RU2801324C2 - Random access method and device - Google Patents

Abstract

FIELD: data management.

SUBSTANCE: invention relates to data buffer management in a two-stage random access procedure. The technical result is a reduction in the likelihood of a conflict in the management of buffers in various random access procedures. The terminal side device receives the first uplink data from the first message buffer, where the first message buffer is a buffer dedicated to the first random access procedure, the first random access procedure is a procedure in which the terminal side device transmits the first random access request, transmits the first uplink data on the first uplink resource and receives response information, and the response information is the first random access response to the first random access request or the response to the first upstream data. The terminal side device transmits the first random access request to the network side device and transmits the first uplink data to the network side device on the first uplink resource. The terminal side device detects the downstream control information, where the downstream control information indicates the resource of the response information. The terminal side device receives the response information on the resource indicated by the downstream control information.

EFFECT: reduction in the likelihood of a conflict in the management of buffers in various random access procedure.

13 cl, 19 dwg

Description

The field of technology to which the invention relates

The present application relates to the field of communications and, in particular, to a random access method and device.

State of the art

In a wireless communication system, a terminal-side device may access a network-side device (eg, a base station) through a four-way random access procedure. As shown in FIG. 1, the four-stage random access procedure comprises: step S1: The terminal side device selects a preamble index (Pr, preamble index) and a physical random access channel (PRACH) resource used to send a preamble (preamble), and transmits the preamble on the resource. Step S2: The base station transmits a random access response (RAR) response to the terminal side device. Step S3: The terminal side device sends a message 3 (message 3, Msg3) to the base station based on the response to the random access request, where Msg3 contains the uplink data. Step S4: The base station sends a message 4 (message 4, Msg4) to the terminal side device, where Msg4 contains contention resolution information, so that the terminal side device accesses the base station.

At present, the 5th generation (5G) mobile communication system proposes a two-stage random access procedure. As shown in FIG. 2, the two-stage random access procedure comprises: Step S1: The terminal side device selects a PRACH resource used to send a preamble, acquires an uplink resource used to send uplink data, transmits a preamble on the PRACH resource, and transmits uplink data on the uplink resource. . Step S2: The base station sends response information to the terminal side apparatus, for example, a message B (message B, MsgB), where the response information may contain contention resolution information.

At present, how a terminal-side device manages data buffers in a two-way random access procedure and a four-way random access procedure to avoid conflict in buffer management of another random access procedure is an urgent problem to be solved.

Disclosure of the essence of the invention

Embodiments of the present application provide a random access method for managing a data buffer in a two-way random access procedure and, additionally, for managing a data buffer in a four-way random access procedure. This avoids conflicts in the management of buffers in different random access routines.

According to a first approach, an embodiment of the present application provides a random access method comprising: a terminal-side device obtains a first upstream data from a first message buffer, where the first message buffer is a buffer dedicated to a first random access procedure, wherein the first the random access procedure is a procedure in which the terminal-side device transmits the first random access request, transmits the first uplink data on the first uplink resource, and receives response information, and the response information is the first random access response to the first random access request or the response to the first uplink data . The terminal side device transmits the first random access request to the network side device and transmits the first uplink data to the network side device on the first uplink resource. The terminal side device detects the downstream control information, where the downstream control information indicates the resource of the response information. The terminal side device receives the response information on the resource indicated by the downstream control information.

Based on the method presented in this embodiment of the present application, after initiating the first random access procedure, the device on the terminal side can receive the first uplink data from the first message buffer. That is, the first upstream data of the first random access procedure may be managed (stored or retrieved) using the first message buffer. Since the first message buffer is a buffer dedicated to the first random access procedure, conflict between buffers of different random access procedures can be avoided.

In a possible implementation of the first approach, when the first random access procedure fails or when the second message buffer has no upstream data and the first message buffer has upstream data, the second message buffer is dedicated to the second random access procedure and the second random access procedure is a procedure in which the terminal side device transmits the second random access request, receives the second response to the second random access request, and transmits the second uplink data based on the second response to the random access request; and the method further comprises: the terminal side device obtains the second upstream data from the first message buffer in the second random access procedure. Thus, in the second random access procedure, the device on the terminal side can receive from the second message buffer the second upstream data corresponding to the second random access procedure, so that it is not necessary to regenerate the first upstream data using multiplexing and reassembly of the object after the first random access procedure. access fails, thereby improving the efficiency of data transmission.

In a possible implementation of the first approach, when the first random access procedure fails or when there is no upstream data in the second message buffer and there is upstream data in the first message buffer, the second message buffer is dedicated to the second random access procedure and the method further comprises: The terminal side device stores the uplink data in the first message buffer in the second message buffer, and the terminal side device acquires the second uplink data from the second message buffer in the second random access procedure. Thus, in the second random access procedure, the terminal side device can obtain from the second message buffer the second uplink data corresponding to the second random access procedure, so that it is not necessary to regenerate the first uplink data using multiplexing and object assembly after the first random access procedure access has been randomized, thereby improving the efficiency of data transmission.

In a possible implementation of the first approach, the device on the terminal side stores the first upstream data in the first message buffer and in the second message buffer. Thus, if the first random access procedure initiated by the terminal-side device fails and the terminal-side device needs to transition to the second random access procedure, the terminal-side device can directly receive upstream data from the first message buffer or from the second message buffer instead of to regenerate upstream data. This improves the efficiency of data transmission. Alternatively, the terminal side device stores the second upstream data in the first message buffer and in the second message buffer. Thus, if the second random access procedure initiated by the terminal-side device fails and the terminal-side device is forced to jump to the first random access procedure, the terminal-side device may receive upstream data from the first message buffer or from the second message buffer instead of to reshape upstream data. This improves the efficiency of data transmission.

In a possible implementation of the first approach, when the second random access procedure fails, or when the first message buffer contains no upstream data and the second message buffer has upstream data, the second message buffer is for the second random access procedure, and the method further comprises: on the terminal side receives the first upstream data from the second message buffer. In other words, when changing from the second random access procedure to the first random access procedure, the terminal-side device can obtain the first upstream data corresponding to the first random access procedure from the second message buffer, and there is no need to regenerate the first upstream data. This improves the efficiency of data transmission.

In an exemplary implementation of the first approach, the method further comprises receiving the first uplink data from the third message buffer in the first random access procedure, and obtaining the second uplink data from the third message buffer in the second random access procedure, where the third message buffer is a buffer shared by the first random access procedure and the second random access procedure.

In a possible implementation of the first approach, the method further comprises, when the terminal side device initiates the first random access procedure, the terminal side device sets the first counter to an initial value, where the first counter is for the first random access procedure. If the contention resolution in the first random access procedure fails, the terminal side device increments the count value of the first counter by 1. access fails to prevent the terminal-side device from frequently restarting the first random access procedure so as to reduce resource consumption of the terminal-side device.

In a possible implementation of the first approach, the first counter contains the first random access preamble burst counter and the first power hop counter.

In an exemplary implementation of the first approach, the method further comprises, when the terminal side device initiates the first random access procedure, the terminal side device sets the second counter to an initial value, where the second counter is the counter shared by the first random access procedure and the second procedure. random access. If the contention resolution in the first random access procedure fails, the terminal side device increments the second counter by 1. access failed to avoid frequently restarting the first random access procedure by the terminal-side device, and thereby reduce the resource consumption of the terminal-side device.

In a possible implementation of the first approach, the second counter contains a second random access preamble burst counter and/or a second power hop counter.

In a possible implementation of the first approach, if the contention resolution in the first random access procedure or in the second random access procedure fails, the device at the terminal side increments the count value of the second random access preamble burst counter by 1.

In a possible implementation of the first approach, if the terminal side device initiates the first random access procedure again or initiates the second random access procedure, the terminal side device increments the second power hop counter by 1.

According to the second approach, an embodiment of the present application provides a random access method comprising: a network-side device receives a first random access request from a terminal-side device, and receives a first uplink data from a terminal-side device on a first uplink resource, where the terminal side device receives the first uplink data from the first message buffer, the first message buffer is a buffer dedicated to the first random access procedure, and the first random access procedure is a procedure in which the terminal side device transmits the first random access request, transmits the first uplink data on the first uplink resource and receives response information, and the response information is a first random access response to the first random access request or a response to the first upstream data. The network side device transmits downlink control information, where the downlink control information indicates a resource of response information. The network-side device transmits response information on the resource indicated by the downstream control information.

According to a third approach, an embodiment of the present application provides a random access method comprising the steps of: when a first random access procedure is initiated, a terminal-side device sets a first counter to an initial value, where the first counter is to perform the first random access procedure , the first random access procedure is a random access procedure in which the terminal side device transmits the first random access request, transmits the first uplink data on the first uplink resource, and receives response information, and the response information is the first random access response received in response to the first request random access or response to the first upstream data. The terminal side device performs the first random access procedure.

