equal to a total length of M time units, M=W-L, W is a number of time units included in the first access period, and L is a number of time units included in the access request frame.

[0013] The method for random access provided in the embodiments of the present application can ensure that the access request is successfully sent in the first access period, so as to not affect the transmission of other information after the first access period, and especially can ensure the normal transmission of subsequent response information as much as possible in the case that the response period for transmitting each response information is preconfigured by the system.

[0014] With reference to the first aspect, in some implementations of the first aspect, the length of the first timer is determined based on the priority of the terminal device.

[0015] The method for random access provided in the embodiments of the present application can realize dynamic adjustment of the length of the first timer and improve system flexibility by determining the length of the first timer based on the priority of the terminal device.

[0016] With reference to the first aspect, in some implementations of the first aspect, the start time of the first timer is the start time of the first access period.

[0017] The method for random access provided in the embodiments of the present application limits the start time of the first timer to the start time of the first access period, so that the first terminal device can listen to the channel at the start time of the first access period. In the case that the lengths of the timers of all terminal devices are the same, the first terminal device can listen to the channel the fastest and send the access request the earliest, so as to occupy the channel the earliest. Other terminal devices with a later start time than the first terminal device will have a high probability of listening to the channel in a busy state, so as to give up attempting to access the network in the first access period, thereby further improving the success rate of random access of the first terminal device.

[0018] With reference to the first aspect, in some implementations of the first aspect, the start time of the first timer is determined based on the priority of the terminal device.

[0019] The method for random access provided in the embodiments of the present application can realize dynamic adjustment of the start time of the first timer and improve system flexibility by determining the start time of the first timer based on the priority of the terminal device.

[0020] With reference to the first aspect, in some implementations of the first aspect, if the channel is listened to in a busy state in the period of the first timer, the random access is stopped in the first access period and after the first timer times out.

[0021] With reference to the first aspect, in some implementations of the first aspect, the method further includes: receiving, in a first response period after the first access period, first response information in response to the access request; transmitting, in a second response period after the first predetermined period, second response information in response to the first response information; receiving, in a third response period after the second predetermined period, third response information in response to the second response information; wherein the first response period, the second response period and the third response period are preconfigured periods.

[0022] The second aspect provides a terminal device, which is configured to perform the method provided in any of the first aspect.

[0023] The third aspect provides a terminal device, which includes a processor. The processor is coupled with a memory and is configured to execute instructions in the memory to implement the method in any of the possible implementations of the first aspect. Optionally, the terminal device further includes the memory. Optionally, the terminal device further includes a communication interface, and the processor is coupled with the communication interface.

[0024] The fourth aspect provides a computer readable storage medium, which stores a computer program. When the computer program is executed by an apparatus, the apparatus implements the method in any of the possible implementations of the first aspect.

[0025] The fifth aspect provides a computer program product including instructions, which, when executed by a computer, cause an apparatus to implement the method in any of the possible implementations of the first aspect.

[0026] The sixth aspect provides a chip, which includes an input interface, an output interface, a processor and a memory. The input interface, the output interface, the processor and the memory are connected through internal connection paths. The processor is configured to execute code in the memory. When the code is executed, the processor is configured to execute the method in any of the possible implementations of the first aspect. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 FIG. 1 is a schematic diagram of a wireless ad hoc network architecture suitable for embodiments of the present application.

[0028] Figure 2 FIG. 2 is a schematic flow chart of a random access method provided by embodiments of the present application.

[0029] Figure 3 FIG. 3 is a schematic diagram of the behaviors of a first terminal device and a second terminal device in a random access process according to embodiments of the present application.

[0030] Figure 4 is another behavior diagram of a first terminal device and a second terminal device in a random access process according to an embodiment of the present application.

[0031] Figure 5 is a behavior diagram of multiple terminal devices and a second terminal device in a random access process according to an embodiment of the present application.

[0032] Figure 6 shows a schematic block diagram of a terminal device according to an embodiment of the present application.

[0033] Figure 7 shows a schematic structural diagram of a terminal device according to an embodiment of the present application. DETAILED DESCRIPTION

[0034] The technical solutions in the present application will be described below with reference to the accompanying drawings.

[0035] The technical solutions of the embodiments of the present application can be applied to a wireless ad hoc network. The wireless ad hoc network is a new and developing network technology in the current wireless communication field, which is rapidly penetrating from military communication to related civilian communication fields. The wireless ad hoc network is a distributed, centerless, multi-hop routing network. Each terminal device has the function of a host and a router, and there is no master-slave relationship. As long as the connection condition is met, it can be deployed at will and is easy to operate. As a host, the terminal device needs to run user-oriented application programs; as a router, the terminal device needs to run corresponding routing protocols and participate in packet forwarding and routing maintenance according to routing strategies and routing tables.

[0036] Since the wireless transmission range of the terminal device is limited, two terminal devices that cannot directly communicate often communicate through at least one relay device. Therefore, the wireless ad hoc network is also called a multi-hop wireless network, a self-organizing network, a fixed-free network, or a peer-to-peer network. The wireless ad hoc network has the characteristics of both mobile communication networks and computer networks, and is a special mobile computer network.

