WO2018202048A1

WO2018202048A1 - Random access method, network device and terminal device

Info

Publication number: WO2018202048A1
Application number: PCT/CN2018/085358
Authority: WO
Inventors: 费永强; 孙伟; 谢信乾; 郭志恒
Original assignee: 华为技术有限公司
Priority date: 2017-05-05
Filing date: 2018-05-02
Publication date: 2018-11-08

Abstract

Provided in the embodiments of the present application are a random access method, a network device and a terminal device. The random access method comprises: a terminal device receiving a system message transmitted, on a first downlink carrier, by a network device, the system message comprising first information required for random access on a first uplink carrier and second information required for random access on a second uplink carrier, the frequency of the first uplink carrier being greater than the frequency of the second uplink carrier, the frequency of the first downlink carrier being equal to the frequency of the first uplink carrier; the terminal device transmitting, on the first uplink carrier or on the second uplink carrier, a random access request message; the terminal device receiving a random access response message transmitted by the network device on the first downlink carrier. With the random access method provided in the embodiments of the present application, the terminal device can complete random access on the first uplink carrier or on the second uplink carrier, improving the success rate of random access, and improving uplink coverage performance of the network device.

Description

Random access method, network device and terminal device

This application claims the priority of the Chinese Patent Application submitted to the China Patent Office on September 30, 2017, the application number is 201710939568.3, and the application name is "Random Access Method, Network Equipment and Terminal Equipment", and the requirements are in May 2017. The priority of the Chinese Patent Application entitled "Random Access Method, Network Equipment, and Terminal Equipment" is filed on the Japanese Patent Application Serial No. No. No. No. No. Publication No.

Technical field

The embodiments of the present disclosure relate to the field of communications technologies, and in particular, to a random access method, a network device, and a terminal device.

Background technique

At present, Long Term Evolution (LTE) and its evolution system (LTE Advanced, LTE-A) are widely deployed around the world, and will provide communication services for users for a long time. The fifth generation communication system (5th-Generation, 5G)'s new radio access technology (NR) standard is underway and is expected to be put into commercial use around 2018. Therefore, the scenario where LTE and NR coexist will exist for a long period of time in the future. In the NR research project, the technical research on the coexistence scenarios of LTE and NR is also included.

When the LTE cell and the NR cell are deployed, the NR cell is deployed in the high frequency band, and the LTE cell is deployed in the low frequency band. For example, one important deployment frequency band for an NR cell is 3.5 GHz, while an important deployment frequency band for an LTE cell is 1.8 GHz. The NR uses an asymmetric carrier F1 that operates in a Time Division Duplexing (TDD) mode, and the LTE uses a symmetric carrier F2 that operates in a Frequency Division Duplexing (FDD) mode. Since LTE's current uplink spectrum utilization is not high, and the 1.8 GHz band has lower channel fading and better coverage than the 3.5 GHz band, the LTE F2 uplink carrier can be shared with 5G. The NR's user equipment (UE) and the LTE UE are used together for uplink transmission, which improves the spectrum utilization of the F2 uplink carrier and enhances the uplink coverage capability of the 5G NR. However, the F2 downlink carrier of the LTE is not necessarily shared by the UE of the 5G NR. Therefore, the NR UE can only perform downlink transmission in the F1 downlink carrier and receive the downlink signal of the NR.

The UE needs to perform random access in order to access the wireless network system and obtain communication services. Currently, the initiation random access procedure of a UE can be briefly described as follows. For example, a working cell always transmits synchronization signals and broadcast system information periodically on the F1 downlink carrier. The system information includes the information needed to perform random access on the F1 carrier. The UE starts searching for cells that may provide services for each frequency band, and selects a target cell for initial random access. After the UE acquires the random access information from the F1 downlink carrier of the target cell, the UE sends a random access request on the F1 uplink carrier for random access.

It can be seen from the above random access procedure that the UE can only perform random access on the F1 uplink carrier, and cannot perform random access on the F2 uplink carrier.

Summary of the invention

The embodiment of the present application provides a random access method, a network device, and a terminal device, which can implement random access on any uplink carrier.

In a first aspect, the embodiment of the present application provides a random access method, where the method includes: receiving, by the terminal device, a system message sent by the network device on the first downlink carrier, where the terminal device is on the first uplink carrier or on the second uplink. A random access request message is sent on the carrier, and the terminal device receives the random access response message sent by the network device on the first downlink carrier.

With the random access method provided by the first aspect, the terminal device receives the system message on the first downlink carrier. Since the system message carries the first information required for random access of the first uplink carrier and the second information required for random access of the second uplink carrier, the terminal device can not only initiate random connection on the first uplink carrier. In addition, since the second uplink carrier can obtain the necessary information for initiating random access, random access on the second uplink carrier can also be completed. The frequency of the second uplink carrier is lower than the frequency of the first uplink carrier, so that the random access is initiated on the second uplink carrier, the random access success rate is improved, and the uplink coverage performance of the network device is improved.

Optionally, in a possible implementation manner of the first aspect, the first information includes a center frequency, a bandwidth, and PRACH resource configuration information of the first uplink carrier, where the second information includes a center frequency of the second uplink carrier, Bandwidth and PRACH resource configuration information.

Optionally, in a possible implementation manner of the first aspect, before the terminal device sends the random access request message on the first uplink carrier or on the second uplink carrier, the method further includes: determining, by the terminal device, that A random access request message is sent on an uplink carrier or on a second uplink carrier.

Optionally, in a possible implementation manner of the first aspect, the terminal device determines to send a random access request message on the first uplink carrier or on the second uplink carrier, including: the terminal device is included according to the system message The second information determines that the random access request message is sent on the second uplink carrier.

With the random access method provided by the possible implementation, since the frequency of the first uplink carrier is greater than the frequency of the second uplink carrier, the second uplink carrier generally has lower channel fading and better uplink with respect to the first uplink carrier. cover. If the system message includes the second information required for the second uplink carrier random access, the terminal device may directly determine to send the random access request message on the second uplink carrier. The determination process is simple, the time of random access is shortened, and the success rate of random access is improved.

Optionally, in a possible implementation manner of the first aspect, the system message further includes access indication information. Determining, by the terminal device, that the random access request message is sent on the first uplink carrier or the second uplink carrier, the terminal device: determining, according to the access indication information included in the system message, that the random access request is sent on the second uplink carrier Message.

With the random access method provided by the possible implementation, since the frequency of the first uplink carrier is greater than the frequency of the second uplink carrier, the second uplink carrier generally has lower channel fading and better uplink with respect to the first uplink carrier. cover. When the second uplink carrier load is small and the random access request message collision probability is low, the network device can directly instruct the terminal device to send a random access request message on the second uplink carrier, which is simple in process and shortens the random access time. Improve the random access success rate.

Optionally, in a possible implementation manner of the first aspect, the second information further includes power threshold information of the PRACH. Determining, by the terminal device, that the random access request message is sent on the first uplink carrier or the second uplink carrier, the method includes: determining, by the terminal device, the first uplink in the information according to the received power information of the first downlink carrier and the power threshold information of the PRACH A random access request message is sent on the carrier or on the second uplink carrier.

According to the random access method provided by the possible implementation, the terminal device can accurately determine whether the first uplink carrier or the second uplink carrier satisfies the random access according to the information about the received power of the first downlink carrier and the power threshold information of the PRACH. condition. Sending a random access request message by selecting a better uplink carrier in the first uplink carrier and the second uplink carrier may further improve the random access success rate.

Optionally, in a possible implementation manner of the first aspect, the information about the received power of the first downlink carrier is the reference signal received power of the first downlink carrier. The power threshold information of the PRACH is a first power threshold value when the terminal device sends a random access request message on the first uplink carrier. The terminal device determines, according to the information about the received power of the first downlink carrier and the power threshold information of the PRACH, that the random access request message is sent on the first uplink carrier or on the second uplink carrier, including: if the first downlink carrier is If the reference signal received power is greater than or equal to the first power threshold, the terminal device determines to send a random access request message on the first uplink carrier; if the reference signal received power of the first downlink carrier is less than the first power threshold, Then the terminal device determines to send a random access request message on the second uplink carrier.

