CN111867132A

CN111867132A - Random access method and device

Info

Publication number: CN111867132A
Application number: CN201910351831.6A
Authority: CN
Inventors: 黄曲芳; 徐小英; 娄崇
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-04-28
Filing date: 2019-04-28
Publication date: 2020-10-30
Anticipated expiration: 2039-04-28
Also published as: CN111867132B

Abstract

The application provides a random access method, wherein a terminal device firstly determines a random access type corresponding to a random access resource which appears firstly, and then determines a random access type which is adopted for initiating random access at present according to the random access type corresponding to the random access resource which appears firstly. Therefore, the terminal equipment can flexibly adjust the random access type to be adopted for initiating the random access according to the type of the random access resource appearing each time, thereby being capable of rapidly initiating the random access. Instead of after selecting a random access type, the random access can be performed by passively waiting for the resource access resource adaptive to the selected random access type, so that the time delay of the random access can be reduced.

Description

Random access method and device

Technical Field

The present application relates to the field of wireless communications technologies, and in particular, to a method and an apparatus for random access.

Background

In the wireless communication technology, a terminal device obtains uplink synchronization with a network device through a random access process. Currently, the random access types include a four-step random access type and a two-step random access type. The network device may configure Physical Random Access Channel (PRACH) resources for the two types of random access respectively. After selecting a certain random access type, the terminal device waits for the occurrence of the PRACH resource configured for the random access type, thereby initiating random access on the PRACH resource. For example, if the terminal device selects the four-step random access type, the terminal device may initiate random access only on PRACH resource configured to the four-step random access type by the network device. If the terminal equipment selects to adopt the two-step random access type, the terminal equipment only initiates random access on the PRACH resource configured to the two-step random access type by the network equipment.

However, in general, PRACH resources configured for four-step Random Access (RA) and PRACH resources configured for two-step RA may not be equal. For example, PRACH resources that the network device configures for the two-step RA may be sparse. If the terminal device just selects to initiate random access by adopting a two-step random access type, once the random access fails, the terminal device needs to wait for a longer time before waiting for the next PRACH resource configured for the two-step RA, and the time delay of the random access is longer.

Disclosure of Invention

The application provides a random access method and a random access device, which can reduce the time delay of random access.

In a first aspect, the present application provides a method for random access, including: when the terminal equipment determines to initiate random access, the terminal equipment determines a random access type corresponding to a first random access resource which appears first; the terminal equipment determines a random access type to be adopted currently according to the random access type corresponding to the first random access resource; and the terminal equipment adopts the determined random access type to be adopted currently to initiate random access. Wherein the first occurrence means the first occurrence on a time domain resource of the first random access resource.

According to the technical scheme, when the terminal equipment determines to initiate random access, the random access type corresponding to the random access resource which appears first is determined, and then the random access type which is adopted by the random access to initiate the random access at present is determined according to the random access type corresponding to the random access resource which appears first. Therefore, the terminal equipment selects the random access type every time, and can flexibly adjust the random access type to be adopted for initiating the random access according to the type of the random access resource appearing first every time, thereby being capable of rapidly initiating the random access. In the existing scheme, the terminal equipment selects a certain random access type, and then passively waits for resource access resources adaptive to the selected random access type to appear for random access, so that the technical scheme of the application can reduce the time delay of random access.

With reference to the first aspect, in some implementation manners of the first aspect, the determining, by the terminal device, a random access type to be currently used according to a random access type corresponding to the first random access resource includes: the terminal device determines a random access type corresponding to a first random access resource as a random access type to be currently adopted, wherein the random access type corresponding to the first random access resource may be two-step random access (type) or four-step random access (type).

Here, the terminal device initiates random access on the first random access resource, that is, the terminal device initiates random access by using a random access type corresponding to the first random access resource.

In the embodiment of the application, the UE can flexibly select the type of each random access attempt, and selects the random access type corresponding to the random access resource which appears first to initiate random access. Compared with the prior art that the UE selects the random access type first and then waits for the PRACH resource corresponding to the selected random access type to initiate random access, the scheme of the application can enable the UE to seize each random access opportunity, and reduces the time delay of the random access.

With reference to the first aspect, in some implementation manners of the first aspect, the determining, by the terminal device, a random access type to be currently used according to a random access type corresponding to the first random access resource includes: the terminal equipment determines that a first random access resource corresponds to a four-step random access type, and a second random access resource appearing after the first random access resource corresponds to a two-step random access type; and the terminal equipment determines the two-step random access type corresponding to the second random access resource as the random access type to be adopted currently under the condition that the difference value of the first random access resource and the second random access resource in time is smaller than a first threshold. Optionally, a second random access resource appearing first after the first random access resource corresponds to the two-step random access type.

Here, the terminal device does not initiate random access on the first random access resource, that is, the terminal device does not perform random access by using the random access type corresponding to the first random access resource. Similarly, the terminal device initiates random access on the second random access resource, that is, the terminal device initiates random access by using the random access type corresponding to the second random access resource.

In addition, the difference in time between the first random access resource and the second random access resource may be a difference between a starting time of the first random access resource in the time domain and a starting time of the second random access resource in the time domain.

Since the time required for the two-step RA is relatively short, the time required for the four-step RA is relatively long. Therefore, if the terminal device determines that the four-step random access resource is first present after the first time, but the four-step random access resource is followed by the two-step random access resource, it determines that the two-step random access resource and the four-step random access resource meet a certain condition in terms of time (that is, the time difference between the two random access resources is smaller than the first threshold), and even if the PRACH resources corresponding to the two-step RA are later in terms of time, the terminal device may select to initiate random access on the two-step random access resource that is later in terms of time, which may cause the UE to complete RA earlier, or may obtain success of RA earlier, thereby contributing to reducing the delay of random access.