In an optional implementation of the third approach, the method further comprises: upon initiating the first random access procedure, the terminal-side device sets the second counter to an initial value, where the second counter is the counter shared by the first random access procedure and the second random access procedure, and the second random access procedure is a procedure in which the terminal-side device transmits the second random access request, receives the second random access response, and transmits the second uplink data based on the second random access response.

According to a fourth approach, an embodiment of the present application provides a terminal side apparatus comprising a processor configured to receive first uplink data from a first message buffer, where the first message buffer is a buffer dedicated to a first random access procedure, the first random access procedure is a procedure in which the terminal-side device transmits the first random access request, transmits the first uplink data on the first uplink resource, and receives response information, and the response information is a first random access response to the first random access request or a response to the first uplink data; and a transmitting unit configured to send a first random access request to the network side device and send first uplink data to the network side device on the first uplink resource, where the processor is further configured to detect downlink control information and the downlink control information indicates a response information resource; and a receiving unit configured to receive the response information on the resource indicated by the downstream control information.

In a possible implementation of the fourth approach, when the first random access procedure fails or when there is no upstream data in the second message buffer and the first message buffer has upstream data, the second message buffer is a buffer dedicated to the second random access procedure, and the second random access procedure is a procedure in which a terminal-side device transmits a second random access request; receives a second random access response to the second random access request, and transmits a second uplink data based on the second random access response; and the processing unit is further configured to receive the second uplink data from the first message buffer in the second random access procedure.

In a possible implementation of the fourth approach, when the first random access procedure fails or when there is no upstream data in the second message buffer and the first message buffer has upstream data, the second message buffer is a buffer dedicated to the second random access procedure, and the processing unit is further executed with the ability to store the uplink data in the first message buffer in the second message buffer and obtain the second uplink data from the second message buffer in the second random access procedure.

With a possible implementation of the fourth approach, the processing unit is configured to store the first ascending data in the first message buffer and in the second message buffer. Alternatively, the processing unit is configured to store the second uplink data in the first message buffer and in the second message buffer.

In a possible implementation of the fourth approach, when the second random access procedure fails, or when there is no upstream data in the first message buffer and there is upstream data in the second message buffer, the second message buffer is dedicated to the second random access procedure, and the processing unit is further configured to receiving the first upstream data from the second message buffer.

In a possible implementation of the fourth approach, the processing unit is further configured to receive the first upstream data from the third message buffer in the first random access procedure and obtain the second upstream data from the third message buffer in the second random access procedure, where the third message buffer is a buffer shared by the first random access procedure. a random access procedure and a second random access procedure.

In a possible implementation of the fourth approach, the processing unit is further configured to set the first counter to an initial value when the terminal side device initiates the first random access procedure, where the first counter is for the first random access procedure.

With a possible implementation of the fourth approach, the processing unit is further configured to set the second counter to an initial value when the terminal-side device initiates the first random access procedure, where the second counter is intended to be shared between the first random access procedure and the second random access procedure.

According to the fifth approach, an embodiment of the present application provides a network-side device comprising a receiving unit configured to receive a first random access request from a terminal-side device and receive first uplink data from a terminal-side device on a first uplink resource, where the device on the terminal side receives the first uplink data from the first message buffer, the first message buffer is a buffer dedicated to the first random access procedure, the first random access procedure is a procedure in which the terminal side device transmits the first random access request, transmits the first uplink data on the first an upstream resource and receives response information, where the response information is a first random access response to the first random access request, or a response to the first upstream data; and a transmitting unit configured to send downlink control information, where the downlink control information indicates a resource of response information. The transmitting unit is further configured to send response information on the resource indicated by the downstream control information.

According to the sixth approach, an embodiment of the present application further provides a communication device. The communication device may be a terminal side device or a chip. The communication device contains a processor configured to implement any method presented in the first approach. The communication device may further comprise a memory configured to store program instructions and data. The memory may be memory integrated into the communication device or off-chip memory located outside the communication device. The memory is associated with the processor. The processor may call and execute program instructions stored in memory to implement any of the methods presented in the first approach. The communication device may further comprise a communication interface. The communication interface is used by the communication device to communicate with another device (for example, a device on the network side).

According to the seventh approach, an embodiment of the present application further provides a communication device. The communication device may be a network side device or a chip. The communication device comprises a processor configured to implement the method provided in the second approach. The communication device may further comprise a memory configured to store program instructions and data. The memory may be memory integrated into the communication device or off-chip memory located outside the communication device. The memory is connected to the processor. The processor may call and execute program instructions stored in memory to implement the method presented in the second approach. The communication device may further comprise a communication interface. The communication interface is used by a communication device to communicate with another device (eg, a device on the terminal side).

According to the eighth approach, an embodiment of the present application provides a computer-readable medium containing instructions. When the instructions are executed on the computer, the computer may perform any of the methods presented in the first approach or the second approach.

According to the ninth approach, an embodiment of the present application provides a computer program product containing instructions. When the computer program product is running on the computer, the computer may perform any of the methods presented in the first approach or the second approach.

According to the tenth approach, an embodiment of the present application provides a chip system. The chip system comprises a processor and may further comprise a memory. The chip system is configured to implement any method presented in the first approach or in the second approach. The chip system may include a chip, or may include a chip and another discrete component.

According to the eleventh approach, an embodiment of the present application provides a system. The system comprises a terminal side device presented in the third approach and a network side device presented in the fourth approach.

Brief description of the drawings

Fig. 1 is a four-stage random access procedure according to an embodiment of the present application;

Fig. 2 shows a two-stage random access procedure according to an embodiment of the present application;

Fig. 3 is a system applied to the random access method according to the embodiment of the present application;

Fig. 4 is an internal structure of a terminal-side device according to an embodiment of the present application;

Fig. 5 is an internal structure of a network side device according to an embodiment of the present application;

Fig. 6a is a diagram of a RAR window according to an embodiment of the present application;

Fig. 6b is a diagram of an existing MAC PDU;

Fig. 6c is a sub-header diagram of a MAC sub-PDU according to an embodiment of the present application;

Fig. 6d is a diagram of a MAC SDU according to an embodiment of the present application;

Fig. 7 is a signaling diagram applicable to a random access method according to an embodiment of the present application;

Fig. 8 - control window corresponding to the embodiment of the present application;

Fig. 9 is a diagram of a MAC PDU according to an embodiment of the present application;

Fig. 10 is a diagram of another MAC PDU according to an embodiment of the present application;

Fig. 11 is a diagram of another MAC PDU according to an embodiment of the present application;

Fig. 12 is a diagram of yet another MAC PDU according to an embodiment of the present application;

Fig. 13 is a diagram of yet another MAC PDU according to an embodiment of the present application;

Fig. 14 is a diagram of yet another MAC PDU according to an embodiment of the present application;

Fig. 15 is an internal structure of another terminal-side device according to an embodiment of the present application; And

Fig. 16 is an internal structure of another network side device according to an embodiment of the present application.

Implementation of the invention

Embodiments of the present application provide a random access method and apparatus. The random access method and device are used in a mobile communication network, for example, in a mobile communication network that supports a variety of radio interface technologies (RIT).

In FIG. 3 is a schematic representation of a communication system to which the technical solution according to an embodiment of the present application is applicable. The communication system may include a network side device 100 and one or more terminal side devices 200 (only one terminal side device 200 is shown in FIG. 3. 3) connected to the network side device 100. Data communication may be performed between a network side device and a terminal side device.

The network side device 100 may be a device capable of communicating with the terminal side device 200. For example, network side device 100 may be a base station. The base station can be a base transceiver station (BTS) in the global system for mobile communication (GSM) or a code division multiple access (CDMA) NodeB (NodeB, NB) system in a wideband code division multiple access (WCDMA) system, an evolved NodeB (evolved NodeB, eNB or eNodeB) in LTE, a base station in NR, a relay station, an access point, a base station in a future network, etc. n. This is not limited to embodiments of the present application. A base station in NR may also be referred to as a transmission reception point (TRP) or gNB. In embodiments of the present application, the network side device may be an independently marketable network side device, such as a base station, or may be a chip that implements the corresponding function in the network side device. In embodiments of the present application, the chip system may include a chip, or may include a chip and another discrete component. The technical solutions presented in the embodiments of the present application are described using an example in which the device for realizing the function of the network side device is the network side device.