Optionally, in a possible implementation manner of the first aspect, the information about the received power of the first downlink carrier is the reference signal received power of the first downlink carrier. The power threshold information of the PRACH is a second power threshold value when the terminal device sends a random access request message on the second uplink carrier. The terminal device determines, according to the reference signal received power of the first downlink carrier and the power threshold information of the PRACH, that the random access request message is sent on the first uplink carrier or on the second uplink carrier, including: if the reference of the first downlink carrier If the received power of the signal is greater than or equal to the second power threshold, the terminal device determines to send a random access request message on the second uplink carrier; if the reference signal received power of the first downlink carrier is less than the second power threshold, The terminal device determines to transmit a random access request message on the first uplink carrier.

Optionally, in a possible implementation manner of the first aspect, the information about the received power of the first downlink carrier is the reference signal received power of the first downlink carrier. The power threshold information of the PRACH includes a third power threshold value when the terminal device sends the random access request message on the second uplink carrier, and a path loss offset value between the second uplink carrier and the first uplink carrier. The terminal device determines, according to the reference signal received power of the first downlink carrier and the power threshold information of the PRACH, that the random access request message is sent on the first uplink carrier or on the second uplink carrier, including: if the reference of the first downlink carrier The signal receiving power + the path loss offset value - the third power threshold value ≥ 0, the terminal device determines to send the random access request message on the second uplink carrier; if the reference signal receiving power of the first downlink carrier + path loss The offset value - the third power threshold < 0, the terminal device determines to send a random access request message on the first uplink carrier.

Optionally, in a possible implementation manner of the first aspect, the second information further includes power threshold information of the PRACH, and the power threshold information of the PRACH is the third information. The determining, by the terminal device, the sending the random access request message on the first uplink carrier or the second uplink carrier, includes: determining, by the terminal device, sending the random access request message on the second uplink carrier according to the third information.

Optionally, in a possible implementation manner of the first aspect, the terminal device sends the random access request message on the first uplink carrier or the second uplink carrier, where the terminal device determines by using the first information. And a random access request message is sent to the network device by using the resource on the first uplink carrier or the resource on the second uplink carrier determined according to the second information.

Optionally, in a possible implementation manner of the first aspect, the terminal device sends an RRC connection request message on the first uplink carrier or on the second uplink carrier.

Optionally, in a possible implementation manner of the first aspect, the terminal device receives the RRC connection configuration message sent by the network device on the first downlink carrier.

In a second aspect, the embodiment of the present application provides a random access method, where the method includes: the network device sends a system message to the terminal device on the first downlink carrier, where the network device is on the first uplink carrier or on the second uplink carrier. Receiving a random access request message sent by the terminal device, the network device sends a random access response message to the terminal device on the first downlink carrier.

Optionally, in a possible implementation manner of the second aspect, the first information includes a center frequency, a bandwidth, and PRACH resource configuration information of the first uplink carrier, where the second information includes a center frequency of the second uplink carrier, Bandwidth and PRACH resource configuration information.

Optionally, in a possible implementation manner of the second aspect, the second information further includes power threshold information of the PRACH.

Optionally, in a possible implementation manner of the second aspect, the power threshold information of the PRACH is the third information, where the third information is used to indicate that the terminal device sends the random access request message on the second uplink carrier.

Optionally, in a possible implementation manner of the second aspect, the power threshold information of the PRACH is a first power threshold that is set by the network device for the terminal device when the random access request message is sent on the first uplink carrier. value.

Optionally, in a possible implementation manner of the second aspect, the power threshold information of the PRACH is a second power threshold that is set by the network device for the terminal device when the random access request message is sent on the second uplink carrier. value.

Optionally, in a possible implementation manner of the second aspect, the power threshold information of the PRACH includes a third power threshold value and a path loss offset value, where the third power threshold value is set by the network device for the terminal device. And a power threshold value when the random access request message is sent on the second uplink carrier, where the path loss offset value is a path loss offset value between the second uplink carrier and the first uplink carrier.

Optionally, in a possible implementation manner of the second aspect, the system message further includes the access indication information, where the access indication information is used to indicate that the terminal device sends the random access request message on the second uplink carrier.

In a third aspect, the embodiment of the present application provides a terminal device, where the terminal device may include a receiving module and a sending module. The receiving module is configured to receive a system message sent by the network device on the first downlink carrier, where the sending module is configured to send a random access request message on the first uplink carrier or on the second uplink carrier, where the receiving module is further configured to receive the network. A random access response message sent by the device on the first downlink carrier.

Optionally, in a possible implementation manner of the third aspect, the first information includes a center frequency of the first uplink carrier, a bandwidth, and physical random access channel (PRACH) resource configuration information, where the second information includes the second uplink carrier. Central frequency, bandwidth, and PRACH resource configuration information.

Optionally, in a possible implementation manner of the third aspect, the terminal device further includes a processing module. The processing module is configured to determine to send a random access request message on the first uplink carrier or on the second uplink carrier.

Optionally, in a possible implementation manner of the third aspect, the processing module is specifically configured to determine, according to the second information included in the system message, that the random access request message is sent on the second uplink carrier.

Optionally, in a possible implementation manner of the third aspect, the system message further includes access indication information, where the access indication information is used to indicate that the terminal device sends the random access request message on the second uplink carrier; Specifically, the terminal device determines, according to the access indication information, that the random access request message is sent on the second uplink carrier.

Optionally, in a possible implementation manner of the third aspect, the second information further includes power threshold information of the PRACH. The processing module is specifically configured to: according to the information about the received power of the first downlink carrier and the power threshold information of the PRACH, determine to send a random access request message on the first uplink carrier or on the second uplink carrier.

Optionally, in a possible implementation manner of the third aspect, the information about the received power of the first downlink carrier is the reference signal received power of the first downlink carrier. The power threshold information of the PRACH is a first power threshold value when the terminal device sends a random access request message on the first uplink carrier. The processing module is specifically configured to: if the reference signal received power of the first downlink carrier is greater than or equal to the first power threshold, determine to send a random access request message on the first uplink carrier; if the first downlink carrier is referenced If the signal received power is less than the first power threshold, it is determined that the random access request message is sent on the second uplink carrier.

Optionally, in a possible implementation manner of the third aspect, the information about the received power of the first downlink carrier is the reference signal received power of the first downlink carrier. The power threshold information of the PRACH is a second power threshold value when the terminal device sends a random access request message on the second uplink carrier. The processing module is specifically configured to: if the reference signal received power of the first downlink carrier is greater than or equal to the second power threshold, determine to send a random access request message on the second uplink carrier; if the first downlink carrier is referenced If the signal received power is less than the second power threshold, it is determined that the random access request message is sent on the first uplink carrier.

Optionally, in a possible implementation manner of the third aspect, the information about the received power of the first downlink carrier is the reference signal received power of the first downlink carrier. The power threshold information of the PRACH includes a third power threshold value when the terminal device sends the random access request message on the second uplink carrier, and a path loss offset value between the second uplink carrier and the first uplink carrier. The processing module is specifically configured to: if the reference signal received power of the first downlink carrier + the path loss offset value - the third power threshold value ≥ 0, determine to send a random access request message on the second uplink carrier; A reference signal received power + path loss offset value - third power threshold < 0 of a downlink carrier determines to send a random access request message on the first uplink carrier.

Optionally, in a possible implementation manner of the third aspect, the second information further includes power threshold information of the PRACH, the power threshold information of the PRACH is the third information, and the third information is used to indicate that the terminal device is in the second uplink. The random access request message is sent on the carrier; the processing module is specifically configured to: the terminal device determines, according to the third information, that the random access request message is sent on the second uplink carrier.

Optionally, in a possible implementation manner of the third aspect, the sending module is specifically configured to: determine, by using, according to the first information, resources on the first uplink carrier, or by determining, according to the second information, The resource on the second uplink carrier sends a random access request message to the network device.