As can be seen from the above, when the type of the random access resource appearing first is the two-step random access type, the terminal device may directly determine that the two-step random access type is the random access type to be currently used, and when the type of the random access resource appearing first is the four-step random access type, the terminal device may perform a judgment in combination with the first threshold, and further determine whether the four-step random access type is the random access type to be currently used or the two-step random access type is the random access type to be currently used, thereby flexibly adjusting the random access type to be used for initiating the random access, and thus, the random access may be quickly initiated.

With reference to the first aspect, in certain implementations of the first aspect, the method further includes: the terminal equipment determines that a second random access resource also exists on the time domain resource corresponding to the first random access resource, the random access type corresponding to the second random access resource is different from the random access type corresponding to the first random access resource, the terminal equipment determines the random access type to be adopted currently according to a selection strategy, and the selection strategy is used for selecting and determining the random access type to be adopted currently when different random access types exist on the time domain resource of the same random access resource. Selection strategies include, but are not limited to: the terminal equipment randomly selects a random access type corresponding to the first random access resource or a random access type corresponding to the second random access resource as a random access type to be adopted currently; or, the terminal device selects the random access type adopted by the last random access as the random access type to be adopted currently; or the terminal equipment selects the random access type to be adopted currently from the random access type corresponding to the first random access resource and the random access type corresponding to the second random access resource according to the random number.

Here, the second random access resource also exists on the time domain resource corresponding to the first random access resource, which means that the first random access resource and the second random access resource occupy the same time domain resource.

If the terminal device determines that the four-step random access resources and the two-step random access resources appear at the same time after the first time, for example, the same time-frequency resources are occupied in a code division manner, the terminal device can select the random access type to be adopted for currently initiating the random access in a plurality of manners, and the flexibility in selecting the random access type is improved.

Optionally, in an implementation manner, selecting, by the terminal device, a random access type to be currently used from a random access type corresponding to the first random access resource and a random access type corresponding to the second random access resource according to the random number includes: the terminal equipment generates a random number and compares the random number with a second threshold; if the random number is greater than or equal to the second threshold, the terminal equipment selects two steps of random access resources, and if the random number is less than the second threshold, the terminal equipment selects four steps of random access resources; or if the random number is greater than or equal to the second threshold, the terminal equipment selects four steps of random access resources, and if the random number is less than the second threshold, the terminal equipment selects two steps of random access resources. Wherein, one of the first random access resource and the second random access resource is a two-step random access resource, and the other is a four-step random access resource. The second threshold may be set according to network device and UE negotiation, or according to network device configuration, or according to UE internal algorithm.

Here, the random numbers (0,1) generated by the UE are evenly distributed within the range. Therefore, by setting the second threshold, the terminal device compares the generated random number with the second threshold, so that the probability of each terminal device selecting the two-step random access resource and the four-step random access resource can be controlled. Therefore, in the case that the two-step random access resources are sparse compared with the four-step random access resources, each UE can select the two-step random access resources or the four-step random access resources with a reasonable probability, thereby improving the system performance.

In a second aspect, the present application provides a communication device having the functionality to implement the method of the first aspect and any possible implementation thereof. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more units corresponding to the above functions.

In a third aspect, the present application provides a terminal device comprising a processor and a memory. The memory is used for storing the computer program, and the processor is used for calling and executing the computer program stored in the memory, so that the terminal device executes the method in the first aspect or any possible implementation manner of the first aspect.

Optionally, the terminal device may further include a transceiver.

In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when run on a computer, causes the computer to perform the method of the first aspect or any possible implementation thereof.

In a fifth aspect, the present application provides a chip comprising a processor. The processor is adapted to read and execute the computer program stored in the memory to perform the method of the first aspect or any possible implementation thereof.

Optionally, the chip further comprises a memory, and the memory and the processor are connected with the memory through a circuit or a wire.

Further optionally, the chip further comprises a communication interface.

Alternatively, the memory may be a physically separate unit or may be integrated with the processor

In a sixth aspect, the present application provides a computer program product comprising computer program code which, when run on a computer, causes the computer to perform the method of the first aspect or any possible implementation thereof.

According to the technical scheme, the UE firstly determines the random access type corresponding to the random access resource (namely, the PRACH resource) which appears firstly, and then determines the random access type to be adopted for initiating the random access according to the random access type corresponding to the random access resource which appears firstly. In the existing scheme, the UE selects a random access type first, and then waits for a PRACH resource corresponding to the selected random access type to initiate random access. In contrast, in the technical scheme of the present application, the UE can flexibly adjust the random access type to be used for initiating the random access according to the type of the random access resource appearing each time, and the random access can be performed without waiting for the occurrence of the PRACH resource corresponding to the selected random access type, so that the time delay of the random access can be reduced.

Drawings

Fig. 1 is an architecture diagram of a communication system suitable for use with embodiments of the present application.

Fig. 2 is a schematic diagram of a random access procedure of a four-step random access type.

Fig. 3 is a schematic diagram of a random access procedure of a two-step random access type.

Fig. 4 is a schematic diagram of a random access procedure in which a UE falls back from a two-step random access type to a four-step random access type.

Fig. 5 is an example of UE initiated random access provided in the present application.

Fig. 6 is another example of UE initiated random access provided herein.

Fig. 7 shows a schematic diagram of a plurality of random access preambles occupying time-frequency resources.

Fig. 8 is a schematic block diagram of a communication device 500 provided herein.