The terminal side device 200 in this embodiment of the present application may also be referred to as a terminal, and may be a device with a wireless transceiver function. The terminal can be deployed on the ground, including as an indoor or outdoor terminal, a portable terminal or a vehicle-mounted terminal; or can be deployed on the water surface (for example, on a ship) or in the air (for example, on an airplane, balloon and satellite). The terminal side device may be a user equipment (UE). The UE may be a portable device, a vehicle-mounted device, a wearable device, or a computing device having a radio communication function. For example, the UE may be a mobile phone, a tablet computer, or a computer having a wireless transceiver function. Alternatively, the terminal-side device may be a virtual reality (VR) terminal-side device, an augmented reality (AR) terminal-side device, a wireless terminal in process control, a wireless terminal in an unmanned device, a wireless terminal in telemedicine, a wireless terminal in a smart network, a wireless terminal in a smart city, a wireless terminal in a smart home, and the like. or may be a chip in the terminal. In the technical solutions presented in the embodiments of the present application, the technical solutions presented in the embodiments of the present application are described using an example in which the device for realizing the terminal function is a terminal-side device.

Network side device 100 or terminal side device 200 shown in FIG. 3 in embodiments of the present application may be implemented by a device or may be a functional module in a device. In the embodiments of the present application, this is not specifically limited. It may be understood that the aforementioned function may be a network element in a hardware device, a software function running on dedicated hardware, a virtualized function built on a platform (eg, a cloud platform), or a chip system. In embodiments of the present application, the chip system may include a chip, or may include a chip and another discrete component.

For example, a device for realizing the function of a terminal-side device provided in the embodiments of the present application may be implemented by the device 400 shown in FIG. 4. In FIG. 4 shows the hardware structure of a device 400 according to an embodiment of the present application. The device 400 includes at least one processor 401 configured to implement the function of the terminal side device shown in the embodiments of the present application. The device 400 may further comprise a bus 402 and at least one communication interface 404. The device 400 may further comprise a memory 403.

In embodiments of the present application, the processor may be a central processing unit (CPU), a general-purpose processor, a network processor (network processor, NP), a digital signal processor (digital signal processing, DSP), a microprocessor, a microcontroller, a programmable logic device (programmable logic device, PLD) or any combination thereof. The processor may alternatively be any other device having a processing function, such as a circuit, component, or software module.

Bus 402 may be configured to transfer information between the above components.

The communication interface 404 is configured to communicate with another device or communication system, such as an Ethernet, a radio access network (RAN), or a wireless local area network (WLAN). Communication interface 404 may be an interface, circuit, transceiver, or other device that can communicate. This is not limited in the present application. Communication interface 404 may be coupled to processor 401. Communication in embodiments of the present application may be an indirect connection or communication connection between devices, blocks or modules in electrical form, mechanical form or other form and used for information exchange between devices, blocks or modules.

In embodiments of the present application, the memory may be a read-only memory (ROM) or other type of static storage device that can store static information and commands, random access memory (RAM) or other type of dynamic memory device, which can store information and instructions, electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM), or other compact disc storage device. discs, optical disc storage media (including CDs, laser discs, optical discs, digital versatile discs, Blu-ray optical discs, etc.), magnetic disc storage media, or other magnetic storage media. a device or any other medium that can be used to carry or store the expected control program in the form of an instruction or data structure and that can be accessed by a computer. However, memory is not limited to this. The memory may exist independently or may be coupled to the processor, such as via bus 402. Alternatively, the memory may be integrated with the processor.

The memory 403 is configured to store program instructions, and the processor 401 may control the execution of the program instructions to implement the method presented in subsequent embodiments of the present application. The processor 401 is configured to call and execute instructions stored in the memory 403 to implement the resource scheduling method presented in subsequent embodiments of the present application.

Alternatively, the computer-executable instructions in the embodiments of the present application may also be referred to as an application control program. This is not specifically limited in the embodiments of the present application.

Alternatively, memory 403 may be included with processor 401.

In a specific implementation, in an embodiment, the processor 401 may include one or more CPUs, such as CPU 0 and CPU 1, as shown in FIG. 4.

In a particular implementation, in an embodiment, device 400 may comprise a plurality of processors, such as processor 401 and processor 407 as shown in FIG. 4. Each of these processors can be a single-core processor (with a single CPU) or a multi-core processor (with multiple CPUs). A processor here can be one or more devices, circuits, and/or processing cores configured to process data (eg, computer program instructions).

With a specific implementation in the embodiment, the device 400 may further comprise an output device 405 and an input device 406. An output device 405 communicates with the processor 401 and can display information in a variety of ways. For example, output device 405 may be a liquid crystal display (LCD), a light emitting diode (LED) display, a cathode ray tube (CRT) display, or a projector. Input device 406 communicates with the processor 401 and may receive input from the user in a variety of ways.For example, the input device 406 may be a mouse, keyboard, touch screen device, or sensor.

Device 400 may be a general purpose device or a special purpose device. In a specific implementation, the terminal-side device 400 may be a desktop computer, a laptop computer, a network server, a personal digital assistant (for example, a personal digital assistant (PDA)), a mobile phone, a tablet computer, a wireless terminal-side device, an embedded device or a device with a structure similar to that shown in FIG. 4. The type of device 400 is not limited in the embodiments of the present application.

For example, the apparatus for realizing the function of a network-side device presented in the embodiments of the present application may be implemented by the apparatus 500 shown in FIG. 5. In FIG. 5 shows the hardware structure of a device 500 according to an embodiment of the present application. The device 500 includes at least one processor 501 configured to implement the function of the network side device shown in the embodiments of the present application. Device 500 may further comprise a bus 502 and at least one communication interface 504. The device 500 may further comprise a memory 503.

Bus 502 may be configured to transfer information between the components described above.

Communication interface 504 is configured to communicate with another device or communication network, such as Ethernet, RAN, or WLAN. The communication interface 504 may be an interface, circuit, transceiver, or other device that can implement communication. This is not limited in the present application. Communication interface 504 may be coupled to processor 501.

The memory 503 is configured to store program instructions, and the processor 501 may control the execution of the program instructions to implement the resource scheduling method presented in subsequent embodiments of the present application. For example, processor 501 is configured to call and execute instructions stored in memory 503 to implement the resource scheduling method presented in subsequent embodiments of the present application.

Additionally, memory 503 may be included with processor 501.

In a specific implementation, in an embodiment, processor 501 may comprise one or more CPUs, such as CPU 0 and CPU 1 in FIG. 5.

In a particular implementation, in an embodiment, device 500 may comprise a plurality of processors, such as processor 501 and processor 505 shown in FIG. 5. Each of these processors may be a single-core processor or a multi-core processor. A processor here can be one or more devices, circuits, and/or processing cores configured to process data (eg, computer program instructions).

In order to make the descriptions of the following embodiments clearer and more concise, the respective concepts or technologies are briefly described first.

Operations related to the random access buffer (four-stage random access procedure) in the long-term evolution (LTE) system: When a terminal-side device initiates a random access procedure in a served cell, the MAC the terminal side clears the MSG3 buffer. If the response to the random access request indicates that the terminal side device has successfully performed random access, the MAC PDU to be transmitted is obtained from the mux and assembly entity and stored in the Msg3 buffer. Then, using a hybrid automatic repeat request (HARQ), the entity obtains the MAC PDU to be transmitted from the MSG3 buffer and indicates the HARQ process corresponding to the MAC PDU to be transmitted to initiate a new transmission. After MSG3 is sent, the MAC entity clears the HARQ buffer used to send the MAC PDU in the Msg3 buffer.

LTE Random Access Response Reception Operation: The UE receives a physical random access channel (PRACH) resource configuration from the network side, where the PRACH resource contains the time frequency resource configuration. After sending a preamble to the base station on the PRACH resource, the UE should receive within the random access response (RAR) window scheduling the base station using physical downlink control channel (PDCCH) signaling. The PDCCH signaling is scrambled using RA-RNTI and the RA-RNTI value can be calculated according to formula (1):

RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id (1)

s_id is the number of the 1st symbol of the PRACH resource index (0 ≤ s_id <14), t_id is the number of the 1st slot of the PRACH resource index in the system frame (0 ≤ t_id <80), f_id is the PUSCH number of the resource index in the frequency domain (0 ≤ f_id < 8), and ul_carrier_id is the carrier identifier for sending the preamble.

Thus, after sending the preamble on the PRACH resource, the UE can calculate the unique RA-RNTI according to formula (1) using the time-frequency position of the PRACH resource, and then obtain, within the RAR window, a PDCCH signaling indication scrambled using the RA-RNTI. In LTE, the RAR window start location is the third subframe after the subframe in which the UE transmits the preamble.

As shown in FIG. 6a, the start location of the RAR window is located after the symbol that is after the appearance of the PRACH, the type 1 PDCCH can be received within the RAR window, and the RAR search space control resource set is determined using downlink control information (DCI) carried on the channel. PDCCH. The RAR window length may be indicated by the base station using radio resource control (RRC) signaling.

