CN111757537A

CN111757537A - Random access method and device

Info

Publication number: CN111757537A
Application number: CN201910252477.1A
Authority: CN
Inventors: 赵力; 酉春华; 郭英昊
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-03-28
Filing date: 2019-03-29
Publication date: 2020-10-09
Anticipated expiration: 2039-03-29
Also published as: CN111757537B

Abstract

The embodiment of the application provides a random access method and a device, wherein the random access method comprises the following steps: the terminal equipment sends a message to the network equipment, wherein the message is used for requesting random access to the network equipment by the terminal equipment; the terminal equipment receives a response message of a message from the network equipment, wherein the response message comprises a MAC layer data packet, the MAC layer data packet comprises a load and a MAC subheader of the load, and the MAC subheader comprises first indication information which is used for determining the length of the load. According to the random access method provided by the embodiment of the application, the terminal equipment can determine the initial position of the MAC layer data packet by setting the first indication information in the MAC subheader of the MAC layer data packet, so that the detection of the response message is realized.

Description

Random access method and device

This application claims priority from chinese patent application filed on 28/03/2019 under the name of "random access method and apparatus", with the application number 201910245788.5, which is incorporated herein by reference in its entirety.

Technical Field

The embodiment of the application relates to the technical field of communication, in particular to a random access method and a random access device.

Background

The terminal device can implement uplink synchronization with the network device through a Random Access (RA) process. The random access procedure includes a contention-based random access procedure and a non-contention random access procedure. At present, the contention-based random access procedure is completed in four steps: the first step is that the terminal device sends a random access request to the network device, where the random access request may also be referred to as message 1(Msg1), which contains a random access preamble (preamble); the second step is that the network device sends a Random Access Response (RAR) message to the terminal device, where the RAR message may also be referred to as message 2(Msg 2); the third step is that after receiving the RAR, the terminal device performs message transmission based on RAR scheduling, where the message may also be referred to as message 3(Msg 3); the fourth step is that the network device sends contention resolution information to the terminal device, and the message carrying this information is called message 4(Msg 4). The RAR message may include a random access preamble identifier (RAP ID), and the RAP ID matches (or is the same as) the preamble ID selected by the terminal device, so that the RAR message is considered to be successfully received. After the RAR is determined to be successfully received, the terminal equipment does not monitor subsequent RARs.

The 4-step random access process based on competition needs more interactive processes, has larger time delay, and cannot be well applied to scenes with higher requirements on time delay. Therefore, a 2-step random access process based on contention is introduced, but in the 2-step random access process, the sizes of response messages of different terminal devices may be different, which results in that when the terminal device determines that the currently detected response message is not the response message of the terminal device, the starting position of the next response message to be detected cannot be determined, and thus the next detection cannot be performed.

Disclosure of Invention

In view of this, embodiments of the present application provide a random access method and apparatus, so that a terminal device may detect a response message.

In a first aspect, a random access method is provided, including:

the terminal device sends a message for requesting random access to the network device. Thereafter, the terminal device receives a response message to the message from the network device. The response message may include a MAC layer packet, which includes a payload and a MAC subheader. In the MAC subheader of the MAC layer packet, first indication information is included. The first indication information is used to determine the length of the load.

In a second aspect, a random access method is provided, including:

the network equipment receives a message which is sent by the terminal equipment and used for requesting random access. After that, the network device sends a response message of the message to the terminal device. The response message may include a MAC layer packet, which includes a payload and a MAC subheader. In the MAC subheader of the MAC layer packet, first indication information is included. The first indication information is used to determine the length of the load.

In a third aspect, an apparatus is provided, comprising: means or units (means) for performing the steps of the first aspect above.

In a fourth aspect, an apparatus is provided that includes: means for performing the steps of the second aspect above.

In a fifth aspect, there is provided an apparatus comprising a processor and an interface circuit, the processor being configured to communicate with other apparatuses via the interface circuit and to perform the method provided in the first aspect above. The processor includes one or more.

In a sixth aspect, there is provided an apparatus comprising a processor and an interface circuit, the processor being configured to communicate with other apparatuses via the interface circuit and to perform the method provided in the second aspect above. The processor includes one or more.

In a seventh aspect, an apparatus is provided, which includes a processor, connected to a memory, for calling a program stored in the memory to execute the method provided in the first aspect above. The memory may be located within the device or external to the device. And the processor includes one or more.

In an eighth aspect, an apparatus is provided, which includes a processor, connected to a memory, for calling a program stored in the memory to execute the method provided in the second aspect above. The memory may be located within the device or external to the device. And the processor includes one or more.

In a ninth aspect, there is provided a program for performing the method of the above first aspect, or for performing the method of the above second aspect, when executed by a processor.

A tenth aspect provides a program product, such as a computer readable storage medium, comprising the program provided in the ninth aspect.

An eleventh aspect provides a terminal device comprising any one of the apparatus of the third aspect above, or comprising any one of the apparatus of the fifth aspect above, or comprising any one of the apparatus of the seventh aspect above.

In a twelfth aspect, there is provided a network device comprising the apparatus of any of the above fourth aspects, or comprising the apparatus of any of the above sixth aspects, or comprising the apparatus of any of the above eighth aspects.

It can be seen that in the above aspects, the terminal device sends a message to the network device, the message being for the terminal device to request random access from the network device. After that, the network device sends a response message of the message to the terminal device. The response message may include a MAC layer packet, among others. The MAC layer packet includes a payload of the MAC layer packet and a MAC subheader of the MAC layer packet. The MAC subheader comprises first indication information. In a scenario where the response message length is not fixed, for example, in a contention-based 2-step random access procedure, by setting first indication information in a MAC subheader of a MAC layer packet, the length of the payload of the MAC layer packet may be determined according to the first indication information. Further, the length of the MAC layer packet may be determined. Therefore, when the MAC PDU includes response messages corresponding to the plurality of terminal devices, the terminal device may determine the start position of each response message in the MAC PDU according to the first indication information carried in the MAC subheader of the MAC layer packet included in each response message in the MAC PDU, thereby implementing correct detection on the response message in a scene where the length of the response message is not fixed.

In the foregoing aspects, optionally, in a possible implementation manner, the message sent by the terminal device to the network device includes a random access signal and information for contention resolution, where the random access signal is used to request random access. Wherein the load includes contention resolution information for indicating contention resolution or for indicating success of random access, and the contention resolution information is obtained according to the information for contention resolution; alternatively, the load does not include contention resolution information for indicating a contention resolution failure or for indicating a random access backoff.

In the above aspects, optionally, in one possible implementation, the contention resolution information includes part or all of the content of the information for contention resolution.

In the above aspects, optionally, in a possible implementation, the load further includes one or more of the following information: uplink authorization information, timing advance command, TC-RNTI and RRC message.

In the above aspects, optionally, in one possible implementation, the first indication information is used for indicating the length of the load.

By the possible implementation manner, the length of the load of the MAC layer packet can be directly indicated through the first indication information, so that the starting position of the MAC layer packet can be determined through the first indication information, and the detection of the response message is realized in a scene where the length of the response message is not fixed.

In the above aspects, optionally, in a possible implementation, the first indication information is a preset bit length.

In the above aspects, optionally, in a possible implementation, the first indication information includes N indication fields, where N is greater than or equal to 1; each indication field corresponds to one kind of information, and the indication field is used for indicating whether the load contains the information corresponding to the indication field.

Through the possible implementation manner, through the N indication fields, it can be determined whether the load of the MAC layer packet includes information corresponding to each indication field. When the information included in the payload of the MAC layer packet is determined, the length of the payload of the MAC layer packet may be determined. Therefore, the starting position of the MAC layer data packet can be determined according to the load length of the MAC layer data packet, and the detection of the response message is realized in a scene that the length of the response message is not fixed.

In each of the above aspects, optionally, in a possible implementation manner, the information corresponding to the N indication fields includes contention resolution information, the contention resolution information is a preset length, and the indication field corresponding to the contention resolution information is 1 bit. Or, the information corresponding to the N indication fields includes contention resolution information, the indication field corresponding to the contention resolution information is 2bits, and the indication field corresponding to the contention resolution information is further used to indicate the length of the contention resolution information.

In the above aspects, optionally, in one possible implementation, the valid bits of the contention resolution information are a preset length or a part of the preset length.

In the above aspects, optionally, in a possible implementation, the first indication information includes an information index value, and the information index value has a corresponding relationship with the length of the load; the information index value is used for determining the length of the load according to the corresponding relation between the preset information index value and the length of the load.

With this possible implementation, there is a correspondence between the information index value and the length of the payload of the MAC layer packet. After the terminal device obtains the information index value carried in the MAC subheader of the MAC layer packet, the length of the load of the MAC layer packet can be determined according to the correspondence between the information index value and the load length of the MAC layer packet. After the length of the load of the MAC layer packet is determined, the terminal device may determine the start position of the MAC layer packet, and implement detection on the response message in a scenario where the length of the response message is not fixed. And moreover, the bit length occupied by the first indication information is further reduced through the information index value, the bit waste is further reduced, and the resource utilization rate is improved.

In each of the above aspects, optionally, in a possible implementation manner, if the first indication information is used to indicate the length of the payload, or the first indication information includes an information index value, the MAC subheader further includes second indication information, where the second indication information is used to indicate the content of information included in the payload.

With this possible embodiment, the length of the payload of the MAC layer packet can be determined by the first indication information. However, the load of the MAC layer packet includes more contents, and when the load of the MAC layer packet includes at least two kinds of information with the same length, the second indication information is set in the MAC subheader of the MAC layer packet, so that the content of the information included in the load of the MAC layer packet can be indicated, the specific content included in the load of the MAC layer packet can be determined conveniently, and the data processing efficiency is improved.

In the above aspects, optionally, in one possible implementation, the terminal device sends a message for requesting random access to the network device. The message includes information for contention resolution. The network device may not send a response message to the terminal device if the network device fails to successfully decode the information for contention resolution.

With this possible implementation, after the terminal device sends the message for requesting random access to the network device, the network device may not send a response message if the network device does not successfully decode the information for contention resolution. Therefore, the terminal equipment is controlled to perform the 2-step random access process based on the competition again or perform the 4-step random access process based on the competition, and the flexibility of random access is improved.

In the above aspects, optionally, in a possible implementation, the MAC subheader further includes backoff indication information, where the backoff indication information is used to indicate whether to perform random access backoff.

With this possible implementation, after the terminal device sends the message for requesting random access to the network device, if the network device fails to decode the information for contention resolution, the network device may control whether the terminal device performs random access backoff by setting backoff indication information in the MAC subheader of the MAC layer packet. When the backoff indication information indicates that the terminal device performs random access backoff, the terminal device may backoff from the contention-based 2-step random access procedure to the contention-based 4-step random access procedure. When the backoff indication information indicates that the terminal device does not perform random access backoff, the terminal device may perform the contention-based 2-step random access procedure or perform the contention-based 4-step random access procedure again, thereby improving the flexibility of random access.

In each of the above aspects, optionally, in a possible implementation manner, when the value of the first indication information is a preset value, the first indication information is further used for instructing the terminal device to perform a contention-based 2-step random access procedure again, or the first indication information is further used for instructing the terminal device to perform a contention-based 4-step random access procedure, or the first indication information is further used for instructing the terminal device to perform a random access backoff.

Through the possible implementation manner, after the terminal device sends the message for requesting random access to the network device, if the network device fails to decode the information for contention resolution, the network device may control the terminal device to perform random access backoff, or perform the contention-based 2-step random access process again, or perform the contention-based 4-step random access process through the value of the first indication information, thereby improving the flexibility of random access.