Fig. 9 is a schematic structural diagram of a terminal device provided in the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

The technical scheme of the embodiment of the application can be applied to various communication systems, for example: a global system for mobile communications (GSM) system, a Code Division Multiple Access (CDMA) system, a Wideband Code Division Multiple Access (WCDMA) system, a General Packet Radio Service (GPRS), a long term evolution (long term evolution, LTE) system, an LTE Frequency Division Duplex (FDD) system, an LTE Time Division Duplex (TDD), a Universal Mobile Telecommunications System (UMTS), a Worldwide Interoperability for Microwave Access (WiMAX) communication system, a future fifth (5 generation,5G) system, a New Radio (NR), or the like.

Terminal equipment in the embodiments of the present application may refer to user equipment, access terminals, subscriber units, subscriber stations, mobile stations, remote terminals, mobile devices, user terminals, wireless communication devices, user agents, or user devices. The terminal device may also be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a future 5G network or a terminal device in a future evolved Public Land Mobile Network (PLMN), and the like, which are not limited in this embodiment.

The network device in the embodiment of the present application may be any device having a wireless transceiving function. Such devices include, but are not limited to: evolved Node B (eNB), Radio Network Controller (RNC), Node B (NB), Base Station Controller (BSC), Base Transceiver Station (BTS), home base station (home NodeB, HNB), baseband unit (BBU), Access Point (AP) in wireless fidelity (WIFI) system, wireless relay Node, wireless backhaul Node, Transmission Point (TP), or Transmission and Reception Point (TRP), etc., and may also be a fifth generation (transmission, 5G) system, for example, a G system or a group of NB or NB of a new air interface (NR), or a G system, or a system of a group of NB or NB including a base station panel or a plurality of NB or NB, such as a baseband unit (BBU) or a Distributed Unit (DU), etc.

In some deployments, the gNB may include a Centralized Unit (CU) and a Distributed Unit (DU). The gNB may also include an Active Antenna Unit (AAU). The CU implements part of the function of the gNB and the DU implements part of the function of the gNB. For example, the CU is responsible for processing non-real-time protocols and services, and implementing functions of a Radio Resource Control (RRC) layer and a Packet Data Convergence Protocol (PDCP) layer. The DU is responsible for processing a physical layer protocol and a real-time service, and implements functions of a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and a Physical (PHY) layer. The AAU implements part of the physical layer processing functions, radio frequency processing and active antenna related functions. Since the information of the RRC layer eventually becomes or is converted from the information of the PHY layer, the higher layer signaling, such as the RRC layer signaling, may also be considered to be transmitted by the DU or by the DU + AAU under this architecture. It is to be understood that the network device may be a device comprising one or more of a CU node, a DU node, an AAU node. In addition, the CU may be divided into network devices in an access network (RAN), or may be divided into network devices in a Core Network (CN), which is not limited in this application.

Referring to fig. 1, fig. 1 is an architecture diagram of a communication system suitable for use with embodiments of the present application. As shown in fig. 1, the wireless communication system may include at least one network device 101, where the network device 101 communicates with one or more terminal devices (e.g., terminal device 102 and terminal device 103 shown in fig. 1). When the network device sends a signal, the network device is a transmitting end, and the terminal device is a receiving end. Otherwise, when the terminal device sends a signal, the terminal device is a transmitting end, and the network device is a receiving end.

In order to facilitate understanding of the technical solutions of the present application, first, related technologies related to the present application are briefly described.

After the terminal equipment selects a proper cell to finish the residence, the random access can be initiated

Referring to fig. 2, fig. 2 is a schematic diagram of a random access procedure of a four-step random access type. As shown in fig. 2, the UE sends a message 1(message 1, abbreviated as msg 1) to the network device, where the message 1 is also a random access preamble (preamble). After detecting the random access preamble, the network device returns a response message, i.e., message 2(message 2), to the UE. And the message 2 contains uplink resources allocated to the UE by the network device. After receiving the message 2, the UE sends a message 3 on the uplink resource indicated by the message 2. If the network device can correctly decode the message 3(message 3), a message 4(message 4) is returned to the UE, and the message 4 is used for informing the UE that the competition is successful. Through the 4 steps, the random access process is successful.

With the introduction of new wireless terminal types such as Machine Type Communication (MTC), narrowband internet of things (NB-IoT), the number of UEs increases exponentially. If all the UEs adopt the four-step random access type for random access, the network equipment will be overloaded. In addition, the time delay of the four-step random access is also longer.

To solve these problems, a two-step random access type is introduced.

Referring to fig. 3, fig. 3 is a schematic diagram of a random access procedure of a two-step random access type. In the two-step random access procedure, the UE simultaneously carries a random access preamble and data (i.e., preamble and data) in message 1. The data portion is used for contention resolution, such as Radio Resource Control (RRC) messages. If there is no conflict between the UEs, the network device returns a message 2 to the UE after successfully decoding the message 1. The message 2 includes both a response to the random access preamble and a response to the data. Among them, the response to the random access preamble is also called a Random Access Response (RAR). The response to the data is typically an RRC message. The two responses may be sent simultaneously or sequentially. The UE may decode the two part responses independently. And the UE acquires the success of random access after receiving the message 2. If there is a collision between UEs, the network device may not be able to successfully resolve the data in message 1, and at this time the network device does not send message 2 to the UE. The UE waits a time window after sending out message 1 and considers that the random access fails if message 2 is not received.

In some cases, the UE sends message 1, i.e. including the random access preamble and data, on the PRACH resources configured for two-step random access. If the network device can only successfully decode the random access preamble and cannot successfully decode the data, the network device replies only the RAR to the UE and not a response to the data. And after receiving the RAR, the UE sends a message 3 by using the uplink resource indicated in the RAR, thereby returning to the four-step random access process. This process is referred to as two-step random access back to four-step random access.