As shown in FIG. 6b, RAR may be included in a MAC PDU, and one MAC PDU may contain multiple MAC sub-PDUs. A MAC sub-PDU may contain a subhead and a payload, and the payload may carry a RAR. Alternatively, the MAC sub-PDU may only contain a subtitle. As shown in FIG. 6c, a MAC sub-PDU may contain an E field, a T field, an R field, and a BI field, or a MAC sub-PDU may contain an E field, a T field, and a RAP ID field. The E field is used to indicate whether the MAC sub-PDU containing this subheader is the last MAC sub-PDU in the MAC PDU, the T field indicates whether the MAC subheader contains a random access preamble identifier or return indicator information, the R field is a reserved bit, the BI field identifies the congestion condition in this cell; and the RAP ID field identifies the identifier of the random access preamble that was sent. As shown in FIG. 6d, a MAC service data unit (SDU) may contain one or more fields. For example, the MAC SDU contains an R field, a timing advance command, an upstream grant (UL Grant), and a temporary cell radio network identifier (C-RNTI).

In the NR system, the size of the RAR is fixed in seven bytes (byte) and the UE, using the MAC sub-header, can locate the start location of the MAC RAR reading. If the UE detects in the MAC subheader that the RAP ID is the same as the preamble ID sent from the UE, the UE reads the 7-byte RAR information that follows the MAC subheader.

For the two-stage random access procedure as shown in FIG. 2, the terminal transmits message A, where message A contains a preamble and uplink data. A terminal-side device may determine a random access channel (RACH) resource and a 2-way random access data resource, send a preamble on the RACH resource, and send uplink data on the data resource. After sending message A, the terminal receives message B. If the terminal confirms that the contention resolution information contained in message B is successful, the random access is successful. If the network side is unable to decode message A, the network side may send response information to indicate to the UE to return to the four-way random access procedure or to indicate to the UE to continue to perform the two-way random access procedure.

At present, with further implementation of the 2-way random access solution and how the 4-way random access solution is compatible with the 2-way random access solution, there is the following problem: Since the request response message formats are different, after the UE performs the 4-way random access procedure access or a two-step random access procedure, a solution needs to be worked out on how to prevent the device on the terminal side from performing incorrect parsing.

Based on the random access method presented in the present application, a terminal side device may search for other PDCCH search spaces based on the identifiers of different search spaces, or a terminal side device may discover PDCCHs based on different RNTIs, where the downlink control information, carried on the PDCCH indicates a request response information resource, and the terminal-side device receives the request response information on the resource indicated by the downlink control information; or, the terminal side device can identify corresponding response messages based on different MAC PDU formats, so that the terminal side device can quickly identify response messages of different random access procedures to prevent the terminal side device from performing incorrect parsing.

The following describes the technical solutions shown in the embodiments of the present application, with reference to the accompanying drawings in the embodiments of the present application. In the descriptions of the present application, unless otherwise indicated, "at least one" means one or more, and "many" means two or more. In addition, in order to clearly describe the technical solutions in the embodiments of the present application, in the embodiments of the present application, terms such as "first" and "second" are used to distinguish between the same objects or similar objects whose functions and purposes are basically the same. . Those skilled in the art will understand that terms such as "first" and "second" are not intended to limit the number and sequence of execution, and do not indicate a specific difference.

For ease of understanding, hereinafter, with reference to the accompanying drawings, the random access method presented in the embodiments of the present application will be specifically described.

As shown in FIG. 7, an embodiment of the present application provides a random access method comprising the following steps.

701: The network-side device transmits the first configuration parameter of the first random access procedure to the terminal-side device.

The first configuration parameter contains the identifier of the first search space and the configuration of the first upstream resource. Alternatively, the first configuration parameter contains the configuration of the first upstream resource.

702: The terminal side device receives from the network side device the first configuration parameter of the first random access procedure.

The first random access procedure is a procedure in which the terminal-side device transmits the first random access request, transmits the first uplink data on the first uplink resource, and receives response information, and the response information is the first random access response for the first random access request or a response to first ascending data. It should be understood that the first upstream resource is a resource obtained before the response to the random access request. Therefore, the terminal may send the first uplink data before it receives the resource in the random access response. The response to the first upstream data may contain conflict resolution information, acknowledgment (acknowledge, ACK), negative acknowledgment (negative acknowledge, NACK), etc.

For example, the first random access procedure may be a two-stage random access procedure, that is, a random access procedure in which a terminal-side device transmits the MSGA and receives the MSGB.

The first configuration parameter contains the identifier of the first search space and the configuration of the first upstream resource. The first search space identifier may be specifically allocated to the first random access procedure, in other words, the first search space identifier is allocated to the first random access procedure. The terminal side device can quickly identify the search space of the first random access procedure based on the identifier of the first search space, and further detect downlink control information (DCI) of the first random access procedure in the search space. The first configuration parameter may further comprise a DCI format, a controlled slot frequency, a controlled slot location, and the like, which are associated with the first search space identifier.

The first configuration parameter may further comprise an identifier of the first control resource set, and the first control resource set is a resource set for discovering downstream control information carried in the first search space. The identifier of the first set of control resources is associated with a frequency domain resource and a duration carried by the downstream control information.

In other words, the terminal-side device may search, based on the time-frequency control resource set indicated by the first control resource set identifier, for the PDCCH corresponding to the first random access procedure for DCI. The time-frequency control resource set indicated by the identifier of the first control resource set may contain one or more time-frequency resources. The identifier of the first search space is associated with the identifier of the first control resource set.

703: The terminal side device transmits the first random access request to the network side device, and transmits the first uplink data on the first uplink resource to the network side device.

The first random access request may comprise a first random access preamble or a first demodulation reference signal (DMRS). It should be understood that the first random access preamble and the first DMRS may be sent together.

The terminal side device can obtain from the resource configuration message of the first random access procedure the first upstream resource used to send the first upstream data. The terminal side device selects the first random access preamble or the first DMRS that corresponds to the first random access procedure, and selects the PRACH resource used to send the first random access preamble or the first DMRS. The terminal side device transmits the first uplink data on the first uplink resource and transmits the first random access preamble or the first DMRS on the PRACH resource. It should be understood that a DMRS may be sent on a PUSCH resource to send data.

In an exemplary embodiment, the terminal side device may receive the first upstream data to be sent from the multiplexing and assembly entity and store the first upstream data in a first message buffer. The first message buffer is a buffer dedicated to the first random access procedure. In other words, the first message buffer may be allocated to the first random access procedure. The first message buffer may also be referred to as the MSGA buffer, and any concept used to identify the message buffer of the first random access procedure is the same as the definition of the first message buffer in the present specification. This is not limited in the present application. The terminal side device can then receive the first uplink data from the first message buffer, store the first uplink data in the HARQ buffer, and indicate the HARQ process to initiate transmission of the first uplink data stored in the HARQ buffer. It should be understood that if the first message buffer had a MAC PDU and this resource is an uplink grant resource of the first random access procedure, the HARQ entity may obtain the MAC PDU from the first message buffer.

Alternatively, when deciding to initiate the first random access procedure in the served cell, the terminal side device may flush the first message buffer and/or the second message buffer to remove data from the previous random access procedure that remains in the first message buffer and in the second message buffer. . Thus, the first message buffer may carry the first upstream data of the first random access procedure, and the second message buffer may carry the second upstream data of the second random access procedure.

It should be noted that the first upstream data may be an RRC Connection Establishment Request, an RRC Connection Recovery Request, or an RRC Connection Reconnection Request message. The first upstream data may alternatively be upstream service data or signaling generated at the MAC layer, the radio link control (RLC) layer, the packet data convergence protocol (PDCP) layer, or the access impossibility layer ( non-access stratum, NAS). The first upstream data may alternatively be a combination of one or more of the above data types.

When the first random access procedure fails, or when there is no upstream data in the second message buffer and there is upstream data in the first message buffer, the second message buffer is dedicated to the second random access procedure. The terminal side device re-initiates the second random access procedure and obtains the second upstream data from the first message buffer. In other words, by changing from the first random access procedure to the second random access procedure, the terminal-side device can receive upstream data from the first message buffer and does not need to regenerate the upstream data. This improves the efficiency of data transmission. The second random access procedure is a procedure in which a terminal-side device transmits a second random access request, receives a second random access response to the second random access request, and transmits a second uplink data based on the second random access response. For example, the second random access procedure is a four-stage random access procedure, that is, a random access procedure in which a terminal-side device communicates with a network-side device using MSG1-MSG4.

When the first random access procedure fails, or when the second message buffer has no upstream data and the first message buffer has upstream data, the second message buffer is the buffer used for the second random access procedure, and further, the method comprises: the terminal side device stores the uplink data present in the first message buffer in the second message buffer, and the terminal side device obtains the second uplink data from the second message buffer in the second random access procedure. In other words, by transitioning from the first random access procedure to the second random access procedure, the terminal-side device can copy the upstream data present in the first message buffer to the second message buffer, and receive the upstream data from the second message buffer instead of regenerating the upstream data. data. This improves the efficiency of data transmission.