[0037] Figure 1 is a schematic diagram of the architecture of a wireless ad hoc network suitable for the embodiments of the present application. The wireless ad hoc network includes multiple terminal devices. A terminal device can be regarded as a node, and multiple nodes form a tree structure, Figure 1 shows a wireless ad hoc network composed of six terminal devices. In the wireless ad hoc network, Figure 1In the figure, the double-headed arrow indicates that the adjacent terminal devices can realize uplink and downlink communication, and each terminal device has host function and routing function. Taking terminal device N4 as an example, by taking terminal device N4 as a relay device, communication between terminal device N1 and terminal device N5 can be realized, and communication between terminal device N1 and terminal device N6 can be realized. When terminal device N1 and terminal device N5 need to communicate, the transmission path is N1→N4→N5 or N5→N4→N1, and when terminal device N1 and terminal device N6 need to communicate, the transmission path is N1→N4→N6 or N6→N4→N1.

[0038] If there is a direct wireless connection between two terminal devices, one terminal device can act as a "master device" and the other terminal device can act as a "controlled device". The master device has the functions of allocating wireless resources, managing other devices in the network it is in, processing access requests of devices to be accessed in the network, etc., and the controlled device can communicate with the master device based on the instructions of the master device. For example, in Figure 1 In the figure, there are direct wireless connections between N1 and N2, N1 and N3, N1 and N4, N4 and N5, and N4 and N6, and the corresponding master devices are N1, N1, N1, N4, N4 in turn, and the controlled devices are N2, N3, N4, N5, N6 in turn.

[0039] One master device can simultaneously establish wireless connections with multiple controlled devices. In order to facilitate description, the network formed by the master device and all its controlled devices can be referred to as a "subnet", and one wireless ad hoc network can include one or more subnets. For example, in Figure 1 In the figure, terminal device N1, terminal device N2, terminal device N4, and terminal device N3 form a subnet, which is referred to as "subnet 1", terminal device N1 acts as a master device, and the remaining devices in subnet 1 act as controlled devices; terminal device N4, terminal device N5, and terminal device N6 form another subnet, which is referred to as "subnet 2", terminal device N4 acts as a master device, and the remaining devices in subnet 2 act as controlled devices. For terminal device N4, it acts as a controlled device of terminal device N1 in subnet 1, and acts as a master device of subnet 2 in subnet 2.

[0040] It should be understood that Figure 1 The structure of the wireless ad hoc network shown in the figure is only illustrative, and more or fewer terminal devices (or nodes) can be included in the wireless ad hoc network, and the topology between multiple terminal devices can be various forms, which are not limited by the embodiments of the present application.

[0041] The terminal device of the embodiments of the present application can be any device with wireless communication function, such as a mobile phone, a tablet computer, a keyboard, a mouse, an electronic book, a headset, a screen, a camera, a helmet, a drone, a VR glasses, a smart watch, a vehicle-mounted central control console, and a smart home device, etc.

[0042] In the random access of the cellular communication system, since there are more resources in the time domain, the frequency domain, and the code domain, and there is a base station as a central scheduling role, more access resources can be reserved for random access. The terminal device to be accessed can directly select a resource in the random access resource to send an access request to the base station. The base station randomly selects one from all non-collision signals to respond to the access, so as to complete the random access.

[0043] Carrier sense multiple access with collision avoidance (CSMA-CA) is a random access method commonly used in wireless communication without time slot division. Through carrier sensing and interference avoidance, multiple devices can efficiently compete for channel resources without the need for central node (base station) scheduling. Distributed coordination function (DCF) is a typical CSMA-CA access method, widely used in WIFI devices. Before sending an access request, WIFI devices need to perform carrier sensing. If the channel is idle, a timer needs to be started after waiting for a distributed interframe space (DIFS) and randomly selecting a time length. The access request is sent after the timer expires. If the channel is busy during the timer period, the timer needs to be paused, and the timer needs to be started again after waiting for the channel to be idle for DIFS. If the sent access request does not receive an acknowledgement, the above process needs to be repeated until the access request is successfully sent. In this method, WIFI devices randomly select a time to access the network, and increase the time length of the timer to improve the success rate of random access.

[0044] In the random access of the wireless ad hoc network, the device to be accessed first needs to send an access request to the device in the wireless ad hoc network. The device in the wireless ad hoc network responds after receiving the access request, and then the two devices continue to interact to complete the random access. However, the resources used for communication between terminal devices in the wireless ad hoc network are limited, and the resources used for random access are even less. Therefore, if more terminal devices initiate an access request at the same time, collision will occur, resulting in access failure.

[0045] Based on this, the embodiment of the present application provides a random access method, which is suitable for a wireless ad hoc network with time slot division, and improves the success rate of random access of a terminal device in limited time domain resources. Specifically, a periodic access period is configured in the wireless ad hoc network, which is equivalent to configuring fixed resources for random access, and a timer for listening to a channel is configured for the terminal device. When the terminal device wants to access the wireless ad hoc network, the timer is started in the access period. If the terminal device listens to the channel idle in the period of the timer, the terminal device sends an access request in the access period and after the timer expires, so as to successfully send the access request, reduce the probability of collision of multiple terminal devices due to sending access requests in the same period, and thus improve the success rate of random access.

[0046] Figure 2 is a schematic flowchart of the random access method 100 provided by the embodiment of the present application. In the embodiment of the present application, the first terminal device and the second terminal device are taken as an example of an execution subject of the method 100, and the method 100 is described, wherein the first terminal device is any device to be accessed to the wireless ad hoc network, and the second terminal device is a device in the wireless ad hoc network. As an example but not limitation, the execution subject of the method 100 can also be a chip corresponding to the first terminal device and a chip corresponding to the second terminal device.