Currently, the above-described four-step random access type and two-step random access type are simultaneously used in a wireless communication system. No matter which random access type is adopted by the UE for random access, corresponding random access resources, that is, Physical Random Access Channel (PRACH) resources, are adopted. The network device typically informs the UE via a broadcast message which PRACH resources are configured for the four-step random access procedure and which PRACH resources are configured for the two-step random access procedure. If the UE determines in advance that the four-step random access type is adopted for random access, the UE initiates random access on the PRACH resource configured to the four-step random access process. If the UE determines in advance that the two-step random access type is adopted for random access, the UE initiates random access on the PRACH resource configured to the two-step random access process. If the two-step random access fails, the UE returns to the four-step random access process from the two-step random access process, and at this time, the UE sends a message 3 on the uplink resource indicated in the RAR replied by the network equipment.

Accordingly, if the network device detects a random access preamble on the PRACH resource configured for four steps, it can be known that the UE initiates four-step random access. If the network device detects a random access preamble on the PRACH resources configured for two steps, it can be known that the UE initiated two-step random access. Thus, the network device can distinguish the processing.

As can be seen from the above description of the random access procedure, after determining the random access type, the UE only chooses to initiate random access on the PRACH resource configured by the network device for the random access type. For example, if the UE selects the four-step random access type, the UE may only initiate random access on PRACH resources configured by the network device for the four-step random access procedure. If the UE selects the two-step random access type, the UE only initiates random access on PRACH resources configured to the two-step random access process by the network equipment.

Referring to fig. 4, fig. 4 is a schematic diagram of a random access procedure in which a UE falls back from a two-step random access type to a four-step random access type. As shown in fig. 4, the RRC layer of the UE determines that the UE can perform two-step random access or four-step random access according to the service type or other factors. The RRC layer of the UE sends a notification to the MAC layer of the UE that the random access request is to be performed, and the four-step random access type or the two-step random access type is available. After the MAC layer of the UE selects the two RA steps, it initiates random access on the PRACH resource configured by the network device for the two RA steps. Specifically, the UE is at T ₁And sending a message 1 by adopting a two-step random access type at the moment, wherein the message 1 carries a random access lead code and data. After waiting a time window, if the UE receives only RAR without receiving a response for data, the two-step random access procedure is considered to fail. Wherein, the RAR indicates the uplink resource configured for the UE by the network device. And the UE sends a message 3 on the uplink resource indicated by the RAR. If the network device correctly decodes message 3, it replies with message 4 to the UE. In this way, the UE initiates random access from the two-step random access type back to the four-step random access type.

The above RRC determination of the type of random access by the UE is merely an example, and may also be determined by the MAC layer of the UE.

It can be understood that if the MAC layer of the UE chooses to be a four-step random access procedure. After the four-step random access process fails, the UE continues to wait for the next PRACH resource configured for the four-step RA.

In such random access procedure described above, the UE initiates random access only on PRACH resources configured by the network device for the selected random access type. In practice, the PRACH resources configured by the network device for the four-step RA and the PRACH resources configured for the two-step RA may not be equal. Or, the UE does not have as many opportunities to perform four-step random access and two-step random access. For example, the chance of two-step random access may be less than the chance of four-step random access. That is, the PRACH resources allocated to the two-step RA are sparse compared to the PRACH resources allocated to the four-step RA. If the UE just selects to adopt the two-step random access type to initiate random access, once the random access fails, the UE needs to wait for a longer time before waiting for the next PRACH resource configured for the two-step RA, and the time delay of the random access is longer.

Therefore, the application provides a random access method, aiming at reducing the time delay of random access.

The technical scheme of the application provides that before initiating random access, the UE firstly determines the random access type corresponding to the PRACH resource appearing next, and then determines the random access type adopted by the current random access to initiate according to the random access type corresponding to the PRACH resource appearing next. Therefore, the UE can flexibly select the type of the next random access attempt, and the time delay of the random access is favorably reduced.

Alternatively, the "PRACH resource appearing next" here is the PRACH resource appearing first after the time when the UE determines to initiate the random access. Wherein the first-occurring PRACH resource refers to a PRACH resource that occurs first on a time domain resource.

In the embodiment of the present application, the random access types corresponding to the PRACH resource include a four-step random access type and a two-step random access type.

In one implementation, when the UE determines to initiate random access, the UE first determines a random access type corresponding to a PRACH resource that occurs first, and initiates random access using the random access type corresponding to the PRACH resource that occurs first. In other words, the next occurring PRACH resource corresponds to what random access type, and the UE initiates random access using the random access type.

For convenience of description, a time at which the UE determines the random access type is hereinafter referred to as a first time, and a PRACH resource occurring first after the first time is referred to as a first PRACH resource.

Alternatively, if the random access type is notified to the MAC layer after being determined by the RRC layer of the UE, the first time may be a time at which the RRC determines the random access type.

Alternatively, if the random access type is determined by the MAC layer of the UE itself, the first time may be a time at which the MAC layer determines the random access type.

That is, if the MAC layer determines that the random access type corresponding to the first PRACH resource is a two-step random access resource, the MAC layer determines to initiate random access by using a two-step random access procedure. Specifically, the UE may transmit a message 1 on the first PRACH resource, where the message 1 includes a random access preamble and data.

And if the MAC layer determines that the random access type corresponding to the first PRACH resource is the four-step random access resource, the MAC layer determines to initiate random access by adopting the four-step random access. Specifically, the UE may send message 1 on the first PRACH resource, where message 1 includes only the random access preamble.