Optionally, the terminal side device may store the first upstream data in a first message buffer and a second message buffer. In other words, when the first random access procedure is initiated, the terminal side device may store the first uplink data in the first message buffer and the second message buffer. If the first random access procedure initiated by the terminal-side device fails and the terminal-side device must proceed to the second random access procedure, the terminal-side device can directly receive upstream data from the second message buffer instead of regenerating the upstream data. This improves the efficiency of data transmission.

In an exemplary embodiment, the terminal side device may receive the first uplink data to be transmitted from the mux-and-assemble entity in the first random access procedure and store the first uplink data in a third message buffer (eg, RACH buffer). Then, the terminal side device receives the first uplink data from the third message buffer, stores the first uplink data in the HARQ buffer, and indicates the HARQ process to initiate transmission of the first uplink data present in the HARQ buffer. The third message buffer is a buffer shared by the first random access procedure and the second random access procedure.

Alternatively, when deciding to initiate the first random access procedure in the served cell, the terminal side device may clear the third message buffer to remove data from the previous random access procedure that remains in the third message buffer. Thus, the third message buffer may carry the first upstream data of the first random access procedure and the second upstream data of the second random access procedure.

Optionally, after instructing the HARQ process to initiate transmission of the first uplink data present in the HARQ buffer, the terminal side device may temporarily store the first uplink data in the HARQ buffer. If the first random access procedure fails, the terminal side device may retransmit the first uplink data present in the HARQ buffer based on the first uplink grant, or recover and then send the first uplink data present in the HARQ buffer. According to conventional technology, after the data present in the HARQ buffer is transmitted, the HARQ buffer is cleared in a timely manner. However, with this application, the first uplink data present in the HARQ buffer can be temporarily stored to avoid the case that after the first random access procedure fails, the first uplink data needs to be retrieved again from the message buffer (e.g., from the first message buffer) or from the multiplex and assembly object. This approach improves the efficiency of data transmission.

In all previous designs, if the size of the resource used to send uplink data in the first random access procedure or in the second random access procedure cannot match the size of the MAC PDU obtained from the message buffer, the mux and assembly entity is indicated to perform processing. For example, some or all of the MAC SDUs are derived from the MAC PDUs, MAC sub-PDUs are generated for these MAC SDUs, and then the MAC PDUs are generated.

When the terminal side device initiates the first random access procedure, the terminal side device may set the first counter to an initial value, for example, may set the value of the first counter to 0 or 1. The first counter is for the first random access procedure, in other words, the first counter is allocated the first random access procedure. The first counter may be the first random access preamble burst counter (PREAMBLE_TRANSMISSION_COUNTER). If the contention resolution in the first random access procedure fails, then the terminal-side device increments the count value of the first counter by 1. When the contention resolution in the first random access procedure fails, it is possible that when the PDCCH discovery window ends, the response message of the first random access procedure , which is received by the terminal side device, does not match the first random access preamble sent by the terminal side device, or the terminal side device did not receive the first random access procedure response message, or the terminal side device did not receive the scheduled PDCCH using the terminal's C-RNTI , or the contention resolution information field in the received response message of the first random access procedure cannot be checked. If the first counter reaches the set maximum value, the terminal side device indicates to the higher layer (eg, the RRC layer) that the first random access procedure has failed. The maximum value of the first counter can be either (preambleTransMax) or (preambleTransMax+1).

Alternatively, when the terminal side device initiates the first random access procedure, the terminal side device sets the second counter to an initial value, where the second counter is the counter shared by the first random access procedure and the second random access procedure. For the corresponding operation of the second counter, refer to the description for the first counter. Details are not described here. It should be understood that if the contention resolution in the first random access procedure or the second random access procedure fails, the terminal-side device increments the shared counter count value by 1.

Further, the terminal may count the number of times the first random access procedure fails and report the number to the network side device using higher layer signaling. For example, the number of failures is reported to the network side device using the assistance information message. It should be understood that the terminal can count the number of times the second random access procedure fails and report the number to the network side device using higher layer signaling. The number of times the first random access procedure fails and the number of times the second random access procedure fails may be counted and reported separately.

Further, when the terminal side device initiates the first random access procedure, the terminal side device may set the first power hop counter to an initial value (eg, 1). The first power hop counter may be dedicated to the first random access procedure, in other words, the first power hop counter may be dedicated to the first random access procedure. If the terminal side device needs to send (resend) the first random access request or the first uplink data and the synchronization signal block (SSB) does not change, the terminal side device increments the count value of the first power hop counter by 1.

Alternatively, when the terminal side device initiates the first random access procedure, the terminal side device sets the second power hop counter to an initial value, where the second power hop counter is the power hop counter shared by the first random access procedure and the second random access procedure. . If the terminal side device initiates the first random access procedure again or initiates the second random access procedure and the SSB does not change, the terminal side device increments the count value of the second power hop counter by 1. Refer to the corresponding description of the first one for the corresponding operation of the second power hop counter. power surge counter. Details are not described here. It should be understood that if the second random access procedure is initiated and the sync signal block is not changed, the count value of the second power hop counter is incremented by 1.

704: The network side device transmits downstream control information.

The downlink control information is used to indicate the response information resource of the first random access procedure.

705: The terminal side device detects downstream control information.

The network side device searches for the DCI time-frequency PDCCH resource corresponding to the first random access procedure. As shown in FIG. 8, after sending the first message on the PUSCH resource, the terminal side device starts a discovery window to receive the PDCCH corresponding to the first random access procedure. The window may be a RAR window or a window determined by a timer configured via a device on the network side.

The window start case may be one of the following: (1) the symbol that appears after the last PRACH presence symbol for sending the preamble and that is in the earliest control resource set of the type 1 PDCCH search space used to receive the RAR; (2) the symbol that appears after the last PUSCH presence symbol to send data and that is in the earliest control resource set of the type 1 PDCCH search space used to receive the MsgB; and (3) the case of starting after the last symbol of the PUSCH resource to send data.

In an exemplary embodiment, the terminal side device, based on the identifier of the first search space, detects the downstream control information carried in the first search space, where the downstream control information indicates the resource of the response information.

In an exemplary embodiment, the terminal side device, based on the first RNTI, detects the downstream control information corresponding to the first random access procedure, where the downstream control information indicates the resource of the response information. The first RNTI is a downlink control information scrambling identifier corresponding to the first random access procedure. That is, the DCI on the PDCCH corresponding to the first random access procedure may be scrambled in the first DCI format (eg, DCI format 0_0 or 1_0 or other format) using the first RNTI. The first RNTI may be allocated to the first random access procedure, in other words, the first RNTI is assigned to the first random access procedure. The terminal side device may, using the first RNTI, descramble the PDCCH corresponding to the first random access procedure. It should be understood that the first RNTI is different from the RA-RNTI defined in the protocol.

The first RNTI is reported by the network side device using a dedicated message or a normal message, or determined in advance. For example, the first RNTI may be included in the resource configuration message of the first random access procedure. The first RNTI may be assigned to the UE via a higher layer or via a physical layer. Multiple UEs may share one first RNTI. The terminal side device may correspond to different first RNTIs in the idle state, the inactive state, and the connected state. There is a correspondence between the first RNTI and the resource for sending the first uplink data. The first RNTI may be associated with one or more PUSCH resources indicated by one or more uplink grant configurations. After sending the first uplink data on the first uplink grant, the terminal side device receives the DCI on the PDCCH using the first RNTI associated with the first uplink grant.

In an exemplary embodiment, the terminal side device, based on the identifier of the first search space, detects the downstream control information carried in the first search space, and, based on the first RNTI, descrambles the downstream control information corresponding to the first random access procedure.

706: The terminal side device receives the response information on the resource indicated by the downstream control information.

That is, the terminal side device receives the response information on the resource dedicated to the response information, and this is indicated by the downstream control information.

After receiving and descrambling the DCI corresponding to the first random access procedure, the terminal side device may receive a MAC PDU on a physical downlink shared channel (PDSCH) indicated by the DCI, where the MAC PDU contains the first MAC sub-PDU corresponding to the first random access procedure, and the first MAC sub-PDU contains response information.

Optionally, the first MAC sub-PDU further contains the identifier of the first random access request. For example, the MAC sub-header in the first MAC sub-PDU may contain an identifier (eg, preamble ID) of the first random access request.