Drawings

Fig. 1 is an architecture diagram of a communication system to which embodiments of the present application are applicable;

fig. 2 is an architecture diagram of another communication system to which embodiments of the present application are applicable;

fig. 3 is an architecture diagram of another communication system to which embodiments of the present application are applicable;

fig. 4 is a message interaction diagram of a conventional contention-based 4-step random access procedure;

FIG. 5 is a diagram illustrating the structure of a conventional MAC PDU and MAC sub-PDU;

fig. 6 is a message interaction diagram of a random access method according to an embodiment of the present application;

fig. 7 is a schematic diagram of a general structure of a MAC sub-PDU provided in an embodiment of the present application;

fig. 8A to 8C are schematic structural diagrams of a MAC PDU and a MAC sub-PDU provided in the embodiment of the present application;

fig. 9 is a schematic structural diagram of an implementation manner of a MAC subheader of a MAC layer packet according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of another implementation manner of a MAC subheader of a MAC layer packet according to an embodiment of the present application;

fig. 11 is a schematic structural diagram of another implementation manner of a MAC subheader of a MAC layer packet according to an embodiment of the present application;

fig. 12 is a schematic structural diagram of another implementation manner of a MAC subheader of a MAC layer packet according to an embodiment of the present application;

fig. 13 is a schematic structural diagram of another implementation manner of a MAC subheader of a MAC layer packet according to an embodiment of the present application;

FIG. 14 is a schematic diagram of an apparatus according to an embodiment of the present disclosure;

FIG. 15 is a schematic structural diagram of another apparatus provided in an embodiment of the present application;

fig. 16 is a schematic structural diagram of a network device according to an embodiment of the present application;

fig. 17 is a schematic structural diagram of a terminal device according to an embodiment of the present application.

Detailed Description

Embodiments of the present application are described below with reference to the drawings.

Please refer to fig. 1, which is an architecture diagram of a communication system according to an embodiment of the present application. As shown in fig. 1, the communication system may include a terminal device 100 and a network device 200. The number of the terminal devices 100 and the number of the network devices 200 are not limited in the embodiment of the present application. The terminal device 100 located within the coverage of the network device 200 can communicate with the network device 200 in a wireless manner. Specifically, when the network device 200 is the sender, the downlink information may be transmitted to the terminal device 100. Accordingly, the terminal device 100 can receive the downlink information transmitted by the network device 200 as a receiver. When the terminal device 100 is the sender, the uplink information may be transmitted to the network device 200. Accordingly, the network device 200 can receive, as a receiver, the uplink information transmitted by the terminal device 100. The terminal device 100 may be fixed in position or may be movable.

Optionally, the communication system may also comprise other devices. The communication system may also comprise core network equipment (not shown in fig. 1), for example. The network device 200 may be connected to the core network device by wireless or wired means. The core network device and the network device 200 may be separate physical devices, or the function of the core network device and the function of the network device 200 may be integrated on the same physical device, or a physical device may be integrated with a part of the functions of the core network device and a part of the functions of the network device 200. Also for example, the communication system may also include a wireless relay device or a wireless backhaul device (not shown in fig. 1).

The network device 200 is a device for transmitting and receiving signals in a network side, for example, a Radio Access Network (RAN) node for accessing a terminal device to a wireless network. Currently, some examples of RAN nodes are: a new generation base station (generation Node B, gNB), a Transmission Reception Point (TRP), an evolved Node B (eNB), a Radio Network Controller (RNC), a Node B (NB), a Base Station Controller (BSC), a Base Transceiver Station (BTS), a home base station (e.g., home evolved Node B, HNB), a Base Band Unit (BBU), a relay station, or a wireless fidelity (Wifi) Access Point (AP), etc. in a new radio access technology (NR) (or 5G) system. In one network configuration, a network device may include a Central Unit (CU) node, or a Distributed Unit (DU) node, or a RAN device including a CU node and a DU node. The wireless coverage area of network device 200 may include one or more cells. A terminal device 100 within the coverage of a cell communicates with a network device 200 via transmission resources (e.g., frequency domain resources, spectrum resources, or time-frequency resources) of the cell. The cell may be a macro cell or a small cell (small cell). Optionally, the small cell may include: a metro cell (metro cell), a micro cell (microcell), a pico cell (pico cell), a femto cell (femtocell), or the like. The embodiment of the present application does not limit the specific technology and the specific device form adopted by the network device 200.

The terminal 100, also called User Equipment (UE), a Mobile Station (MS), or a Mobile Terminal (MT), is a device providing voice/data connectivity to a user, for example, a handheld device with a wireless connection function, or a vehicle-mounted device. Currently, some examples of terminal devices are: a mobile phone (mobile phone), a tablet computer, a notebook computer, a palm top 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 (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote surgery (remote medical supply), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety (smart security), a wireless terminal in city (smart city), a wireless terminal in smart home (smart home), and the like.

Please refer to fig. 2, which is a schematic diagram of another network architecture according to an embodiment of the present application. As shown in fig. 2, the network architecture includes Core Network (CN) devices and RAN devices. The RAN device includes a baseband device and a radio frequency device, where the baseband device may be implemented by one node or by multiple nodes, and the radio frequency device may be implemented independently by being pulled away from the baseband device, may also be integrated in the baseband device, or may be partially pulled away and partially integrated in the baseband device. For example, in a Long Term Evolution (LTE) communication system, a RAN equipment (eNB) includes a baseband device and a radio frequency device, where the radio frequency device may be remotely located with respect to the baseband device, e.g., a Remote Radio Unit (RRU) is remotely located with respect to a BBU.

The communication between the RAN equipment and the terminal equipment follows a certain protocol layer structure. For example, the control plane protocol layer structure may include functions of protocol layers such as a Radio Resource Control (RRC) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and a physical layer. The user plane protocol layer structure can comprise functions of protocol layers such as a PDCP layer, an RLC layer, an MAC layer, a physical layer and the like; in one implementation, a Service Data Adaptation Protocol (SDAP) layer may be further included above the PDCP layer.

The functions of these protocol layers may be implemented by one node, or may be implemented by a plurality of nodes; for example, in an evolved structure, the RAN equipment may include CUs and DUs, and a plurality of DUs may be centrally controlled by one CU. As shown in fig. 2, the CU and the DU may be divided according to protocol layers of the radio network, for example, functions of a PDCP layer and above protocol layers are provided in the CU, and functions of protocol layers below the PDCP layer, for example, functions of an RLC layer and a MAC layer, are provided in the DU.

This division of the protocol layers is only an example, and it is also possible to divide the protocol layers at other protocol layers, for example, at the RLC layer, and the functions of the RLC layer and the protocol layers above are set in the CU, and the functions of the protocol layers below the RLC layer are set in the DU; alternatively, the functions are divided into some protocol layers, for example, a part of the functions of the RLC layer and the functions of the protocol layers above the RLC layer are provided in the CU, and the remaining functions of the RLC layer and the functions of the protocol layers below the RLC layer are provided in the DU. In addition, the processing time may be divided in other manners, for example, by time delay, a function that needs to satisfy the time delay requirement for processing is provided in the DU, and a function that does not need to satisfy the time delay requirement is provided in the CU.

In addition, the radio frequency device may be pulled away, not placed in the DU, or integrated in the DU, or partially pulled away and partially integrated in the DU, which is not limited herein.

With continued reference to fig. 3, with respect to the architecture shown in fig. 2, the Control Plane (CP) and the User Plane (UP) of the CU may be separated and implemented by being divided into different entities, namely a control plane CU entity (CU-CP entity) and a user plane CU entity (CU-UP entity).

In the above network architecture, the signaling generated by the CU may be sent to the terminal device through the DU, or the signaling generated by the terminal device may be sent to the CU through the DU. The DU may pass through the protocol layer encapsulation directly to the terminal device or CU without parsing the signaling. In the following embodiments, if transmission of such signaling between the DU and the terminal device is involved, in this case, the transmission or reception of the signaling by the DU includes such a scenario. For example, the signaling of the RRC or PDCP layer is finally processed as the signaling of the PHY layer to be sent to the terminal device, or is converted from the received signaling of the PHY layer. Under this architecture, the signaling of the RRC or PDCP layer can also be considered to be sent by the DU, or by the DU and the radio frequency.

In the above embodiment, the CU is divided into the network devices on the RAN side, and in addition, the CU may also be divided into the network devices on the CN side, which is not limited herein.

When the above CU-DU structure is adopted, the network device in the embodiments of the present application may be a CU node, or a DU node, or a RAN device including the CU node and the DU node.

The terminal equipment can realize uplink synchronization with the network equipment through a random access process. Please refer to fig. 4, which is a message interaction diagram of a conventional contention-based random access procedure. As shown in fig. 4, the process mainly includes 4 steps, and thus may be referred to as a 4-step random access process.

S401, the terminal device sends a random access request to the network device, where the random access request may also be referred to as message 1(Msg1), and includes a random access preamble (preamble).

Correspondingly, the network device receives the preamble, learns that the terminal device requests access, and then executes the following step S402.

S402, the network device sends a Random Access Response (RAR) message to the terminal device, where the RAR message may also be referred to as message 2(Msg 2).

The RAR may include the following: 1) RAPID, which is a preamble index (preamble index) obtained when the network device detects the preamble. 2) A timing advance command (TA command) for specifying a time adjustment amount (also referred to as a timing advance) required for uplink synchronization by the terminal device. 3) And uplink grant information (UL grant) for specifying an uplink resource allocated by the network device to the terminal device for sending Msg3 (message 3). 4) A temporary cell radio network temporary identity (TC-RNTI) used for subsequent data transmission between the terminal device and the network device.

Correspondingly, the terminal equipment calculates a random access radio network temporary identifier (RA-RNTI) through sending the time-frequency resource of the preamble, and monitors a Physical Downlink Control Channel (PDCCH) scrambled by the RA-RNTI in an RAR time window so as to receive the RAR corresponding to the RA-RNTI. And when the terminal equipment uses the RA-RNTI for decoding and successfully receives an RAR, and the RAPID value in the RAR is the same as the index value used when the terminal equipment sends the preamble, the RAR is considered to be successfully received. And the terminal equipment starts to process the TA command, the UL grant and the TC-RNTI contained in the RAR. And if the terminal equipment does not receive the RAR aiming at the Preamble within the RAR time window, the RAR is considered to be failed to receive. Subsequently, the process returns to S401 to perform 4-step contention-based random access again.

With reference to fig. 5, a 5G air interface Technology (NR) system is taken as an example to exemplarily explain how a terminal device detects RAR in a scenario where multiple terminal devices transmit preamble on the same time-frequency resource. Wherein, the plurality of terminal devices which send the preamble in the same time frequency resource have the same RA-RNTI. The RARs corresponding to the terminal devices may be multiplexed in one MAC Protocol Data Unit (PDU).

As shown in fig. 5, the MAC PDU may include a plurality of MAC sub-PDUs (MAC sub-PDUs). The MAC sub-PDU structurally includes a MAC sub-header and a payload of the MAC sub-PDU. The RAR of one terminal device may correspond to one MAC sub-PDU, e.g., MAC sub-PDU 3. The MAC sub-header of the MAC sub-PDU may include a RAPID, and the payload of the MAC sub-PDU may include a RAR. The RAR may include a timing advance command, uplink grant information, and TC-RNTI. Wherein the MAC subheader is a fixed 1byte size and the RAR is a fixed 7byte size.

And when the terminal equipment monitors the MAC PDU scheduled by the PDCCH scrambled by the RA-RNTI, decoding the MAC PDU and determining whether the RAR of the terminal equipment is received. Specifically, the terminal device obtains the MAC sub-PDU to be detected in the MAC PDU according to a preset sequence, and determines whether an RAPID carried by an MAC sub-header of the MAC sub-PDU to be detected is the same as a preamble ID sent by the terminal device. The preset sequence is not limited in this embodiment. For example, it may be in order from the head to the tail of the MAC PDU. If the RAPID carried by the MAC sub-header of the MAC sub-PDU to be detected is the same as the preamble ID sent by the terminal device, the terminal device determines that the RAR is successfully received, and may process the RAR carried by the load of the MAC sub-PDU to be detected, which specifically includes a timing advance command, uplink authorization information and TC-RNTI. And if the RAPID carried by the MAC sub-head of the MAC sub-PDU to be detected is different from the preamble ID sent by the terminal equipment, the terminal equipment acquires the next undetected MAC sub-PDU behind the MAC sub-PDU to be detected according to a preset sequence, and repeatedly executes the operation by taking the next undetected MAC sub-PDU as a new MAC sub-PDU to be detected. And if the terminal equipment does not detect the RAR of the terminal equipment within the RAR time window, the RAR reception is considered to be failed. The terminal device may initiate the contention-based 4-step random access procedure again after a period of time.