In a fourth aspect, an embodiment of the present application provides a network device, where the network device includes a sending module and a receiving module. The sending module is configured to send a system message to the terminal device on the first downlink carrier, where the receiving module is configured to receive the random access request message sent by the terminal device on the first uplink carrier or on the second uplink carrier, where the sending module further uses And transmitting a random access response message to the terminal device on the first downlink carrier.

Optionally, in a possible implementation manner of the fourth aspect, the first information includes a center frequency of the first uplink carrier, a bandwidth, and physical random access channel (PRACH) resource configuration information, where the second information includes the second uplink carrier. Central frequency, bandwidth, and PRACH resource configuration information.

Optionally, in a possible implementation manner of the fourth aspect, the second information further includes power threshold information of the PRACH.

Optionally, in a possible implementation manner of the fourth aspect, the power threshold information of the PRACH is the third information, where the third information is used to indicate that the terminal device sends the random access request message on the second uplink carrier.

Optionally, in a possible implementation manner of the fourth aspect, the power threshold information of the PRACH is a first power threshold that is set by the network device for the terminal device when the random access request message is sent on the first uplink carrier. value.

Optionally, in a possible implementation manner of the fourth aspect, the power threshold information of the PRACH is a second power threshold that is set by the network device for the terminal device when the random access request message is sent on the second uplink carrier. value.

Optionally, in a possible implementation manner of the fourth aspect, the power threshold information of the PRACH includes a third power threshold value and a path loss offset value, where the third power threshold is set by the network device for the terminal device. And a power threshold value when the random access request message is sent on the second uplink carrier, where the path loss offset value is a path loss offset value between the second uplink carrier and the first uplink carrier.

Optionally, in a possible implementation manner of the fourth aspect, the system message further includes access indication information, where the access indication information is used to indicate that the terminal device sends the random access request message on the second uplink carrier.

In a fifth aspect, an embodiment of the present application provides a terminal device, where the terminal device includes a processor, a memory, and a transceiver, where the memory is used to store instructions, the transceiver is used to communicate with other devices, and the processor is configured to execute instructions stored in the memory. To cause the terminal device to perform the method of the above first aspect.

In a sixth aspect, an embodiment of the present application provides a network device, where the network device includes a processor, a memory, and a transceiver, where the memory is used to store instructions, the transceiver is used to communicate with other devices, and the processor is configured to execute instructions stored in the memory. To cause the terminal device to perform the method of the second aspect described above.

Combining the above first aspect and each possible embodiment of the first aspect, the second aspect, and the possible possible embodiments of the second aspect, the third aspect, and the possible embodiments, the fourth aspect, and the fourth aspect of the third aspect Each of the possible implementation manners of the aspect, the fifth aspect, and the possible implementation manners of the fifth aspect, the sixth aspect, and the possible implementation manners of the sixth aspect, the system message includes a random access required by the first uplink carrier The first information, and the second information required for the second uplink carrier random access, the frequency of the first uplink carrier is greater than the frequency of the second uplink carrier, and the frequency of the first downlink carrier is the same as the frequency of the first uplink carrier.

In a seventh aspect, an embodiment of the present application provides a program, when executed by a processor, is configured to perform the method of the foregoing first aspect.

In an eighth aspect, an embodiment of the present application provides a program product, such as a computer readable storage medium, including the program of the seventh aspect.

In a ninth aspect, the embodiment of the present application provides a computer readable storage medium, where the computer readable storage medium stores instructions, when executed on a computer, causing the computer to execute the method of the first aspect.

In a tenth aspect, the embodiment of the present application provides a program, when executed by a processor, is used to execute the method of the second aspect.

In an eleventh aspect, an embodiment of the present application provides a program product, such as a computer readable storage medium, including the program of the tenth aspect.

According to a twelfth aspect, the embodiment of the present application provides a computer readable storage medium, where the computer readable storage medium stores instructions that, when run on a computer, cause the computer to perform the method of the second aspect.

The embodiment of the present application provides a random access method, a network device, and a terminal device. The network device sends a system message to the terminal device on the first downlink carrier, by carrying the first information required for random access of the first uplink carrier and the second required for random access of the second uplink carrier in the system message. Information, the terminal device may obtain second information that is randomly accessed by the second uplink carrier. Therefore, the terminal device can complete the random access not only on the first uplink carrier but also on the second uplink carrier. Since the frequency of the second uplink carrier is lower than the frequency of the first uplink carrier, the random access success rate is improved, and the uplink coverage performance of the network device is improved. And the program also increases the flexibility of spectrum partitioning and the efficiency of the use of fragmented spectrum.

DRAWINGS

1 is a network architecture diagram applicable to an embodiment of the present application;

2 is a flow chart of an existing random access method;

FIG. 3 is a flowchart of a random access method according to an embodiment of the present application;

4 is a schematic structural diagram of a terminal device according to Embodiment 1 of the present application;

FIG. 5 is a schematic structural diagram of a network device according to Embodiment 1 of the present application.

FIG. 6 is a schematic structural diagram of a terminal device according to Embodiment 2 of the present application;

FIG. 7 is a schematic structural diagram of a network device according to Embodiment 2 of the present application.

detailed description

The random access method provided by the embodiment of the present application can be applied to a 5G communication system and other communication systems, as long as there are scenarios in which the number of uplink carriers and the number of downlink carriers are not equal, and the number of uplink carriers is greater than the number of downlink carriers. FIG. 1 is a network architecture diagram applicable to an embodiment of the present application. As shown in FIG. 1, the system includes a network device and a terminal device, and the network device has a certain signal coverage. Within the signal coverage, the network device is configured with an uplink carrier and a downlink carrier. The terminal device can send data and control signaling to the network device by using the time-frequency resource of the uplink carrier. The network device can send data and control signaling to the terminal device through the time-frequency resource of the downlink carrier. In FIG. 1, carrier F2 is an uplink carrier, and carrier F1 is an uplink carrier and a downlink carrier. Wherein, the frequency of the carrier F2 is lower than the frequency of the carrier F1, and the carrier F2 has lower channel fading and better coverage. In the LTE and NR coexistence scenario, the carrier F2 may be an LTE band carrier, and the frequency band may be 1.8 GHz. Carrier F1 can be an NR-band carrier and the frequency band can be 3.5 GHz.

The random access method provided by the embodiment of the present application is to solve the technical problem that the terminal device cannot perform random access on the low frequency uplink carrier when the user equipment can only use the low frequency uplink carrier and the high frequency uplink and downlink carrier in the prior art. .

2 is a flow chart of an existing random access method. For the scenario shown in FIG. 1, as shown in FIG. 2, the existing random access method process is as follows. Synchronization signal: The network device periodically sends a synchronization signal on F1, wherein the synchronization signal may include a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS), and the terminal device may detect the synchronization signal. Obtain the ID of the network device, obtain the downlink synchronization with the network device, and so on. System message: The network device periodically broadcasts system messages on F1. The system message may include random access information. The random access information is specifically the required random access information for accessing F1, and the system message sent on F1 does not include the random access information required for accessing F2. The random access information may include a random access pilot code sequence number and a configuration index for transmitting a physical random access channel (Physical Random Access Channel, PRACH). Msgl: The terminal device determines, according to the time-frequency resource configuration of the transmitted PRACH in the system message, the resource that sends the random access request on the F1 uplink carrier, and sends a random access request message to the network device. The random access request message may include a resource random access sequence determined according to the random access pilot code sequence number in the system message. Msg2: The network device sends a random access response message to the terminal device on the F1 downlink carrier according to Msg1. The random access response message may include a Time Advance (TA) corresponding to F1. The TA is used by the terminal device to determine the timing relationship of the uplink transmission. Msg3: The terminal device adjusts its own TA according to Msg2, and transmits an RRC Connection Request message (RRC Connection Request) to the network device. Msg4: The network device sends an RRC Connection Configuration message to the terminal device to complete the entire random access procedure. It can be seen that, in the prior art, when the user equipment can only use the low frequency uplink carrier F2 and the high frequency uplink and downlink carrier F1, the terminal device cannot know the information required for random access on the low frequency F2 uplink carrier, and Random access is performed on the low frequency F2 uplink carrier.