Optionally, a MAC PDU may comprise one or more MAC sub-PDUs. The MAC PDU may include not only the first MAC sub-PDU corresponding to the first random access procedure, but also the second MAC sub-PDU corresponding to the second random access procedure. The second MAC sub-PDU contains the second random access response in the second random access procedure. The second random access procedure is a procedure in which the terminal side device transmits the second random access request, receives the second random access response to the second random access request, and transmits the second uplink data based on the second random access response.

Alternatively, the second MAC sub-PDU further comprises a second random access request identifier. For example, the MAC sub-header in the second MAC sub-PDU may contain the identifier of the second random access request. The payload in the second MAC sub-PDU is the RAR field.

Optionally, in the MAC PDU, the second MAC sub-PDU is located before the first MAC sub-PDU.

For example, as shown in FIG. 9, the first MAC PDU may contain three MAC sub-PDUs, the 1st MAC sub-PDU may carry the response of the second random access procedure initiated by the first device at the terminal side, and the 2nd MAC sub-PDU may carry the response of the first random access procedure. initiated by the second device on the terminal side. The 3rd MAC sub-PDU may carry the response of the first random access procedure initiated by the third device on the terminal side. Alternatively, the MAC sub-header for the 1st MAC sub-PDU carries a logical channel identifier, and the identifier indicates that the payload (namely, the RAR field) after the MAC sub-header is a response to the second random access procedure initiated by the first device on the terminal side. The MAC sub-header for the 2nd MAC sub-PDU carries a logical channel identifier and the identifier indicates that the payload (namely, the RAR field and the CR field) after the MAC sub-header is a response to the first random access procedure initiated by the second terminal side device. The MAC sub-header of the 3rd MAC sub-PDU carries a logical channel identifier and the identifier indicates that the payload after the MAC sub-header is a response to the first random access procedure initiated by the third device on the terminal side. Alternatively, each MAC subheader carries length field information or length indication bit information, and the information indicates the length of the payload after the MAC subheader to support variable payload length.

For example, as shown in FIG. 10, the first MAC PDU may contain two sub-MAC PDUs. The 1st MAC sub-PDU contains one MAC sub-header and one RAR field. The 2nd MAC sub-PDU contains a CR field, one MAC sub-header and one RAR field. One or more CR fields are possible (one CR field is used as an example in the drawing).

For example, as shown in FIG. 11, the first MAC PDU may contain two sub-MAC PDUs. The 1st MAC sub-PDU contains one MAC sub-header and one RAR field. The 2nd MAC sub-PDU contains a CR field and one MAC sub-header. One or more CR fields are possible.

For example, as shown in FIG. 12, the first MAC PDU may contain three sub-MAC PDUs. The 1st MAC sub-PDU contains one MAC sub-header and one RAR field. The 2nd MAC sub-PDU contains one MAC sub-header and one CR field. The 3rd MAC sub-PDU contains one MAC sub-header and one CR field.

For example, as shown in FIG. 13, the first MAC PDU may contain two sub-MAC PDUs. The 1st MAC sub-PDU contains one MAC sub-header and one enhanced RAR field. The 2nd MAC sub-PDU contains one MAC sub-header and an enhanced RAR field. The improved RAR field contains at least one or more of the following: a timing control field, an uplink grant field, a temporary cellular radio network identifier field, and a CR field.

For example, the first MAC PDU may contain two MAC sub-PDUs. The 1st MAC sub-PDU contains one MAC sub-header, one RAR field and a CR field. The second MAC sub-PDU contains one MAC sub-header, a RAR field and a CR field.

Optionally, the 1st MAC sub-PDU contains one MAC sub-header and one or more CR fields.

Optionally, the payload or subheader of the subheader in the first MAC sub-PDU indicates whether a contention resolution information field exists. When the contention resolution information field exists, the first MAC sub-PDU further comprises one or more contention resolution information fields. In other words, the CR fields in the responses for the first random access procedures initiated by the plurality of terminal-side devices may be cascaded into the first MAC sub-PDU. Alternatively, the first MAC sub-PDU may be the last MAC sub-PDU in the MAC PDU. For example, one R bit of the MAC payload in RAR is used to indicate whether a CR field exists. For example, R=0 indicates that the CR field does not exist, and R=1 indicates that the CR field exists. The CR field may be placed before, inside, or after the RAR field.

In an exemplary embodiment, the subheader of the first MAC sub-PDU carries the logical channel identifier and the logical channel identifier indicates that the first MAC sub-PDU contains only the contention resolution information field. It should be understood that there are one or more conflict resolution information fields. Alternatively, the subheader of the first MAC sub-PDU indicates the number of contention resolution information fields to carry.

In the present invention, the information in the contention resolution information field may be part or all of the terminal identifiers for the terminals, or may be part or all of the upstream data. Optionally, the MAC sub-header carries a logical channel identifier and the logical channel identifier indicates that the payload is a MAC PDU format or a MAC sub-PDU for a previous random access response (eg, two-stage random access).

In an exemplary embodiment, the terminal determines the format of the MAC PDU or MAC sub-PDU of the first random access response (eg, two-way random access) based on an identifier that belongs to the first random access request and that is in the first MAC subheader. The first random access request ID corresponds to the MAC PDU or MAC sub-PDU format of the previous 2-round random access request response in the present invention, and the second random access request ID corresponds to the MAC PDU or MAC sub-PDU format of the existing 4-round random access response response.

For example, as shown in FIG. 14, an example is used in which the MAC PDU contains three MAC sub-PDUs. The first MAC sub-PDU may be the last MAC sub-PDU (namely, the 3rd MAC sub-PDU), and E=0 in the MAC sub-header of the 3rd MAC sub-PDU may be used to indicate that after the RAR field of the last sub-PDU MAC possibly CR field. By default, the terminal side device reads the CR information using a fixed bit size (eg, 48 bits).

For the E bit of the MAC Sub-Header of an existing Random Access Response, 0 indicates that the MAC Sub-PDU containing the MAC Sub-Header is the last MAC Sub-PDU of this MAC PDU. In the present invention, the terminal determines, based on the size of the MAC PDU, whether a CR field exists. Thus, after the MAC sub-PDU, padding is possible instead of the CR field. Optionally, indication information is added to the MAC subheader. When E=0, this indicates that the CR field exists after the last MAC sub-PDU. Alternatively, the number of CR fields that exist or the length of all CR fields may be specified. Optionally, indication information is added to the MAC subheader. When E=0, this indicates that a MAC sub-PDU containing a CR field exists after the last MAC sub-PDU. Alternatively, the number of MAC sub-PDUs containing CR fields or the length of all MAC sub-PDUs containing CR fields may be specified.

Optionally, a MAC PDU may comprise one or more MAC sub-PDUs. The RAR field and the CR field are not in the same MAC PDU. The MAC PDU contains only the first MAC sub-PDU. In this case, the first MAC sub-PDU contains the first MAC sub-header and one or more CR fields. The MAC PDU does not contain a RAR field. The MAC PDU contains only the second MAC sub-PDU and the second MAC sub-PDU contains the second MAC sub-header and the RAR field. The MAC PDU does not contain a CR field.

707: The network side device transmits the second configuration parameter of the second random access procedure to the terminal side device.

The second configuration parameter may contain the identifier of the second search space and the upstream grant of the second random access procedure. Alternatively, the second configuration parameter contains an upstream grant of the second random access procedure.

708: The terminal side device receives from the network side device the second configuration parameter of the second random access procedure.

The second random access procedure is a procedure in which a terminal-side device transmits a second random access request, receives a second random access request response to a second random access request, and transmits a second uplink data based on the second random access request response. For example, the second random access procedure is a four-stage random access procedure, that is, a random access procedure in which a terminal-side device communicates with a network-side device using MSG1-MSG4.

The second configuration parameter contains the identifier of the second search space and the identifier of the second search space is different from the identifier of the first search space. The second search space may be used to carry downstream control information indicating the resource of the second response to the random access request. The terminal-side device may identify the search space of the second random access procedure based on the identifier of the second search space, and further detect the DCI of the second random access procedure in the search space.

The second configuration parameter may further comprise an identifier of the second control resource set, and the second control resource set is a resource set for detecting downstream control information carried in the second search space. In other words, the terminal-side device may search for the DCI corresponding to the second random access procedure for the time-frequency control resource set indicated by the second control resource set identifier.

709: The terminal side device transmits the second random access request to the network side device in the second random access procedure.

The second random access request may comprise a second random access preamble of the second random access procedure. The terminal side device transmits the second random access preamble to the network side device on the selected PRACH resource.

710: The network side device transmits DCI on the second random access response resource.

The downstream control information indicates the resource of the second random access response.

711: The terminal side device receives the DCI on the second random access response resource.

In an exemplary embodiment, the terminal side device receives, based on the identifier of the second search space, the PDCCH corresponding to the second random access procedure. See description of step 706. The second search space identifier contains the identifier of the second control resource set, and the terminal side device may search the PDCCH corresponding to the second random access procedure for the time frequency control resource set indicated by the second control resource set identifier.