As can be seen, in the above example, since the sizes of the MAC subheader and the RAR are fixed, when the terminal device determines that the RAPID carried in the MAC subheader of the currently detected MAC sub-PDU is different from the preamble ID sent by the terminal device, the terminal device can know the starting position of the next MAC sub-PDU to be detected exactly, so that the MAC subheader of the next MAC sub-PDU can be detected.

And S403, the terminal equipment sends Msg3 to the network equipment by using the timing advance indicated by the network equipment on the uplink resource allocated by the network equipment according to the RAR (message 3).

Specifically, after the terminal device sends Msg3, the contention resolution timer is started or restarted. Wherein, the Msg3 includes the identifier of the terminal device. The identification of the terminal device will be used for contention resolution in S404.

Alternatively, the identity of the terminal device may be related to the state of the terminal device in the communication system. For example, in the NR system, when the terminal device is in an RRC CONNECTED state (RRC _ CONNECTED state), the identity of the terminal device may be a Cell Radio Network Temporary identity (C-RNTI). When the terminal device is in the non-RRC connected state, the identifier of the terminal device may be the identifier of the terminal device from the core network. Optionally, the terminal equipment identifier from the core network may be a system architecture evolution temporary mobile station identifier (S-TMSI) or a random number.

Optionally, the Msg3 may also carry a Radio Resource Control (RRC) message. The RRC message is related to the triggering mode of the random access, and can be seen in table 1.

TABLE 1

S404, the network device sends the Msg4 to the terminal device (message 4).

The Msg4 may include contention resolution information to indicate that contention resolution was successful. Optionally, the contention resolution information may be a partial content of the Msg3, or an entire content of the Msg3, or a PDCCH scrambled by a cell radio network temporary identifier (C-RNTI). Accordingly, the terminal device waits for the reception of the Msg4 within the contention resolution timer. If the contention resolution timer is overtime and the terminal device has not received the contention resolution information, the process returns to S401 to perform 4-step contention-based random access again.

Optionally, if the Msg3 carries an RRC message, the network device needs to reply the RRC message after the contention resolution of the terminal device is successful. The RRC message returned is related to the triggering mode of random access, which can be seen in table 2.

TABLE 2

When the 4-step random access process based on the competition is applied to a scene with a high requirement on the time delay, the problem that the time delay requirement is difficult to meet due to more interactive flows and larger time delay exists. Thus, a 2-step random access procedure is introduced. However, in the 2-step random access procedure, the sizes of the response messages of different terminal devices may be different. It is assumed that the MAC PDU structure shown in fig. 5 is used, that is, one MAC PDU includes response messages corresponding to a plurality of terminal devices. In this scenario, when the terminal device determines that the currently detected response message in the MAC PDU is not a response message of the terminal device, the terminal device cannot determine the start position of the next undetected response message following the currently detected response message due to uncertainty of the response message size. Therefore, the next detection cannot be performed.

In view of this, embodiments of the present application provide a random access method, which can be applied to a contention-based 2-step random access process. The response message of the terminal device may include a MAC layer packet, which may include a MAC subheader and a payload. By adding indication information in the MAC subheader of the MAC layer packet, the size of the payload of the MAC layer packet can be determined. Furthermore, when the MAC PDU includes response messages respectively corresponding to a plurality of terminal devices, the terminal device may determine the size of each MAC layer packet and the start position of each response message according to the indication information in the MAC layer packet included in each response message in the MAC PDU. When the terminal device determines that the currently detected response message is not the response message of the terminal device, the terminal device can exactly know the starting position of the next undetected response message after the currently detected response message, thereby realizing the detection of the response message in the random access process.

The following description is made with reference to the accompanying drawings.

An execution main body relates to a network device and a terminal device. Fig. 6 is a message interaction diagram of a random access method according to an embodiment of the present application. As shown in fig. 6, the random access method may include:

s601, the terminal device sends a message to the network device.

Accordingly, the network device may receive the message sent by the terminal device.

The message is used for the terminal equipment to request random access from the network equipment. It should be noted that, in this embodiment, the name of the message is not limited.

Optionally, the message may include, but is not limited to, the following information: a random access signal and information for contention resolution.

Wherein the random access signal is used to request random access. The network device may detect a random access signal and learn that the random access signal is used for the terminal device to request random access. It should be noted that, in different communication systems and different application scenarios, the implementation manner of the random access signal may be different. For example, in the NR system, the random access Signal may be a Preamble, a Demodulation Reference Signal (DMRS), or another detection Signal for random access. The name and length of the random access signal are not limited in this embodiment.

Wherein, the information for contention resolution is sent by the terminal device to the network device for contention resolution. Optionally, the information for contention resolution at least includes an identifier of the terminal device. For the identifier of the terminal device, reference may be made to the related description in S403, and the principle is similar, which is not described herein again.

Alternatively, the Random access signal may be transmitted on a Physical Random Access Channel (PRACH) resource. The information for contention resolution may be transmitted on a Physical Uplink Shared Channel (PUSCH) resource.

S602, the network equipment sends a response message of the message to the terminal equipment.

Correspondingly, the terminal equipment receives the response message of the message from the network equipment. It should be noted that, the name of the response message is not limited in this embodiment.

Wherein the response message may include a MAC layer packet. The MAC layer packet may include a payload and a MAC subheader of the payload. The MAC subheader includes first indication information. The first indication information is used for determining the length of the load. It should be noted that, for convenience of distinction and convenience of description, the MAC subheader included in the MAC layer packet may be referred to as a MAC subheader of the MAC layer packet, and the payload included in the MAC layer packet may be referred to as a payload of the MAC layer packet.

In the random access method provided by this embodiment, by setting the first indication information in the MAC subheader of the MAC layer packet, the length of the payload of the MAC layer packet may be determined according to the first indication information. Further, the length of the MAC layer packet may be determined. When the MAC PDU includes response messages corresponding to the plurality of terminal devices, the terminal device may determine an initial position of each response message in the MAC PDU according to first indication information carried in a MAC subheader of a MAC layer packet included in each response message in the MAC PDU, so that correct detection of the response message is achieved in a scenario where the length of the response message is not fixed, for example, in a contention-based 2-step random access process.

Optionally, the MAC subheader of the MAC layer packet may further include a random access signal identifier. The random access signal identification is derived from the random access signal.

Specifically, for a terminal device requesting random access, a network device determines whether to obtain a random access signal sent by the terminal device according to a message sent by the terminal device. If the network device obtains the random access signal, the network device may obtain a random access signal identifier according to the random access signal. The random access signal identifier may be carried in a MAC subheader of a MAC layer packet included in the response message of the terminal device. It should be noted that, in this embodiment, the name, implementation manner, and length of the random access signal identifier are not limited. The random access signals are different and the random access signal identities may be different. For example, when the random access signal is Preamble, the random access signal identifier may be RAPID. RAPID may be 6bits long.

Optionally, the response message may include contention resolution information, where the contention resolution information is used to indicate contention resolution or is used to indicate success of random access, and the contention resolution information is obtained according to the information for contention resolution; or, the response message does not include contention resolution information for indicating a contention resolution failure or for indicating a random access backoff.

Specifically, for a terminal device requesting random access, a network device determines whether to obtain information for contention resolution sent by the terminal device according to a message sent by the terminal device. If the network device obtains the information for contention resolution, the network device may obtain the contention resolution information according to the information for contention resolution. The response message may include contention resolution information. At this time, the terminal device determines contention resolution or determines that random access is successful according to the contention resolution information. The response message does not include contention resolution information if the network device does not obtain the information for contention resolution. At this time, the terminal device determines that contention resolution fails or random access backoff may be performed. The random access backoff refers to a backoff from a 2-step contention-based random access procedure to a 4-step contention-based random access procedure. It should be noted that the contention resolution information may be a contention resolution message in a 4-step contention-based random access process, which may specifically refer to the relevant description in S404 in fig. 4, and is not described herein again. It should be noted that the length and implementation of the contention resolution information are not limited in this embodiment. For example, in the NR system, the Contention Resolution information may be a UE Contention Resolution Identity MAC CE (UE Contention Resolution Identity MAC CE) of 48 bits.

It should be noted that the following concepts are involved in the embodiments of the present application: a response message to the message (also referred to as a response message or a response message to the terminal device), a MAC PDU, a MAC sub-PDU, and a MAC layer packet. These concepts are explained below.

In the contention based 2-step random access procedure, the response message of one terminal device may include a first response to the random access signal and a second response to the information for contention resolution. Wherein the first response may include a random access signal identification and a load (payload), and the second response may include contention resolution information. For the response message of a terminal device, according to the receiving and processing conditions of the random access signal and the information for contention resolution in the request message by the network device, the response message may include only the first response, may also include only the second response, or includes both the first response and the second response. In addition, the first response and the second response may be located in the same MAC sub-PDU (MAC sub-PDU), or may be located in different MAC sub-PDUs. Alternatively, the first response and the second response may be located in different MAC PDUs, and may be MAC sub-PDUs in the different MAC PDUs. The load (Payload) in the first response may include part or all of the content in the RAR in the contention-based 4-step random access procedure. For example, one or any combination of the following information may be included: uplink grant information (UL grant), timing advance command (TA command), TC-RNTI and RRC messages. The RRC message is related to a contention-based 2-step random access triggering method, and the corresponding relationship can be seen in table 2. The MAC layer packet may include one or more MAC sub-PDUs, may include a first response, or may include a second response, or may include both a first response and a second response.

Next, the response message, the MAC PDU, the MAC sub-PDU, and the MAC layer packet will be described in detail with reference to fig. 7 and fig. 8A to 8C. Fig. 7 is a schematic diagram of a general structure of a MAC sub-PDU provided in an embodiment of the present application, and fig. 8A to 8C are schematic diagrams of structures of a MAC PDU and a MAC sub-PDU provided in the embodiment of the present application.

As shown in fig. 7, a general structure of the MAC sub-PDU may include a MAC sub-header (MAC sub-header) and a payload. It should be noted that, for convenience of differentiation and convenience of description, the MAC subheader included in the MAC sub-PDU may be referred to as a MAC subheader of the MAC sub-PDU, and the payload included in the MAC sub-PDU may be referred to as a payload of the MAC sub-PDU. It should be noted that, in this embodiment, the name of the payload of the MAC sub-PDU, the content included in the payload of the MAC sub-PDU, and the length are not limited, and may be different in different communication systems and different scenarios. For example, in the NR system, when the payload of the MAC sub-PDU includes only Contention Resolution information, the payload of the MAC sub-PDU may also be referred to as UE Contention Resolution Identity MAC CE (UE Contention Resolution Identity MAC CE).

It should be noted that, in the embodiments of the present application, for convenience of describing the structure of the MAC sub-PDU, the name of "random access response" is used. The name of "random access response" is merely an example, and this embodiment does not limit this. The random access response is a payload of the first response, and in the structure shown in this embodiment, is located in a payload of the MAC sub-PDU. The content of the random access response may include information in the existing RAR payload, such as one or more of uplink grant information, timing advance commands, TC-RNTIs and RRC messages.

Optionally, in a first implementation, refer to fig. 8A. The response message of one terminal device corresponds to one MAC sub-PDU among one MAC PDU. The response message of the terminal device is designed as follows: the MAC sub-header of the MAC sub-PDU includes a random access signal identification. If the response message of the terminal device includes the contention resolution information, the load of the MAC sub-PDU may include the random access response and the contention resolution information.

In this implementation, the MAC sub-PDU has the same meaning as the MAC layer packet included in the response message.

In this implementation, the load of the MAC sub-PDU or the load of the MAC layer packet includes contention resolution information, where the contention resolution information is used to indicate contention resolution or to indicate success of random access, and the contention resolution information is obtained according to the information for contention resolution; or the load of the MAC sub-PDU or the load of the MAC layer packet does not include contention resolution information for indicating a contention resolution failure or for indicating a random access backoff.

In this implementation manner, the load of the MAC sub-PDU or the load of the MAC layer packet may further include 0, one, two, three, or all four items in the uplink grant information, the timing advance command, the TC-RNTI, and the RRC message.

In this implementation manner, the content included in the MAC sub-PDU corresponding to the response message of one terminal device may be any one of the following:

1) a MAC subheader comprising: a random access signal identification; a payload of the MAC sub-PDU, comprising: contention resolution information.

