CN111866972A

CN111866972A - Cell selection method, cell reselection method and chip

Info

Publication number: CN111866972A
Application number: CN201910651489.1A
Authority: CN
Inventors: 李勇; 侯志远
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-04-26
Filing date: 2019-07-18
Publication date: 2020-10-30
Anticipated expiration: 2039-07-18
Also published as: CN111866972B

Abstract

The application provides a cell selection method, a cell reselection method and a chip, which can improve user experience. The cell selection method comprises the following steps: the terminal equipment searches for a first candidate cell and receives a system message of the first candidate cell, wherein the system message comprises parameter information of the first candidate cell and bandwidth information of the first candidate cell, and the bandwidth information is used for indicating the bandwidth of the first candidate cell; the terminal equipment determines a cell selection receiving grade value Srxlev and a cell selection quality value Squal of a first candidate cell according to the cell measurement value and the parameter information of the first candidate cell, and determines that Srxlev is greater than 0 and the Squal is greater than 0; and under the condition that the bandwidth of the first candidate cell is larger than a preset threshold value, the terminal equipment resides in the first candidate cell.

Description

Cell selection method, cell reselection method and chip

Technical Field

The present application relates to the field of communications, and in particular, to a cell selection method, a cell reselection method, and a chip.

Background

After the terminal device is powered on, it needs to execute a Public Land Mobile Network (PLMN) selection and cell selection procedure, and then camp and register in the selected cell, so as to enjoy network services. Specifically, a non-access stratum (NAS) of the terminal device first performs Public Land Mobile Network (PLMN) selection. After selecting the PLMN and Radio Access Technology (RAT), the Access Stratum (AS) of the terminal device performs a cell selection procedure. In the cell selection process, the terminal device searches for a cell meeting a preset condition and resides in the selected cell. The conditions for selecting the cell mainly include cell parameter information, cell measurement results, and other information, but the information considered by the cell selection method is not comprehensive, which sometimes results in poor communication quality of the cell where the terminal device resides and poor user experience.

Disclosure of Invention

The application provides a cell selection method, a cell reselection method, terminal equipment and a chip, which can improve user experience.

In a first aspect, a method for cell selection is provided, including: the terminal equipment searches a first candidate cell; the terminal equipment receives the system message of the first candidate cell, wherein the system message of the first candidate cell comprises information used for indicating the following contents: the PLMN of the first candidate cell is a NAS selected PLMN, or the PLMN of the first candidate cell is a registered PLMN, or the PLMN of the first candidate cell is a PLMN in an equivalent PLMN list; the first candidate cell is a cell that is not barred; the TAI of the first candidate cell is not a TAI in a roaming-forbidden tracking area list; parameter information of the first candidate cell; bandwidth information of the first candidate cell, the bandwidth information indicating a bandwidth of the first candidate cell; the terminal equipment determines a cell selection receiving grade value Srxlev and a cell selection quality value Squal of the first candidate cell according to the cell measurement value and the parameter information of the first candidate cell, and determines that Srxlev is greater than 0 and the Squal is greater than 0; and the terminal equipment resides in the first candidate cell under the condition that the bandwidth of the first candidate cell is larger than a preset threshold value.

In the embodiment of the application, the cell bandwidth factor is considered in the cell selection process of the terminal device, so that when the terminal device selects the resident cell, the cell with the bandwidth larger than the preset threshold value can be preferentially selected, the reduction of the data transmission rate caused by the bandwidth can be avoided, and the user experience is improved.

With reference to the first aspect, in a possible implementation manner, the method further includes: and the terminal equipment does not reside in the first candidate cell under the condition that the bandwidth of the first candidate cell is less than or equal to the preset threshold value.

In the embodiment of the application, if the bandwidth of the candidate cell is less than or equal to the preset threshold, the terminal device does not reside in the candidate cell, so as to continue to search for a cell with a bandwidth greater than the preset threshold, thereby ensuring that the data transmission rate is not reduced due to the bandwidth, and improving the user experience.

