WO2020077486A1

WO2020077486A1 - Cell selection method and terminal device

Info

Publication number: WO2020077486A1
Application number: PCT/CN2018/110209
Authority: WO
Inventors: 欧阳晓宇; 胡筱
Original assignee: 华为技术有限公司
Priority date: 2018-10-15
Filing date: 2018-10-15
Publication date: 2020-04-23
Also published as: CN112840703B; CN115379517A; CN112840703A

Abstract

Provided by the present application are a cell selection method and a terminal device. The cell selection method comprises: a terminal device acquiring first information before entering power saving mode (PSM), the first information comprising information of multiple frequency points, at least one two frequency points differing, and the frequency points being used for cell searching; the terminal device searching for cells on the basis of the multiple saved frequency points and selecting a suitable service cell after exiting PSM. The technical solution provided by the present application enables the terminal device to search for cells according to multiple frequency points and promptly select a service cell when the terminal device exits PSM to perform cell selection.

Description

Method for selecting cell and terminal equipment

Technical field

The present application relates to the communication field, and more specifically, to a method for selecting a cell and terminal equipment.

Background technique

Due to the advantages of low power consumption, wide coverage, low cost, and large capacity, the narrowband Internet of Things technology can be widely used in the field of Internet of Things. However, the narrowband IoT technology is not widely used in scenarios where terminal devices move. The reason is that in the scenario where the terminal device moves, network services are constantly changing. The terminal equipment needs to switch the serving cell in time. Due to the service life of the terminal equipment, the terminal equipment cannot always be in an active state to detect changes in network services.

In the prior art, in order to increase the service life of the terminal device, the terminal device is operated in a low power consumption mode (power saving mode, PSM). However, when the terminal device exits the PSM, it can only perform cell search based on the last camped frequency point to select a suitable cell, resulting in that the terminal device can only perform a full-band search when selecting a cell in the inter-frequency networking . Therefore, how to timely select the serving cell in the inter-frequency networking mode of the terminal equipment has become an urgent problem to be solved.

Summary of the invention

The present application provides a method for selecting a cell and a terminal device, so that the terminal device can select a serving cell in a timely manner in an inter-frequency networking mode.

In a first aspect, a method for selecting a cell is provided, which includes: before entering a low power consumption mode PSM, a terminal device obtains first information, where the first information includes information of multiple frequency points, and the frequency points are used During cell search, at least two of the multiple frequency points are different; after exiting the PSM, the terminal device selects a cell according to the first information.

According to the method for selecting a cell provided by an embodiment of the present application, the terminal device can acquire and save information of multiple frequency points before entering the PSM. Then, when exiting the PSM, the terminal device can perform cell search based on the saved multiple frequency points and select a suitable cell to camp on. It can reduce the delay and power consumption when the terminal device selects a cell.

With reference to the first aspect, in some implementations of the first aspect, the terminal device selecting the cell according to the first information includes: when the terminal device exits the PSM, reading the plurality of frequency points; The terminal device performs energy detection on the plurality of frequency points; the terminal device selects frequency points in order of cell search according to the energy of each frequency point in the plurality of frequency points to select a cell.

According to the method for selecting a cell provided by an embodiment of the present application, the terminal device selects frequency points from large to small according to the energy of each frequency point for cell search based on the energy of multiple frequency points, and selects a suitable serving cell. So that the terminal equipment can select the appropriate cell as soon as possible.

With reference to the first aspect and the foregoing implementation manners of the first aspect, in another implementation manner of the first aspect, the first information further includes information of a land-based public mobile communication network PLMN of at least one network, where the The PLMN corresponds to one or more frequency points, and the one frequency point corresponds to a PLMN of one or more networks; acquiring the first information by the terminal device includes: the terminal device acquiring and storing the PLMN and the PLMN of the at least one network Correspondence between the multiple frequency points.

According to the method for selecting a cell provided by an embodiment of the present application, the first information acquired by the terminal device may further include information of the PLMN of the network. Specifically, the PLMN of the network in the first information has a corresponding relationship with multiple frequency points. The terminal device stores the correspondence between the PLMN of the network and multiple frequency points, so that the terminal device can quickly determine the frequency point that can be used to select a cell based on the correspondence between the PLMN of the network and multiple frequency points. Reduce the delay when the terminal device selects a cell.

With reference to the first aspect and the foregoing implementation manners, in another implementation manner of the first aspect, the method further includes: after exiting the PSM, the terminal device selects from the PLMN of the surrounding network of the terminal device from the Extracting, from the first information, a first set of frequency points corresponding to the PLMN of the surrounding network, the first set of frequency points including at least one frequency point; the selection of a cell by the terminal device according to the first information includes: the terminal device Energy detection is performed on the first frequency point set; the terminal device selects frequency points in order of cell search according to the energy of each frequency point in the first frequency point set to select a cell.

According to the method for cell selection provided in the embodiment of the present application, when the terminal device saves the correspondence between the PLMN of at least one network and multiple frequency points, when the terminal device exits the PSM, the terminal device selects from the stored first information according to the PLMN of the surrounding network The first frequency point set corresponding to the PLMN of the surrounding network is extracted, and then the frequency points are selected in sequence from large to small according to the energy of each frequency point in the first frequency point set for cell search. So that the terminal equipment can select the appropriate cell as soon as possible.

With reference to the first aspect and the foregoing implementation manners, in another implementation manner of the first aspect, before the terminal device enters the PSM, the method further includes: the terminal device detects the first frequency point and saves the The first frequency point, wherein the first frequency point is a frequency point other than the plurality of frequency points.

According to the method for selecting a cell provided by an embodiment of the present application, when detecting a new frequency point, the terminal device saves the new frequency point. It can avoid missing the frequency points that need to be saved. Improve the performance of terminal equipment to select cells.

With reference to the first aspect and the foregoing implementation manners, in another implementation manner of the first aspect, the method further includes: the terminal device reads system information of the serving cell to obtain information about the multiple frequency points; Alternatively, the terminal device acquires information of the multiple frequency points when the multiple cells corresponding to the multiple frequency points are camped on.

According to the method for selecting a cell provided by an embodiment of the present application, the information of multiple frequency points acquired by the terminal device may be extracted from the system information, or may be the frequency point of the cell where the cell has resided. Provide flexible selection solutions for the terminal device to obtain the first information.