Referring to fig. 5, fig. 5 is a diagram illustrating an example of UE initiating random access provided by the present application. As shown in fig. 5, the RRC layer of the UE informs the MAC layer to perform RA, and "two-step RA or four-step RA is possible". Alternatively, the MAC layer of the UE may determine to perform RA by itself and determine the random access type to initiate random access. For example, the MAC layer may determine the random access type according to a traffic type of the UE, and quality of service (QoS) of a traffic priority service. MAC layer at T ₁Time of day determination T₁And the PRACH resource appearing first after the moment corresponds to the two-step random access type, and the MAC layer determines to adopt the two-step random access type. UE is in T₂Message 1 is sent at a time, message 1 comprising a random access preamble and data. After waiting a time window, the UE is at T₃It is determined at time that both RA steps fail. That is, the length of the time window for the UE to wait is T₃-T₂. After determining that two-step RA fails, the MAC layer of the UE is at T₄Time of day determination T₄The PRACH resource that appears first after the moment is of a four-step random access type. The MAC layer of the UE determines to adopt a four-step random access type. At T₅At time, the UE is at T₄And sending a message 1 on the PRACH resource corresponding to the RA which occurs at the first four steps after the moment, wherein the message 1 only comprises a random access preamble. Alternatively, T₄Time and T₃The moments may overlap, i.e. correspond to the same moment.

Note that T is introduced in FIG. 5₁～T₅The technical solutions of the present application are merely for clarity of description, and the solutions themselves should not be limited in any way.

In the embodiment of the application, the UE can flexibly select the type of the next random access attempt, and select the random access type corresponding to the first occurring random access resource to initiate random access. Compared with the prior art that the UE selects the random access type first and then waits for the PRACH resource corresponding to the selected random access type to initiate random access, the scheme of the application can enable the UE to seize each random access opportunity, and reduces the time delay of the random access.

In another implementation, if the UE determines that a first PRACH resource after a first time corresponds to a four-step random access type and a PRACH resource appearing after the first random access resource (hereinafter, referred to as a second PRACH resource) corresponds to a two-step random access type, the UE may compare a difference in time between the first PRACH resource and the second PRACH resource with a first threshold and determine a random access type for initiating random access according to a comparison result. Optionally, the PRACH resource appearing first after the first random access resource is a second PRACH resource

As a specific implementation, the difference between the first PRACH resource and the second PRACH resource in time may be a difference between a starting time of the first PRACH resource in time domain and a starting time of the second PRACH resource in time domain.

Optionally, if a difference between the first PRACH resource and the second PRACH resource in time is greater than or equal to a first threshold, the MAC layer of the UE determines to initiate random access using a four-step random access type. And if the difference value of the first PRACH resource and the second PRACH resource in time is smaller than a first threshold, the MAC layer of the UE determines to initiate random access by adopting a two-step random access type.

Alternatively, the terminal device determines to initiate random access by adopting a four-step random access type, that is, the terminal device initiates random access on a four-step random access resource. Similarly, the terminal device determines to initiate random access by adopting a two-step random access type, that is, the terminal device initiates random access on two-step random access resources.

Referring to fig. 6, fig. 6 shows another example of UE initiated random access provided by the present application. As shown in fig. 6, the PRACH resources corresponding to the four-step RA are in the front, the PRACH resources corresponding to the two-step RA are in the back, but the difference between the two PRACH resources in terms of time is smaller than the first threshold, and then the MAC layer of the UE selects two-step random access types.

Since the time required for the two-step RA is relatively short, the time required for the four-step RA is relatively long. Therefore, even if the PRACH resources corresponding to the two RA steps are later in time, it is possible for the UE to complete RA earlier. Therefore, the time delay of the UE for RA is reduced.

It should be understood that the PRACH resources corresponding to the two RA steps are later in time, which means that the PRACH resources corresponding to the two RA steps are later in time than the PRACH resources corresponding to the four RA steps.

Alternatively, the first threshold may be configured by the network device, and the UE may be notified of the configured first threshold through a system broadcast message or dedicated signaling. Alternatively, the first threshold may be specified by a protocol, or the first threshold may be determined by an algorithm of the UE, which is not limited in this application.

As can be seen from the above embodiments, when the terminal device determines that the type of the random access resource that appears first is the two-step random access type, the terminal device may directly determine that the two-step random access type is the random access type to be currently used; when the type of the random access resource appearing first is a four-step random access type, the terminal equipment can judge by combining the first threshold, and further determine whether the four-step random access type is used as the random access type to be adopted currently or the two-step random access type is used as the random access type to be adopted currently, so that the random access type to be adopted for initiating the random access can be flexibly adjusted, and the random access can be quickly initiated.

In another implementation, after determining that the PRACH resources corresponding to the two RA steps and the PRACH resources corresponding to the four RA steps occur at the same time after the first time (that is, the PRACH resources corresponding to the two RA steps and the PRACH resources corresponding to the four RA steps occupy the same time domain resource), the MAC layer may select a random access type for initiating random access in multiple ways.

Here, the PRACH resources corresponding to the two RA steps and the PRACH resources corresponding to the four RA steps after the first time may be frequency division or code division, and occupy the same time domain resource. For example, multiple orthogonal random access preambles exist on the same time-frequency resource. The plurality of orthogonal random access preambles is used in part for a two-step RA and in part for a four-step RA.

Referring to fig. 7, fig. 7 is a diagram illustrating that a plurality of random access preambles occupy time-frequency resources. As shown in fig. 7, the indexes of the PRACH resources configured by the network device for the two-step RA include 0,1,2 to 15, and the indexes of the PRACH resources configured for the four-step RA include 16 to 63. In the time dimension, these PRACH resources occupy the same time domain resource. Alternatively, the PRACH resources configured for the two-step RA and the RPACH resources configured for the four-step RA may be frequency or code division.