With reference to the first aspect, in a possible implementation manner, the method further includes: under the condition that the bandwidths of all candidate cells meeting a first preset condition, searched by the terminal equipment, are less than or equal to the preset threshold, the terminal equipment determines a resident cell in the candidate cells meeting the first preset condition; the first preset condition includes: the PLMN of the candidate cell is a NAS selected PLMN, or the PLMN of the candidate cell is a registered PLMN, or the PLMN of the candidate cell is a PLMN in an equivalent PLMN list; the candidate cell is a cell that is not barred; the TAI of the candidate cell is not a TAI in a roaming forbidden tracking area list; srxlev >0, and Squal > 0.

In the embodiment of the application, if the bandwidths of the searched candidate cells meeting the first preset condition are all smaller than or equal to the preset threshold, the terminal device selects the resident cell from the searched cells, so that the terminal device can be ensured to be resident in the cells smoothly, and the user experience is improved.

With reference to the first aspect, in a possible implementation manner, the method further includes: and under the condition that the bandwidth of the first candidate cell is less than or equal to a preset threshold, the terminal equipment marks the first candidate cell as a cell with the lowest priority in the current Radio Access Technology (RAT), or marks the first candidate cell as a cell with the lowest priority in all RATs supported by the terminal equipment.

In the embodiment of the application, the cell with the bandwidth less than or equal to the preset threshold is marked as the cell with the lowest priority, so that the cell with the bandwidth greater than the preset threshold can be preferentially resided in the cell according to the locally modified priority information in the subsequent cell reselection process, and the user experience is improved.

With reference to the first aspect, in a possible implementation manner, the searching, by the terminal device, a first candidate cell includes: under the condition that prior information is locally stored, the terminal equipment searches the first candidate cell according to the prior information, wherein the prior information is used for indicating cell information of a historical resident cell.

With reference to the first aspect, in a possible implementation manner, the searching, by the terminal device, a first candidate cell further includes: and under the condition that the first candidate cell is not searched according to the prior message, the terminal equipment determines the first candidate cell through full-band search.

With reference to the first aspect, in a possible implementation manner, the searching, by the terminal device, a first candidate cell includes: and under the condition that no prior message is stored locally, the terminal equipment searches the first candidate cell in the full frequency band, wherein the prior message is used for indicating the cell information of the historical resident cell.

In a second aspect, a method for cell reselection is provided, including: the method comprises the steps that terminal equipment receives a system message of a resident serving cell, wherein the system message comprises neighbor cell information, and the neighbor cell information comprises priority information and parameter information of a first candidate cell; the terminal equipment determines that the first candidate cell meets cell reselection conditions according to the priority information and the parameter information of the first candidate cell; the terminal equipment receives a system message of the first candidate cell, wherein the system message of the first candidate cell comprises bandwidth information of the first candidate cell, and the bandwidth information is used for indicating the bandwidth of the first candidate cell; and under the condition that the bandwidth of the first candidate cell is larger than a preset threshold value, the terminal equipment is switched from the serving cell to the first candidate cell.

In the embodiment of the application, the cell bandwidth factor is considered in the cell reselection process of the terminal device, so that when the terminal device selects the resident cell, a cell with a bandwidth larger than a preset threshold value can be preferentially selected as the resident cell, and therefore it can be ensured that the data transmission rate is not reduced due to the bandwidth, and the user experience is improved.

With reference to the second aspect, in a possible implementation manner, the terminal device determines to continue camping on the current serving cell when the bandwidth of the first candidate cell is less than or equal to the preset threshold.

In the embodiment of the application, in the cell reselection process, if the bandwidth of the candidate cell is less than or equal to the preset threshold, the terminal device does not switch to the candidate cell, so that it can be ensured that the data transmission rate is not reduced due to the bandwidth, and the user experience is improved.

With reference to the second aspect, in a possible implementation manner, the terminal device marks the first candidate cell as a forbidden cell when a bandwidth of the first candidate cell is less than or equal to the preset threshold.