In a second aspect, a terminal device is provided, and the terminal device is configured to perform the method for selecting a cell in the first aspect or any possible implementation manner of the first aspect.

Specifically, the terminal device may include a unit for performing the method for selecting a cell in the first aspect or any possible implementation manner of the first aspect.

In a third aspect, a terminal device is provided. The terminal device includes a processor and a transceiver. Among them, the processor and the transceiver communicate with each other through an internal connection channel.

Optionally, the terminal device further includes a memory, the memory is used to store instructions, and the processor is used to execute the instructions stored in the memory.

As an optional implementation manner, the processor executes the method in the first aspect or any possible implementation manner of the first aspect.

According to a fourth aspect, there is provided a computer-readable storage medium on which a computer program is stored, which when executed by a processor implements the method in the first aspect or any possible implementation manner of the first aspect.

According to a fifth aspect, a computer program product is provided. The computer program product includes: computer program code, which causes the terminal device to execute the above when the computer program code is executed by a communication unit, processing unit, transceiver, or processor of the terminal device The first aspect.

In a sixth aspect, a chip system is provided, including: a processor, for supporting a terminal device to implement the method of the first aspect described above.

The method for selecting a cell and the terminal device provided by the embodiments of the present application enable the terminal device to save information of multiple frequency points before entering the PSM, and perform cell search based on the multiple frequency points when exiting the PSM to select a suitable cell. It can reduce the delay and power consumption when the terminal device selects a cell.

BRIEF DESCRIPTION

FIG. 1 is a schematic diagram of a system 100 that can apply the method for cell selection according to an embodiment of the present application.

Figure 2 is a schematic diagram of the same frequency networking.

Figure 3 is a schematic diagram of an inter-frequency networking.

FIG. 4 is a schematic diagram of the terminal device provided in this application working in the DRX mode.

FIG. 5 is a schematic diagram of the terminal device provided by the present application working under the PSM.

6 is a schematic diagram of a method for selecting a cell provided by an embodiment of the present application.

FIG. 7 a is a flowchart of using a shared bicycle provided by an embodiment of the present application; FIG. 7 b is a schematic diagram of a shared bicycle network service switching provided by an embodiment of the present application.

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

9 is a schematic structural diagram of a terminal device 20 provided in this application.

detailed description

The technical solutions in this application will be described below with reference to the drawings.

The technical solution of the embodiment of the present application is applied to a communication system in which a terminal device can work in a low power consumption mode (power saving mode, PSM).

For example: applied to narrow-band Internet of Things (NB-IoT) system, or applied to enhanced machine type communication (EMTC) system; also applied to the future fifth generation ( 5th generation (5G) system. Or it is used in mass machine type communication (mMTC) system.

It should be understood that the above technical solutions of the embodiments of the present application can be applied to the NB-IoT communication system or the 5G communication system as examples, and cannot limit the scope of protection of this application. Other communication systems that can support terminal devices to work in PSM are also Within the scope of protection of this application. No more examples are given here.

The terminal device in the embodiment of the present application may refer to user equipment, access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or User device. Terminal devices can also be cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (personal digital assistants, PDAs), and wireless communication Functional handheld devices, computing devices or other processing devices connected to wireless modems, in-vehicle devices, wearable devices, terminal devices in future 5G networks or public land mobile communications networks (PLMN) in the future evolution The terminal device and the like are not limited in this embodiment of the present application.

The network device in the embodiment of the present application may be a device for communicating with the terminal device, and the network device may be the above-mentioned NB-IoT, EMTC communication system, or network device in the 5G, mMTC communication system, etc. Not limited.

In the embodiments of the present application, the terminal device or the network device includes a hardware layer, an operating system layer running on the hardware layer, and an application layer running on the operating system layer. The hardware layer includes central processing unit (CPU), memory management unit (memory management unit, MMU), and memory (also called main memory) and other hardware. The operating system may be any one or more computer operating systems that implement business processes through processes. For example, Linux operating system, Unix operating system, Android operating system, iOS operating system or windows operating system, etc. The application layer includes browser, address book, word processing software, instant messaging software and other applications. In addition, the embodiment of the present application does not specifically limit the specific structure of the execution body of the method provided in the embodiment of the present application, as long as it can run the program that records the code of the method provided by the embodiment of the present application to provide according to the embodiment of the present application The method may be used for communication. For example, the execution body of the method provided in the embodiments of the present application may be a terminal device or a network device, or a functional module in the terminal device or network device that can call a program and execute the program.

In addition, various aspects or features of the present application may be implemented as methods, devices, or articles using standard programming and / or engineering techniques. The term "article of manufacture" as used in this application encompasses a computer program accessible from any computer-readable device, carrier, or medium. For example, the computer-readable medium may include, but is not limited to: magnetic storage devices (for example, hard disks, floppy disks, or magnetic tapes, etc.), optical disks (for example, compact discs (CD), digital universal discs (digital discs, digital discs, DVD)) Etc.), smart cards and flash memory devices (for example, erasable programmable read-only memory (EPROM), cards, sticks or key drives, etc.). In addition, the various storage media described herein may represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing, and / or carrying instructions and / or data.

As shown in FIG. 1, the system 100 includes a network device 102, and the network device 102 may include one antenna or multiple antennas. For example,

antennas

104, 106, 108, 110, 112, and 114. In addition, the network device 102 may additionally include a transmitter chain and a receiver chain.

Those of ordinary skill in the art can understand that both the transmitter chain and the receiver chain can include multiple components related to signal transmission and reception (for example, a processor, modulator, multiplexer, demodulator, demultiplexer, or Antenna, etc.).

The network device 102 can communicate with multiple terminal devices (eg, the terminal device 116 and the terminal device 122 shown in FIG. 1). However, it can be understood that the network device 102 can communicate with any number of terminal devices similar to the terminal device 116 or the terminal device 122. The

terminal devices

116 and 122 may be various devices that communicate with the network device 102, for example, the terminal device 116 may be a cellular phone, smart phone, portable computer, handheld communication device, handheld computing device, satellite radio, global positioning system, PDA And / or any other suitable device for communicating on the wireless communication system 100.

As shown in FIG. 1, the terminal device 116 communicates with the

antennas

112 and 114. Among them, the

antennas

112 and 114 transmit information to the terminal device 116 through a forward link (also called downlink) 118 and receive information from the terminal device 116 through a reverse link (also called uplink) 120.