In this case, the UE may determine the random access type to be currently used according to a selection policy, where the selection policy is used to select and determine the random access type to be currently used when different random access types exist on the time domain resource of the same random access resource.

Optionally, the selection policy includes, but is not limited to, the following:

a four-step random access type or a two-step random access type is randomly selected. For example, it may be randomly selected by the MAC layer of the terminal device.

If the UE is a non-first random access, the same random access type as the last RA may be selected, for example, by the MAC layer of the terminal device.

The UE selects according to the random number. For example, the UE sets a second threshold, and the value of the second threshold is 0-1. And when the UE determines the random access type, generating a random number and comparing the random number with a second threshold. A two-step RA is selected if the random number is greater than a second threshold and a four-step RA is selected if the random number is less than the second threshold. Alternatively, a four-step RA is selected if the random number is greater than a second threshold, and a two-step RA is selected if the random number is less than the second threshold.

Here, the random numbers generated by the UE are uniformly distributed in the (0,1) range. The second threshold may be set based on network device and UE negotiation. For example, the second threshold is set to 0.6, and if the UE-generated random number is greater than or equal to 0.6, the two-step random access type is employed. And if the random number generated by the UE is less than 0.6, adopting a four-step random access type. Since the generation of random numbers is uniformly distributed, the probability that the UE generates a random number greater than or equal to 0.6 is 40%, so that the UE may select two-step random access with a probability of 40% and select four-step random access with a probability of 60%.

Here, the second threshold is set flexibly, and the application does not limit this. For example, the second threshold may be 0.7. 0.8, etc. Alternatively, the setting of the second threshold may be related to the sparseness of the two-step random access resources. For example, since two-step random access resources are sparse, the probability that the UE employs two-step random access resources should be correspondingly smaller. Assuming that the second threshold is 0.7, the probability that the UE generates a random number greater than or equal to 0.7 is 30%, and the UE has a 30% probability of selecting the two-step random access type. In contrast, the probability of the random number being less than 0.7 is 70%, and the UE has a 70% probability of selecting the four-step random access type. It can be seen that the setting of the second threshold and the distribution ratio of the two-step random access resource and the four-step random access resource may be adapted.

Optionally, the second threshold may be configured by the network device, may also be specified by a protocol, or may be determined by an algorithm of the UE, which is not limited in this application.

The above methods can make the UE select the random access type for initiating the random access according to the closest PRACH resource, thereby reducing the time delay of the random access.

The random access method provided by the present application is described in detail above with reference to fig. 1 to 7. The following describes an apparatus for random access provided in the present application.

Referring to fig. 8, fig. 8 is a schematic block diagram of a communication device 500 provided herein. The communication device 500 comprises a processing unit 510 and a transceiving unit 520.

A processing unit 510, configured to determine, when it is determined to initiate random access, a random access type corresponding to a first random access resource that appears first, and determine, according to the random access type corresponding to the first random access resource, a random access type to be currently used;

a transceiver 520, configured to initiate random access by using the random access type currently to be used, which is determined by the processing unit 510.

Alternatively, the transceiver unit 520 may be replaced by a receiving unit and/or a transmitting unit.

For example, the transceiving unit 520 may be replaced by a receiving unit when performing the step of receiving. The transceiving unit 520 may be replaced by a transmitting unit when performing the step of transmitting.

In one implementation, the processing unit 510 may be a processor.

Alternatively, the processing unit 510 may be a processing device, and the functions of the processing device may be partially or wholly implemented by software.

Alternatively, the functions of the processing means may be partly or wholly implemented by software. At this time, the processing device may include a memory for storing the computer program and a processor for reading and executing the computer program stored in the memory to perform the steps implemented internally by the terminal device in the method embodiments. For example, to perform the operations and/or processes described above as being performed by processing unit 510.

Alternatively, the processing means may comprise only a processor. The memory for storing the computer program is located outside the processing device and the processor is connected to the memory by means of circuits/wires to read and execute the computer program stored in the memory.

Alternatively, the functions of the processing means may be partly or wholly implemented by hardware. At this time, the processing device may include an input interface circuit, a logic circuit, and an output interface circuit. The input interface circuit is used for acquiring a first moment; the logic circuit is used for determining a random access type corresponding to a first random access resource appearing first after a first time, and determining a random access type for initiating random access according to the random access type corresponding to the first random access resource; and the output interface circuit is used for outputting the random access type which is determined by the logic circuit and used for initiating the random access.

Alternatively, the processing means may be one or more chips, or one or more integrated circuits.

For example, the processing device may be one or more field-programmable gate arrays (FPGAs), Application Specific Integrated Circuits (ASICs), system on chips (socs), Central Processing Units (CPUs), Network Processors (NPs), digital signal processing circuits (DSPs), Micro Controllers (MCUs), Programmable Logic Devices (PLDs), or other integrated chips, or any combination of the above chips or processors.

Alternatively, the transceiver unit 520 may be a transceiver having a function of transmitting and/or receiving, and the transceiver may be replaced by a receiver and/or a transmitter.

Here, the communication apparatus 500 may correspond exactly to the terminal device in the method embodiment. Corresponding units included in the communication apparatus 500 are respectively configured to execute corresponding operations and/or processes executed by the terminal device in each method embodiment, and reference may be specifically made to the description of the method embodiment, which is appropriately omitted here to avoid redundant description.

In another implementation, the communication device 500 may be a chip. The terminal device provided with the chip can perform random access according to the random access method provided by the application.