The random access method provided by the embodiment of the present application may randomly acquire the F1 uplink carrier and the F2 uplink carrier by using the F1 uplink carrier and the F2 uplink carrier random access information carried in the system message sent by the network device on the F1 downlink carrier. The access information is notified to the terminal device. Therefore, the terminal device can complete random access on the F2 uplink carrier according to the random access information of the F2 uplink carrier.

The terminal device in the embodiment of the present application may be a wireless terminal such as a mobile phone or a tablet computer, and the wireless terminal includes a device for providing voice and/or data services to the user, and the terminal device may also be a handheld device with an wireless connection function and an in-vehicle device. The embodiment of the present application is not limited to a device, a computing device, and a user equipment UE, a mobile station (MS), and a terminal.

The network device involved in the embodiment of the present application may be any device that manages wireless network resources in any of the 5G communication system and other communication systems. For example, the network device may be a 5G base station (g Node B, gNB) in a 5G communication system, or a radio transceiver (NeXt Node, NX) in a 5G communication system, which is not limited in this embodiment.

The technical solutions of the present application and the technical solutions of the present application are described in detail in the following specific embodiments to solve the above technical problems. The following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be described in some embodiments.

FIG. 3 is a flowchart of a random access method according to an embodiment of the present application. As shown in FIG. 3, the random access method provided in this embodiment of the present application may include:

S101. The network device sends a system message to the terminal device on the first downlink carrier.

The system message may include first information required for random access of the first uplink carrier and second information required for random access of the second uplink carrier, where a frequency of the first uplink carrier is greater than a frequency of the second uplink carrier, The first downlink carrier has the same frequency as the first uplink carrier.

Correspondingly, the terminal device can receive the system message sent by the network device on the first downlink carrier.

Specifically, the network device can be configured with one downlink carrier and two uplink carriers. The one downlink carrier may be referred to as a first downlink carrier. The two uplink carriers may be referred to as a first uplink carrier and a second uplink carrier. The first downlink carrier has the same frequency as the first uplink carrier, and the frequency of the first uplink carrier is greater than the frequency of the second uplink carrier. Or it can be understood with reference to FIG. 1 that the network device can be configured with two carriers (F1 and F2). One of the carriers (F1) can be used for uplink information transmission and downlink information transmission, and can be referred to as a first uplink carrier and a first downlink carrier according to the transmission direction. The other carrier (F2) is only used for uplink information transmission and may be referred to as a second uplink carrier. Since the frequency of the second uplink carrier is low, the second uplink carrier has lower channel fading and larger uplink coverage than the first uplink carrier.

In the embodiment of the present application, the network device sends a system message to the terminal device on the first downlink carrier, where the system message includes the first information randomly accessed on the first uplink carrier, and the second uplink is also included. The second information randomly accessed on the carrier. In this way, the network device notifies the terminal device of the random access information of the second uplink carrier, and may enable the terminal device to initiate random access on the second uplink carrier according to the second information.

The first information includes necessary information that the terminal device needs to obtain when the first uplink carrier initiates random access. Through the first information, the terminal device can be caused to determine resources on the first uplink carrier. Similarly, the second information includes necessary information that the terminal device needs to obtain when the second uplink carrier initiates random access. Through the second information, the terminal device can be caused to determine resources on the second uplink carrier.

In this embodiment, the implementation manner of the first information is not limited, and may be random access information of the first uplink carrier carried in the system message sent by the existing downlink carrier. Optionally, the first information may include a center frequency point, a bandwidth, and PRACH resource configuration information of the first uplink carrier. Optionally, the PRACH resource configuration information may include a PRACH configuration index.

The implementation of the second information is not limited in this embodiment, and may be similar to the random access information of the first uplink carrier carried in the system message sent on the first downlink carrier. Optionally, the second information may include a center frequency, a bandwidth, and PRACH resource configuration information of the second uplink carrier. Optionally, the PRACH resource configuration information may include a PRACH configuration index.

Optionally, the system information may further include access indication information. The access indication information is used to instruct the terminal device to send a random access request message on the second uplink carrier.

Optionally, the indication may be indicated by configuring different values of the access indication information. For example, when the access indication information is configured to be "1", the network device instructs the terminal device to send a random access request message on the second uplink carrier.

Optionally, the indication information indicating the target carrier may be indicated by the access indication information. For example, when the access indication information indicates the ID of the second uplink carrier, the network device instructs the terminal device to send a random access request message on the second uplink carrier.

Optionally, the indication may be indicated by whether the access indication information is included in the system message. For example, when the system information includes the access indication information, the network device instructs the terminal device to send a random access request message on the second uplink carrier.

Optionally, the second information may further include power threshold information of the PRACH. The power threshold information of the PRACH is set by the network device for the terminal device, and is used by the terminal device to determine whether to initiate random access on the first uplink carrier or random access on the second uplink carrier.

Optionally, the power threshold information of the PRACH may be a first power threshold that is set by the network device for the terminal device when the random access request message is sent on the first uplink carrier.

Optionally, the power threshold information of the PRACH may be a second power threshold that is set by the network device for the terminal device when the random access request message is sent on the second uplink carrier.

Optionally, the power threshold information of the PRACH may include a third power threshold and a path loss offset value, where the third power threshold may be set by the network device for the terminal device, and the random access is sent on the second uplink carrier. The power threshold value when the message is requested, and the path loss offset value may be a path loss offset value between the second uplink carrier and the first uplink carrier.

Optionally, the power threshold information of the PRACH may be the third information. The third information is used to instruct the terminal device to initiate random access on the second uplink carrier. The third information may be directly an indication information or a special value.

Correspondingly, if the power threshold information of the PRACH is the third information, the terminal device determines, according to the third information, that the random access is initiated on the second uplink carrier. If the power threshold information of the PRACH is not the third information, for example, the power threshold information of the PRACH is a certain power threshold, the terminal device may determine according to the power threshold to determine which uplink carrier is selected to initiate a random Access. The power threshold may be the foregoing first power threshold or the second power threshold, and specific implementations based on the power thresholds are described in detail later.

It should be noted that the specific values of the first power threshold, the second power threshold, the third power threshold, and the path loss offset value are not limited in this embodiment.

Optionally, the value range of the first power threshold may include a value range of the reference signal received power of the terminal device. For example, if the reference signal receiving power of the terminal device ranges from [-110 dBm, -60 dBm], the first power threshold value ranges from [-110 dBm, -60 dBm].

Optionally, the system message may further include public random access information.

Specifically, the first information may be information related to the first uplink carrier when the first uplink carrier is randomly accessed, and the second information may be information related to the second uplink carrier when the second uplink carrier is randomly accessed. The public random access information may be random access information applicable to both the first uplink carrier random access and the second uplink carrier random access. This embodiment does not limit the implementation manner of the public random access information. Optionally, the public random access information may include frequency hopping indication information or retransmission indication information.

S102. The terminal device sends a random access request message on the first uplink carrier or on the second uplink carrier.

Correspondingly, the network device may receive the random access request message sent by the terminal device on the first uplink carrier or on the second uplink carrier.

Specifically, for a specific terminal device, a random access request message is usually sent only on one uplink carrier. The terminal device may be in the first uplink carrier, because the system message received by the terminal device includes the first information required for the first uplink carrier random access and the second information required for the second uplink carrier random access. A random access request message is sent on or on the second uplink carrier. If the terminal device sends a random access request message on the first uplink carrier, the network device may receive the random access request message sent by the terminal device on the first uplink carrier. If the terminal device sends a random access request message on the second uplink carrier, the network device may receive the random access request message sent by the terminal device on the second uplink carrier.

It should be noted that the network device has a certain signal coverage, and there may be more than one terminal device that communicates with the network device within the signal coverage. Therefore, for a case where a plurality of terminal devices communicate with the network device, the network device may receive a random access request message sent by each terminal device on the first uplink carrier and on the second uplink carrier.