2) A MAC subheader comprising: a random access signal identification; a payload of the MAC sub-PDU, comprising: random access response and contention resolution information. The random access response may include any one, any two, any three, or all four of uplink authorization information, a timing advance command, a TC-RNTI, and an RRC message.

3) A MAC subheader comprising: a random access signal identification; a payload of the MAC sub-PDU, comprising: and (4) random access response. The random access response comprises uplink authorization information, a timing advance command and a TC-RNTI.

Optionally, in a second implementation manner, the response message of one terminal device corresponds to two MAC sub-PDUs in one MAC PDU. The embodiment of the present application does not limit the positions of the two MAC sub-PDUs. For example, as shown in fig. 8B, the two MAC sub-PDUs are two adjacent MAC sub-PDUs. For another example, the two MAC sub-PDUs may not be adjacent. The response message of the terminal device is designed as follows: one of the MAC sub-PDUs may include a random access signal identification and a random access response. Wherein the random access signal identifier is located in a MAC sub-header of the MAC sub-PDU, and the payload of the MAC sub-PDU may include the random access response. The random access response may include 0, any one, any two, any three, or all four of the uplink grant information, the timing advance command, the TC-RNTI, and the RRC message. If the response message of the terminal device includes contention resolution information, another MAC sub-PDU includes the contention resolution information. Wherein the contention resolution information is located in a payload of another MAC sub-PDU. The other MAC sub-PDU may refer to an existing structure in the NR system. Optionally, the one MAC sub-PDU may be located before or after the other MAC sub-PDU.

In this implementation, the one of the MAC sub-PDUs has the same meaning as the MAC layer packet included in the response message.

In this implementation manner, the two MAC sub-PDUs corresponding to the response message of the terminal device may respectively include any one of the following contents:

1) the MAC sub-header of one MAC sub-PDU comprises: a random access signal identification. A payload of another MAC sub-PDU, comprising: contention resolution information.

2) The MAC sub-header of one MAC sub-PDU comprises: a random access signal identification; the loading of one MAC sub-PDU comprises the following steps: and (4) random access response. The random access response may include any one, any two, any three, or all four of uplink authorization information, a timing advance command, a TC-RNTI, and an RRC message. A payload of another MAC sub-PDU, comprising: contention resolution information.

3) The MAC sub-header of one MAC sub-PDU comprises: a random access signal identification; the loading of one MAC sub-PDU comprises the following steps: and (4) random access response. The random access response comprises uplink authorization information, a timing advance command and a TC-RNTI. At this time, there is no other MAC sub-PDU, and the response message of one terminal device corresponds to only the one MAC sub-PDU.

Optionally, in a third implementation, refer to fig. 8C. The response message of one terminal device may be located in two MAC PDUs. The MAC sub-PDU carrying the random access signal identification is positioned in one MAC PDU, and the MAC sub-PDU carrying the contention resolution information is positioned in the other MAC PDU. The response message of one terminal device specifically corresponds to one MAC sub-PDU of one MAC PDU and one MAC sub-PDU of another MAC PDU. The response message of the terminal device is designed as follows: one of the MAC sub-PDUs in one of the MAC PDUs may include a random access signal identification and a random access response. Wherein the random access signal identifier is located in a MAC sub-header of the MAC sub-PDU, and the payload of the MAC sub-PDU may include the random access response. The random access response may include 0, any one, any two, any three, or all four of the uplink grant information, the timing advance command, the TC-RNTI, and the RRC message. If the response message of the terminal device includes contention resolution information, one MAC sub-PDU of the other MAC PDU includes the contention resolution information.

In this implementation, one of the MAC sub-PDUs in the one of the MAC PDUs has the same meaning as the MAC layer packet included in the response message.

In this implementation, the content included in each of the two MAC sub-PDUs corresponding to the response message of the terminal device may refer to the content included in each of the two MAC sub-PDUs in the second implementation. The difference is that in the second implementation manner, two MAC sub-PDUs corresponding to the response message are in the same MAC PDU. In this implementation, the two MAC sub-PDUs corresponding to the response message are in different MAC PDUs.

Next, contents included in the response message and the random access response of the terminal device will be described with reference to the state of the terminal device and whether contention is resolved.

In the first case: the terminal device contends for resolution and is in a non-RRC _ Connected state.

In this case, the condition for the terminal device to trigger the contention-based 2-step random access procedure may be initial access from RRC idle (initial access in RRC idle state), RRC connection re-establishment procedure, Transition from RRC _ INACTIVE (RRC INACTIVE state transfer), or the like.

Optionally, the response message of the terminal device may include the uplink grant information, or may not include the uplink grant information. When the response message includes the uplink grant information, the uplink grant information may be used for the terminal device to send new data.

Optionally, the response message of the terminal device may include the timing advance command, or may not include the timing advance command. For example, timing advance commands may not be needed in certain scenarios (such as small cells).

Optionally, the response message of the terminal device may include TC-RNTI/C-RNTI.

In this case, since the terminal device is in the non-RRC _ Connected state, the terminal device has not obtained the C-RNTI, and thus the network device is required to allocate the C-RNTI/TC-RNTI.

Optionally, the response message of the terminal device may include contention resolution information.

It can be seen that, in this case, the random access response may include TC-RNTI/C-RNTI, and may further include 0, any one, or both of the uplink grant information and the timing advance command. Optionally, the random access response may further include an RRC message.

In the second case: the terminal device performs contention resolution and is in the RRC _ Connected state.

In this case, the condition for the terminal device to trigger the 2-step contention-based random access procedure may be Handover, DL or UL data acquisition and reducing RRC _ CONNECTED while UL synchronization status is "non-synchronized" (when RRC is CONNECTED and uplink is out of synchronization, there is uplink/downlink data arriving), and the like.

Optionally, the response message of the terminal device may include the uplink grant information, or may not include the uplink grant information.

Optionally, the response message of the terminal device may include the timing advance command, or may not include the timing advance command.

Optionally, the response message of the terminal device may include the TC-RNTI/C-RNTI, or may not include the TC-RNTI/C-RNTI.

In this case, the terminal device may not need to have network device reassigned since it is already in RRC _ Connected state and has obtained the C-RNTI.

It can be seen that, in this case, the random access response may include 0, any one, any two, or all three of the uplink grant information, the timing advance command, and the TC-RNTI/C-RNTI. Optionally, the random access response may further include an RRC message.

In the third case: the terminal equipment fails to solve the competition in the 2-step random access process based on the competition.

In this case, the network device does not obtain information for contention resolution according to the message sent by the terminal device, and at this time, the response message or the random access response of the terminal device may include uplink grant information, a timing advance command, and a TC-RNTI. Optionally, the response message or the random access response may further include an RRC message. Alternatively, the network device may instruct the terminal device to fall back from the contention-based 2-step random access procedure to the contention-based 4-step random access procedure. Accordingly, the terminal device may perform an operation shown in S403 in fig. 4 according to the parameter included in the response message or the random access response, and fall back from the contention based 2-step random access procedure to the 4-step based random access procedure. Optionally, the network device may instruct the terminal device to perform the contention-based 2-step random access procedure again. Accordingly, the terminal device may re-perform S601.

The embodiment provides a random access method, which includes: the terminal device sends a message to the network device, and the network device sends a response message of the message to the terminal device, wherein the response message comprises a MAC layer data packet, the MAC layer data packet comprises a load and a MAC subheader of the load, the MAC subheader comprises first indication information, and the first indication information is used for determining the length of the load. In the random access method provided by this embodiment, the terminal device may determine the start position of the MAC layer packet by setting the first indication information in the MAC subheader of the MAC layer packet, so as to implement detection of the response message. The method can be applied to a scene that the size of the response message is not fixed, for example, in a 2-step random access process based on competition.

Next, the first identification information will be described in detail with reference to the configurations shown in fig. 8A to 8C.

The second embodiment of the present application provides a random access method, and provides a specific implementation manner of the first identification information on the basis of the embodiment shown in fig. 6. Can be applied to the structures shown in fig. 8A to 8C.

In this embodiment, the first indication information is used to indicate the length of the payload of the MAC layer packet.

Because the length of the load of the MAC layer data packet can be directly indicated through the first indication information, the terminal equipment can determine the starting position of the MAC layer data packet through the first indication information, and the detection of the response message is realized in the 2-step random access process based on competition.

The length of the first indication information and the occupied position of the first indication information in the MAC subheader of the MAC layer packet are not limited in this embodiment. Optionally, the first indication information may be a preset bit length. The specific value of the preset bit length is not limited in this embodiment. For example, the predetermined bit length may be 7bits, 8bits, 15bits, or 16bits, etc. In this embodiment, the unit of the length of the payload of the MAC layer packet is not limited. For example, the unit of the length may be byte (byte) or bit (bit).

This is illustrated by way of example.

Fig. 9 is a schematic structural diagram of an implementation manner of a MAC subheader of a MAC layer packet according to an embodiment of the present application. In this example, the random access signal identification may be RAPID. The first indication information is represented by an L field, occupying 8bits in length.

As shown in fig. 9, the MAC subheader of the MAC layer packet includes first indication information (L field). The L field is 8bits long. Optionally, in an implementation, the length unit of the payload of the MAC layer packet is byte (byte), and the L field may indicate 255byte at the highest. The length of the load of the MAC layer packet can be directly indicated through the L field regardless of whether the load of the MAC layer packet includes uplink grant information, a timing advance command, a TC-RNTI, an RRC message, and contention resolution information. For example, when the L field is a binary sequence 00001111, it indicates that the payload of the MAC layer packet has a length of 15 bytes. For another example, when the L field is the binary sequence 00011111, the length of the payload representing the MAC layer packet is 31 bytes. Optionally, in another implementation, the length unit of the payload of the MAC layer packet is a bit (bit), and the L field may indicate 255 bits at the highest. For example, when the L field is a binary sequence 00011011, it indicates that the payload of the MAC layer packet has a length of 27 bits. For another example, when the L field is a binary sequence 00110111, the length of the payload of the MAC layer packet is 55 bits.

Optionally, the MAC subheader of the MAC layer packet may further include second indication information. The second indication information indicates the content of information included in the payload of the MAC layer packet.

Specifically, the first indication information indicates a length of a payload of the MAC layer packet. The payload of the MAC layer packet includes more contents, and may include, for example, a combination of one or more of uplink grant information, a timing advance command, a TC-RNTI, an RRC message, and contention resolution information. The following scenarios may exist: the payload of the MAC layer packet includes at least two kinds of information having the same length. For example, in the first example, the payload of the MAC layer packet includes information a and information B having the same length. In the second example, the payload of the MAC layer packet includes information a and information B having the same length, and also includes information C and information D having the same length. Wherein, the length of the information A is different from that of the information C. In this scenario, only by indicating the length of the payload of the MAC layer packet through the first indication information, it may not be possible to determine which kind of information is included in the payload of the MAC layer packet at all. For example, it cannot be determined whether the payload of the MAC layer packet includes information a or information B at all, or includes information C or information D. Therefore, by setting the second indication information in the MAC subheader of the MAC layer packet, which is used for indicating the content of the information included in the load of the MAC layer packet, the specific content included in the load of the MAC layer packet is convenient to determine, and the data processing efficiency is improved.

Optionally, the length and the number of the second indication information are related to the same length of information groups possibly included in the payload of the MAC layer packet and the number of information in each information group. For example, in the first example described above, the information a and the information B are one information group, and the number of pieces of information in the information group is 2. In the second example described above, information a and information B are one information group, information C and information D are another information group, and the number of information in each information group is 2. The number of the second indication information, the occupied bit length and the occupied position in the MAC subheader of the MAC layer packet are not limited in this embodiment.

This is illustrated by way of example.