In this case, the transceiver unit 520 may be a communication interface. In particular, the communication interface may be an input-output interface or a transceiving circuit. The input-output interface may include an input interface and an output interface. The transceiver circuitry may include input interface circuitry and output interface circuitry.

Optionally, as an embodiment, the processing unit 510 determines a random access type corresponding to the first random access resource as a random access type to be adopted for currently initiating random access. In this case, the transceiver unit 520 is further configured to initiate a random access type on the first random access resource.

Optionally, as another embodiment, when the processing unit 510 determines that the first random access resource corresponds to a four-step random access type, and a second random access resource appearing after the first random access resource corresponds to a two-step random access type, and when the processing unit 510 determines that a difference between the four-step random access type and the two-step random access type in terms of time is smaller than a first threshold, the processing unit 510 determines the two-step random access type corresponding to the second random access resource as a random access type to be used for currently initiating random access. Optionally, a second random access resource appearing first after the first random access resource corresponds to the two-step random access type. In this case, the transceiver unit 520 is further configured to initiate random access on the second random access resource, and not to initiate random access on the first random access resource.

Optionally, as another embodiment, in a case that the processing unit 510 determines that the first random access resource and the second random access resource occupy the same time-frequency resource, and the first random access resource and the second random access resource are code-division-encoded, the processing unit 510 determines a random access type to be currently used according to a selection policy, where the selection policy is used to select and determine the random access type to be currently used when different random access types exist on a time-domain resource of the same random access resource, and includes but is not limited to:

the processing unit 510 may randomly select a random access type corresponding to the first random access resource or a random access type corresponding to the second random access resource, and the transceiver unit 520 is further configured to initiate random access by using the random access type randomly selected by the processing unit 510. For example, when the processing unit 510 randomly selects a random access type corresponding to the first random access resource as a random access type for initiating random access, the transceiver unit 520 initiates random access on the first random access resource. Or, when the processing unit 510 randomly selects the random access type corresponding to the second random access resource as the random access type for initiating the random access, the transceiver unit 520 initiates the random access on the second random access resource.

The processing unit 510 selects a random access type that is the same as the random access type used in the previous random access, and the transceiver unit 520 initiates the random access.

The processing unit 510 selects a random access type for initiating random access from the random access type corresponding to the first random access resource and the random access type corresponding to the second random access resource according to the random number, and the transceiver unit 520 initiates random access.

Here, for the description of selecting the random access type to be currently adopted from the random access type corresponding to the first random access resource and the random access type corresponding to the second random access resource according to the random number, reference may be made to the description of the above method embodiment, and details are not repeated.

It should be understood that the transceiver unit 520 in the above-described apparatus embodiment initiates random access, and may be that the transceiver unit 520 transmits the message 1.

In addition, the present application also provides a terminal device, which is described below with reference to fig. 9.

Referring to fig. 9, fig. 9 is a schematic structural diagram of a terminal device provided in the present application. As shown in fig. 9, the terminal device 7000 includes a processor 7001 and a transceiver 7002.

Optionally, terminal device 7000 also includes a memory 7003. The processor 7001, the transceiver 7002, and the memory 7003 may communicate with each other via internal connection paths to transmit control and/or data signals. The memory 7003 is used for storing computer programs, and the processor 7001 is used for calling and executing the computer programs from the memory 7003 to control the transceiver 7002 to transmit and receive signals.

Optionally, the terminal device 7000 may further include an antenna 7004 for transmitting information or data output from the transceiver 7002 via a wireless signal.

Alternatively, the processor 7001 and the memory 7003 may be integrated into one processing apparatus, and the processor 7001 is configured to execute the program codes stored in the memory 7003 to realize the above-described functions. In particular, the memory 7003 may be integrated in the processor 7001, i.e., an on-chip memory. Alternatively, the memory 7003 is separate from the processor 7001, and is located outside the processor 7001, i.e., an off-chip memory.

The processor 7001 may be used to perform the actions described in the previous method embodiments as being implemented internally by the terminal device, while the transceiver 7002 may be used to perform the actions of receiving or transmitting performed by the terminal device.

For example, the processor 7001 performs the determination of the random access type to be employed when the random access is currently initiated in the method embodiments. The transceiver 7002 performs the steps of initiating random access in the method embodiments. For example, send message 1, receive message 2, send message 3, and receive message 4, etc.

Alternatively, the processing and/or operations performed by the processing unit 510 described above in fig. 8 may be implemented by the processor 7001 shown in fig. 9, and the processing and/or operations performed by the transceiving unit 520 may be implemented by the transceiver 7002.

Optionally, terminal device 7000 may also include a power supply 7005 for providing power to various devices or circuits in the terminal device.

In addition to this, in order to further improve the functions of the terminal device, the terminal device 7000 may further include one or more of the input unit 7006, the display unit 7007, the audio circuit 7008, the camera 7009, the sensor 7010, and the like. The audio circuitry may also include a speaker 70082, a microphone 70084, and the like.

Alternatively, the input unit 7006 may be a signal input interface, and the display unit 7007 may also be regarded as a signal output interface.

In addition, the present application also provides a communication system, including the terminal device described in the method embodiments provided in the present application.

The present application also provides a computer-readable storage medium having a computer program stored thereon, where the computer program, when executed by a computer, causes the computer to perform the operations and/or processes performed by the terminal device in any one of the method embodiments.

The present application also provides a computer program product comprising computer program code to, when run on a computer, cause the computer to perform the operations and/or processes performed by the terminal device in any of the method embodiments.

The present application further provides a chip comprising a processor. A memory for storing the computer program is provided separately from the chip, and a processor is configured to execute the computer program stored in the memory to perform the operations and/or processes performed by the terminal device in any one of the method embodiments.