In the embodiment of the application, the cell with the bandwidth less than or equal to the preset threshold is marked as the forbidden cell, so that the cell staying in the cell with the bandwidth not meeting the condition is avoided in the cell reselection process, and the user experience is improved.

With reference to the second aspect, in a possible implementation manner, the determining, by the terminal device, that the first candidate cell satisfies the cell reselection condition according to the priority information and the parameter information of the first candidate cell includes: the terminal equipment determines that the priority of the first candidate cell is greater than that of the serving cell according to the priority information of the first candidate cell; the terminal equipment determines a cell selection receiving grade value Srxlev of the first candidate cell according to the cell measurement value of the first candidate cell and the parameter information of the first candidate cell; the terminal equipment determines that Srxlev of the first candidate cell is larger than a first threshold value within a preset time period; and the terminal device determines to camp on the serving cell for more than one second.

With reference to the second aspect, in a possible implementation manner, the determining, by the terminal device, that the first candidate cell satisfies the cell reselection condition according to the priority information and the parameter information of the first candidate cell includes: the terminal equipment determines that the priority of the first candidate cell is equal to the priority of the serving cell according to the priority information of the first candidate cell; the terminal equipment determines a cell ranking criterion Rn of the first candidate cell according to the parameter information of the first candidate cell; the terminal device determines that Rn is greater than Rs, which represents a cell ranking criterion for the serving cell.

With reference to the second aspect, in a possible implementation manner, the determining, by the terminal device, that the first candidate cell satisfies the cell reselection condition according to the priority information and the parameter information of the first candidate cell includes: the terminal equipment determines that the priority of the first candidate cell is smaller than the priority of the serving cell according to the priority information of the first candidate cell; the terminal equipment determines a cell selection receiving grade value Srxlev of the first candidate cell according to the cell measurement value of the first candidate cell and the parameter information of the first candidate cell; the terminal device determines that the Srxlev of the first candidate cell is larger than a second threshold value and the Srxlev of the serving cell is smaller than a third threshold value within a preset time period; and determining that the terminal device is camped on the serving cell for more than one second.

In a third aspect, a terminal device is provided, where the terminal device has a function of implementing the method performed by the terminal device in the first or second aspect. These functions may be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more units corresponding to the above functions.

In a fourth aspect, a chip is provided, the chip comprising a processor for calling a computer program from a memory, the computer program, when executed, causing a terminal device in which the chip is installed to perform the method of the first or second aspect.

In a fifth aspect, a communication apparatus is provided, where the communication apparatus may be the terminal device in the above method embodiment, or a chip provided in the terminal device. The communication device includes: a memory and a processor. The memory is used for storing computer executable program codes, and the processor is coupled with the memory. Wherein the program code stored by the memory comprises instructions which, when executed by the processor, cause the communication apparatus to perform the method performed by the terminal device of the first or second aspect.

In a sixth aspect, there is provided a computer program product comprising: computer program code for causing a computer to perform the method of the first or second aspect described above when said computer program code is run on a computer.

In a seventh aspect, a computer-readable medium is provided, which stores program code, which, when run on a computer, causes the computer to perform the method of the first or second aspect.

Drawings

Fig. 1 is a schematic diagram of an application scenario of an embodiment of the present application.

Fig. 2 is a flowchart illustrating a cell selection method according to an embodiment of the present application.

Fig. 3 is a flowchart illustrating a cell selection method according to another embodiment of the present application.

Fig. 4 is a flowchart illustrating a cell reselection method according to an embodiment of the present application.

Fig. 5 is a flowchart illustrating a cell selection method according to another embodiment of the present application.

Fig. 6 is a flowchart illustrating a cell selection method and a cell reselection method according to another embodiment of the present application.

Fig. 7 is a schematic structural diagram of a terminal device according to an embodiment of the present application.

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

Fig. 9 is a schematic structural diagram of a terminal device according to another embodiment of the present application.