Optionally, the terminal device sends the random access request message on the first uplink carrier or the second uplink carrier, which may include:

The terminal device sends a random access request message to the network device by using the resource on the first uplink carrier determined according to the first information or by using the resource on the second uplink carrier determined according to the second information.

The method for determining, by the terminal device, the resource on the first uplink carrier according to the first information, and determining the resource on the second uplink carrier according to the second information, is not limited in this embodiment, and the existing random connection may be adopted. Any method of determining resources in the process.

Optionally, if the first information includes a center frequency, a bandwidth, and a PRACH configuration index of the first uplink carrier, the terminal device may be configured according to the PRACH configuration index, the center frequency of the first uplink carrier, and the bandwidth of the first uplink carrier. The resource for transmitting the random access request message is determined on the time-frequency resource.

Optionally, if the second information includes a center frequency, a bandwidth, and a PRACH configuration index of the second uplink carrier, the terminal device may be configured according to the PRACH configuration index, the center frequency of the second uplink carrier, and the bandwidth of the second uplink carrier. The resource for transmitting the random access request message is determined on the time-frequency resource.

The specific information included in the random access request message is not limited in this embodiment, and may be the same as the information included in the existing random access request message. Optionally, the random access request message may include a random access sequence.

S103. The network device sends a random access response message to the terminal device on the first downlink carrier.

Correspondingly, the terminal device can receive the random access response message sent by the network device on the first downlink carrier.

The specific information included in the random access response message is not limited in this embodiment, and may be the same as the information included in the existing random access response message. Optionally, the random access response message may include a TA. It should be noted that if the terminal device sends a random access request message on the first uplink carrier, the TA corresponds to the first uplink carrier. If the terminal device sends a random access request message on the second uplink carrier, the TA corresponds to the second uplink carrier.

It can be seen that, in the scenario of the random access method provided by the embodiment of the present application, in a scenario where the number of uplink carriers is different from the number of downlink carriers, and the number of uplink carriers is greater than the number of downlink carriers, the network device sends the information to the terminal device on the first downlink carrier. The system message may be used to obtain random access information of two uplink carriers by using the first information required for random access of the first uplink carrier and the second information required for random access of the second uplink carrier carried in the system message. Also sent to the terminal device. Thereby, the terminal device can obtain the necessary information for initiating random access on the second uplink carrier, and complete random access on the second uplink carrier. The frequency of the second uplink carrier is lower than the frequency of the first uplink carrier, so that the random access is initiated on the second uplink carrier, the random access success rate is improved, and the uplink coverage performance of the network device is improved.

Optionally, the random access method provided in this embodiment may further include:

S104. The terminal device sends an RRC connection request message on the first uplink carrier or on the second uplink carrier.

Correspondingly, the network device receives the RRC connection request message sent by the terminal device on the first uplink carrier or on the second uplink carrier.

Specifically, for a specific terminal device, the terminal device may send an RRC connection request message on the first uplink carrier or on the second uplink carrier. It should be noted that, in a case that a plurality of terminal devices communicate with the network device, the network device may receive an RRC connection request message sent by each terminal device on the first uplink carrier and on the second uplink carrier.

S105. The network device sends an RRC connection configuration message to the terminal device on the first downlink carrier.

Correspondingly, the terminal device can receive an RRC connection configuration message sent by the network device on the first downlink carrier.

It should be noted that the specific information included in the RRC connection request message and the RRC connection configuration message is not limited in this embodiment, and may be the same as the RRC message in the existing access procedure.

Further, before the S102 terminal device sends the random access request message on the first uplink carrier or the second uplink carrier, the method may further include:

The terminal device determines to transmit a random access request message on the first uplink carrier or on the second uplink carrier.

Optionally, as a specific implementation, the determining, by the terminal device, that the random access request message is sent on the first uplink carrier or the second uplink carrier, may include:

The terminal device determines to send a random access request message on the second uplink carrier according to the second information included in the system message.

Specifically, since the frequency of the first uplink carrier is greater than the frequency of the second uplink carrier, the second uplink carrier generally has lower channel fading and better uplink coverage than the first uplink carrier. The coverage of the second uplink carrier will be greater than the coverage of the first uplink carrier. At a particular location within the signal coverage of the network device, the power of the second uplink carrier is typically greater than the power of the first uplink carrier. Therefore, if the system message includes the second information required for the second uplink carrier random access, the terminal device may directly determine to send the random access request message on the second uplink carrier. The determination process is simple, the time of random access is shortened, and the success rate of random access is improved.

Optionally, as another specific implementation manner, if the system information further includes the access indication information, the determining, by the terminal device, the sending the random access request message on the first uplink carrier or the second uplink carrier, may include:

The terminal device determines to send a random access request message on the second uplink carrier according to the access indication information.

Specifically, since the frequency of the first uplink carrier is greater than the frequency of the second uplink carrier, the second uplink carrier generally has lower channel fading and better uplink coverage than the first uplink carrier. The coverage of the second uplink carrier will be greater than the coverage of the first uplink carrier. When the second uplink carrier load is small and the random access request message collision probability is low, the network device may directly instruct the terminal device to send the random access request message on the second uplink carrier by using the access indication information. Correspondingly, the terminal device directly determines to send a random access request message on the second uplink carrier according to the access indication information. The determination process is simple, the time of random access is shortened, and the success rate of random access is improved.

Optionally, as another specific implementation, if the second information further includes the power threshold information of the PRACH, the terminal device determines to send the random access request message on the first uplink carrier or on the second uplink carrier, which may include :

The terminal device determines to send a random access request message on the first uplink carrier or on the second uplink carrier according to the information about the received power of the first downlink carrier and the power threshold information of the PRACH.

Specifically, in the communication process, when the uplink and downlink carrier frequencies are the same, the uplink power attenuation and the downlink power attenuation have a certain correspondence, and the power attenuation in one transmission direction may reflect the power attenuation in the other transmission direction. The information about the received power of the first downlink carrier is the actual value of the downlink power obtained by the terminal device, and reflects the power attenuation level of the first downlink carrier. The terminal device can obtain the power attenuation of the first uplink carrier by referring to the information about the received power of the first downlink carrier. The implementation manner of the information about the received power of the first downlink carrier is not limited in this embodiment. Optionally, the information about the received power of the first downlink carrier may be Reference Signal Received Power (RSRP) or Reference Signal Received Quality (RSRQ). The power threshold information of the PRACH reflects the minimum power conditions that need to be met during the random access procedure. Therefore, according to the information about the received power of the first downlink carrier and the power threshold information of the PRACH, whether the first uplink carrier or the second uplink carrier satisfies the random access condition can be determined. In this way, selecting a better uplink carrier to send a random access request message in the first uplink carrier and in the second uplink carrier can further improve the random access success rate.

Optionally, as a first implementation manner, if the information about the received power of the first downlink carrier is the reference signal received power of the first downlink carrier, the power threshold information of the PRACH is that the terminal device sends the random number on the first uplink carrier. The first power threshold of the access request message, the terminal device determines to send the random on the first uplink carrier or the second uplink carrier according to the information about the received power of the first downlink carrier and the power threshold information of the PRACH. The access request message may include:

If the reference signal received power of the first downlink carrier is greater than or equal to the first power threshold, the terminal device determines to send a random access request message on the first uplink carrier;

And if the reference signal received power of the first downlink carrier is less than the first power threshold, the terminal device determines to send a random access request message on the second uplink carrier.

Specifically, the first power threshold is configured by the network device. The configuration of the first power threshold is not limited in this embodiment. Optionally, the first power threshold may reflect a minimum power requirement that needs to be met when the random access request message is sent on the first uplink carrier. If the reference signal received power of the first downlink carrier is greater than or equal to the first power threshold, the first uplink carrier may meet the random access condition, and the terminal device may send a random access request message on the first uplink carrier. It is not necessary to send a random access request message on the second uplink carrier with a better power level. If the reference signal received power of the first downlink carrier is less than the first power threshold, the first uplink carrier cannot meet the random access condition, and the terminal device can send the random access on the second uplink carrier with the better power level. Request message.