[0047] It should be understood that the second terminal device is a master device in the wireless ad hoc network, which has functions of allocating wireless resources, managing devices in the network, processing access requests of the terminal devices to be accessed in the network, and the like. For example, the second terminal device can be Figure 1 terminal device N1 or terminal device N4 in the wireless ad hoc network.

[0048] The embodiment of the present application is suitable for a wireless ad hoc network with time slot division, and a periodic access period is configured in the wireless ad hoc network. The periodic access period is a time domain resource specially used for random access and preconfigured by the system, and specifically is a time domain resource specially used for an access request first sent by a terminal device to be accessed in random access. In the access period, the terminal device to be accessed attempts to access the network, and as long as the channel condition permits, the terminal device to be accessed can send an access request to complete random access. The above-mentioned time domain resource includes multiple access periods arranged at intervals. The time length of each access period can be the same or different, and the interval time length of any two adjacent access periods can be the same or different, which are not limited by the embodiment of the present application. The periodic access period means that after a period of time is interval, an access period is entered, and after an access period ends, a period of time is interval again, and then the next access period is entered, and this continues.

[0049] In S110, the first terminal device starts a first timer in a first access period in the periodic access period.

[0050] In this step, the first terminal device to be accessed wants to access the wireless ad hoc network in which the second terminal device is located, and waits until the nearest access period (for example, the first access period). The first terminal device starts a first timer in the first access period, and listens to the state (idle state or busy state) of the channel in the period of the first timer to perform the subsequent steps.

[0051] It should be understood that the first timer is a period for the first terminal device to listen to the channel, and in the period of the first timer, the first terminal device listens to the channel state and does not send any information.

[0052] In some embodiments, before S110, when the first terminal device is synchronized with the network in the downlink, the first information for determining the periodic access period and the second information for determining the first timer can be obtained.

[0053] For example, the first information can include at least one of the following: the length of each access period in the periodic access period, the start time of each access period, or the end time of each access period, etc.

[0054] For example, the second information can include at least one of the following: the start time of the first timer, the length of the first timer, or the end time of the first timer, etc.

[0055] In S120, if the channel is in an idle state in the period of the first timer, the first terminal device sends an access request to the second terminal device in the first access period and after the first timer expires, and the access request is used to request access to the wireless ad hoc network.

[0056] For example, the access request can include the source address, the destination address, the device identifier of the first terminal device, the identifier of the wireless ad hoc network, and other information for accessing the wireless ad hoc network, which is not limited here.

[0057] In this step, if the first terminal device listens to the channel in an idle state in the period of the first timer, it means that the channel is not occupied by signals sent by other devices, and it also means that there is a high probability that other signals will not occupy the channel in the period near the period of the first timer. Therefore, the first terminal device sends an access request in the first access period and after the first timer expires, so that the first terminal device successfully occupies the channel in the first access period to successfully send the access request, thereby improving the success rate of random access.

[0058] If the first terminal device listens to the channel in a busy state in the period of the first timer, it stops random access in the first access period and after the first timer expires, and does not send an access request.

[0059] Specifically, when the first terminal device listens to the channel being busy, it means that the channel is occupied by the signal sent by other devices, and also means that the channel is occupied all the time in the first access period. The first terminal device fails to preempt the channel in the first access period and cannot successfully send the access request, and the random access has failed. Therefore, the first terminal device stops the random access after the first timer expires and does not send the access request, so as to avoid collision with the signal sent by other devices and affect the random access of other devices.

[0060] If the first terminal device wants to continue to access the wireless ad hoc network, it can try random access again in another access period after the first access period, and repeat S110. Exemplarily, the other access period can be an access period adjacent to the first access period. It should be understood that during the process in which the first terminal device turns on the first timer to listen to the channel in the other access period, the first timer has been reset and starts timing from zero until the first timer expires.

[0061] In the above embodiment, when multiple terminal devices including the first terminal device want to access the wireless ad hoc network, each terminal device starts its own timer in the first access period, and each terminal device listens to the channel in the period of its own timer to determine whether to continue to access the network according to the channel state. Taking the above first terminal device as an example, if the first terminal device listens to the channel being idle in the period of the first timer, it means that the channel is not occupied by the access request sent by other terminal devices to be accessed, and the access request is sent in the first access period and after the first timer expires. In this way, the first terminal device successfully preempts the channel in the first access period. If the first terminal device listens to the channel being busy in the period of the first timer, it means that the channel is occupied by the access request sent by other terminal devices to be accessed, that is, other terminal devices to be accessed successfully preempt the channel in the first access period, and the first terminal device fails to preempt the channel in the first access period. Therefore, the random access is stopped.

[0062] In the prior art, because the resources for random access of terminal devices in the wireless ad hoc network are few, the terminal devices to be accessed cannot obtain fixed resources to send the access request, resulting in the situation that multiple terminal devices send the access request in the same period and collide to cause access failure.