Detailed Description

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

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

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

The network device in this embodiment may be a device for communicating with a terminal device, where the network device may be an evolved node b (eNB) or an eNodeB in an LTE system, and may also be a wireless controller in a Cloud Radio Access Network (CRAN) scenario, or the network device may be a relay station, an access point, a vehicle-mounted device, a wearable device, a network device in a future 5G network, a network device in a future evolved PLMN network, or the like, and the embodiment of the present application is not limited.

Fig. 1 is a schematic diagram of a communication scenario according to an embodiment of the present application. As shown in fig. 1, the application scenario includes a terminal device 10 and a network device 20, where the network device 20 may be an access network device, such as a base station. Each network device 20 includes one or more cells. When the terminal device 10 moves into the coverage of a cell, cell selection or cell reselection may be performed. The cell selection refers to a process of selecting a cell meeting a preset condition and performing camping when the terminal device first accesses a network, for example, the cell selection may occur when the terminal device is powered on or re-accesses the network after being disconnected. Or cell selection may occur when the terminal device enters an idle state from a connected state. The cell reselection refers to a process that after the terminal device accesses the network, the terminal device reselects a cell and camps on the cell when the cell with better signal quality than that of a current serving cell exists. For example, cell reselection may occur when the terminal device is in an idle state.

In the existing cell selection process, when a terminal device is turned on or in other scenes, a NAS of the terminal device first performs PLMN selection, selects a Radio Access Technology (RAT) in the selected PLMN, then performs a cell search procedure by an AS of the terminal device, and determines whether the searched cell meets a camping condition. As an example, the prior art for determining whether a cell meets the camping condition includes the following:

(1) The PLMN of the cell is a PLMN selected by NAS, the PLMN of the cell is a registered PLMN, or the PLMN of the cell is a PLMN in an equivalent PLMN list;

(2) the cell is not a forbidden cell;

(3) a Tracking Area Identifier (TAI) of a cell is not a TAI in a forbidden roaming tracking area list (forbidden tracking areas for roaming);

(4) the cell satisfies a cell selection criterion (cell selection criterion) that is: srxlev >0, where Srxlev represents a cell selection Reception (RX) level value (dB), and Squal >0, where Squal represents a cell selection quality value (dB). Wherein, as an example, Sxlev and Squal may be respectively expressed by the following formulas:

Srxlev＝Q_rxlevmeas–(Q_rxlevmin+Q_{rxlevminoffset})–Pcompensation-Qoffset_temp(1)

Squal＝Q_qualmeas–(Q_qualmin+Q_{qualminoffset})-Qoffset_temp(2)

taking the LTE system as an example, the parameters related to the above formula may be as shown in table 1.

TABLE 1

In some examples, Q_rxlevmeasMay be Reference Signal Received Power (RSRP), Q_qualmeasMay be a Reference Signal Receiving Quality (RSRQ).

Optionally, the measured cell reception level value Q_rxlevmeasAnd measured cell selection quality value Q_qualmeasAnd may also be referred to collectively as cell measurements. Alternatively, other parameters in equation (1) and equation (2) may be obtained from the system message.

In the cell selection process, after the terminal device successfully resides in a certain cell, a cell with better signal quality is searched according to a cell reselection criterion (cell reselection criterion). As an example, according to the priority information configured on the network side, the cell reselection criteria can be divided into the following three scenarios (a) - (c).

Scenario (a): if the priority of the target cell is higher than that of the serving cell, the conditions for triggering cell reselection are as follows:

(1) the Srxlev of the target cell is larger than a first threshold value within a preset time period;

(2) and the terminal equipment resides in the serving cell for more than one second.

Wherein Srxlev represents a cell selection Reception (RX) rank value, and the first threshold represents a threshold condition that Srxlev needs to satisfy when the terminal device reselects a RAT/frequency with a higher priority than a current serving frequency. For example, the first threshold may be represented as Thresh_X,HighThe unit may be decibels (dB). Optionally, in this embodiment of the present application, the size of the preset time period may be defined according to a standard, and the preset time period may be expressed as Treselection_RAT. The size of the preset time period may be different in different situations, for example, the size of the preset time period may be different between the candidate cell and the serving cell in the same frequency and different frequency situations.