Optionally, in an example, the payload of the MAC layer packet includes information a and information B having the same length. Referring to fig. 10, fig. 10 is a schematic structural diagram of another implementation manner of a MAC subheader of a MAC layer packet according to an embodiment of the present application. Wherein, the first indication information is represented by an L1 field, and occupies a length of 7 bits. The second indication information is represented by the L2 field, occupying a length of 1 bit. As shown in fig. 10, assuming that the length unit of the payload of the MAC layer packet is byte (byte), the first indication information (L1 field) is 7bits long, and 127 bytes can be indicated highest. And when the value of the L2 field is 0, indicating that the load of the MAC layer packet comprises information A, and when the value of the L2 field is 1, indicating that the load of the MAC layer packet comprises information B. Or, when the value of the L2 field is 1, the load of the MAC layer packet is indicated to include the information a, and when the value of the L2 field is 0, the load of the MAC layer packet is indicated to include the information B.

Optionally, in another example, the payload of the MAC layer packet includes information a and information B having the same length, and further includes information C and information D having the same length. The number of the second indication information may be 2, and each second indication information occupies a length of 1 bit. The value of one of the second indication information may indicate that the load of the MAC layer packet includes information a or information B. The value of the other second indication information may indicate that the load of the MAC layer packet includes information C or information D.

Optionally, in another example, the payload of the MAC layer packet includes information a and information B having the same length, and further includes information C and information D having the same length. The number of the second indication information may be 1, occupying 2bit length. By taking the value of the second indication information, it can be indicated that the load of the MAC layer packet includes a combination of information a, information B, information C, or information D. For example, when the second indication information is a binary sequence 01, the payload indicating the MAC layer packet includes information a and information C. When the second indication information is the binary sequence 11, the payload indicating the MAC layer packet includes information B and information C. When the second indication information is the binary sequence 00, the payload indicating the MAC layer packet includes information a and information D. When the second indication information is the binary sequence 10, the payload indicating the MAC layer packet includes information B and information D. The meaning of each value is not limited and can be adjusted.

In the random access method provided in this embodiment, the first indication information directly indicates the length of the payload of the MAC layer packet. The terminal equipment can determine the starting position of the MAC layer data packet through the first indication information, and detection of the response message is realized in the 2-step random access process based on competition.

A third embodiment of the present application provides a random access method, and provides another specific implementation manner of the first identification information on the basis of the embodiment shown in fig. 6. Can be applied to the structures shown in fig. 8A to 8C.

In this embodiment, the first indication information may include N indication fields, where N is greater than or equal to 1. Each indication field corresponds to one kind of information, and the indication field is used for indicating whether the load of the MAC layer data packet contains the information corresponding to the indication field.

Through the N indication fields, the terminal device can determine whether the load of the MAC layer data packet comprises information corresponding to each indication field. When the information included in the payload of the MAC layer packet is determined, the length of the payload of the MAC layer packet may be determined. Therefore, the terminal equipment can determine the initial position of the MAC layer data packet according to the length of the load of the MAC layer data packet, and the detection of the response message is realized in the 2-step random access process based on competition.

It should be noted that, in this embodiment, specific values of N, bit lengths occupied by each indication field, and occupied positions of the N indication fields in the MAC subheader of the MAC layer packet are not limited. Optionally, the bit lengths occupied by the indication fields corresponding to different information may be the same or different.

Next, N instruction fields included in the first instruction information will be described with reference to the configuration shown in fig. 8A.

Fig. 11 is a schematic structural diagram of another implementation manner of a MAC subheader of a MAC layer packet provided in an embodiment of the present application, and fig. 12 is a schematic structural diagram of another implementation manner of a MAC subheader of a MAC layer packet provided in an embodiment of the present application. Fig. 11 and 12 differ in the bit length of the CR field.

In the structure shown in fig. 8A, the payload of the MAC layer packet may include 0, any one, any two, or all three of the uplink grant information, the timing advance command, and the TC-RNTI. Therefore, the N indication fields include at least 3 indication fields corresponding to the uplink grant information, the timing advance command, and the TC-RNTI, respectively. For convenience of illustration, indication fields corresponding to the uplink grant information, the timing advance command, and the TC-RNTI are marked as a U field, a T1 field, and a T2 field, respectively. The present embodiment does not limit the names of the U field, the T1 field, and the T2 field, the bit lengths occupied respectively, and the occupied positions in the MAC subheader of the MAC layer packet. Optionally, in order to save resources, the U field, the T1 field, and the T2 field may all be 1-bit long, which may be referred to as the U field, the T1 field, and the T2 field in fig. 11 or fig. 12.

Optionally, for the U field, when the value of the U field is the first value, the load of the MAC layer packet may be indicated to include the uplink grant information. When the value of the U field is the second value, it may indicate that the load of the MAC layer packet does not include the uplink grant information. The specific values of the first numerical value and the second numerical value are not limited in this embodiment. For example, when the U field has a length of 1bit, the first value is 0 and the second value is 1. Alternatively, the first value is 1 and the second value is 0.

Similarly, the value of the T1 field indicates whether the load of the MAC layer packet contains the timing advance command, and the value of the T2 field indicates whether the load of the MAC layer packet contains the TC-RNTI, which is similar to the U field and is not described herein again.

In the structure shown in fig. 8A, the payload of the MAC layer packet may further include contention resolution information. Therefore, the N indication fields further include at least an indication field corresponding to the contention resolution information. For convenience of illustration, the indication field corresponding to the contention resolution information is marked as a CR field. The name, bit length and occupied position in the MAC subheader of the MAC layer packet of the CR field are not limited in this embodiment.

Optionally, when the information corresponding to the N indication fields includes contention resolution information, and the contention resolution information is a preset length, the indication field corresponding to the contention resolution information is 1 bit. For example, see the CR field in fig. 11. It should be noted that, the specific value of the preset length is not limited in this embodiment, for example, the preset length may be 48 bits.

How to indicate whether the load of the MAC layer packet contains contention resolution information through the value of the CR field is similar to the U field, and is not described here again.

Optionally, the valid bit of the contention resolution information is a preset length or a part of the preset length.

It should be noted that, in this embodiment, the specific length of the valid bit of the contention resolution information is not limited. For example, the predetermined length is 48bits, and the length of the valid bit of the contention resolution information may be 16bits, 32bits, 48bits, or the like.

It should be noted that, in the present embodiment, the occupied position of the valid bit of the contention resolution information in the preset length is not limited. For example, the predetermined length is 48bits, and the length of the valid bit of the contention resolution information is 16 bits. The 16bits can be the first 16bits with a preset length, or the last 16bits, etc.

The following description will be made with reference to two application scenarios, in which the effective bit of the contention resolution information is a preset length and is a part of the preset length, and the preset length is 48 bits.

Optionally, in an application scenario, the valid bit of the contention resolution information is a preset length. For example, the contention resolution information may refer to Msg4 in example S404 shown in fig. 4. For terminal devices in non-RRC _ CONNECTED state, Msg4 is fixed 48 bits. In this way, in the contention-based 2-step random access procedure applied in this embodiment, for the terminal device in the non-RRC _ CONNECTED state, the valid bit of the contention resolution information is a preset length. Through the CR field of 1bit, it can be indicated whether the payload of the MAC layer packet includes contention resolution information.

Optionally, in another application scenario, the valid bits of the contention resolution information are a part of the preset length. Specifically, in the 4-step contention-based random access procedure, referring to the example S404 shown in fig. 4, for a terminal device in an RRC _ CONNECTED state, Msg4 is implemented by a PDCCH scrambled by a C-RNTI. In the contention-based 2-step random access procedure applied in this embodiment, for a terminal device in an RRC _ CONNECTED state, the terminal device has already obtained a C-RNTI. In S601, the terminal device may transmit the C-RNTI to the network device as information for contention resolution in a message transmitted to the network device. Accordingly, when the payload of the MAC layer packet includes contention resolution information, the network device may carry the C-RNTI indication in the payload of the MAC layer packet. Therefore, the contention resolution information may also be a C-RNTI of 16bits in length. Since the preset length is 48bits, the significant bits of the contention resolution information are a part of the preset length. Through the CR field of 1bit, it can be indicated whether the payload of the MAC layer packet includes contention resolution information.

Optionally, when the information corresponding to the N indication fields includes contention resolution information, the indication field corresponding to the contention resolution information may be 2bits, and the indication field corresponding to the contention resolution information indicates whether the load of the MAC layer packet includes the contention resolution information and also indicates the length of the contention resolution information. For example, see the CR field in fig. 12. It should be noted that, in this embodiment, a specific value of the length of the contention resolution information is not limited. For example, referring to the above description, the Contention Resolution information may be a UE context Resolution Identity MAC CE of 48bits or C-RNTI MAC CE of 16bits, etc.

How to indicate whether the load of the MAC layer packet contains contention resolution information and the length of the contention resolution information by the value of the CR field is described below. It is assumed that there are two lengths of contention resolution information, one is 48bits and the other is 16 bits.

Optionally, in an implementation, the 2-bit CR field directly indicates whether the payload of the MAC layer packet includes contention resolution information and the length of the contention resolution information.

For example, when the CR field is a binary sequence 00, the payload for indicating the MAC layer packet does not include contention resolution information. When the CR field is a binary sequence 01, the CR field is used to indicate that the payload of the MAC layer packet includes contention resolution information, and the length of the contention resolution information is 16 bits. When the CR field is the binary sequence 10, the CR field is used to indicate that the payload of the MAC layer packet includes contention resolution information, and the length of the contention resolution information is 48 bits.

Optionally, in another implementation, 1bit in the CR field is used to indicate whether the payload of the MAC layer packet includes contention resolution information, and another 1bit in the CR field is used to indicate the length of the contention resolution information.

For example, the first bit in the CR field is used to indicate whether the payload of the MAC layer packet includes contention resolution information. And when the value is 0, indicating that the load of the MAC layer data packet does not comprise the competition resolving information, and when the value is 1, indicating that the load of the MAC layer data packet comprises the competition resolving information. The second bit is used to indicate the length of the contention resolution information. When the value is 0, the length of the contention resolution information is indicated to be 48bits, and when the value is 1, the length of the contention resolution information is indicated to be 16 bits. Thus, when the CR field is a binary sequence 00 or 01, the payload for indicating the MAC layer packet does not include contention resolution information. When the CR field is the binary sequence 11, the CR field is used to indicate that the payload of the MAC layer packet includes contention resolution information, and the length of the contention resolution information is 16 bits. When the CR field is the binary sequence 10, the CR field is used to indicate that the payload of the MAC layer packet includes contention resolution information, and the length of the contention resolution information is 48 bits.

Next, N instruction fields included in the first instruction information will be described with reference to the configurations shown in fig. 8B to 8C.

Fig. 13 is a schematic structural diagram of another implementation manner of a MAC subheader of a MAC layer packet according to an embodiment of the present application. Fig. 13 is different from fig. 11 and 12 in that there is no CR field corresponding to contention resolution information in fig. 13.

The descriptions of the U field, the T1 field, and the T2 field in fig. 13 can refer to the related descriptions in the structure shown in fig. 8A, and the principles are similar and are not repeated here.

In the random access method provided in this embodiment, the first indication information may include N indication fields, where N is greater than or equal to 1. Each indication field corresponds to one kind of information, and the indication field is used for indicating whether the load of the MAC layer data packet contains the information corresponding to the indication field. Through the N indication domains, the terminal device can determine whether the load of the MAC layer data packet comprises information corresponding to each indication domain, and further can determine the length of the load of the MAC layer data packet. The terminal equipment can determine the initial position of the MAC layer data packet through the N indication domains, and the detection of the MAC layer data packet is realized in the 2-step random access process based on competition.

A random access method is provided in the fourth embodiment of the present application, and on the basis of the embodiment shown in fig. 6, another specific implementation manner of the first indication information is provided. Can be applied to the structures shown in fig. 8A to 8C.

In this embodiment, the first indication information may include an information index value, and the information index value has a corresponding relationship with the length of the payload of the MAC layer packet. The information index value is used for determining the length of the load of the MAC layer data packet according to the corresponding relation between the preset information index value and the load length of the MAC layer data packet.

Specifically, in this implementation, there is a correspondence between the information index value and the length of the payload of the MAC layer packet. After the terminal device obtains the information index value carried in the MAC subheader of the MAC layer packet, the length of the load of the MAC layer packet can be determined according to the correspondence between the information index value and the load length of the MAC layer packet. After the length of the load of the MAC layer packet is determined, the terminal device may determine the start position of the MAC layer packet, and implement detection of the response message in the contention-based 2-step random access process. In addition, the bit length occupied by the first indication information can be further reduced, the bit waste is further reduced, and the resource utilization rate is improved.