In addition, the terminal device 122 communicates with the

antennas

104 and 106. Among them, the

antennas

104 and 106 send information to the terminal device 122 through the forward link 124 and receive information from the terminal device 122 through the reverse link 126.

For example, in a frequency division duplex (FDD) system. For example, forward link 118 may use a different frequency band from reverse link 120, and forward link 124 may use a different frequency band from reverse link 126.

As another example, in a time division duplex (TDD) system and a full duplex system, the forward link 118 and the reverse link 120 can use a common frequency band, the forward link 124 and the reverse link The link 126 may use a common frequency band.

Each antenna (or an antenna group consisting of multiple antennas) and / or area designed for communication is called a sector of the network device 102.

For example, the antenna group may be designed to communicate with terminal devices in sectors in the coverage area of the network device 102. The network device may send signals to all terminal devices in its corresponding sector through a single antenna or multiple antenna transmit diversity. In the process of the network device 102 communicating with the

terminal devices

116 and 122 through the

forward links

118 and 124, respectively, the transmit antenna of the network device 102 may also use beamforming to improve the signal-to-noise ratio of the

forward links

118 and 124.

In addition, when the network device 102 uses beamforming to transmit signals to randomly distributed

terminal devices

116 and 122 in the relevant coverage area, compared to the way that the network device sends signals to all of its terminal devices through single antenna or multi-antenna transmit diversity, Mobile devices in neighboring cells will experience less interference.

At a given time, the network device 102, the terminal device 116, or the terminal device 122 may be a wireless communication transmitting device and / or a wireless communication receiving device. When transmitting data, the wireless communication transmitting device may encode the data for transmission. Specifically, the wireless communication transmitting device may acquire (eg, generate, receive from other communication devices, or store in a memory, etc.) a certain number of data bits to be transmitted to the wireless communication receiving device through the channel. Such data bits may be contained in a transport block (or multiple transport blocks) of data, which may be segmented to produce multiple code blocks.

In addition, the system 100 may be a PLMN network, a D2D network, an M2M network, an IoT network, or other networks. FIG. 1 is only a simplified schematic diagram of an example, and the network may also include other network devices, which are not shown in FIG. 1.

It should be understood that FIG. 1 is only a simple schematic diagram used to illustrate the applicable scenarios of the cell selection method provided in the embodiments of the present application, and does not constitute any limitation to the present application.

In the following, in order to facilitate the understanding of the method for selecting a cell provided in the embodiments of the present application, several basic concepts are first introduced.

1. Same frequency networking.

In the divided cells, the same carrier frequency is used uniformly. The method of co-frequency networking is suitable for the situation where the operator's spectrum resources are tight and the communication system bandwidth is relatively wide. as shown in picture 2.

Figure 2 is a schematic diagram of the same frequency networking. The diagram includes multiple cells using carrier frequency 1.

The advantages of co-frequency networking include:

1) Utilize the least spectrum resources, high spectrum efficiency;

2) The location of the cell edge can overcome the interference problem to a certain extent and improve the user experience.

The disadvantages of co-frequency networking include:

1) Network construction is difficult, with high requirements for overlapping coverage control and strict requirements for network structure and site conditions;

2) The performance of the same-frequency network decreases rapidly as the load increases, the edge rate is low, and the user's perception ability deteriorates.

2. Inter-frequency networking.

In the divided cells, different carrier frequencies are used. As shown in Figure 3.

Figure 3 is a schematic diagram of an inter-frequency networking. The diagram includes multiple cells using different carrier frequencies.

The advantages of inter-frequency networking include:

1) The difficulty of network construction is low, and the control requirements for overlapping coverage and the requirements for network structure and site conditions are low;

2) The performance of the same-frequency network is less affected by the network load, and the user perception is good;

3) Can greatly reduce co-channel interference, easily achieve higher throughput rate, and improve the network competitive advantage;

4) When the spectrum resources are sufficient, the throughput rate can be effectively improved.

Disadvantages of inter-frequency networking include:

1) Utilize more spectrum resources;

2) A small amount of power consumption for cell reselection will increase.

3. System news.

System messages include a master message block (master information block, MIB) and multiple system message blocks (system information block, SIB).

Among them, the MIB message is broadcast on a physical broadcast channel (physical broadcast channel, PBCH); the SIB is delivered through a radio resource control (RRC) message of a physical downlink shared channel (physical downlink shared channel, PDSCH).

Specifically, this application mainly relates to SIB1 and SIB5 in the above SIB. The following briefly introduces SIB1 and SIB5.

1) SIB1 in the system message block type 1 (system information block type 1) message, including terminal cell access information and other SIB scheduling information:

The identification code of the public land mobile network (PLMN) of the network;

Tracking area code (tracking area code, TAC) and cell identification (identify, ID);

Cell prohibition status, indicating whether the user can reside in the cell;

Select the cell standard and indicate the minimum acceptance level required;

Transmission time and period of other SIBs.

2) SIB5 includes neighbor cell information for inter-frequency cell reselection, such as: neighbor cell list, carrier frequency, cell reselection priority, user threshold from the current serving cell to other high or low priority frequencies, etc.

Under the rapid development of communication technology, mobile communication is moving from the connection between people to the connection between people and things, and the interconnection of all things is an inevitable trend.

However, based on the current 4G network, the connection ability between objects is insufficient. In fact, compared with short-range communication technologies such as Bluetooth and wireless personal area network (ZigBee), cellular networks have the characteristics of wide coverage, mobility, and a large number of terminal devices that can be connected. Cellular networks can bring things to things. Richer application scenarios. Cellular network communication technology should become the main connection technology of the Internet of Things.

NB-IoT is an emerging technology in the field of Internet of Things. NB-IoT is built on a cellular network and consumes only about 180KHz of bandwidth. NB-IoT can be directly deployed in a global mobile communication system (GSM) network, universal mobile communication system (UMTS) network or long term evolution (LTE) network to reduce NB -Deployment cost of IoT and smooth upgrade of communication technology.

Specifically, NB-IoT includes the following four characteristics:

1. Wide coverage. In the same frequency band, the gain of NB-IoT is 20dB larger than that of the existing network, which is equivalent to improving the ability to cover the area by 100 times;

2. Ability to support massive connections. One sector of NB-IoT can support 100,000 connections, support low latency sensitivity, ultra-low device cost, low device power consumption, and optimized network architecture;

3. Lower power consumption. NB-IoT connected terminals can support up to 10 years of standby time;

Fourth, lower cost. The company expects that the single connection module of NB-IoT will not exceed US $ 5.