Optionally, the first power threshold may be set to be greater than the reference signal received power of the terminal device, for example, the first power threshold may be positive infinity or greater than the reference signal received power maximum of the terminal device. Any value.

Optionally, as a second implementation manner, if the information about the received power of the first downlink carrier is the reference signal received power of the first downlink carrier, the power threshold information of the PRACH is that the terminal device sends the random on the second uplink carrier. And the second power threshold of the access request message, the terminal device determines to send the random connection on the first uplink carrier or the second uplink carrier according to the reference signal received power of the first downlink carrier and the power threshold information of the PRACH. The incoming request message may include:

If the reference signal received power of the first downlink carrier is greater than or equal to the second power threshold, the terminal device determines to send a random access request message on the second uplink carrier;

And if the reference signal received power of the first downlink carrier is less than the second power threshold, the terminal device determines to send a random access request message on the first uplink carrier.

Specifically, the second power threshold is configured by the network device, and the configuration manner of the second power threshold is not limited in this embodiment. Optionally, the second power threshold may reflect a minimum power requirement, a path loss offset value, and a network device selection tendency of the random access carrier when the random access request message is sent on the second uplink carrier. If the reference signal received power of the first downlink carrier is greater than or equal to the second power threshold, the terminal device may send a random access request message on the second uplink carrier. If the reference signal received power of the first downlink carrier is less than the second power threshold, the terminal device may send a random access request message on the first uplink carrier.

Optionally, as a third implementation manner, if the information about the received power of the first downlink carrier is the reference signal received power of the first downlink carrier, the power threshold information of the PRACH includes the terminal device sending the random on the second uplink carrier. The third power threshold value when the request message is accessed, and the path loss offset value between the second uplink carrier and the first uplink carrier, and the terminal device receives the power and the power of the PRACH according to the reference signal of the first downlink carrier. The threshold information, the determining that the random access request message is sent on the first uplink carrier or the second uplink carrier may include:

If the reference signal received power of the first downlink carrier + the path loss offset value - the third power threshold value ≥ 0, the terminal device determines to send a random access request message on the second uplink carrier;

If the reference signal received power + path loss offset value - third power threshold value < 0 of the first downlink carrier, the terminal device determines to send a random access request message on the first uplink carrier.

Specifically, the third power threshold is configured by the network device, and the configuration manner of the third power threshold is not limited in this embodiment. Optionally, the third power threshold may reflect a minimum power requirement that needs to be met when the random access request message is sent on the second uplink carrier, and a network device selection tendency of the random access carrier. The path loss offset value between the second uplink carrier and the first uplink carrier is a difference between the path loss value of the second uplink carrier and the path loss value of the first uplink carrier, and the path loss value is measured in this embodiment. And the configuration method is not limited. If the sum of the reference signal received power of the first downlink carrier and the path loss offset value is greater than or equal to the third power threshold, the terminal device may send a random access request message on the second uplink carrier. If the sum of the reference signal received power of the first downlink carrier and the path loss offset value is less than the third power threshold, the terminal device may send a random access request message on the first uplink carrier.

Optionally, as another implementation manner, if the second information further includes the power threshold information of the PRACH, if the power threshold information of the PRACH is the third information, the terminal device determines whether the first uplink carrier or the second uplink carrier is used. Sending a random access request message may include:

The terminal device determines to send a random access request message on the second uplink carrier according to the third information.

Specifically, the third information may be used as an indication information, where the indication information indicates that the terminal device does not need to determine the size between the reference signal received power of the first downlink carrier and any power threshold, and determines that the random transmission is sent from the second uplink carrier. Access request message. The determination process is simple, the time of random access is shortened, and the success rate of random access is improved.

The embodiment of the present application provides a random access method, including: the network device sends a system message to the terminal device on the first downlink carrier, where the system message includes the first information required for random access in the first uplink carrier, and The second information required for the second uplink carrier random access, the frequency of the first uplink carrier is greater than the frequency of the second uplink carrier, and the frequency of the first downlink carrier is the same as the frequency of the first uplink carrier. The terminal device sends a random access request message on the first uplink carrier or the second uplink carrier. The network device sends a random access response message to the terminal device on the first downlink carrier. In the scenario of the random access method provided by the embodiment of the present application, in a scenario where the number of uplink carriers is different from the number of downlink carriers, and the number of uplink carriers is greater than the number of downlink carriers, the terminal device may complete a random access procedure on any uplink carrier, thereby improving The random access success rate improves the uplink coverage performance of network devices.

FIG. 4 is a schematic structural diagram of a terminal device according to Embodiment 1 of the present application. The terminal device provided by the embodiment of the present application is configured to perform the operations performed by the terminal device in the random access method provided by the embodiment shown in FIG. As shown in FIG. 4, the terminal device provided by the embodiment of the present application may include:

The receiving module 11 is configured to receive a system message sent by the network device on the first downlink carrier. The system message includes first information required for random access of the first uplink carrier, and second information required for random access of the second uplink carrier, where the frequency of the first uplink carrier is greater than the frequency of the second uplink carrier, first The downlink carrier is the same frequency as the first uplink carrier.

The sending module 12 is configured to send a random access request message on the first uplink carrier or on the second uplink carrier.

The receiving module 11 is further configured to receive a random access response message sent by the network device on the first downlink carrier.

Optionally, the first information includes: a center frequency of the first uplink carrier, a bandwidth, and PRACH resource configuration information.

The second information includes: a center frequency point, a bandwidth, and PRACH resource configuration information of the second uplink carrier.

Optionally, the processing module 13 is further included, and the processing module 13 is configured to:

Determining to send a random access request message on the first uplink carrier or on the second uplink carrier.

Optionally, the processing module 13 is specifically configured to:

And determining to send a random access request message on the second uplink carrier according to the second information included in the system message.

Optionally, the system message further includes access indication information, where the access indication information is used to instruct the terminal device to send a random access request message on the second uplink carrier.

The processing module 13 is specifically configured to:

Optionally, the second information further includes power threshold information of the PRACH.

The processing module 13 is specifically configured to:

And determining, according to the information about the received power of the first downlink carrier and the power threshold information of the PRACH, to send a random access request message on the first uplink carrier or on the second uplink carrier.

Optionally, the information about the received power of the first downlink carrier is the reference signal received power of the first downlink carrier.

The power threshold information of the PRACH is a first power threshold value when the terminal device sends a random access request message on the first uplink carrier.

The processing module 13 is specifically configured to:

And if the reference signal received power of the first downlink carrier is greater than or equal to the first power threshold, determining to send a random access request message on the first uplink carrier.

And if the reference signal received power of the first downlink carrier is less than the first power threshold, determining to send a random access request message on the second uplink carrier.

The power threshold information of the PRACH is a second power threshold value when the terminal device sends a random access request message on the second uplink carrier.

The processing module 13 is specifically configured to:

And if the reference signal received power of the first downlink carrier is greater than or equal to the second power threshold, determining to send a random access request message on the second uplink carrier.

And if the reference signal received power of the first downlink carrier is less than the second power threshold, determining to send a random access request message on the first uplink carrier.

The power threshold information of the PRACH includes a third power threshold value when the terminal device sends the random access request message on the second uplink carrier, and a path loss offset value between the second uplink carrier and the first uplink carrier.

The processing module 13 is specifically configured to:

If the reference signal received power + path loss offset value - third power threshold value ≥ 0 of the first downlink carrier, it is determined that the random access request message is sent on the second uplink carrier.

If the reference signal received power of the first downlink carrier + the path loss offset value - the third power threshold value < 0, it is determined that the random access request message is sent on the first uplink carrier.

Optionally, the power threshold information of the PRACH is the third information, where the third information is used to instruct the terminal device to send the random access request message on the second uplink carrier.

The processing module 13 is specifically configured to:

Optionally, the sending module 12 is specifically configured to:

The random access request message is sent to the network device by the resource on the first uplink carrier determined according to the first information or by the resource on the second uplink carrier determined according to the second information.