[0063] The method for random access provided by the embodiments of the present application is configured with a periodic access period in the wireless ad hoc network, which is equivalent to configuring a fixed resource for random access. The periodic access period is specially used for random access of the terminal device, and a timer for channel listening is configured for the terminal device. If the terminal device wants to access the wireless ad hoc network, a first timer is started in a first access period (any access period in the periodic access period). If the terminal device listens to the idle channel in the period of the first timer, it means that the channel is not occupied by other devices in the period of the first timer, that is, even if multiple terminal devices want to access the wireless ad hoc network in the first access period, it means that other terminal devices to be accessed do not occupy the channel to send an access request. Therefore, the access request is sent in the first access period and after the first timer expires, and the probability of successfully sending the access request is high, which reduces the probability of collision of multiple terminal devices sending access requests in the same period, thereby improving the success rate of random access.

[0064] After the first terminal device sends the access request in S120, the first terminal device and the second terminal device can further interact to complete the entire random access process. Hereinafter, the subsequent steps are briefly described in combination with steps S130, S140 and S150.

[0065] In S130, the second terminal device sends first response information to the first terminal device in response to the access request.

[0066] In this step, after receiving the access request, the second terminal device knows that the first terminal device wants to access the wireless ad hoc network, generates and sends the first response information to facilitate the first terminal device to perform the subsequent steps.

[0067] Exemplarily, the first response information includes a random sequence, which is used for verifying a key between the first terminal device and the second terminal device.

[0068] In some embodiments, the second terminal device sends the first response information to the first terminal device in a first response period after the first access period.

[0069] In an example, the first response period is a period for sending the first response information, which is preconfigured by the system. In this way, the conflict with other signals can be avoided, and the success rate of random access is further improved.

[0070] Exemplarily, the first response period and the first access period can be continuous or discontinuous, and a preset interval is provided between the two periods, which is not limited here.

[0071] In S140, the first terminal device sends second response information to the second terminal device in response to the first response information.

[0072] In this step, the first terminal device generates and sends second response information after receiving the first response information.

[0073] In the embodiment in which the first response information comprises the random sequence, the first terminal device may, for example, encrypt the random sequence based on its own key and an initialization vector (IV), and send the IV and the encrypted random sequence to the second terminal device through the second response information.

[0074] In some embodiments, the first terminal device sends the second response information to the second terminal device within a second response period after the first response period.

[0075] In an example, the second response period is a period pre-configured by the system for sending the second response information. In this way, it is possible to avoid collision with other signals, further improving the success rate of random access.

[0076] The second response period may or may not be continuous with the first response period, and there is a preset interval between the two periods, which is not limited here.

[0077] In S150, the second terminal device sends third response information to the first terminal device in response to the second response information.

[0078] In this step, the second terminal device generates and sends the third response information after receiving the second response information, for indicating that the first terminal device has successfully accessed the wireless ad hoc network in which the second terminal device is located. In this way, the first terminal device successfully completes random access.

[0079] In the embodiment in which the second response information comprises the IV and the encrypted random sequence, the second terminal device may, for example, encrypt the random sequence based on its own key and the IV in the received second response information using the same algorithm as the first terminal device. If the encrypted random sequence of the second terminal device is the same as the encrypted random sequence of the first terminal device obtained from the second response information, it means that the key of the first terminal device is the same as the key of the second terminal device, which means that the first terminal device can access the wireless ad hoc network in which the second terminal device is located. The second terminal device sends the final response information (i.e., the third response information) to the first terminal device to indicate that the first terminal device can access the wireless ad hoc network.

[0080] In some embodiments, the second terminal device sends the third response information to the first terminal device within a third response period after the second response period.

[0081] In an example, the third response period is a period pre-configured by the system for sending the third response information. In this way, the conflict with other signals can be avoided, and the success rate of random access is further improved.

[0082] In an example, the third response period can be continuous with the second response period, or discontinuous with the second response period, and a preset interval is provided between the two periods, which is not limited herein.

[0083] It should be understood that the subsequent steps of random access shown in S130 to S150 are only illustrative, and should not be construed as limiting the embodiments of the present application. In implementation, the information exchanged between the first terminal device and the second terminal device in the wireless ad hoc network after the first terminal device sends the access request can include other contents, which are not limited by the embodiments of the present application.

[0084] After the first terminal device successfully accesses the wireless ad hoc network, the first terminal device and the devices in the wireless ad hoc network can transmit data in a period for data transmission after the third response period to communicate normally. The period for data transmission can be used for communication between the first terminal device and the second terminal device, or can be used for communication between other terminal devices in the wireless ad hoc network, which is not limited by the embodiments of the present application, and is determined by resource allocation. In an example, the first terminal device can indicate the period for data transmission through the second response information or the third response information in the random access process described above, or the first terminal device can determine the period for data transmission by sending a resource request to the second terminal device after the random access is successful (i.e., after step S150 is performed).

[0085] After the period for data transmission described above, in the next access period, other devices to be accessed attempt to access the wireless ad hoc network again in the next access period, and the steps S110 to S150 described above are repeated.

[0086] Figure 3 is a schematic diagram of the behaviors of the first terminal device and the second terminal device in the random access process of the embodiments of the present application. Referring to Figure 3, the first terminal device starts a timer 1 (an example of a first timer) in an access period 1 (an example of a first access period), listens to the channel in the period of the timer 1, and keeps listening until the channel is idle. After the expiration of the timer 1, the first terminal device sends an access request. After receiving the access request, the second terminal device sends response information 1 (an example of a first response information) in a response period 1 (an example of a first response period) after the access period 1. After receiving the response information 1, the first terminal device sends response information 2 (an example of a second response information) in response to the response information 1 in a second response period (an example of a second response period) after the response period 1. After receiving the response information 2, the second terminal device sends response information 3 (an example of a third response information) in response to the response information 2 in a third response period (an example of a third response period) after the response period 2. At this time, the random access of the first terminal device is completed, and the first terminal device successfully accesses the wireless ad hoc network. After the response period 3, the first terminal device can transmit data with the second terminal device in a period for transmitting data. After the period for transmitting data, the next access period (denoted as an access period 2) after the access period 1 is entered. At this time, other terminal devices to be accessed attempt to access the network again in the access period 2, and the above S110 to S150 are repeatedly performed.