Further, the chip may also include a memory and/or a communication interface. The communication interface may be an input-output interface, an input-output circuit, etc.

The processor referred to in the embodiments above may be an integrated circuit chip having the capability of processing signals. In implementation, the steps of the above method embodiments may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The processor may be a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, or discrete hardware components. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in the embodiments of the present application may be directly implemented by a hardware encoding processor, or implemented by a combination of hardware and software modules in the encoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

The memory referred to in the embodiments above may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM), which acts as external cache memory. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), double data rate SDRAM, enhanced SDRAM, SLDRAM, Synchronous Link DRAM (SLDRAM), and Direct Rambus RAM (DRRAM). It should be noted that the memory of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware, depending on the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of random access, comprising:

when terminal equipment determines to initiate random access, the terminal equipment determines a random access type corresponding to a first random access resource which appears firstly;

the terminal equipment determines a random access type to be adopted currently according to the random access type corresponding to the first random access resource;

and the terminal equipment adopts the determined random access type to be adopted currently to initiate random access.

2. The method of claim 1, wherein the determining, by the terminal device, the random access type to be currently used according to the random access type corresponding to the first random access resource comprises:

and the terminal equipment determines the random access type corresponding to the first random access resource as the random access type to be adopted currently.

3. The method of claim 2, wherein the random access type corresponding to the first random access resource is a two-step random access type.

4. The method of claim 1, wherein the determining, by the terminal device, the random access type to be currently used according to the random access type corresponding to the first random access resource comprises:

the terminal equipment determines that the first random access resource corresponds to a four-step random access type, and a second random access resource appearing after the first random access resource corresponds to a two-step random access type;

and the terminal equipment determines the two-step random access types corresponding to the second random access resource as random access types under the condition that the difference value of the first random access resource and the second random access resource in time is smaller than a first threshold.

5. The method of claim 1, further comprising:

the terminal device determines that a second random access resource also exists on the time domain resource corresponding to the first random access resource, the random access type corresponding to the second random access resource is different from the random access type corresponding to the first random access resource, and the terminal device determines the random access type to be adopted currently according to the random access type corresponding to the first random access resource, and the method comprises the following steps:

The terminal equipment randomly selects a random access type corresponding to the first random access resource or a random access type corresponding to the second random access resource as a random access type to be adopted currently; or,

the terminal equipment selects a random access type adopted by the last random access as a random access type to be adopted currently; or,

and the terminal equipment selects a random access type to be adopted currently from the random access type corresponding to the first random access resource and the random access type corresponding to the second random access resource according to the random number.

6. The method of claim 5, wherein the selecting, by the terminal device, the random access type to be currently used from the random access type corresponding to the first random access resource and the random access type corresponding to the second random access resource according to a random number comprises:

the terminal device generates a random number and compares the random number with a second threshold,

if the random number is greater than or equal to the second threshold, the terminal equipment selects two-step random access resources, and if the random number is less than the second threshold, the terminal equipment selects four-step random access resources;

Or, if the random number is greater than or equal to the second threshold, the terminal device selects four-step random access resources, and if the random number is less than the second threshold, the terminal device selects two-step random access resources;

wherein one of the first random access resource and the second random access resource is a four-step random access resource, and the other is a two-step random access resource.

7. An apparatus for random access, comprising:

the processing unit is used for determining a random access type corresponding to a first random access resource which appears first when determining to initiate random access, and determining a random access type to be adopted currently according to the random access type corresponding to the first random access resource;

and the transceiver unit is used for initiating random access by adopting the determined random access type to be adopted currently.

8. The apparatus according to claim 7, wherein the processing unit is specifically configured to determine a random access type corresponding to the first random access resource as a random access type to be currently used.

9. The apparatus of claim 8, wherein the random access type corresponding to the first random access resource is a two-step random access type.

10. The apparatus according to claim 7, wherein the processing unit is specifically configured to:

determining that the first random access resource corresponds to a four-step random access type, and a second random access resource appearing after the first random access resource corresponds to a two-step random access type;

and under the condition that the difference value of the first random access resource and the second random access resource in time is smaller than a first threshold, determining the two-step random access type corresponding to the second random access resource as the random access type to be adopted currently.

11. The apparatus of claim 7, wherein the processing unit is further configured to determine that a second random access resource exists on a time domain resource corresponding to the first random access resource;

and the processing unit is specifically configured to:

randomly selecting a random access type corresponding to the first random access resource or a random access type corresponding to the second random access resource as a random access type to be adopted currently; or,

selecting the random access type adopted by the last random access as the random access type to be adopted currently; or,

And selecting a random access type to be adopted currently from the random access type corresponding to the first random access resource and the random access type corresponding to the second random access resource according to the random number.

12. The apparatus of claim 11, wherein the selecting a random access type to be currently used from a random access type corresponding to the first random access resource and a random access type corresponding to the second random access resource according to a preset random number comprises:

the processing unit generates a random number and compares the random number to a second threshold,

if the random number is determined to be greater than or equal to the second threshold, selecting two-step random access resources, and if the random number is determined to be less than the second threshold, selecting four-step random access resources; or

If the random number is determined to be greater than or equal to the second threshold, selecting four-step random access resources, and if the random number is determined to be less than the second threshold, selecting two-step random access resources;

13. A computer-readable storage medium, in which a computer program is stored which, when executed on a computer, causes the computer to carry out the method according to any one of claims 1 to 6.

14. A chip, characterized in that it comprises a memory for storing a computer program and a processor for reading and executing the computer program stored in the memory to cause a terminal device in which the chip is installed to perform the method according to any one of claims 1 to 6.