The terminal device provided by the embodiment of the present application is used to perform the operations performed by the terminal device in the method embodiment shown in FIG. 3, and the technical principles and technical effects thereof are similar, and details are not described herein again.

FIG. 5 is a schematic structural diagram of a network device according to Embodiment 1 of the present application. The network device provided by the embodiment of the present application is used to perform the operations performed by the network device in the random access method provided by the embodiment shown in FIG. As shown in FIG. 5, the network device provided in this embodiment of the present application may include:

The sending module 21 is configured to send a system message to the terminal device on the first downlink carrier, where the system message includes the first information required for random access in the first uplink carrier and the first required for random access in the second uplink carrier In the second information, the frequency of the first uplink carrier is greater than the frequency of the second uplink carrier, and the frequency of the first downlink carrier is the same as the frequency of the first uplink carrier.

The receiving module 22 is configured to receive a random access request message sent by the terminal device on the first uplink carrier or on the second uplink carrier.

The sending module 21 is further configured to send a random access response message to the terminal device on the first downlink carrier.

Optionally, the first information includes: a center frequency point of the first uplink carrier, a bandwidth, and physical random access channel PRACH resource configuration information.

Optionally, the power threshold information of the PRACH is a first power threshold value that is set by the network device for the terminal device when the random access request message is sent on the first uplink carrier.

Optionally, the power threshold information of the PRACH is a second power threshold value that is set by the network device for the terminal device when the random access request message is sent on the second uplink carrier.

Optionally, the power threshold information of the PRACH includes a third power threshold value and a path loss offset value, where the third power threshold value is set by the network device for the terminal device, and the random access request message is sent on the second uplink carrier. The power threshold value at the time, the path loss offset value is a path loss offset value between the second uplink carrier and the first uplink carrier.

The network device provided by the embodiment of the present application is used to perform the operations performed by the network device in the method embodiment shown in FIG. 3, and the technical principles and technical effects thereof are similar, and details are not described herein again.

FIG. 6 is a schematic structural diagram of a terminal device according to Embodiment 2 of the present application. As shown in FIG. 6, the terminal device includes a processor 31, a memory 32, and a transceiver 33. The memory 32 is configured to store an instruction, and the transceiver 33 for communicating with other devices, the processor 31 is configured to execute instructions stored in the memory 32, so that the terminal device performs operations performed by the terminal device in the embodiment shown in FIG. 3, and the specific implementation manner and technology The effect is similar and will not be described here.

FIG. 7 is a schematic structural diagram of a network device according to Embodiment 2 of the present application. As shown in FIG. 7, the network device includes a processor 41, a memory 42 and a transceiver 43. The memory 42 is configured to store an instruction, the transceiver. 43 for communicating with other devices, the processor 41 is configured to execute instructions stored in the memory 42 to enable the network device to perform operations performed by the network device in the embodiment shown in FIG. 3, and the specific implementation and technology The effect is similar and will not be described here.

It can be understood that the processor used by the network device or the terminal device in the present application may be a central processing unit (CPU), a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), and a field programmable gate array (FPGA). Or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It is possible to implement or carry out the various illustrative logical blocks, modules and circuits described in connection with the present disclosure. The processor may also be a combination of computing functions, for example, including one or more microprocessor combinations, a combination of a DSP and a microprocessor, and the like.

One of ordinary skill in the art will appreciate that all or part of the steps to implement the various method embodiments described above may be accomplished by hardware associated with the program instructions. The aforementioned program can be stored in a computer readable storage medium. The program, when executed, performs the steps including the foregoing method embodiments; and the foregoing storage medium includes various media that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

It should be noted that the above embodiments are only used to explain the technical solutions of the embodiments of the present application, and are not limited thereto; although the embodiments of the present application are described in detail with reference to the foregoing embodiments, those skilled in the art It should be understood that the technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the essence of the corresponding technical solutions. The scope of the technical solution.

Claims

A random access method, comprising:

Receiving, by the terminal device, a system message sent by the network device on the first downlink carrier, where the system message includes first information required for random access of the first uplink carrier, and required for random access of the second uplink carrier a second information, the frequency of the first uplink carrier is greater than the frequency of the second uplink carrier, and the frequency of the first downlink carrier is the same as the frequency of the first uplink carrier;

Sending, by the terminal device, a random access request message on the first uplink carrier or on the second uplink carrier;

The terminal device receives a random access response message sent by the network device on the first downlink carrier.
The method of claim 1 wherein

The first information includes: a center frequency point, a bandwidth, and a physical random access channel PRACH resource configuration information of the first uplink carrier;

The second information includes: a center frequency point, a bandwidth, and PRACH resource configuration information of the second uplink carrier.
The method according to claim 1 or 2, wherein, before the terminal device sends a random access request message on the first uplink carrier or on the second uplink carrier, the method further includes:

The terminal device determines to send a random access request message on the first uplink carrier or on the second uplink carrier.
The method according to claim 3, wherein the determining, by the terminal device, that the random access request message is sent on the first uplink carrier or on the second uplink carrier, includes:

The terminal device determines to send a random access request message on the second uplink carrier according to the second information included in the system message.
The method according to claim 3, wherein the second information further comprises power threshold information of the PRACH;

The determining, by the terminal device, that the random access request message is sent on the first uplink carrier or on the second uplink carrier, includes:

Determining, by the terminal device, that the random access is sent on the first uplink carrier or on the second uplink carrier according to the information about the received power of the first downlink carrier and the power threshold information of the PRACH Request message.
The method of claim 5 wherein:

The information about the received power of the first downlink carrier is the reference signal received power of the first downlink carrier;

The power threshold information of the PRACH is a first power threshold value when the terminal device sends a random access request message on the first uplink carrier;

Determining, by the terminal device, that the random access is sent on the first uplink carrier or on the second uplink carrier according to the information about the received power of the first downlink carrier and the power threshold information of the PRACH Request message, including:

And if the reference signal received power of the first downlink carrier is greater than or equal to the first power threshold, the terminal device determines to send the random access request message on the first uplink carrier;

And if the reference signal received power of the first downlink carrier is less than the first power threshold, the terminal device determines to send the random access request message on the second uplink carrier.
The method of claim 5 wherein:

The information about the received power of the first downlink carrier is the reference signal received power of the first downlink carrier;

The power threshold information of the PRACH is a second power threshold value when the terminal device sends a random access request message on the second uplink carrier;

Determining, by the terminal device, that the random access request is sent on the first uplink carrier or on the second uplink carrier according to the reference signal received power of the first downlink carrier and the power threshold information of the PRACH News, including:

And if the reference signal received power of the first downlink carrier is greater than or equal to the second power threshold, the terminal device determines to send the random access request message on the second uplink carrier;

And if the reference signal received power of the first downlink carrier is less than the second power threshold, the terminal device determines to send the random access request message on the first uplink carrier.
The method of claim 5 wherein:

The information about the received power of the first downlink carrier is the reference signal received power of the first downlink carrier;

The power threshold information of the PRACH includes a third power threshold value when the terminal device sends a random access request message on the second uplink carrier, and the second uplink carrier and the first uplink carrier Path loss offset value between;

Determining, by the terminal device, that the random access request is sent on the first uplink carrier or on the second uplink carrier according to the reference signal received power of the first downlink carrier and the power threshold information of the PRACH News, including:

And if the reference signal received power of the first downlink carrier + the path loss offset value - the third power threshold value ≥ 0, the terminal device determines to send the the uplink carrier Random access request message;

And if the reference signal received power of the first downlink carrier + the path loss offset value - the third power threshold value <0, the terminal device determines to send the the uplink carrier on the first uplink carrier Random access request message.
The method according to any one of claims 1 to 7, wherein the terminal device sends a random access request message on the first uplink carrier or on the second uplink carrier, including:

Transmitting, by the terminal device, the resource on the first uplink carrier determined by the first information, or the resource on the second uplink carrier determined according to the second information, to the The network device sends the random access request message.
The method according to claim 3, wherein the system message further comprises access indication information, the access indication information is used to instruct the terminal device to send a random access request on the second uplink carrier. Message