[0087] The above describes the process of the random access in the wireless ad hoc network according to the embodiments of the present application. The first access period and the first timer are described in detail below.

[0088] In some embodiments, the access request is carried in an access request frame, and the length of the first access period is greater than the length of the access request frame.

[0089] In this way, as long as the first timer is properly set, the first terminal device can successfully send the access request frame in the first access period after the expiration of the first timer (as shown in FIG. 2), thereby not affecting the transmission of other information after the first access period, especially when the response periods for transmitting the response information are preconfigured by the system, the normal transmission of the subsequent response information can be ensured as much as possible. Figure 3

[0090] In some embodiments, the length of the first access period is less than or equal to the total length of two access request frames.

[0091] Since the resources for random access in the wireless ad hoc network are limited, if the length of the first access period is set too long, the resources are wasted. Therefore, the length of the first access period is set to be less than or equal to the total length of two access request frames, so that unnecessary resource waste can be reduced while ensuring the success of the random access as much as possible.

[0092] ​Of course, in other embodiments, the length of the first access period can be any value without considering other factors, not limited to the above-mentioned embodiments. For example, the length of the first access period is greater than or equal to the length of one access request frame, and less than or equal to the total length of three or more access request frames.

[0093] In the embodiments of the present application, the length of the access period in different cycles can be the same or different, and the embodiments of the present application do not make any limitation. For example, the length of the access period in the first cycle is equal to the total length of two access request frames, and the length of the access period in the n th cycle is 1.5 times the total length of the access request frame, n is an integer greater than 1.

[0094] Regarding the start time of the first timer, in some embodiments, the start time of the first timer is the start time of the first access period.

[0095] In this way, the first terminal device can listen to the channel at the start time of the first access period. Under the condition that the lengths of the timers of the terminal devices are the same, the first terminal device can listen to the channel the fastest and send the access request the earliest, thereby occupying the channel the earliest, and other devices with a later start time than the first terminal device will have a high probability of listening to the channel in a busy state, thereby giving up attempting to access the network in the first access period, further improving the success rate of random access of the first terminal device.

[0096] In other embodiments, the start time of the first timer can also be any time of the first access period.

[0097] The start time of the first timer of the embodiments of the present application can be predefined or dynamically determined based on actual conditions, and the embodiments of the present application do not make any limitation. For example, the start time of the first timer defined in the above-mentioned embodiments can be predefined or dynamically determined.

[0098] In the above-mentioned embodiments in which the start time of the first timer can be dynamically determined, the start time of the first timer in different cycles can be different or the same, and the embodiments of the present application do not make any limitation.

[0099] Regarding the embodiment of dynamically determining the start time of the first timer, in some embodiments, the start time of the first timer is determined based on the priority of the first terminal device.

[0100] The first terminal device has a high priority, and the time interval between the start time of the first timer and the start time of the first access period can be set to be short, for example, the start time of the first timer is the start time of the first access period, and there is no time interval between the two start times; the first terminal device has a low priority, and the time interval between the start time of the first timer and the start time of the first access period can be set to be long. In this way, the terminal device with high priority can be made to successfully send the access request as much as possible to improve the success rate of random access, so as to not affect the communication of important devices.

[0101] In an example, the priority of the device can be defined from the type of the device. For example, the higher the usage rate of the device by the user during the movement, the higher the priority of the device, and vice versa, the lower the usage rate of the device by the user during the movement, the lower the priority of the device. For example, taking a mobile phone, a watch, and a personal computer (PC) as examples, the priority order of the devices can be as follows: mobile phone > watch > PC, and the first terminal device can be any of the devices.

[0102] In another example, the priority of the device can be defined from the remaining power of the device. For example, the lower the remaining power of the device, the higher the priority of the device, and vice versa, the higher the remaining power of the device, the lower the priority of the device.

[0103] In another example, the priority of the device can be defined from the attribute of the user corresponding to the device. The user corresponding to the device means the owner of the device, which is generally registered by the user's certificate or phone. For example, if the user corresponding to the device belongs to the user in the contact list of the master device (for example, the second terminal device) in the wireless ad hoc network, the priority of the device is high, and vice versa, if the user corresponding to the device does not belong to the user in the contact list of the master device in the wireless ad hoc network, that is, the user corresponding to the device is a stranger to the user corresponding to the master device in the wireless ad hoc network, the priority of the device is low.

[0104] In another example, the priority of the device can be defined from the priority of the service of the device. If the priority of the service of the device is high, the priority of the device is high, and vice versa, if the priority of the service of the device is low, the priority of the device is low.

[0105] For example, the priority of the service can be defined from the emergency degree of the service. For example, if the emergency degree of the service is high, the priority of the service is high, and vice versa, if the emergency degree of the service is low, the priority of the service is low.