It should be noted that, in this embodiment, there is no limitation on the corresponding relationship between the bit length of the information index value, the occupied position in the MAC subheader of the MAC layer packet, and the information index value and the load length of the MAC layer packet.

The correspondence between the information index value and the payload length of the MAC layer packet will be described with reference to the structures shown in fig. 8A to 8C. Suppose that the uplink grant information is 27bits, the timing advance command is 12bits, and the TC-RNTI is 16 bits. The contention resolution information includes two lengths, one is 48bits long, and the other is 16bits long. It should be noted that the length of each piece of information is not limited in this embodiment, and this is merely an example.

In the structure shown in fig. 8A, the payload of the MAC layer packet may include 0, any one, any two, or all three of the uplink grant information, the timing advance command, and the TC-RNTI, and may further include contention resolution information, and the contention resolution information may have various lengths. By combining the permutations between different information, the length of the payload of the MAC layer packet can be determined. The bit length occupied by the information index value and the corresponding relation between the information index value and the load length of the MAC layer data packet can be determined according to the number of the load lengths of the MAC layer data packets. Illustratively, table 3 shows some examples of the correspondence between the information index value and the payload length of the MAC layer packet. Wherein, the information index value may be 5bits long.

In the structures shown in fig. 8B to 8C, the payload of the MAC layer packet may include 0, any one, any two, or all three of the uplink grant information, the timing advance command, and the TC-RNTI. Illustratively, table 4 shows some examples of the correspondence between the information index value and the payload length of the MAC layer packet. Wherein, the information index value may be 3 bits long.

Specifically, refer to the description about the second indication information in the second embodiment. The principle is similar, and the detailed description is omitted here.

TABLE 3

TABLE 4

In the random access method provided in this embodiment, the first indication information may include an information index value, and the information index value has a corresponding relationship with a length of a load of the MAC layer packet. The information index value is used for determining the length of the load of the MAC layer data packet according to the corresponding relation between the preset information index value and the load length of the MAC layer data packet. Through the information index value, the terminal equipment can determine the length of the load of the MAC layer data packet, further, the terminal equipment can determine the initial position of the MAC layer data packet, and the detection of the response message is realized in the 2-step random access process based on competition.

The embodiment of the application also relates to the following scenes: the terminal equipment performs 2-step random access process based on competition. Specifically, the network device may determine that the terminal device performs a contention-based 2-step random access procedure. For example, in S601, the terminal device transmits a message to the network device. The message may include a random access signal and information for contention resolution. The network device may determine whether the terminal device performs the contention-based 2-step random access procedure according to the type of the random access signal or a time-frequency resource (e.g., PRACH time-frequency resource) transmitted by the random access signal. If the network device determines that the terminal device performs the 2-step random access process based on the competition, but the network device does not successfully decode the information for solving the competition, at this time, the network device may control the terminal device to fall back from the 2-step random access process based on the competition to the 4-step random access process based on the competition; or, the network device may control the terminal device to perform the contention-based 2-step random access process again; or, the network device may control the terminal device to perform a contention-based 4-step random access procedure. If the network device controls the terminal device to fall back from the contention-based 2-step random access procedure to the contention-based 4-step random access procedure, at this time, the network device may send a response message of the message to the terminal device. Optionally, the response message of the message includes uplink grant information, a timing advance command, and a TC-RNTI. Subsequently, the terminal device may execute S403 to S404 in fig. 4 according to the received response message of the message, and perform random access backoff. If the network device controls the terminal device to perform the contention-based 2-step random access procedure again, or controls the terminal device to perform the contention-based 4-step random access procedure, at this time, the network device may send a response message of the message to the terminal device, or the network device does not send a response message of the message to the terminal device. Optionally, the response message of the message may include 0, any one, or any two of the uplink grant information, the timing advance command, and the TC-RNTI. Subsequently, the terminal device may perform the contention-based 2-step random access procedure again, and re-execute S601 in fig. 6; alternatively, the terminal device may perform a contention-based 4-step random access procedure, and execute S401 to S404 in fig. 4.

Next, a random access method provided in the embodiments of the present application is described with reference to the above scenarios in fifth to seventh embodiments. The fifth to seventh embodiments and the first embodiment can be combined with each other. It should be noted that, in the fifth to seventh embodiments, if response messages corresponding to a plurality of terminal devices that send random access signals on the same time-frequency resource are multiplexed into one MAC PDU, the terminal device may detect and obtain the response message of the terminal device in the MAC PDU. It should be noted that, in the fifth to seventh embodiments, if the network device sends a response message of the message to the terminal device, the response message of the message does not include the contention resolution information.

The fifth embodiment of the present application provides a random access method, and an execution subject relates to a network device and a terminal device. The random access method provided by this embodiment may include:

the terminal device sends a message to the network device. Specifically, the description of S601 may be referred to, and the principle is similar, which is not described herein again. Correspondingly, the network equipment receives the message sent by the terminal equipment.

After the terminal equipment sends a message to the network equipment, the timer is started. And the terminal equipment waits for receiving the response message of the message sent by the network equipment within the time range indicated by the timer. The present embodiment does not limit the names of the timers and the indicated time ranges. For example, reference may be made to the RAR time window in S402 in the example shown in fig. 4.

The network device receives the message sent by the terminal device, and determines that the terminal device performs a 2-step random access process based on contention, but the network device does not successfully decode the information for contention resolution. At this time, the network device may not transmit a response message to the terminal device. Accordingly, the terminal device does not receive the response message of the message sent by the network device before the timer is overtime.

Optionally, in an embodiment, after the timer expires, the terminal device may perform the contention-based 2-step random access procedure again. For example, S601 in fig. 6 is re-executed.

Optionally, in another embodiment, after the timer expires, the terminal device may perform a contention-based 4-step random access procedure. For example, S401 to S404 in fig. 4 are executed.

In the random access method provided in this embodiment, the terminal device sends a message to the network device, starts the timer, and when the timer times out, the terminal device does not receive a response message of the terminal device, and the terminal device will perform the contention-based 2-step random access procedure again or perform the contention-based 4-step random access procedure. In the random access method provided by this embodiment, the terminal device performs a 2-step random access process based on contention, and the network device may control the terminal device to perform the 2-step random access process based on contention again or perform a 4-step random access process based on contention, thereby improving the flexibility of random access.

The sixth embodiment of the present application provides a random access method. In the random access method provided in this embodiment, the execution subject relates to a network device and a terminal device, and the related message interaction flow may refer to S601 to S602 in fig. 6.

In this embodiment, the MAC subheader of the MAC layer packet may further include backoff indication information, where the backoff indication information is used to indicate whether to perform random access backoff. Wherein, the random access fallback refers to fallback from a 2-step random access process based on contention to a 4-step random access process based on contention.

Specifically, after sending a message to the network device, the terminal device receives a response message of the message sent by the network device. If the MAC subheader of the MAC layer packet included in the response message carries the backoff indication information, the terminal device may determine whether to perform random access backoff according to the backoff indication information. If the backoff indication information indicates that the terminal device performs random access backoff, the response message of the message includes uplink grant information, a timing advance command and a TC-RNTI, and subsequently, the terminal device may perform a contention-based 4-step random access process according to information carried in the response message of the message, and execute S403 and S404 in fig. 4. If the backoff indication information indicates that the terminal device does not perform random access backoff, then, optionally, in an implementation manner, the terminal device may perform a contention-based 2-step random access procedure again, and execute S601 to S602 in fig. 6. Optionally, in another implementation manner, the terminal device may perform a contention-based 4-step random access procedure, and execute S401 to S404 in fig. 4.

It should be noted that, the length of the fallback indication information and the occupied location in the MAC subheader of the MAC layer packet are not limited in this embodiment. For example, the length of the back-off indication information is 1bit length. Optionally, when the value of the backoff indication information is the first value, the terminal device is indicated to perform random access backoff. Optionally, when the value of the backoff indication information is the second value, the terminal device is indicated not to perform random access backoff. It should be noted that, in this embodiment, specific values of the first numerical value and the second numerical value are not limited. For example, when the back-off indication information has a length of 1bit, the first value is 0, and the second value is 1. Alternatively, the first value is 1 and the second value is 0.

In the random access method provided in this embodiment, the backoff indication information is set in the MAC subheader of the MAC layer packet, and in the 2-step random access process based on contention, the network device may control whether the terminal device backs to the 4-step random access process based on contention through the backoff indication information. And when the network device controls the terminal device not to perform random access backoff through the backoff indication information, the terminal device may perform the 2-step random access process based on contention or perform the 4-step random access process based on contention again, thereby improving the flexibility of random access.

The seventh embodiment of the present application provides a random access method. In the random access method provided in this embodiment, the execution subject relates to a network device and a terminal device, and the related message interaction flow may refer to S601 to S602 in fig. 6.

In this embodiment, the MAC subheader of the MAC layer packet includes the first indication information. The first indication information is used for determining the length of the load of the MAC layer data packet, and the value of the first indication information is a preset value.

Optionally, in an embodiment, the first indication information is further used to instruct the terminal device to perform the contention-based 2-step random access procedure again. At this time, the response message of the message includes 0 item, any one item or any two items in the uplink authorization information, the timing advance command and the TC-RNTI. Subsequently, the terminal device may perform the contention based 2-step random access procedure again, and execute S601 to S602 in fig. 6.

Optionally, in another embodiment, the first indication information is further used to instruct the terminal device to perform a contention-based 4-step random access procedure. At this time, the response message of the message includes 0 item, any one item or any two items in the uplink authorization information, the timing advance command and the TC-RNTI. Subsequently, the terminal device performs a 4-step random access process based on contention, and executes S401 to S404 in fig. 4.

Optionally, in another embodiment, the first indication information is further used for indicating the terminal device to perform random access backoff. At this time, the response message of the message includes uplink grant information, a timing advance command, and a TC-RNTI. Subsequently, the terminal device may fall back from the contention based 2-step random access procedure to the contention based 4-step random access procedure according to the response message of the message, and execute S403 to S404 in fig. 4.

It should be noted that, in this embodiment, specific values of the preset values are not limited.

The preset value will be described below with reference to different implementation manners of the first indication information in the second to fourth embodiments.

With reference to the second embodiment, the first indication information is used to indicate the length of the payload of the MAC layer packet. The first indication information may be a preset bit length. Optionally, the MAC subheader of the MAC layer packet may further include second indication information, where the second indication information is used to indicate content of information included in a payload of the MAC layer packet. Illustratively, the length unit of the payload of the MAC layer packet is a bit (bit).

Optionally, in the first example, referring to fig. 9, the MAC subheader of the MAC layer packet includes first indication information (L field) which is 8bits long. The preset value of the first indication information (L field) is a binary sequence 00000000, corresponding to a decimal number of 0. At this time, the first indication information (L field) indicates that the length of the payload of the MAC layer packet is 0 bit. The first indication information is a preset value, and is used to indicate the terminal device to perform the contention-based 2-step random access procedure again, and execute S601 to S602 in fig. 6, or is used to indicate the terminal device to perform the contention-based 4-step random access procedure, and execute S401 to S404 in fig. 4.

Alternatively, in the second example, referring to fig. 9, the MAC subheader of the MAC layer packet includes the first indication information (L field), which is 8bits long. The preset value of the first indication (L field) is a binary sequence 00011011, corresponding to the decimal value 27. At this time, the first indication information (L field) indicates that the length of the payload of the MAC layer packet is 27 bits. It may be determined that the response message of the message includes only the uplink grant information. The first indication information is a preset value, and is used to indicate the terminal device to perform the contention-based 2-step random access procedure again, and execute S601 to S602 in fig. 6, or is used to indicate the terminal device to perform the contention-based 4-step random access procedure, and execute S401 to S404 in fig. 4.

Alternatively, in the third example, referring to fig. 10, the MAC subheader of the MAC layer packet includes first indication information (L1 field) and second indication information (L2 field). The L1 field is 7bits long and the L2 field is 1bit long. The preset value of the first indication information (L field) is a binary sequence 00000000, corresponding to a decimal number of 0. At this time, the first indication information (L1 field) indicates that the payload of the MAC layer packet has a length of 0 bit. The first indication information is a preset value, and is used to indicate the terminal device to perform the contention-based 2-step random access procedure again, and execute S601 to S602 in fig. 6, or is used to indicate the terminal device to perform the contention-based 4-step random access procedure, and execute S401 to S404 in fig. 4.