The determining, by the terminal device, that the random access request message is sent on the first uplink carrier or on the second uplink carrier, includes:

The terminal device determines, according to the access indication information, that a random access request message is sent on the second uplink carrier.
The method according to claim 3, wherein the second information further includes power threshold information of the PRACH, the power threshold information of the PRACH is third information, and the third information is used to indicate the terminal device. Transmitting a random access request message on the second uplink carrier;

The determining, by the terminal device, that the random access request message is sent on the first uplink carrier or on the second uplink carrier, includes:

The terminal device determines, according to the third information, that a random access request message is sent on the second uplink carrier.
A random access method, comprising:

The network device sends a system message to the terminal device on the first downlink carrier, where the system message includes first information required for random access in the first uplink carrier and second information required for random access in the second uplink carrier The frequency of the first uplink carrier is greater than the frequency of the second uplink carrier, and the frequency of the first downlink carrier is the same as the frequency of the first uplink carrier;

Receiving, by the network device, a random access request message sent by the terminal device on the first uplink carrier or on the second uplink carrier;

The network device sends a random access response message to the terminal device on the first downlink carrier.
The method of claim 12 wherein:

The first information includes: a center frequency point, a bandwidth, and a physical random access channel PRACH resource configuration information of the first uplink carrier;

The second information includes: a center frequency point, a bandwidth, and PRACH resource configuration information of the second uplink carrier.
The method according to claim 13, wherein the second information further comprises power threshold information of the PRACH.
The method according to claim 14, wherein the power threshold information of the PRACH is the first time that the network device is configured by the network device to send a random access request message on the first uplink carrier. a power threshold; or,

The power threshold information of the PRACH is a second power threshold that is set by the network device for the terminal device when the random access request message is sent on the second uplink carrier; or

The power threshold information of the PRACH includes a third power threshold value and a path loss offset value, where the third power threshold is set by the network device for the terminal device on the second uplink carrier. A power threshold value when the random access request message is sent, where the path loss offset value is a path loss offset value between the second uplink carrier and the first uplink carrier.
The method according to claim 14, wherein the power threshold information of the PRACH is third information, and the third information is used to instruct the terminal device to send a random access request on the second uplink carrier. Message.
The method according to claim 12 or 13, wherein the system message further includes access indication information, where the access indication information is used to indicate that the terminal device sends a random connection on the second uplink carrier. Incoming request message.
A terminal device, comprising:

a receiving module, configured to receive a system message sent by the network device on the first downlink carrier, where the system message includes first information required for random access in the first uplink carrier, and a random access device in the second uplink carrier The second information required, the frequency of the first uplink carrier is greater than the frequency of the second uplink carrier, and the frequency of the first downlink carrier is the same as the frequency of the first uplink carrier;

a sending module, configured to send a random access request message on the first uplink carrier or on the second uplink carrier;

The receiving module is further configured to receive a random access response message sent by the network device on the first downlink carrier.
The terminal device according to claim 18, characterized in that

The first information includes: a center frequency point, a bandwidth, and a physical random access channel PRACH resource configuration information of the first uplink carrier;

The second information includes: a center frequency point, a bandwidth, and PRACH resource configuration information of the second uplink carrier.
The terminal device according to claim 18 or 19, further comprising a processing module, wherein the processing module is configured to:

Determining to send a random access request message on the first uplink carrier or on the second uplink carrier.
The terminal device according to claim 20, wherein the processing module is specifically configured to:

And determining to send a random access request message on the second uplink carrier according to the second information included in the system message.
The terminal device according to claim 20, wherein the second information further includes power threshold information of the PRACH;

The processing module is specifically configured to:

And determining, according to the information about the received power of the first downlink carrier and the power threshold information of the PRACH, to send the random access request message on the first uplink carrier or on the second uplink carrier.
The terminal device according to claim 22, characterized in that

The information about the received power of the first downlink carrier is the reference signal received power of the first downlink carrier;

The power threshold information of the PRACH is a first power threshold value when the terminal device sends a random access request message on the first uplink carrier;

The processing module is specifically configured to:

And if the reference signal received power of the first downlink carrier is greater than or equal to the first power threshold, determining to send the random access request message on the first uplink carrier;

And if the reference signal received power of the first downlink carrier is less than the first power threshold, determining to send the random access request message on the second uplink carrier.
The terminal device according to claim 22, characterized in that

The information about the received power of the first downlink carrier is the reference signal received power of the first downlink carrier;

The power threshold information of the PRACH is a second power threshold value when the terminal device sends a random access request message on the second uplink carrier;

The processing module is specifically configured to:

And if the reference signal received power of the first downlink carrier is greater than or equal to the second power threshold, determining to send the random access request message on the second uplink carrier;

And if the reference signal received power of the first downlink carrier is less than the second power threshold, determining to send the random access request message on the first uplink carrier.
The terminal device according to claim 22, characterized in that

The information about the received power of the first downlink carrier is the reference signal received power of the first downlink carrier;

The power threshold information of the PRACH includes a third power threshold value when the terminal device sends a random access request message on the second uplink carrier, and between the second uplink carrier and the first uplink carrier. Road loss offset value;

The processing module is specifically configured to:

Determining to send the random access request on the second uplink carrier if the reference signal received power of the first downlink carrier + the path loss offset value - the third power threshold value ≥ 0 Message

Determining to send the random access request on the first uplink carrier if the reference signal received power of the first downlink carrier + the path loss offset value - the third power threshold value < 0 Message.
The terminal device according to any one of claims 18 to 25, wherein the sending module is specifically configured to:

Transmitting to the network device by using resources on the first uplink carrier determined according to the first information, or by using resources on the second uplink carrier determined according to the second information The random access request message.
The terminal device according to claim 20, wherein the system message further includes access indication information, where the access indication information is used to instruct the terminal device to send random access on the second uplink carrier. Request message

The processing module is specifically configured to:

The terminal device determines, according to the access indication information, that a random access request message is sent on the second uplink carrier.
The terminal device according to claim 20, wherein the second information further includes power threshold information of the PRACH, the power threshold information of the PRACH is third information, and the third information is used to indicate the terminal The device sends a random access request message on the second uplink carrier;

The processing module is specifically configured to:

The terminal device determines, according to the third information, that a random access request message is sent on the second uplink carrier.
A network device, comprising:

a sending module, configured to send, to the terminal device, a system message on the first downlink carrier, where the system message includes first information required for random access in the first uplink carrier and random access required in the second uplink carrier The second information, the frequency of the first uplink carrier is greater than the frequency of the second uplink carrier, and the frequency of the first downlink carrier is the same as the frequency of the first uplink carrier;

a receiving module, configured to receive, on the first uplink carrier or on the second uplink carrier, a random access request message sent by the terminal device;

The sending module is further configured to send a random access response message to the terminal device on the first downlink carrier.
A network device according to claim 29, wherein

The first information includes: a center frequency point, a bandwidth, and a physical random access channel PRACH resource configuration information of the first uplink carrier;

The second information includes: a center frequency point, a bandwidth, and PRACH resource configuration information of the second uplink carrier.
The network device according to claim 30, wherein the second information further comprises power threshold information of the PRACH.
The network device according to claim 31, wherein the power threshold information of the PRACH is the first when the network device sends the random access request message on the first uplink carrier, which is set by the network device Power threshold; or,

The power threshold information of the PRACH is a second power threshold that is set by the network device for the terminal device when the random access request message is sent on the second uplink carrier; or

The power threshold information of the PRACH includes a third power threshold value and a path loss offset value, where the third power threshold is set by the network device for the terminal device, and is randomly sent on the second uplink carrier. a power threshold value when the request message is accessed, where the path loss offset value is a path loss offset value between the second uplink carrier and the first uplink carrier.
The network device according to claim 31, wherein the power threshold information of the PRACH is third information, and the third information is used to indicate that the terminal device sends random access on the second uplink carrier. Request message.
The network device according to claim 29 or 30, wherein the system message further includes access indication information, where the access indication information is used to indicate that the terminal device sends a random number on the second uplink carrier. Access request message.