Because NB-IoT itself has the advantages of low power consumption, wide coverage, low cost and large capacity. The NB-IoT communication technology can be widely used in various industries. For example, remote meter reading, smart parking, smart city, etc.

However, the current application scenarios of NB-IoT communication technology are mostly limited to fixed reporting services. The application in the mobile scenario is not very extensive because the network service in the mobile scenario is constantly changing and needs to be switched in time. However, due to service life considerations, the terminal device cannot always be activated to detect changes in the network service.

In the current mobile scenario, there are two main schemes for terminal devices to switch network services:

1. The terminal device works in extended discontinuous reception (eDRX) mode, or the terminal device works in discontinuous reception (DRX) mode. The terminal equipment realizes the switching of network services through the cell reselection mechanism;

Second, the terminal equipment works in PSM. The terminal device realizes the switching of network services by exiting the PSM re-searching mechanism.

The terminal device works in eDRX, DRX and PSM, which is a technology that can save power consumption when the terminal device in the NB-IoT performs network service switching.

The principle that the terminal device works in the PSM is to allow the terminal device to turn off the signal transmission and reception and access layer related functions after entering the idle state for a period of time, which is equivalent to partial shutdown, thereby reducing the power consumption of the antenna, radio frequency, and signaling processing. During the PSM, the terminal device does not accept any paging from network devices. For the network device side, the terminal device under the PSM is unreachable.

The terminal equipment works in DRX, which is to support the terminal equipment to no longer continuously detect the signal quality of the serving cell and the neighboring cell, thereby achieving the purpose of saving power consumption.

eDRX is an enhancement to DRX technology. Then, when the terminal device works in eDRX, the terminal device supports a longer detection period, thereby achieving the purpose of saving power consumption.

The above-mentioned DRX mode and PSM are briefly introduced in conjunction with FIGS. 4 and 5.

In the scenario where the terminal device moves, a common working mode of the terminal device is to work in the DRX mode, and the network service switching is implemented through a cell reselection mechanism.

FIG. 4 is a schematic diagram of the terminal device provided in this application working in the DRX mode. The schematic diagram includes seven steps S410-S470. The seven steps are described in detail below.

S410, the terminal device enters an idle state.

The terminal device returns to the idle state after the connection is released. Among them, the idle state means that the terminal device is in a radio resource control idle (radio resource control, RRC IDLE) state. Specifically, the idle state may also be referred to as the IDLE state.

Further, the terminal device in the idle state measures the signal of the serving cell with a DRX cycle as a time interval.

Specifically, the terminal equipment measuring the signal of the serving cell includes: measuring the value of the reference signal received power (RSRP) of the serving cell, measuring the value of the reference signal received quality (RSRQ) of the serving cell, and Signal-to-interference ratio (signal to interference plus ratio, SINR) and received signal strength indicator (received signal strength indicator, RSSI).

In this embodiment, the signal value of the serving cell measured by the terminal device or the measurement value based on the signal of the serving cell is referred to as the first measurement value.

S420: Determine whether the first measurement value is lower than the threshold for reselecting measurement start.

Specifically, the reselection measurement start threshold refers to a threshold at which the terminal device starts cell reselection measurement. Specifically, the cell reselection measurement threshold is the reselection measurement threshold specified in the cell reselection criterion when the terminal device in the prior art performs cell reselection measurement. This application does not limit this, so no specific explanations will be given.

When the first measurement value is lower than the reselection measurement start threshold, the terminal device executes S430. When the first measurement value is not lower than the reselection measurement start threshold, the terminal device does not perform cell reselection measurement and is still in an idle state.

S430, the terminal device starts the same frequency or different frequency measurement.

When the first measurement value is lower than the reselection measurement start threshold, the terminal device starts the co-frequency or inter-frequency measurement, and measures the signal of the neighboring cell with one DRX cycle as the time interval.

Specifically, the terminal device measuring the signal of the neighboring cell includes: measuring the value of RSRP of the neighboring cell and measuring the value of RSRQ of the neighboring cell, as well as the SINR and RSSI.

In this embodiment, the signal value of the neighboring cell measured by the terminal device or the measurement value based on the signal of the neighboring cell is called the second measurement value.

Further, whether the terminal device performs on-frequency or off-frequency measurement is related to the condition that the first measurement value meets. This application does not involve this, and will not be described in detail here.

S440: Determine whether the second measurement value meets a preset condition.

When the signal quality of the neighboring cell is higher than the serving cell for a period of time, cell reselection starts. Switch to the network service of the neighboring cell. It should be understood that the specific duration of "a period of time" involved in this application is specified by the communication system, and this application is not limited.

That is, when the above second measurement value meets the reselection criterion, the terminal device executes S450 to perform cell reselection. When the second measurement value does not satisfy the reselection criterion, the terminal device continues to execute S430 to perform co-frequency or inter-frequency measurement.

S460: Determine whether the cell reselection is successful.

When the cell reselection is successful, the terminal device continues to be in an idle state; when the cell reselection fails, the terminal device needs to perform S470, and then continues to camp on the current serving cell.

The terminal device shown in FIG. 4 works in DRX mode. Before the cell reselection is completed, the terminal device needs to keep measuring the signal of the serving cell and the signal of the neighboring cell at intervals of one DRX cycle; The signal of the cell is to ensure that the network service will not change.

Further, the terminal device shown in FIG. 4 works in DRX mode. The terminal equipment needs to spend a lot of time to complete the cell reselection, that is, the delay and power consumption required for the network service switching is very large.

It should be understood that what is shown in FIG. 4 is that the terminal device works in the DRX mode, and when the terminal device works in the eDRX mode, the delay and power consumption required for the network service switching will be very large, which will not be repeated here.

In the scenario where the terminal device is moving, another common working mode of the terminal device is to work under the PSM, and the terminal device switches the network service by exiting the PSM and searching the network again.

FIG. 5 is a schematic diagram of the terminal device provided by the present application working under the PSM. The schematic diagram includes six steps S510-S560. The six steps are described in detail below.

S510, the terminal device enters an idle state.

The terminal device returns to the idle state after the connection is released.

S520, the terminal device enters the PSM.