[0106] For another example, the priority of a service can be defined from aspects of reliability, transmission rate, etc. of the service. If considered from aspects of transmission rate and reliability of the service, the priority of a service with short latency and high reliability is higher than the priority of a service with long latency and low reliability.

[0107] As to the length of the first timer, in some embodiments, the length of the first timer is greater than 0 and less than or equal to the difference between the length of the first access period and the length of the access request frame.

[0108] If the starting time of the first timer is the starting time of the first access period, the length of the first timer is selected within the remaining length after the length of the first access period is subtracted by the length of the access request frame, which can ensure the successful transmission of the access request within the first access period, thereby not affecting the transmission of other information after the first access period, and especially can ensure the normal transmission of subsequent response information as much as possible in the case that the response period for transmitting each response information is pre-configured by the system.

[0109] For the convenience of description, each period in the embodiments of the present application can be defined in the granularity of a time unit, i.e., taking a time unit as a basic unit for dividing the time domain, for example, one specific period includes one or more time units.

[0110] In the embodiments of the present application, the length of one time unit can be arbitrarily set, which is not particularly limited in the embodiments of the present application.

[0111] For example, one time unit can include one or more subframes, and the length of one subframe is 1 ms.

[0112] For another example, one time unit can include one or more slots, and the length of one slot can be 0.5 ms.

[0113] For another example, one time unit can include one or more symbols.

[0114] Here, the symbol, the slot and the subframe are all basic units of time governed by radio resource management.

[0115] It should be understood that the structures of the time units listed above are only exemplary, and the structures of the time units can be arbitrarily changed according to actual needs, which are not particularly limited in the embodiments of the present application.

[0116] The selection range of the length of the first timer described in the time unit can be: the length of the first timer is greater than 0 and less than or equal to the total length of M time units, M=W-L, W is the number of time units included in the first access period, and L is the number of time units included in the access request frame.

[0117] Specifically, the first access period includes W time units, the access request frame includes L time units, and W is greater than L. The length of the first access period is the length of W time units, the length of the access request frame is the length of L time units, and the length of M=(W-L) time units is the length of the first access period minus the length of the access request frame.

[0118] For example, a time slot can be taken as an example of a time unit, that is, the first access period includes W time slots, the access request frame includes L time slots, and the length of the first timer is greater than 0 and less than or equal to the total length of M time slots.

[0119] It should be understood that the shortest length of the first timer is subject to the shortest length of the channel state that can be monitored. For example, the shortest length of the first timer can be 40 microseconds (us).

[0120] If the start time of the first timer is the start time of the first access period, the length of the first timer is selected within the total length of M=(W-L) time units remaining after the length of the first access period minus the length of the access request frame, which can ensure that the access request is successfully sent within the first access period (as shown in Figure 3 ), thereby not affecting the transmission of other information after the first access period, especially when the response period for transmitting each response information is pre-configured by the system, which can ensure the normal transmission of subsequent response information as much as possible.

[0121] Continuing to refer to Figure 3 , the start time of the timer 1 (an example of the first timer) is the start time of the access period 1 (an example of the first access period), the length of the access period 1 is the length of W time units, the length of the access request frame is the length of L time units, and the length of the timer 1 is less than the total length of M=(W-L) time units. After the timeout of the timer 1, the access request frame is sent, which can ensure that the access request frame is successfully sent within the access period 1, thereby not affecting the transmission of the response information in each response period, and thereby ensuring that the first terminal device successfully completes the random access.

[0122] Figure 4 is another behavior diagram of the first terminal device and the second terminal device in the random access process of the embodiments of the present application. Unlike Figure 3 , the length of the timer 1 is exactly equal to the total length of M=(W-L) time units, so that the access request frame is sent after the timeout of the timer 1, and the end time of the sending of the access request frame is exactly the end time of the access period 1, which ensures that the access request frame is successfully sent within the access period 1.

[0123] In the implementation, the time length of the timer of each terminal device in the plurality of terminal devices is set to be as different as possible, so that the time period of each terminal device for listening to the channel can be staggered, so that the terminal device with the shortest time length of the timer can successfully preempt the channel, and it is possible to ensure that at least one terminal device successfully completes random access.

[0124] Figure 5 The figure is a schematic diagram of the behaviors of a plurality of terminal devices and a second terminal device in a random access process provided by the embodiment of the present application, wherein terminal device A is an example of the first terminal device, and terminal device B and terminal device C are other devices to be accessed.

[0125] Reference Figure 5 The terminal device A is configured with timer 1 (an example of the first timer), the terminal device B is configured with timer 2, and the terminal device C is configured with timer 3. The time lengths of the timer 1, the timer 2, and the timer 3 are all different, and the time length of the timer 1 of the terminal device A is the shortest. When entering the access period 1 (an example of the first access period), the three terminal devices all start their respective timers to listen to the channel. Since the time length of the timer 1 is the shortest, the terminal device A ends the channel listening earliest. When the channel is idle, the terminal device A sends an access request after the timer 1 expires. The terminal device A successfully preempts the channel and further performs subsequent steps to complete random access. When the terminal device A starts to send the access request, the terminal device B and the terminal device C start to listen to the channel and find that the channel is busy, and continue until the end time of the timer 2 and the timer 3. Therefore, for the terminal device B and the terminal device C, it is impossible to preempt the channel to send the access request, and thus the random access is stopped.