Alternatively, in the fourth example, referring to fig. 10, the MAC subheader of the MAC layer packet includes first indication information (L1 field) and second indication information (L2 field). The L1 field is 7bits long and the L2 field is 1bit long. The preset value of the first indication information (L1 field) is a binary sequence 00110111. At this time, the first indication information (L1 field) indicates that the payload of the MAC layer packet has a length of 55 bits. The second indication information (L2 field) is a binary value of 0 for indicating that the payload of the MAC layer packet includes TC-RNTI. It may be determined that a response message of the message includes uplink grant information, a timing advance command, and a TC-RNTI. The first indication information is a preset numerical value and is used for indicating the terminal equipment to return from the 2-step random access process based on the competition to the 4-step random access process based on the competition. The terminal device may perform S403 to S404 in fig. 4 according to the response message of the message.

With reference to the third embodiment, the first indication information may include N indication fields, where N is greater than or equal to 1. Each indication field corresponds to one kind of information, and the indication field is used for indicating whether the load of the MAC layer data packet contains the information corresponding to the indication field.

Optionally, in the first example, referring to fig. 11 or 12, in the MAC subheader of the MAC layer packet, the N indication fields include a U field, a T1 field, a T2 field, and a CR field. Wherein, the value of the CR field is 0, which is used to indicate that the load of the MAC layer packet does not include contention resolution information. When the U field, the T1 field, and the T2 field in the first indication information are all binary values of 0, the first indication information indicates that the length of the payload of the MAC layer packet is 0. The first indication information is a preset value, and is used to indicate the terminal device to perform the contention-based 2-step random access procedure again, and execute S601 to S602 in fig. 6, or is used to indicate the terminal device to perform the contention-based 4-step random access procedure, and execute S401 to S404 in fig. 4.

Optionally, in the second example, referring to fig. 11 or 12, in the MAC subheader of the MAC layer packet, the N indication fields include a U field, a T1 field, a T2 field, and a CR field. Wherein, the value of the CR field is 0, which is used to indicate that the load of the MAC layer packet does not include contention resolution information. When the U field and the T1 field in the first indication information are both binary values 0 and the T2 field is binary values 1, the first indication information indicates that the load of the MAC layer packet does not include uplink grant information and TC-RNTI, only includes a timing advance command, and the length of the load of the MAC layer packet is 12 bits. The first indication information is a preset value, and is used to indicate the terminal device to perform the contention-based 2-step random access procedure again, and execute S601 to S602 in fig. 6, or is used to indicate the terminal device to perform the contention-based 4-step random access procedure, and execute S401 to S404 in fig. 4.

Alternatively, in a third example, referring to fig. 11 or 12, in the MAC subheader of the MAC layer packet, the N indication fields include a U field, a T1 field, a T2 field, and a CR field. Wherein, the value of the CR field is 0, which is used to indicate that the load of the MAC layer packet does not include contention resolution information. When the U field, the T1 field, and the T2 field in the first indication information are all binary values of 1, the first indication information indicates that the load of the MAC layer packet includes uplink authorization information, a timing advance command, and TC-RNTI, and the length of the load of the MAC layer packet is 55 bits. The first indication information is a preset numerical value and is used for indicating the terminal equipment to return from the 2-step random access process based on the competition to the 4-step random access process based on the competition. The terminal device may perform S403 to S404 in fig. 4 according to the response message of the message.

In contrast to the structures shown in fig. 11 and 12, the structure shown in fig. 13 does not have a CR field in fig. 13. However, for the values of the U field, the T1 field, and the T2 field, which are similar to the principle that the terminal device performs the random access backoff or re-performs the contention-based 2-step random access procedure or performs the contention-based 4-step random access procedure, reference may be made to the above three examples, and details are not described here.

With reference to the fourth embodiment, the first indication information may include an information index value, and the information index value has a corresponding relationship with the length of the payload of the MAC layer packet. The information index value is used for determining the length of the load of the MAC layer data packet according to the corresponding relation between the preset information index value and the load length of the MAC layer data packet. The information index value may be a preset bit length. Optionally, the MAC subheader of the MAC layer packet may further include second indication information, where the second indication information is used to indicate content of information included in a payload of the MAC layer packet.

Optionally, in the first example, referring to table 3, the MAC subheader of the MAC layer packet includes an information index value, which is 5bits long. The preset value of the information index value is a binary sequence 00000 corresponding to a decimal number of 0. At this time, the information index value indicates that the length of the payload of the MAC layer packet is 0 bit. The first indication information is a preset value, and is used to indicate the terminal device to perform the contention-based 2-step random access procedure again, and execute S601 to S602 in fig. 6, or is used to indicate the terminal device to perform the contention-based 4-step random access procedure, and execute S401 to S404 in fig. 4.

Optionally, in a second example, referring to table 4, the MAC subheader of the MAC layer packet includes an information index value, which is 3 bits long. The predetermined value of the information index value is binary sequence 001. At this time, the information index value indicates that the length of the payload of the MAC layer packet is 27 bits. It may be determined that the response message of the message includes only the uplink grant information. The first indication information is a preset value, and is used to indicate the terminal device to perform the contention-based 2-step random access procedure again, and execute S601 to S602 in fig. 6, or is used to indicate the terminal device to perform the contention-based 4-step random access procedure, and execute S401 to S404 in fig. 4.

Optionally, in a third example, referring to table 3, the MAC subheader of the MAC layer packet includes the information index value and the second indication information. The information index value is 5bits long and the second indication information is 1bit long. The preset value of the information index value is 01001. At this time, the information index value indicates that the length of the payload of the MAC layer packet is 55 bits. The second indication information is a binary value of 0, and is used for indicating that the load of the MAC layer data packet comprises TC-RNTI. It may be determined that a response message of the message includes uplink grant information, a timing advance command, and a TC-RNTI. The first indication information is a preset numerical value and is used for indicating the terminal equipment to return from the 2-step random access process based on the competition to the 4-step random access process based on the competition. The terminal device may perform S403 to S404 in fig. 4 according to the response message of the message.

Optionally, in a fourth example, referring to table 4, the MAC subheader of the MAC layer packet includes an information index value, which is 3 bits long. The predetermined value of the information index value is a binary sequence 111. At this time, the information index value indicates that the length of the payload of the MAC layer packet is 55 bits. It may be determined that a response message of the message includes uplink grant information, a timing advance command, and a TC-RNTI. The first indication information is a preset numerical value and is used for indicating the terminal equipment to return from the 2-step random access process based on the competition to the 4-step random access process based on the competition. The terminal device may perform S403 to S404 in fig. 4 according to the response message of the message.

In the random access method provided in this embodiment, the MAC subheader of the MAC layer packet sets the first indication information. In the 2-step random access process based on the competition, the network device may control the terminal device to perform the 2-step random access process based on the competition again, or perform the 4-step random access process based on the competition, or fall back from the 2-step random access process based on the competition to the 4-step random access process based on the competition by setting the first indication information to a preset value.

The present application further provides an apparatus for implementing any one of the above methods, for example, a chip apparatus, which is used for a terminal device or a network device, and includes a unit (or means) for implementing each step performed by the terminal device in any one of the above methods.

For example, fig. 14 is a schematic structural diagram of an apparatus provided in an embodiment of the present application. As shown in fig. 14, the apparatus provided in this embodiment may include:

a sending module 11, configured to send a message to a network device, where the message is used for a terminal device to request a random access from the network device;

a receiving module 12, configured to receive a response message of the message from the network device, where the response message includes a MAC layer packet, the MAC layer packet includes a payload and a MAC subheader of the payload, and the MAC subheader includes first indication information, and the first indication information is used to determine a length of the payload.

The apparatus may further comprise a processing module 13 for controlling the sending module 11 to send the message. In addition, the processing module 13 may also process the response message, for example, process information carried by a load of the response message, and detect the response message according to the first indication information.

Optionally, the message includes a random access signal and information for contention resolution, where the random access signal is used to request random access;

the load comprises competition resolving information, the competition resolving information is used for indicating competition resolving or indicating success of random access, and the competition resolving information is obtained according to the information for competition resolving; alternatively, the load does not include contention resolution information for indicating a contention resolution failure or for indicating a random access backoff.

Optionally, the load further includes one or more of the following information: the system comprises uplink authorization information, a timing advance command, a temporary cell radio network temporary identifier TC-RNTI and a radio resource control RRC message.

Optionally, the first indication information is used to indicate a length of the load.

Optionally, the first indication information is a preset bit length.

Optionally, the first indication information includes N indication fields, where N is greater than or equal to 1; each indication field corresponds to one kind of information, and the indication field is used for indicating whether the load contains the information corresponding to the indication field.

Optionally, the information corresponding to the N indication fields includes contention resolution information, the contention resolution information is a preset length, and the indication field corresponding to the contention resolution information is 1 bit; or the information corresponding to the N indication fields includes contention resolution information, the indication field corresponding to the contention resolution information is 2bits, and the indication field corresponding to the contention resolution information is further configured to indicate a length of the contention resolution information.

Optionally, the valid bits of the contention resolution information are the preset length or a part of the preset length.

Optionally, the first indication information includes an information index value, and a corresponding relationship exists between the information index value and the length of the load; the information index value is used for determining the length of the load according to the corresponding relation between the preset information index value and the length of the load.

Optionally, the MAC subheader further includes backoff indication information, where the backoff indication information is used to indicate whether to perform random access backoff.

The apparatus provided in this embodiment is configured to execute operations executed by a terminal device in the random access method provided in any of the foregoing embodiments, and the technical principle and the technical effect are similar and will not be described herein again.

For example, fig. 15 is a schematic structural diagram of another apparatus provided in an embodiment of the present application. As shown in fig. 15, the apparatus provided in this embodiment may include:

a receiving module 21, configured to receive a message sent by a terminal device, where the message is used for the terminal device to request a network device for random access;

a sending module 22, configured to send a response message of the message to the terminal device, where the response message includes a MAC layer packet, the MAC layer packet includes a load and a MAC subheader of the load, the MAC subheader includes first indication information, and the first indication information is used to determine a length of the load.

The apparatus may further include a control module 23 for generating a response message and controlling the transmission module 22 to transmit the response message. The generation of the specific response message may refer to the description in the above method embodiment.

Optionally, the first indication information is a preset bit length.

Optionally, the information corresponding to the N indication fields includes contention resolution information, the contention resolution information is a preset length, and the indication field corresponding to the contention resolution information is 1 bit;

alternatively, the first and second electrodes may be,

the information corresponding to the N indication fields includes contention resolution information, the indication field corresponding to the contention resolution information is 2bits, and the indication field corresponding to the contention resolution information is further configured to indicate a length of the contention resolution information.

The apparatus provided in this embodiment is configured to execute operations executed by the network device in the random access method provided in any of the foregoing embodiments, and the technical principle and the technical effect are similar and will not be described herein again.

It should be understood that the division of the modules in the above apparatus is only a division of logical functions, and the actual implementation may be wholly or partially integrated into one physical entity or may be physically separated. And the modules in the device can be realized in the form of software called by the processing element; or may be implemented entirely in hardware; and part of the modules can be realized in the form of software called by the processing element, and part of the modules can be realized in the form of hardware. For example, each module may be a processing element separately set up, or may be implemented by being integrated in a chip of the apparatus, or may be stored in a memory in the form of a program, and a function of the module may be called and executed by a processing element of the apparatus. In addition, all or part of the modules can be integrated together or can be independently realized. The processing element described herein may in turn be a processor, which may be an integrated circuit having signal processing capabilities. In the implementation process, the steps of the method or the modules above may be implemented by integrated logic circuits of hardware in a processor element or in a form called by software through the processor element.