Specifically, after the terminal device is idle for a period of time, it will enter the PSM. Among them, the time period of being in the idle state for a period of time is not limited in this application, and may be specified in the agreement or may be notified by the network device to the terminal device.

It should be understood that the terminal will not detect the surrounding network under the PSM. That is to say, the terminal device under the PSM will not detect the signals of the serving cell and the neighbor cell as shown in FIG. 4, which can save power consumption.

S530, the terminal device exits the PSM.

Specifically, when the terminal device needs to be woken up, the terminal device exits the PSM and enters the idle state. The terminal device being awakened refers to that the terminal device may need to receive information sent by the network device, or the terminal device is awakened when the terminal device meets a preset wake-up condition.

For example, the terminal device meeting the preset wake-up condition may be when the tracking area update (TAU) period request timer expires, or the terminal device has a Monternet (MO) service to process and actively exits the PSM.

In this application, there is no limitation as to whether the terminal device is in a predetermined wake-up condition, and it may be any wake-up condition in the prior art.

S540. The terminal device searches for the last resident frequency.

The terminal device selects a cell according to the frequency of the cell where it last camped. Among them, the cell where the terminal device last camped is the cell where the terminal device camped before entering the idle state.

S550: Determine whether a cell is found.

When the terminal device selects a cell according to the frequency point of the last camped cell, if no suitable cell can be found at that frequency point, the terminal device performs S560 to perform a full-band network search.

Among them, the full-band search refers to the terminal device performing a full-band search according to its own capabilities and settings, trying to read the information of the strongest signal cell on each frequency point. Once the terminal equipment searches the entire frequency band, the power consumption of the terminal equipment is relatively large, and the delay of the selected cell is large.

As shown in Figure 5, the terminal device works under the PSM. The network service switching is realized by exiting the PSM re-searching mechanism. In the same frequency networking mode, this mode has lower latency and power consumption; but in the different frequency networking mode, because the frequency points deployed in each cell are different, it cannot be directly performed according to the frequency point of the last camped cell Select the cell, and the time delay and power consumption of the full-band network search are large, or the service delay and power consumption are large due to the poor cell selection of the terminal device, or the terminal device cannot select the same frequency cell.

In order to solve the problem of delay and power consumption when switching network services. This application proposes a method for cell selection. It can reduce the time delay and power consumption when switching network services, and the terminal device can quickly and accurately select the appropriate service cell after exiting the PSM. The method for selecting a cell provided by an embodiment of the present application is described in detail below with reference to FIG. 6.

6 is a schematic diagram of a method for selecting a cell provided by an embodiment of the present application. The diagram includes S610-S620. Two steps, the two steps are described in detail below.

S610: The terminal device obtains the first information.

The terminal device obtains first information before entering the low power consumption mode PSM, where the first information includes information of multiple frequency points, and the frequency points are used for cell search. Among them, at least two of the plurality of frequency points are different, for example, the plurality of frequency points include frequency point information of the serving cell of the current terminal device and different frequency points different from the frequency point of the serving cell, serving A cell is a cell that provides services to terminal equipment.

Optionally, in some embodiments, the terminal device reads the system information of the serving cell to obtain the first information.

For example, after the terminal device enters the idle state, the terminal device reads the system message of the serving cell. Obtain the PLMN and frequency information of the serving cell in SIB1, and the inter-frequency frequency information in SIB5.

Optionally, in other embodiments, the terminal device acquires the information of the multiple frequency points when multiple cells corresponding to the multiple frequency points are camped on.

For example, the first information includes information of five frequency points of A, B, C, D, and E. Wherein, the information of the frequency points A-E is the information of the frequency points acquired by the terminal device when camping on the cell A-cell E.

That is to say, the first information obtained by the terminal device may be obtained by reading the system message of the serving cell, or by obtaining information of different frequency points when camping on different cells. Specifically, the terminal device may also obtain the first information through other methods, and no further examples are given here.

Optionally, the first information further includes information of a PLMN of at least one network, where the PLMN of the one network corresponds to one or more frequency points, and the one frequency point corresponds to the PLMN of one or more networks;

The terminal device acquiring the first information further includes:

The terminal device acquires the correspondence between the PLMN of the at least one network and the multiple frequency points.

For example, the PLMN of a network in the first information corresponds to one or more frequency points.

The first information includes information of PLMNs (A, B, C) of 3 networks, and also includes information of 9 frequency points (a1, a2, a3, b1, b2, b3, c1, c2, c3). Among them, A corresponds to a1, a2, a3; B corresponds to b1, b2, b3; C corresponds to c1, c2, c3. Then, the above terminal device acquires and stores the correspondence between the PLMN of the at least one network and the multiple frequency points, see the following table-Table 1.

网络的PLMNPLMN of the network	频点Frequency
AA	a1、a2、a3a1, a2, a3
BB	b1、b2、b3b1, b2, b3
CC	c1、c2、c3c1, c2, c3

Or, one frequency point corresponds to one or more network PLMNs.

The first information includes PLMN (A, B, C) information of 3 networks, and also includes information of 3 frequency points (a1, a2, a3). Among them, a1 corresponds to A, B, C; a2 corresponds to A, B, C; a3 corresponds to A, B, C. Then, the corresponding relationship between the PLMN of the at least one network and the multiple frequency points stored by the above terminal device is shown in the following table-table 2.

频点Frequency	网络的PLMNPLMN of the network
a1a1	A、B、CA, B, C
a2a2	A、B、CA, B, C
a3a3	A、B、CA, B, C

Optionally, FIG. 6 further includes S611, the terminal device saves the first frequency point.

Specifically, before the terminal device acquires and saves the first information, the method further includes:

When detecting the first frequency point, the terminal device saves the first frequency point, where the first frequency point is a frequency point other than the plurality of frequency points described in S610.

For example, when the terminal device detects a change in the surrounding network environment, the first frequency point is detected, or the number of frequency points deployed by the network device changes, and the terminal device is notified that the first frequency point is newly added. Specifically, the terminal device stores the first frequency point in the storage unit of the terminal device, which can be understood as the correspondence between updating the first information and updating the PLMN of the network and the multiple frequency points.

It should be understood that the change of the network around the terminal device may be a change of any kind of network environment. I will not list them one by one here. This application is not limited to this, as long as the terminal device detects the information of the frequency point or the information of the PLMN of the network, the terminal device can update the saved first information.