Scenario (b): if the priority of the target cell is the same as the priority of the serving cell, the conditions for triggering cell reselection are as follows:

the target cell satisfies that Rs is greater than Rs within a preset time period.

The cell reselection condition in this scenario may be referred to as a cell-ranking criterion (cell-ranking criterion), or may also be referred to as an R criterion for short. Where Rs and Rn represent the cell ranking criteria of the serving cell and the candidate cell, respectively. In one example, Rs and Rn may be represented by the following formulas:

Rs＝Q_meas,s+Q_hyst–Qoffset_temp； (3)

Rn＝Q_meas,n-Qoffset–Qoffset_temp； (4)

wherein Qmeas, s and Qmeas, n respectively represent Reference Signal Receiving Power (RSRP) measurement quality used by the serving cell and the candidate cell in cell selection, Q_hystHysteresis value representing cell ranking criterion, Qoffset representing offset of cell, Qoffset_tempIndicating an offset temporarily applied to the cell. Alternatively, the parameters involved in formula (3) and formula (4) may be obtained through system messages.

Scenario (c): if the priority of the target cell is lower than that of the serving cell, the conditions for triggering cell reselection are as follows:

(1) the target cell meets the condition that Srxlev is larger than a second threshold value within a preset time period, and the Srxlev of the serving cell is smaller than a third threshold value;

Wherein Srxlev represents a cell selection RX rank value, and the second threshold and the third threshold represent threshold conditions that Srxlev of the target cell and the serving cell needs to satisfy when the terminal device reselects a RAT/frequency with a lower priority than the current serving frequency. For example, the second threshold may be referred to as Thresh_Serving,LowPThe third threshold may be referred to as Thresh_X,LowPThe unit may be in dB. Optionally, in this embodiment of the present application, the size of the preset time period may be defined according to a standard, and the preset time period may be expressed as Treselection_RAT. The size of the preset time period may be different in different situations, for example, the size of the preset time period may be different between the candidate cell and the serving cell in the same frequency and different frequency situations.

Alternatively, the cell reselection conditions are not limited to the above examples, and several conditions may be added or subtracted based on the cell reselection conditions of the above examples. Alternatively, in scenario (a) and scenario (c), Squal may be used instead of Srxlev as a condition for determining cell reselection.

The parameters used for calculating the cell selection and reselection criteria are derived from cell parameters and cell measurements, and mainly depend on cell priority information and measurements, and do not take into account the bandwidth (bandwidth) limitation of the cell. It may happen that the terminal device selects and camps on a narrowband (narrowband) cell. In this case, even if the signal quality of the cell is good, the data transmission rate of the terminal device is low due to the limitation of the bandwidth, thereby affecting the user experience. For example, the data transmission rate may be only a few thousand bits per second (Kbps) or a few tens of Kbps.

In order to solve the above problem, the present application proposes a scheme for cell selection and cell reselection. According to the scheme, the bandwidth information of the cell is considered in the cell selection and cell reselection processes, so that the terminal equipment is resided in the cell with higher data transmission rate, and the user experience is improved.

Fig. 2 is a flowchart illustrating a cell selection method according to an embodiment of the present application. As shown in fig. 2, the details of the method 200 include the following steps.

S201, the terminal device searches for a first candidate cell.

Optionally, the terminal device searches for the first candidate cell through a cell selection procedure. Alternatively, the candidate cell in the embodiment of the present application may also be referred to as a usable cell (usable cell).