[0126] As can be seen from the above, the shorter the time length of the timer, the more opportunities the terminal device has to successfully preempt the channel and thus successfully complete random access. The reason is that the shorter the time length of the timer, the shorter the time for the terminal device to listen to the channel, and thus the terminal device can send the access request earliest after the timer expires, so as to successfully complete random access as much as possible. The terminal devices with longer time lengths of other timers will always listen to the channel busy in the time period of the respective timers, and thus the random access is stopped. Therefore, for the terminal device that fails in random access for multiple times, the time length of the timer of the terminal device can be reduced to improve the probability of successful random access.

[0127] The time length of the first timer of the embodiment of the present application can be predefined or dynamically determined based on actual conditions, and the embodiment of the present application does not make any limitation.

[0128] In the embodiment in which the time length of the first timer can be dynamically determined, the time length of the first timer can be different or the same in different access periods, and the embodiment of the present application does not make any limitation.

[0129] In some embodiments, as mentioned above, for the terminal device that fails in multiple random accesses, the probability of success in random access can be increased by reducing the length of the timer of the terminal device.

[0130] Taking the first terminal device as an example, if the first terminal device fails to access the network in the access period of several consecutive periods, the length of the first timer of the first terminal device can be set to be shorter. As shown in FIG. 1, the timer 1 (an example of the first timer) of the terminal device A (an example of the first terminal device) is the device with the shortest length among the three terminal devices, and the first terminal device successfully occupies the channel and transmits the access request earliest. Figure 5

[0131] In some other embodiments, the length of the first timer is determined based on the priority of the first terminal device.

[0132] The priority of the first terminal device is high, and the length of the first timer can be set to be shorter; the priority of the first terminal device is low, and the length of the first timer can be set to be longer. In this way, the terminal device with high priority can successfully transmit the access request as much as possible to improve the success rate of random access, so as to not affect the communication of important devices.

[0133] The specific description of the related definition of the priority of the device can be referred to the related description above, and will not be repeated here.

[0134] Taking the first access period including W time units and the access request frame including L time units as an example, it is further limited that the length of the first timer is greater than 0 and less than or equal to the total length of M=(W-L) time units, and the starting time of the first timer is the starting time of the first access period, that is, it is limited that if the terminal device successfully occupies the channel, the access request frame needs to be transmitted within the first access period. Then, the success rate of random access of the terminal device executing the embodiments of the present application can be roughly calculated as Wherein, N is the number of terminal devices to be accessed in the same access period.

[0135] When N is 1, there is no other terminal device to occupy the channel with the terminal device, and therefore, the terminal device can successfully complete the random access without special circumstances. When N=2, L=32, W=2L=64, P=31 / 32≈0.969. When N=4, L=32, W=2L=64, P≈0.94. When N=16, L=32, W=2L=64, P≈0.77. When N=32, L=32, W=2L=64, P≈0.58.

[0136] ​From the above data, it can be seen that when W=2L, for the case that there are more terminal devices accessing the wireless ad hoc network in the same access period, the random access procedure of the embodiment of the present application generally maintains a higher success rate.

[0137] In the above various embodiments, if the end time of the access request frame is after the first access period, the first response period and the first access period can be set as discontinuous periods, and the time interval between the first access period and the first response period can allow the sending of the access request frame to be completed.

[0138] The above describes in detail the random access method according to the embodiment of the present application, and the following will describe in detail the terminal device according to the embodiment of the present application. Figures 1 to 5 Figures 6 to 7

[0139] Figure 6 A schematic block diagram of a terminal device 200 provided by the embodiment of the present application is shown, which can be the first terminal device or a chip in the first terminal device. The terminal device 200 includes a transceiver unit 210 and a processing unit 220.

[0140] The processing unit 220 is configured to start a first timer in a first access period in the periodic access period.

[0141] The transceiver unit 210 is configured to send an access request in the first access period and after the first timer expires if the channel is in an idle state during the period of the first timer, and the access request is used to request access to the wireless ad hoc network.

[0142] Optionally, the access request is carried in an access request frame, and the time length of the first access period is greater than the time length of the access request frame.

[0143] Optionally, the time length of the first access period is less than or equal to the total time length of two access request frames.

[0144] Optionally, the time length of the first timer is greater than 0 and less than or equal to the total time length of M time units, M=W-L, W is the number of time units included in the first access period, and L is the number of time units included in the access request frame.

[0145] Optionally, the time length of the first timer is determined based on the priority of the terminal device.

[0146] Optionally, the start time of the first timer is the start time of the first access period.

[0147] Optionally, the start time of the first timer is determined based on the priority of the terminal device.​​

[0148] Optionally, the processing unit 220 is further configured to stop the random access in the first access period and after the first timer expires if the channel is detected to be busy in the period of the first timer.

[0149] It should be understood that the terminal device 200 is embodied in the form of functional units. The term "unit" herein can refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (for example, a shared processor, a dedicated processor, or a group processor, etc.) and a memory for executing one or more software or firmware programs, a combination logic circuit, and / or other suitable components that support the described functions. In an optional example, those skilled in the art can understand that the terminal device 200 can be embodied as the first terminal device in the above embodiments, and the terminal device 200 can be configured to perform the respective processes and / or steps corresponding to the first terminal device in the above method embodiments. To avoid repetition, details are not described here.