Specifically, the terminal device may save the acquired first information in the memory of the terminal device. For example, it is stored in the flash memory of the terminal device.

Further, FIG. 6 further includes S612, the terminal device enters the PSM.

The terminal device enters the PSM when the first preset condition is satisfied. Specifically, the first preset condition may be that the terminal device is in an idle state for a period of time, or the first preset condition may be that the timer for entering the PSM set by the terminal device reaches a preset time, or the first preset condition may be It is any condition in the prior art that allows the terminal device to enter the PSM. This application does not limit this.

S620. The terminal device selects a cell.

After exiting the PSM, the terminal device selects a cell according to the first information.

For example, the terminal device exits the PSM when the second preset condition is satisfied, where the second preset condition may be that the TAU cycle request timer of the terminal device times out, or the terminal device actively processes to exit the PSM due to processing of MO services, or, The second preset condition may be any condition in the prior art that enables the terminal device to exit the PSM. This application does not limit this.

Optionally, in some embodiments, the terminal device selecting the cell according to the first information includes: after exiting the PSM, the terminal device reads the plurality of frequency points saved in S610, and Multiple frequency points are used for energy detection; the terminal device selects frequency points in order of cell search according to the energy of each frequency point in the multiple frequency points to select a cell.

For example, the terminal device stores N frequency points before entering the PSM, and N is an integer greater than 1. Then, after exiting the PSM, the terminal device reads the N frequency points from the storage unit. And detect the energy of the N frequency points, according to the size of the energy of each frequency point, select frequency points in order from the largest to the small cell search. When the cell search is performed based on the frequency point with the highest energy and a suitable cell is found, the cell selection is completed; when the cell search is performed based on the frequency point with the highest energy and no suitable cell is found, then based on the energy second only to the frequency with the highest energy Another frequency point of the point is used for cell search. In this way, the cycle continues until a suitable cell is found. It is assumed that the terminal device performs a cell search based on the N frequency points, and when no suitable cell is found, the terminal device performs a full-band network search.

Optionally, in other embodiments, after the terminal device exits the PSM, the first frequency point set corresponding to the PLMN of the surrounding network is extracted from the first information according to the PLMN of the surrounding network of the terminal device , The first frequency point set includes at least one frequency point; the terminal device selecting a cell according to the first information includes: the terminal device performing energy detection on the first frequency point set; the terminal device according to the first In a frequency point set, the energy of each frequency point is selected from the largest to the smallest frequency point for cell search, and the cell is selected.

For example, after the terminal device exits the PSM, the PLMN of the surrounding network where the terminal device is located includes: A and B.

When the terminal device stores the correspondence between the PLMN of the at least one network and the multiple frequency points as shown in Table 1 above. The first frequency point set is 6 frequency points (a1, a2, a3, b1, b2, b3). According to the acquired information of the 6 frequency points, energy detection is performed on the 6 frequency points. The frequency with the highest energy is preferentially selected for cell search and the cell is selected.

When the terminal device stores the correspondence between the PLMN of the at least one network and the multiple frequency points as shown in Table 2 above. The first frequency point set is 3 frequency points (a1, a2, a3). According to the acquired information of the three frequency points, energy detection is performed on the three frequency points. The frequency with the highest energy is preferentially selected for cell search and the cell is selected.

If no suitable cell is found based on the saved multiple frequency points, a full-band network search is performed.

The method for selecting a cell provided in this application will be described below in conjunction with specific embodiments.

7 is a schematic diagram of a specific embodiment provided by an embodiment of the present application. FIG. 7 a is a flowchart of using a shared bicycle provided by an embodiment of the present application.

Specifically, a in FIG. 7 indicates that during the use of the shared bicycle, the narrowband Internet of Things, the Internet of Things platform, the shared bicycle business platform, and the application (App) corresponding to the mobile phone are required to provide support.

Further, with reference to b in FIG. 7, how to perform network service switching when the shared bicycle is connected in the narrowband Internet of Things is described in detail.

7b is a schematic diagram of a shared bicycle network service switching provided by an embodiment of the present application. The diagram includes S710-S793.

S710, the shared bicycle smart lock enters an idle state.

During driving, the lock module chip of the shared bicycle enters an idle state.

S720, the smart lock obtains the system message.

After the bicycle lock module chip of the shared bicycle enters the idle state, it starts to acquire the system information of the serving cell.

Specifically, taking a shared bicycle as a shared bicycle in an inter-frequency network as an example. Then, the bicycle lock module chip of the shared bicycle receives SIB1 and SIB5 in the system information of the serving cell. Obtain the frequency points of the PLMN and serving cell of the network around the shared bicycle in SIB1, and the frequency points of different frequencies in SIB5.

For example, the smart lock reads system messages and obtains the information of the PLMN of the surrounding network as A and B respectively; and, A corresponds to two frequency points (a1, a2), and B corresponds to three frequency points (b1, b2, b3).

S730, the frequency information of the smart lock is updated.

The smart lock detects when the surrounding network environment changes and there is a new frequency. Then, it is updated to the correspondence between the PLMN of the network maintained by the smart lock and multiple frequency points.

For example, when the smart lock detects that the PLMN of the network is A, a new frequency point a3 is deployed. Then, the correspondence between the PLMN of the network in S720 and multiple frequency points is updated as:

A corresponds to three frequency points (a1, a2, a3), and B corresponds to three frequency points (b1, b2, b3).

S740, the smart lock stores frequency information.

The car lock module chip of the shared bicycle stores the acquired frequency point information, the network PLMN information, and the correspondence between the network PLMN and multiple frequency points in the flash of the car lock module chip.

For example, assume that the information acquired by the smart lock is as shown in S730. Then, the corresponding relationship between the above-mentioned smart lock saving frequency point, the network PLMN, and the network PLMN and multiple frequency points is shown in the following table-Table 3

网络的PLMNPLMN of the network	频点Frequency
AA	a1、a2、a3a1, a2, a3
BB	b1、b2、b3b1, b2, b3

S750, the smart lock enters the PSM.

When the shared bicycle travels long enough, the car lock module chip will enter the PSM.

S760, the smart lock exits the PSM.

After the shared bicycle reaches its destination, the car lock module chip exits the PSM.

S770, the smart lock reads the frequency information.