Alternatively, the cell selection procedure may include two ways. One method is called a stored information cell selection (cell selection) process, which refers to a search performed by a terminal device according to prior information when the prior information is stored. The prior information is used for indicating cell information of the historical resident cell, such as frequency point information, carrier frequency, cell parameters and the like. For example, the terminal device may perform cell synchronization according to cell frequency point information in the prior information, and obtain a system message of the cell after the cell synchronization. The terminal device may perform a search only in the cell in which the cell information is stored. And then judging whether the searched cell meets a preset condition, if so, judging whether the cell resides in the cell, and if not, continuing the cell selection process. Yet another approach is referred to as an initial cell selection (initial cell selection) procedure, which refers to a full band search performed in a situation where no prior information is stored in the terminal device. The terminal equipment can perform full-band search according to the capability and configuration of the terminal equipment.

Optionally, in some specific examples, before S201, the NAS of the terminal device may perform a PLMN selection procedure, and select one PLMN. Wherein PLMN selection may also be referred to as network selection. For example, the terminal device may maintain a PLMN list and select a PLMN from the PLMN list according to a priority ranking. After selecting the PLMN, the NAS of the terminal device may indicate a Radio Access Technology (RAT) related to the selected PLMN to the AS and instruct the AS of the terminal device to perform a cell selection procedure.

S202, the terminal device receives a system message of the first candidate cell, where the system message of the first candidate cell includes information indicating the following: the PLMN of the first candidate cell is a NAS selected PLMN, or the PLMN of the first candidate cell is a registered PLMN, or the PLMN of the first candidate cell is a PLMN in an equivalent PLMN list; the first candidate cell is a cell that is not barred; the TAI of the first candidate cell is not in a roaming area identifier (TAI) list of roaming forbidden tracking areas; parameter information of the first candidate cell; bandwidth information of the first candidate cell, the bandwidth information indicating a bandwidth of the first candidate cell.

Optionally, taking an LTE system as an example, the Bandwidth information may be dl-Bandwidth information in a Master Information Block (MIB) message in a system message. For example, in the communication protocol, dl-Bandwidth information may be expressed as follows:

wherein SQUENCE represents the sequence and ENUMERATED represents the list. n6, n15, n25, n50, n75, etc. are used to indicate different bandwidths.

Alternatively, for example, in the LTE system, PLMN-identity list (PLMN-identity list) information in a system information block type 1 (SIB 1) message may be used to indicate a PLMN of a cell, trackingarea code (tracking area code) in an SIB1 message may be used to indicate whether a TAI of the cell belongs to a TAI list for roaming barring, and cellBarred information in an SIB1 message is used to indicate whether the cell is a barred cell. In the communication protocol, the SIB1 information may be expressed as follows:

optionally, the parameter information of the first candidate cell may include a parameter for calculating a cell selection reception level value Srxlev and a cell selection quality value Squal. The above parameter information may also be carried in SIB1 information. For example, parameter Q may be included in the SIB1 information _rxlevmin(Q-RxLevMin) and parameter Q_{rxlevminoffset}(q-RxLevMinOffset)。

Those skilled in the art will understand that the above description on each piece of information is only an example, and the system message may also carry each piece of information at other locations, which is not limited in the embodiments of the present application.

S203, the terminal device determines a cell selection receiving level value Srxlev and a cell selection quality value Squal of the first candidate cell according to the cell measurement value and the parameter information of the first candidate cell, and determines that Srxlev is greater than 0 and the Squal is greater than 0.

Optionally, the terminal device may determine, according to a system message included in the first candidate cell, whether the first candidate cell meets a cell selection condition, where in this embodiment of the present application, the condition may be referred to as a first preset condition. The first preset condition may include the following:

(1) the PLMN of the first candidate cell is a NAS-selected PLMN, the PLMN of the first candidate cell is a registered PLMN, or the PLMN of the first candidate cell is a PLMN in an equivalent PLMN list;

(2) the first candidate cell is not a forbidden cell;

(3) the TAI of the first candidate cell is not a TAI in a roaming forbidden tracking area list (forbidden tracking areas for roaming);

(4) The first candidate cell satisfies a cell selection criterion (cell selection criterion) that is: srxlev >0, where Srxlev represents a cell selection Reception (RX) level value and Squal >0, where Squal represents a cell selection quality value.