In one example, the modules in any of the above apparatus may be one or more integrated circuits configured to implement the above methods, such as: one or more Application Specific Integrated Circuits (ASICs), or one or more microprocessors (DSPs), or one or more Field Programmable Gate Arrays (FPGAs), or a combination of at least two of these integrated circuit forms. As another example, when a module in a device may be implemented in the form of a Processing element scheduler, the Processing element may be a general-purpose processor, such as a Central Processing Unit (CPU) or other processor that may invoke a program. As another example, these modules may be integrated together, implemented in the form of a system-on-a-chip (SOC).

The above module for receiving is an interface circuit of the apparatus for receiving signals from other apparatuses. For example, when the device is implemented in the form of a chip, the receiving module is an interface circuit for the chip to receive signals from other chips or devices. The above module for transmitting is an interface circuit of the apparatus for transmitting signals to other apparatuses. For example, when the device is implemented in the form of a chip, the transmitting module is an interface circuit used by the chip to transmit signals to other chips or devices.

When the above apparatus is applied to a network device, please refer to fig. 16, which is a schematic structural diagram of a network device according to an embodiment of the present disclosure. Which may be the network device in the above embodiments, for implementing the operations of the network device in the above embodiments.

As shown in fig. 16, the network device includes: antenna 201, radio frequency device 202, baseband device 203. Antenna 201 is connected to radio frequency device 202. In the uplink direction, rf device 202 receives information transmitted by the terminal device through antenna 201, and transmits the information transmitted by the terminal device to baseband device 203 for processing. In the downlink direction, the baseband device 203 processes the information of the terminal device and sends the information to the radio frequency device 202, and the radio frequency device 202 processes the information of the terminal device and sends the information to the terminal device through the antenna 201.

The baseband device 203 may include one or more processing elements 2031, including, for example, a main CPU and other integrated circuits. Further, the baseband apparatus 203 may further include a storage element 2032 and an interface 2033, the storage element 2032 being used for storing programs and data; the interface 2033 is used for exchanging information with the rf device 202, and is, for example, a Common Public Radio Interface (CPRI). The above means for a network device may be located on the baseband means 203, for example, the above means for a network device may be a chip on the baseband means 203, the chip comprising at least one processing element for performing the steps of any of the methods performed by the above network device and interface circuitry for communicating with other devices. In one implementation, the unit of the network device for implementing the steps in the above method may be implemented in the form of a processing element scheduler, for example, an apparatus for the network device includes a processing element and a storage element, and the processing element calls a program stored in the storage element to execute the method executed by the network device in the above method embodiment. The memory elements may be memory elements on the same chip as the processing element, i.e. on-chip memory elements, or may be memory elements on a different chip than the processing element, i.e. off-chip memory elements.

In another implementation, the unit of the network device for implementing the steps of the above method may be configured as one or more processing elements, which are disposed on the baseband apparatus, where the processing elements may be integrated circuits, for example: one or more ASICs, or one or more DSPs, or one or more FPGAs, or a combination of these types of integrated circuits. These integrated circuits may be integrated together to form a chip.

The units of the network device implementing the steps of the above method may be integrated together and implemented in the form of a system-on-a-chip (SOC), for example, a baseband device including the SOC chip for implementing the above method. At least one processing element and a storage element can be integrated in the chip, and the method executed by the network equipment is realized in the form that the processing element calls the stored program of the storage element; or, at least one integrated circuit may be integrated in the chip, for implementing the method executed by the above network device; alternatively, the above implementation modes may be combined, the functions of the partial units are implemented in the form of a processing element calling program, and the functions of the partial units are implemented in the form of an integrated circuit.

It is seen that the above apparatus for a network device may comprise at least one processing element and interface circuitry, wherein the at least one processing element is configured to perform the method performed by any one of the network devices provided by the above method embodiments. The processing element may: namely, calling the program stored in the storage element to execute part or all of the steps executed by the network equipment; it is also possible to: that is, some or all of the steps performed by the network device are performed by integrated logic circuitry of hardware in the processor element in combination with the instructions; of course, some or all of the steps performed by the above network device may also be performed in combination with the first manner and the second manner.

The processing elements herein, like those described above, may be a general purpose processor, such as a CPU, or one or more integrated circuits configured to implement the above methods, such as: one or more ASICs, or one or more microprocessors DSP, or one or more FPGAs, etc., or a combination of at least two of these integrated circuit forms.

The storage element may be a memory or a combination of a plurality of storage elements.

When the above apparatus is applied to a terminal device, please refer to fig. 17, which is a schematic structural diagram of a terminal device according to an embodiment of the present application. It may be the terminal device in the above embodiment, for implementing the operation of the terminal device in the above embodiment. As shown in fig. 17, the terminal device includes: antenna 310, radio frequency device 320, baseband device 330. The antenna 310 is connected to a radio frequency device 320. In the downlink direction, the rf device 320 receives information transmitted by the network device through the antenna 310, and transmits the information transmitted by the network device to the baseband device 330 for processing. In the uplink direction, the baseband device 330 processes the information of the terminal device and sends the information to the radio frequency device 320, and the radio frequency device 320 processes the information of the terminal device and sends the information to the network device through the antenna 310.

The baseband device 330 may include a modem subsystem for implementing processing of various communication protocol layers of data; the system also comprises a central processing subsystem used for realizing the processing of the operating system and the application layer of the terminal equipment; in addition, other subsystems, such as a multimedia subsystem for controlling a camera, a screen display, etc. of the terminal device, a peripheral subsystem for connecting with other devices, etc. may be included. The modem subsystem may be a separately provided chip. Alternatively, the above means for the terminal device may be located at the modem subsystem.

The modem subsystem may include one or more processing elements 331, including, for example, a master CPU and other integrated circuits. The modem subsystem may also include a storage element 332 and an interface circuit 333. The storage element 332 is used to store data and programs, but the program for executing the method executed by the terminal device in the above method may not be stored in the storage element 332, but may be stored in a memory outside the modem subsystem, and the modem subsystem is loaded for use when in use. The interface circuit 333 is used to communicate with other subsystems. The above apparatus for a terminal device may be located in a modem subsystem, which may be implemented by a chip comprising at least one processing element for performing the steps of any of the methods performed by the above terminal device and interface circuitry for communicating with other apparatus. In one implementation, the unit for the terminal device to implement each step in the above method may be implemented in the form of a processing element scheduler, for example, an apparatus for the terminal device includes a processing element and a storage element, and the processing element calls a program stored in the storage element to execute the method executed by the terminal device in the above method embodiment. The memory elements may be memory elements with the processing elements on the same chip, i.e. on-chip memory elements.

In another implementation, the program for performing the method performed by the terminal device in the above method may be a memory element on a different chip than the processing element, i.e. an off-chip memory element. At this time, the processing element calls or loads a program from the off-chip storage element onto the on-chip storage element to call and execute the method executed by the terminal device in the above method embodiment.

In yet another implementation, the unit of the terminal device for implementing the steps of the above method may be configured as one or more processing elements disposed on the modem subsystem, where the processing elements may be integrated circuits, for example: one or more ASICs, or one or more DSPs, or one or more FPGAs, or a combination of these types of integrated circuits. These integrated circuits may be integrated together to form a chip.

The units of the terminal device for implementing the steps of the above method can be integrated together and implemented in the form of a system-on-a-chip (SOC) chip for implementing the above method. At least one processing element and a storage element can be integrated in the chip, and the processing element calls the stored program of the storage element to realize the method executed by the terminal equipment; or, at least one integrated circuit may be integrated in the chip, for implementing the method executed by the above terminal device; alternatively, the above implementation modes may be combined, the functions of the partial units are implemented in the form of a processing element calling program, and the functions of the partial units are implemented in the form of an integrated circuit.

It is seen that the above apparatus for a terminal device may comprise at least one processing element and interface circuitry, wherein the at least one processing element is configured to perform the method performed by any one of the terminal devices provided by the above method embodiments. The processing element may: namely, the method calls the program stored in the storage element to execute part or all of the steps executed by the terminal equipment; it is also possible to: that is, some or all of the steps performed by the terminal device are performed by integrated logic circuits of hardware in the processor element in combination with the instructions; of course, some or all of the steps performed by the terminal device may be performed in combination with the first manner and the second manner.

Claims

1. A random access method, comprising:

a terminal device sends a message to a network device, wherein the message is used for the terminal device to request random access to the network device;

the terminal device receives a response message of the message from the network device, wherein the response message comprises a Media Access Control (MAC) layer data packet, the MAC layer data packet comprises a load and a MAC subheader of the load, and the MAC subheader comprises first indication information which is used for determining the length of the load.

2. The method of claim 1, wherein the message comprises a random access signal and information for contention resolution, wherein the random access signal is used for requesting random access;

3. The method of claim 2, wherein the load further comprises one or more of the following information: the system comprises uplink authorization information, a timing advance command, a temporary cell radio network temporary identifier TC-RNTI and a radio resource control RRC message.

4. The method of claim 1, wherein the first indication information is used for indicating a length of the load.

5. The method of claim 4, wherein the first indication information is a preset bit length.

6. The method of claim 1, wherein the first indication information comprises N indication fields, N being greater than or equal to 1; each indication field corresponds to one kind of information, and the indication field is used for indicating whether the load contains the information corresponding to the indication field.

7. The method according to claim 6, wherein the information corresponding to the N indication fields includes contention resolution information, the contention resolution information has a preset length, and the indication field corresponding to the contention resolution information has 1 bit;

alternatively, the first and second electrodes may be,

8. The method of claim 7, wherein the valid bits of the contention resolution information are the preset length or a portion thereof.

9. The method of claim 1, wherein the first indication information comprises an information index value, and the information index value has a corresponding relationship with a length of the load; the information index value is used for determining the length of the load according to the corresponding relation between the preset information index value and the length of the load.

10. The method according to any of claims 1 to 9, wherein the MAC subheader further comprises a backoff indication information, and the backoff indication information is used to indicate whether to perform a random access backoff.

11. A random access method, comprising:

the method comprises the steps that network equipment receives a message sent by terminal equipment, wherein the message is used for requesting random access from the terminal equipment to the network equipment;

the network equipment sends a response message of the message to the terminal equipment, wherein the response message comprises a Media Access Control (MAC) layer data packet, the MAC layer data packet comprises a load and an MAC subheader of the load, the MAC subheader comprises first indication information, and the first indication information is used for determining the length of the load.

12. The method of claim 11, wherein the message comprises a random access signal and information for contention resolution, and wherein the random access signal is used for requesting random access;

13. The method of claim 12, wherein the load further comprises one or more of the following information: the system comprises uplink authorization information, a timing advance command, a temporary cell radio network temporary identifier TC-RNTI and a radio resource control RRC message.

14. The method of claim 11, wherein the first indication information is used for indicating a length of the load.

15. The method of claim 14, wherein the first indication information is a preset bit length.

16. The method of claim 11, wherein the first indication information comprises N indication fields, N being greater than or equal to 1; each indication field corresponds to one kind of information, and the indication field is used for indicating whether the load contains the information corresponding to the indication field.

17. The method according to claim 16, wherein the information corresponding to the N indication fields includes contention resolution information, the contention resolution information has a preset length, and the indication field corresponding to the contention resolution information has 1 bit;

alternatively, the first and second electrodes may be,

18. The method of claim 17, wherein the valid bits of the contention resolution information are the preset length or a portion thereof.

19. The method of claim 11, wherein the first indication information comprises an information index value, and the information index value has a corresponding relationship with a length of the load; the information index value is used for determining the length of the load according to the corresponding relation between the preset information index value and the length of the load.

20. The method according to any of claims 11 to 19, wherein the MAC subheader further comprises a backoff indication information, and the backoff indication information is used to indicate whether to perform a random access backoff.

21. An arrangement, characterized by comprising means for performing the steps of the random access method according to any of claims 1 to 10, or by comprising means for performing the steps of the random access method according to any of claims 11 to 20.

22. An apparatus, comprising: a processor and an interface circuit, the processor being configured to communicate with other devices via the interface circuit and to perform the random access method of any one of claims 1 to 10 or to perform the random access method of any one of claims 11 to 20.

23. An apparatus comprising a processor for invoking a program stored in a memory to perform a random access method according to any one of claims 1 to 10 or to perform a random access method according to any one of claims 11 to 20.

24. A storage medium storing computer executable instructions which, when executed by a processor, implement the random access method of any one of claims 1 to 10 or the random access method of any one of claims 11 to 20.