It should be noted that the identifier of the first search space may be different from the identifier of the second search space. Specifically, the identifier of the first search space may be assigned to the first random access procedure, in other words, the identifier of the first search space is allocated to the first random access procedure. The second search space identifier may be assigned to the second random access procedure, in other words, the second search space identifier is allocated to the second random access procedure. Thus, if a terminal-side device initiates a first random access procedure (namely, a random access procedure containing two steps), the terminal-side device can receive the PDCCH based on the first search space ID. If a terminal-side device initiates a second random access procedure (namely, a four-stage random access procedure), the terminal-side device may receive the PDCCH based on the identifier of the second search space. Therefore, the terminal side device can quickly identify or distinguish between PDCCHs of different random access procedures based on different search space identifiers to prevent the terminal side device from misparsing response messages of different random access procedures.

The terminal side device, based on the second RNTI, detects the downlink control information corresponding to the second random access procedure, where the downlink control information indicates the resource of the second random access response, and the second RNTI is the downlink control information scrambling identifier corresponding to the second random access procedure.

In an exemplary embodiment, the terminal side device receives the PDCCH corresponding to the second random access procedure and which is scrambled using the second RNTI. That is, the DCI on the PDCCH corresponding to the second random access procedure may be in a second DCI format (eg, DCI formats 0_0 and 1_0 or other format) scrambled using the second RNTI. The terminal side device may, using the second RNTI, descramble the PDCCH corresponding to the second random access procedure.

It should be noted that the first RNTI may be different from the second RNTI. Specifically, the first RNTI may be allocated to the first random access procedure, in other words, the first RNTI is assigned to the first random access procedure. The second RNTI may be allocated to the second random access procedure, in other words, the second RNTI is assigned to the second random access procedure. Thus, if a terminal-side device initiates a first random access procedure (namely, a random access procedure containing two steps), the terminal-side device may descramble the PDCCH based on the first RNTI. If the terminal side device initiates a second random access procedure (namely, a four-stage random access procedure), the terminal side device may descramble the PDCCH based on the second RNTI. Therefore, the terminal side device can quickly identify or distinguish between the PDCCHs of different random access procedures based on different RNTIs so that the terminal side device can prevent misparsing the response messages of different random access procedures.

In an exemplary embodiment, the terminal side device, based on the first search space identifier, receives a PDCCH that corresponds to the first random access procedure and that is scrambled using the first RNTI. The terminal side device can quickly identify or distinguish between PDCCHs of different random access procedures based on different search space identifiers of different RNTIs so that the terminal side device can prevent misparsing of response messages of different random access procedures.

712: The terminal side device transmits the second uplink data based on the second random access response.

The terminal side device receives response information of the second random access preamble based on the PDCCH scheduling information corresponding to the second random access procedure. After receiving and descrambling the PDCCH corresponding to the second random access procedure, the terminal side device can obtain the DCI from the PDSCH indicated by the PDCCH scheduling information, where the DCI indicates the second random access response resource.

The terminal side device may then receive the second uplink data from the second message buffer, store the second uplink data in the HARQ buffer, and indicate the HARQ process to initiate transmission of the second uplink data residing in the HARQ buffer. The second upstream data may be upstream service and/or signaling data.

Alternatively, when deciding to initialize the second random access procedure in the service cell, the terminal side device may clear the second message buffer.

When the second random access procedure fails, or when the first message buffer has no upstream data and the second message buffer has upstream data, the terminal side device re-initiates the first random access procedure and obtains upstream data from the second message buffer. In other words, by changing from the second random access procedure to the first random access procedure, the terminal-side device can receive upstream data from the second message buffer and the upstream data does not need to be regenerated. This improves the efficiency of data transmission.

In an exemplary embodiment, the terminal side device may store the second upstream data in a first message buffer and a second message buffer. In other words, by initiating the second random access procedure, the terminal side device may store the first upstream data in the first message buffer and in the second message buffer. If the second random access procedure initiated by the device on the network side fails, the first random access procedure is performed and the uplink data can be obtained directly from the first message buffer instead of being regenerated, thus improving data transmission efficiency.

In an exemplary embodiment, the terminal side device receives the second uplink data from the third message buffer, stores the second uplink data in the HARQ buffer, and indicates the HARQ process to initiate transmission of the second uplink data residing in the HARQ buffer. The third message buffer is a buffer shared by the first random access procedure and the second random access procedure.

If the transmission resource size of the terminal side device does not match the size of the data received from the buffer, the terminal side device may reassemble the data received from the buffer in the MAC PDU. Refer to the preceding respective descriptions and the details are not re-described here.

Alternatively, when deciding to initialize the second random access procedure in the service cell, the terminal side device may clear the third message buffer.

When the terminal side device initiates the second random access procedure, the terminal side device may set the third counter to an initial value, for example, may set the value of the third counter to 0 or 1. The third counter is for the second random access procedure. The third counter may be a third random access preamble burst counter (PREAMBLE_TRANSMISSION_COUNTER). If the contention resolution in the second random access procedure fails, the terminal side device increments the count value of the third counter by 1. If the third counter reaches the configured maximum value, the terminal side device indicates to a higher layer (eg, RRC layer) that the second random access procedure access has failed. The terminal may count the number of times the second random access procedure failed and report the number of times to the network side device.

Alternatively, when the terminal side device initiates the second random access procedure, the terminal side device sets the counter to an initial value, where the second counter is the counter shared by the first random access procedure and the second random access procedure.

In addition, when the terminal side device initiates the second random access procedure, the terminal side device may set the third power hop counter to an initial value (eg, 1). The third power hop counter may be dedicated to the second random access procedure, in other words, the third power hop counter may be assigned to the second random access procedure. If the terminal side device needs to resend the second random access request or the second uplink data and the sync signal block does not change, the terminal side device increments the count of the third power hop counter by 1.

Alternatively, when the terminal side device initiates the second random access procedure, the terminal side device sets the second power hop counter to an initial value, where the second power hop counter is the power hop counter shared by the first random access procedure and the second random access procedure. . It should be understood that if the first random access procedure and the second random access procedure are initiated and the synchronization signal block is not changed, the count value of the power hop counter is incremented by 1.

713: The network side device sends contention resolution information to the network side device.

Conflict resolution information may be included in Msg4.

714: The terminal side device receives conflict resolution information sent by the network side device.

The contention resolution information corresponding to the second random access procedure may be included in Msg4, and the terminal side device can access the network side device (eg, eNodeB) based on the contention resolution information.

It should be noted that between steps 701 and 714 there is no specific execution sequence. The execution sequence between the steps is not particularly specifically limited in this embodiment.

An embodiment of the present application further provides a random access method comprising the following steps.

S101: When the terminal side device initiates the first random access procedure, the terminal side device sets the first counter to an initial value, where the first counter is for the first random access procedure. Alternatively, when the terminal side device initiates the first random access procedure, the terminal side device sets the second counter to an initial value, where the second counter is the counter shared by the first random access procedure and the second random access procedure.

When the terminal side device initiates the first random access procedure, the terminal side device may set the first counter to an initial value, for example, may set the value of the first counter to 0 or 1. The first counter is specifically for the first random access procedure, in other words, the first counter allocated to the first random access procedure. The first counter may be the first random access preamble send counter (PREAMBLE_TRANSMISSION_COUNTER). If the contention resolution in the first random access procedure fails, the terminal-side device increments the count value of the first counter by 1. The case where the contention resolution in the first procedure fails may be the case when the duration of the PDCCH discovery window expires, the response message of the first random access procedure access that is received by the terminal side device does not match the first random access preamble sent by the terminal side device, or the terminal side device does not receive the response message of the first random access procedure, or the terminal side device does not receive the PDCCH scheduled using C The terminal's -RNTI, or conflict resolution information field, of the received response message of the first random access procedure fails validation. If the first counter reaches the configured maximum value, the terminal side device indicates to the higher layer (eg, the RRC layer) that the first random access procedure has failed. The maximum value of the first counter can be equal to (preambleTransMax) or (preambleTransMax+1).

Alternatively, when the terminal side device initiates the first random access procedure, the terminal side device sets the second counter to an initial value, where the second counter is the counter shared by the first random access procedure and the second random access procedure. For the corresponding operation of the second counter, refer to the description of the operation of the first counter. Details are not provided here. It should be understood that if the contention resolution in the first random access procedure or the second random access procedure fails, the terminal-side device increments the shared counter count value by 1.

Alternatively, the terminal may count the number of times the first random access procedure has failed and report the number of times to the network side device using higher layer signaling. For example, the number of cases is reported to the device on the network side using the help information message. It should be understood that the terminal can count the number of cases during which the second random access procedure fails and report the number of cases to the network side device using a higher signaling level. The number of times the first random access procedure fails and the number of times the second random access procedure fails may be separately counted and reported.