After reaching the destination, the car lock module chip wakes up from the PSM mode, and the network conditions around the shared bicycle have changed. The car lock module chip reads out the frequency information of the network around the shared bicycle stored in the flash.

For example, after reaching the destination, the PLMN of the network around the shared bicycle is A, and the frequency information that the car lock module chip reads from the flash is a1, a2, and a3.

S780. The smart lock performs energy detection on the frequency corresponding to the PLMN of the surrounding network. And according to the energy size of each frequency point, make a sorting from large to small, according to the energy sorting from high to low to select the frequency point for cell search and cell selection.

S790, the smart lock selects the frequency point with the highest energy to perform the cell search.

S791: Determine whether a suitable cell is found.

If a suitable cell has been found, the cell search is completed. If no suitable cell is found, execute S792 to determine whether there are other frequency points. That is, it is judged whether all the frequency points read from the flash have been searched.

If there is no other frequency point, execute S793 to conduct a full-band network search.

If there are other frequency points, execute S790, then select the frequency point with the highest energy among the remaining frequency points for cell search.

For example, the energy of frequency points a1, a2, and a3 in S770 is ranked as a1> a2> a3. Then, the smart lock sequentially selects a1, a2, and a3 for cell search and cell selection. Specifically, when the smart lock selects a1 for cell search and successfully selects a cell, the smart lock completes the cell selection; when the smart lock selects a1 for cell search and fails to select a cell, the smart lock selects a2 for cell search; when the smart lock selects a2 When the cell search fails to select a cell, the smart lock selects a3 for cell search; when the smart lock selects a3 for cell search and fails to select a cell, the smart lock performs a full-band network search.

Those of ordinary skill in the art may realize that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application of the technical solution and design constraints. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

The method for selecting a cell provided by the embodiment of the present application is described in detail above with reference to FIGS. 6 and 7, and the terminal device in the embodiment of the present application is described in detail below with reference to FIGS. 8 and 9.

According to the foregoing method, FIG. 8 is a schematic diagram of the terminal device 10 provided by an embodiment of the present application. As shown in FIG. A chip or circuit for terminal equipment. The terminal device may correspond to the terminal device in the above method.

The apparatus 10 may include a processor 11 (that is, an example of a processing unit) and a memory 12 (that is, an example of a storage unit). The memory 12 is used to store instructions, and the processor 11 is used to execute the instructions stored in the memory 12, so that the apparatus 10 implements the steps performed by the terminal device (eg, terminal device) in the corresponding method in FIG. 6 and FIG. 7 .

Further, the terminal device 10 may further include an input port 13 (that is, an example of a receiving unit) and an output port 14 (that is, another example of a transmitting unit). Further, the processor 11, the memory 12, the input port 13 and the output port 14 can communicate with each other through an internal connection channel to transfer control and / or data signals. The memory 12 is used to store a computer program, and the processor 11 can be used to call and run the computer program from the memory 12 to control the input port 13 to receive signals and the output port 14 to send signals to complete the above method. A step of. The memory 12 may be integrated in the processor 11 or may be provided separately from the processor 11.

Optionally, if the device 10 is a terminal device, the input port 13 is a receiver, and the output port 14 is a transmitter. The receiver and the transmitter may be the same or different physical entities. When they are the same physical entity, they can be collectively referred to as transceivers.

Optionally, if the device 10 is a chip or a circuit, the input port 13 is an input interface, and the output port 14 is an output interface.

As an implementation manner, the functions of the input port 13 and the output port 14 may be implemented through a transceiver circuit or a dedicated chip for transceiver. The processor 11 may be realized by a dedicated processing chip, a processing circuit, a processor, or a general-purpose chip.

As another implementation manner, it may be considered to use a general-purpose computer to implement the terminal device provided by the embodiments of the present application. The program codes that implement the functions of the processor 11, the input port 13, and the output port 14 are stored in the memory 12, and the general processor implements the functions of the processor 11, the input port 13, and the output port 14 by executing the codes in the memory 12.

In the embodiment provided by the present application, the memory 12 is used to acquire and store first information, where the first information includes multiple frequency points, and the frequency points are used for cell search, and at least The two frequencies are different;

The processor 11 is configured to select a cell according to the first information after the terminal device exits the PSM.

The terminal device 10 corresponds exactly to the terminal device in the method embodiment, and the corresponding unit of the terminal device 10 is used to perform the corresponding steps performed by the terminal device in the method embodiment shown in FIGS. 6 and 7.

The memory 12 in the terminal device 10 executes the steps stored in the method embodiment. For example, step S610 of acquiring and saving the first information in the terminal device in FIG. 6 is performed. The processor 11 executes steps internally implemented or processed in the terminal device in the method embodiment. For example, step S620 in which the terminal device selects a cell in FIG. 6 is performed.

For the concepts, explanations, detailed descriptions, and other steps related to the technical solution provided by the embodiments of the present application related to the terminal device 10, please refer to the descriptions of these contents in the foregoing method or other embodiments, and details are not described here.

9 is a schematic structural diagram of a terminal device 20 provided in this application. The terminal device 20 can be applied to the system shown in FIG. 1. For ease of explanation, FIG. 9 shows only the main components of the terminal device. As shown in FIG. 9, the terminal device 20 includes a processor, a memory, a control circuit, an antenna, and input / output devices.

The processor is mainly used to process the communication protocol and communication data, and control the entire terminal device, execute a software program, and process the data of the software program, for example, to support the terminal device to perform the above-mentioned transmission precoding matrix instruction method embodiment Described actions. The memory is mainly used to store software programs and data, for example, the codebook described in the above embodiment. The control circuit is mainly used for the conversion of the baseband signal and the radio frequency signal and the processing of the radio frequency signal. The control circuit and the antenna can also be called a transceiver, which is mainly used to send and receive radio frequency signals in the form of electromagnetic waves. Input and output devices, such as touch screens, display screens, and keyboards, are mainly used to receive data input by users and output data to users.

When the terminal device is turned on, the processor can read the software program in the storage unit, interpret and execute the instructions of the software program, and process the data of the software program. When data needs to be sent wirelessly, the processor performs baseband processing on the data to be sent, and outputs the baseband signal to the radio frequency circuit. The radio frequency circuit processes the baseband signal after radio frequency processing, and then sends the radio frequency signal to the outside in the form of electromagnetic waves through the antenna. When data is sent to the terminal device, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor. The processor converts the baseband signal into data and processes the data.