[0150] The terminal device 200 in each of the above schemes has the function of performing the corresponding steps of the first terminal device in the above method. The function can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions; for example, the sending unit can be replaced by a transmitter, the receiving unit can be replaced by a receiver, and other units such as the determining unit can be replaced by a processor, which respectively performs the transceiving operations and related processing operations in each method embodiment.

[0151] In the embodiments of the present application, Figure 6 The terminal device in the above embodiments can also be a chip or a chip system, for example, a system on chip (SoC). Correspondingly, the receiving unit and the sending unit can be transceiving circuits of the chip, which are not limited here.

[0152] Figure 7 A schematic structural diagram of the terminal device 300 provided by the embodiments of the present application is shown. The terminal device 300 includes a processor 310, a transceiver 320, and a memory 330. The processor 310, the transceiver 320, and the memory 330 communicate with each other through an internal connection path. The memory 330 is configured to store instructions, and the processor 310 is configured to execute the instructions stored in the memory 330 to control the transceiver 320 to transmit and / or receive signals.

[0153] In a possible implementation, the terminal device 300 is configured to perform the respective processes and steps corresponding to the first terminal device in the above method 100.

[0154] The processor 310 is configured to start a first timer in a first access period in the periodic access periods.

[0155] The transceiver 320 is configured to, if the channel is detected to be idle within the period of the first timer, send an access request in the first access period and after the first timer expires, the access request being used to request access to the wireless ad hoc network.

[0156] Optionally, the access request is carried in an access request frame, and a length of the first access period is greater than a length of the access request frame.

[0157] Optionally, the length of the first access period is less than or equal to a total length of 2 access request frames.

[0158] Optionally, a length of the first timer is greater than 0 and less than or equal to a total length of M time units, M = W - L, W is a number of time units included in the first access period, and L is a number of time units included in the access request frame.

[0159] Optionally, the length of the first timer is determined based on a priority of the terminal device.

[0160] Optionally, a start time of the first timer is a start time of the first access period.

[0161] Optionally, the start time of the first timer is determined based on the priority of the terminal device.

[0162] Optionally, the processor 310 is further configured to, if the channel is detected to be busy within the period of the first timer, stop random access in the first access period and after the first timer expires.

[0163] It should be understood that the terminal device 300 can specifically be the first terminal device in the above-described embodiments, and can be configured to perform each step and / or process in the above-described method embodiments corresponding to the first terminal device. Optionally, the memory 330 can include a read-only memory and a random access memory, and provide instructions and data for the processor. A part of the memory can also include a non-volatile random access memory. For example, the memory can also store device type information. The processor 310 can be configured to execute the instructions stored in the memory, and when the processor 310 executes the instructions stored in the memory, the processor 310 is configured to perform each step and / or process in the above-described method embodiments corresponding to the terminal device.

[0164] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, device and unit described above can refer to the corresponding process in the foregoing method embodiment, and will not be repeated here.

[0165] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the above-described embodiment of the terminal device is only illustrative, for example, the division of the modules is only a logical functional division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed units can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0166] The units described as separate components can or can not be physically separated, and the components displayed as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0167] In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit.

[0168] It should be understood that, in various embodiments of the present application, the size of the sequence number of each process does not mean the execution order, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0169] In addition, the term "and / or" in this paper is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B can represent three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents an "or" relationship between the front and rear associated objects.

[0170] If the functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the parts that contribute to the prior art or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0171] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims. In summary, the above is only a preferred embodiment of the technical solutions of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for random access, characterized in that, Applied to wireless ad hoc networks, wherein the wireless ad hoc network is configured with periodic access periods, the method includes: During the first access period in the periodic access period, a first timer is started. The duration of the first timer is determined based on the priority of the terminal device. The start time of the first timer is the start time of the first access period. For terminal devices that fail to access multiple times randomly, the duration of the first timer of the terminal device is reduced. The priority of the terminal device includes the priority defined by the type of the terminal device, the priority defined by the remaining battery power of the terminal device, the priority defined by the user attributes corresponding to the terminal device, and the priority of the terminal device defined by the service of the terminal device. If the channel is detected to be idle during the first timer period, an access request is sent during the first access period and after the first timer expires. The access request is used to request access to the wireless ad hoc network.

2. The method according to claim 1, characterized in that, The access request is carried in an access request frame, and the duration of the first access period is greater than the duration of the access request frame.

3. The method according to claim 2, characterized in that, The duration of the first access period is less than or equal to the total duration of the two access request frames.

4. The method according to claim 2 or 3, characterized in that, The duration of the first timer is greater than 0 and less than or equal to the total duration of M time units, where M = WL, W is the number of time units included in the first access period, and L is the number of time units included in the access request frame.

5. The method according to any one of claims 1 to 4, characterized in that, The start time of the first timer is determined based on the priority of the terminal device.

6. The method according to any one of claims 1 to 5, characterized in that, If the channel is detected to be busy during the first timer period, random access will be stopped during the first access period and after the first timer expires.

7. A randomly accessed terminal device, characterized in that, include: Memory, used to store computer instructions; A processor for invoking computer instructions stored in the memory to perform the method as described in any one of claims 1 to 6.

8. A computer-readable storage medium, characterized in that, Used to store computer instructions for implementing the method as described in any one of claims 1 to 6.

9. A chip, characterized in that, The chip includes: Memory: Used to store instructions; A processor for retrieving and executing the instructions from the memory, causing a communication device on which the chip is mounted to perform the method as described in any one of claims 1 to 6.

Images