For steps S102-S115, refer to steps 701-714. Details are not described here.

In the foregoing embodiments presented in the present application, the methods presented in the embodiments of the present application are described separately in terms of a terminal side device, a network side device, and an interaction between a terminal side device and a network side device. In order to implement the functions in the methods presented in the previous embodiments of the present application, the terminal-side device and the network-side device may comprise a hardware structure and/or a software module, and implement the above functions in the form of a hardware structure, a software module, or a combination of the structure. hardware and software module. Whether a particular function in the above functions is performed by a hardware structure, a software module, or a combination of a hardware structure and a software module depends on the particular application and design constraints of the technical solutions.

When each functional unit is obtained by dividing based on each respective function, FIG. 15 is an exemplary schematic block diagram of the communication device 15 associated with the embodiments described above. The communication device may be a terminal side device. The terminal-side device includes a receiving unit 1501, a transmitting unit 1502, and a processing unit 1503. In this embodiment of the present application, the processing unit 1503 is configured to receive the first uplink data from the first message buffer, where the first message buffer is a buffer dedicated to the first random access procedure, and the first random access procedure is a procedure in which the device on the terminal side transmits the first random access request, transmits the first uplink data on the first uplink resource, and receives response information, and the response information is the first random access response information of the first random access request or a response to the first uplink data. The transmitter module 1502 is configured to send the first random access request to the network side device and send the first uplink data to the network side device on the first uplink resource. The processing unit 1503 is further configured to detect downstream control information, where the downstream control information indicates a resource of response information. The receiving unit 1501 is configured to receive response information on the resource indicated by the downstream control information.

In the embodiment of the method shown in FIG. 7, the receiving unit 1501 is configured to support the terminal side device while executing processes 702, 706, 708, and 714 in FIG. 7. The transmitter unit 1502 is configured to support the terminal side device while executing processes 703, 709, and 712 in FIG. 7. Processing unit 1503 is configured to support the terminal side device while executing process 705 in FIG. 7. All similar material steps in the previous embodiments of the method can be repeated in the descriptions of the functions of the respective functional modules. The details are not re-described here.

When each functional unit is obtained by dividing based on each respective function, FIG. 16 is an exemplary schematic block diagram of the communication device 16 related to the above embodiments. The communication device may be a network side device. The network side device includes a transmitting unit 1601 and a receiving unit 1602. In this embodiment of the present application, the receiving unit 1602 is configured to receive the first random access request from the terminal side device and receive the first uplink data from the terminal side device on the first uplink resource, where the first uplink data is received by the terminal side device from the first message buffer, the first message buffer is a buffer dedicated to the first random access procedure, the first random access procedure is a procedure in which the terminal side device transmits the first random access request, transmits the first uplink data on the first uplink resource and receives response information, and the response information is the first random access request response to the first random access request or the response to the first upstream data. The transmission module 1601 is configured to send downlink control information, where the downlink control information indicates a resource of response information. The transmitting module is further configured to send response information on the resource indicated by the downstream control information.

In the embodiment of the method shown in FIG. 7, the transmission unit 1601 is configured to support the network-side device while executing processes 701, 704, 707, 710, and 713 in FIG. 7. All similar material steps in the previous embodiments of the method can be repeated in the functional descriptions of the respective functional modules. The details are not re-described here.

The division into modules in the embodiments of the present application is an example, it is simply division by logical functions and other division is possible in actual implementation. In addition, the functional modules in the embodiments of the present application may be integrated in a single processor, or each of the modules may exist physically separately, or two or more modules may be integrated into one module. An integrated module may be implemented in the form of hardware or may be implemented in the form of a software functional module. For example, in embodiments of the present application, the receiving module and the transmitting module may be integrated into the transceiver unit.

All or part of the methods presented in the embodiments of the present application may be implemented using software, hardware, firmware, or any combination thereof. When software is used to implement the methods, all or part of the methods may be implemented in the form of a computer program product. The computer program product contains one or more computer instructions. When computer program instructions are downloaded and executed on the computer, all or part of the procedures or functions corresponding to the embodiments of the present invention are generated. The computer may be a mainframe computer, a special purpose computer, a computer network, a network side device, a user equipment, or other programmable device. The computer instructions may be stored on a computer-readable medium or may be transferred from a computer-readable medium to another computer-readable medium. For example, computer commands may be transmitted from a website, computer, server, or information center to another website, computer, server, or information center by wire (for example, coaxial cable, optical fiber, or digital subscriber line, DSL)) or wirelessly (e.g. infrared, radio or microwave). Computer-readable media can be any applicable media accessible to a computer, or a storage device such as a server or information center that integrates one or more applicable media. Usable media can be magnetic media (such as a floppy disk, hard disk, or magnetic tape), optical media (such as a digital video disc (DVD)), semiconductor media (such as a solid state drive (SSD)) and etc.

It is clear that a person skilled in the art can make various modifications and changes to the embodiments of the present application without departing from the essence and scope of protection of the present application. The present application is intended to cover these modifications and changes provided that they fall within the scope of protection defined by the following claims and their equivalent technologies.

Claims (33)

1. A random access method, comprising the steps of: receive, with the terminal side device, the first upstream data from the first message buffer, the first message buffer being the buffer used for the first random access procedure, the first random access procedure being the procedure in which the terminal side device transmits the first random access request, transmits the first uplink data on the first uplink resource and receives response information, the response information being a first random access response to the first random access request or a response to the first uplink data; transmitting, by the terminal side device, a first random access request to the network side device, and transmitting the first uplink data to the network side device on the first uplink resource; detecting downlink control information by the terminal side device, the downlink control information indicating a resource of response information; And receiving, by the terminal-side apparatus, the resource response information indicated by the downstream control information; and the second message buffer is a buffer used for the second random access procedure; and when the first random access procedure fails or when the second message buffer has no upstream data, and the first message buffer has upstream data, the second random access procedure is a procedure in which a terminal-side device transmits a second random access request, receives a second response about random access to the second random access request and transmits the second uplink data based on the second random access response; wherein the method further comprises obtaining, by the terminal-side device, the second upstream data from the first message buffer in the second random access procedure; or storing, by the terminal-side device, the uplink data present in the first message buffer in the second message buffer; And receive, by means of the device on the terminal side, the second uplink data from the second message buffer in the second random access procedure. 2. The random access method according to claim 1, further comprising the step of: storing, by the terminal-side apparatus, the first uplink data in the first message buffer and in the second message buffer; or storing by the terminal-side apparatus the second uplink data in the first message buffer and in the second message buffer. 3. The random access method according to claim 1, wherein when the second random access procedure fails or when there is no upstream data in the first message buffer and there is upstream data in the second message buffer, the method further comprises receiving, by the terminal side device, the first upstream data from the second message buffer. 4. The method of random access according to any one of paragraphs. 1-3, further comprising the steps of: receive, with the help of the device on the side of the terminal, the first ascending data from the third message buffer in the first random access procedure; And receive, by means of the device on the side of the terminal, the second uplink data from the third message buffer in the second random access procedure, and the third message buffer is a buffer shared by the first random access procedure and the second random access procedure. 5. The method of random access according to any one of paragraphs. 1-4, further comprising the step of: set, by the terminal side apparatus, when the terminal side apparatus initiates the first random access procedure, the first counter to an initial value, the first counter being for the first random access procedure. 6. The random access method according to claim 5, wherein the first counter comprises at least one of the first random access preamble transmission counter and the first power hop counter. 7. The method of random access according to any one of paragraphs. 1-6, further comprising the step of: set, by the terminal-side apparatus, when the terminal-side apparatus initiates the first random access procedure, the second counter to an initial value, the second counter being the counter shared by the first random access procedure and the second random access procedure. 8. The random access method according to claim 7, wherein the second counter comprises at least one of the second random access preamble transmission counter and the second power hop counter. 9. The random access method according to claim 8, wherein increase, by the device on the terminal side, when the contention resolution in the first random access procedure or in the second random access procedure fails, the second random access preamble transmission count count value by 1. 10. The random access method according to claim 8, wherein increase, by the terminal side device, when the terminal side device re-initiates the first random access procedure or initiates the second random access procedure, the count value of the second power hop counter by 1. 11. A communication device, characterized in that it is configured to implement a random access method, according to any one of paragraphs. 1-10. 12. The communication device containing the processor and memory, while the memory stores commands; moreover, these commands cause, when executed by the processor, the execution by the communication device of the random access method according to any one of paragraphs. 1-10. 13. A computer-readable storage medium that stores commands, wherein said commands cause, when executed by the computer, the computer to execute the random access method according to any one of paragraphs. 1-10.

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