Those skilled in the art can understand that, for ease of description, FIG. 9 only shows one memory and processor. In an actual terminal device, there may be multiple processors and memories. The memory may also be referred to as a storage medium or a storage device, etc. This embodiment of the present application does not limit this.

As an optional implementation, the processor may include a baseband processor and a central processor. The baseband processor is mainly used to process communication protocols and communication data, and the central processor is mainly used to control and execute the entire terminal device. Software program, processing software program data.

The processor in FIG. 9 integrates the functions of the baseband processor and the central processor. Those skilled in the art may understand that the baseband processor and the central processor may also be independent processors, which are interconnected through technologies such as a bus. Those skilled in the art may understand that the terminal device may include multiple baseband processors to adapt to different network standards, the terminal device may include multiple central processors to enhance its processing capability, and various components of the terminal device may be connected through various buses. The baseband processor may also be expressed as a baseband processing circuit or a baseband processing chip. The central processor may also be expressed as a central processing circuit or a central processing chip. The function of processing the communication protocol and communication data may be built in the processor, or may be stored in the storage unit in the form of a software program, and the processor executes the software program to realize the baseband processing function.

Exemplarily, in the embodiment of the present application, an antenna and a control circuit with a transceiver function may be regarded as the transceiver unit 201 of the terminal device 20, and a processor with a processing function may be regarded as the processing unit 202 of the terminal device 20. As shown in FIG. 9, the terminal device 20 includes a transceiver unit 201 and a processing unit 202. The transceiver unit may also be called a transceiver, a transceiver, a transceiver device, or the like. Optionally, the device used to implement the receiving function in the transceiver unit 201 can be regarded as a receiving unit, and the device used to implement the sending function in the transceiver unit 201 can be regarded as a sending unit, that is, the transceiver unit 201 includes a receiving unit and a sending unit. Exemplarily, the receiving unit may also be referred to as a receiver, receiver, receiving circuit, etc., and the transmitting unit may be referred to as a transmitter, transmitter, or transmitting circuit, etc.

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

In the several embodiments provided in this application, it should be understood that the disclosed system, device, and method may be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a division of logical functions. In actual implementation, there may be other divisions, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

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

If the function is implemented in the form of a software functional unit and sold or used as an independent product, it may be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application essentially or part of the contribution to the existing technology or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including Several instructions are used to enable a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in the embodiments of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk and other media that can store program codes .

The above is only the specific implementation of this application, but the scope of protection of this application is not limited to this, any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in this application. It should be covered by the scope of protection of this application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

A method for selecting a cell, which includes:

Before entering the low power consumption mode PSM, the terminal device obtains first information, where the first information includes information of multiple frequency points, the frequency points are used for cell search, and at least two of the multiple frequency points Different points

After exiting the PSM, the terminal device selects a cell according to the first information.
The method according to claim 1, wherein the terminal device selecting the cell according to the first information comprises:

The terminal device performs energy detection on the multiple frequency points respectively;

The terminal device selects frequency points in order of cell search according to the energy of each frequency point in the plurality of frequency points to select a cell.
The method according to claim 1 or 2, wherein the first information further includes information of a land public mobile communication network PLMN of at least one network, wherein the PLMN of the one network and one or more frequency Corresponding to a point, the one frequency point corresponds to a PLMN of one or more networks;

The terminal device acquiring the first information further includes:

The terminal device acquires the correspondence between the PLMN of the at least one network and the multiple frequency points.
The method of claim 3, wherein the method further comprises:

After exiting the PSM, the terminal device obtains a first frequency point set corresponding to the PLMN of the surrounding network from the first information according to the PLMN of the surrounding network of the terminal device, the first frequency point set includes at least One of the frequency points;

The terminal device selecting the cell according to the first information includes:

The terminal device performs energy detection on each frequency point in the first frequency point set;

The terminal device selects frequency points in order of cell search according to the energy of each frequency point in the first frequency point set to select a cell.
The method according to any one of claims 1 to 4, wherein before the terminal device enters the PSM, the method further comprises:

The terminal device detects the first frequency point and saves the first frequency point, where the first frequency point is a frequency point other than the plurality of frequency points.
The method according to any one of claims 1 to 5, wherein the method further comprises:

The terminal device reads the system information to obtain the information of the multiple frequency points; or,

The terminal device acquires the information of the multiple frequency points when the multiple cells corresponding to the multiple frequency points are camped.
A terminal device is characterized by comprising:

A storage unit, used to obtain first information before the terminal device enters the low power consumption mode PSM, the first information includes information of multiple frequency points, the frequency points are used for cell search, and the multiple At least two of the frequency points are different;

The processing unit is configured to select a cell according to the first information after the terminal device exits the PSM.
The terminal device according to claim 7, wherein the processing unit selecting the cell according to the first information comprises:

The processing unit performs energy detection on the multiple frequency points respectively;

The processing unit selects frequency points in order of cell search according to the energy of each frequency point in the plurality of frequency points to select a cell.
The terminal device according to claim 7 or 8, wherein the first information further includes information of a land public mobile communication network PLMN of at least one network, wherein the PLMN of the one network and one or more Corresponding to frequency points, the one frequency point corresponds to PLMN of one or more networks;

The storage unit acquiring the first information further includes:

The storage unit obtains the correspondence between the PLMN of the at least one network and the multiple frequency points.
The terminal device according to claim 9, wherein the processing unit is further configured to:

After the terminal device exits the PSM, the first frequency point set corresponding to the PLMN of the surrounding network is read from the first information according to the PLMN of the surrounding network of the terminal device. At least one of the frequency points;

The processing unit selecting the cell according to the first information includes:

The processing unit performs energy detection on each frequency point in the first frequency point set;

The processing unit selects frequency points in order of cell search according to the energy of each frequency point in the first frequency point set to select a cell.
The terminal device according to any one of claims 7-10, wherein, before the terminal device enters the PSM, the storage unit is further used to:

When the processing unit detects the first frequency point, the first frequency point is saved, wherein the first frequency point is a frequency point other than the plurality of frequency points.
The terminal device according to any one of claims 7-11, wherein the processing unit is further configured to read system information of a serving cell to obtain information of the plurality of frequency points; or,

The storage unit is further used for the terminal device to acquire information of the multiple frequency points when the multiple cells corresponding to the multiple frequency points are camped on.