Wherein, according to the information in S202, the first candidate cell has satisfied the conditions (1) - (3). In S203, the terminal device may determine the cell selection reception level value Srxlev and the cell selection quality value Squal according to the cell measurement value and the parameter information of the first candidate cell, and determine that the cell selection reception level value Srxlev and the cell selection quality value Squal meet the requirement of the condition (4).

Wherein, the cell measurement value may include a measured cell reception level value Q_rxlevmeasAnd measured cell selection quality value Q_qualmeas. For a specific way of determining the cell selection reception level value Srxlev and the cell selection quality value Squal, reference may be made to the description of the formula (1) and the formula (2) in the foregoing, and details are not repeated here.

S204, the terminal device resides in the first candidate cell under the condition that the bandwidth of the first candidate cell is larger than a preset threshold value.

Optionally, on the basis that the first candidate cell satisfies the first preset condition, the terminal device further needs to determine whether the bandwidth of the first candidate cell is greater than a preset threshold, and the terminal device determines to camp in the first candidate cell only when the bandwidth of the first candidate cell is greater than the preset threshold. The terminal device may determine the bandwidth of the first candidate cell according to the bandwidth information acquired in S202.

In the embodiment of the application, the terminal device selects the cell with the bandwidth larger than the preset threshold value as the resident cell in the cell selection process, so that the data transmission rate is not reduced due to the bandwidth, and the user experience is improved.

In the embodiment of the present application, the size of the preset threshold is not limited, and may be set according to communication practice. For example, a preset threshold may be set such that the data transmission rate is greater than a certain preset value when the bandwidth of the cell is greater than the preset threshold.

Alternatively, in addition to comparing the bandwidth with the preset threshold, the terminal device may also determine whether the bandwidth of the first candidate cell meets the camping condition in other manners. For example, the bandwidth size of a cell may be corresponded to a bandwidth class. For example, the bandwidth levels may be classified into level 1, level 2, level 3, level 4, and the like according to the order of the bandwidths from small to large. The terminal device may determine whether to camp in the first candidate cell according to the bandwidth level corresponding to the bandwidth of the first candidate cell. For example, assume that the terminal device determines to camp on a first candidate cell in a case where a bandwidth level of the first candidate cell is greater than or equal to level 3.

In some examples, the terminal device determines not to camp on the first candidate cell if the bandwidth of the first candidate cell is less than or equal to a preset threshold. Further, the terminal device may continue to search for other candidate cells meeting the first preset condition, and if the bandwidth of the second candidate cell is found to be greater than the preset threshold, the terminal device resides in the second candidate cell.

In the embodiment of the application, if the bandwidth of the candidate cell is less than or equal to the preset threshold, the terminal device continues to search for other cells until a cell with a bandwidth meeting the condition is found, so that it can be ensured that the data transmission rate is not reduced due to the bandwidth, and the user experience is improved.

In some examples, the terminal device determines a camped cell among candidate cells meeting a first preset condition in a case that bandwidths of all candidate cells meeting the first preset condition searched by the terminal device are less than or equal to a preset threshold, where the candidate cells meeting the first preset condition include the first candidate cell.

For example, when the bandwidth of the first candidate cell is less than or equal to the preset threshold, the terminal device may temporarily not camp in the first candidate cell, and continue to search for other candidate cells, and if the bandwidths of all the candidate cells are less than or equal to the preset threshold, the terminal device may arbitrarily select one cell from the searched candidate cells to camp on. And the periodic search can be started to search the cell with the bandwidth larger than the preset threshold, and if the cell meeting the condition is searched, the cell can be switched in the cell reselection process. Alternatively, other equivalent or changing manners may also be adopted to determine whether the cell bandwidth meets the condition of camping in the cell, which is not limited in this embodiment of the present application.

In the embodiment of the application, if the bandwidths of the searched candidate cells do not meet the preset condition, the terminal device selects the resident cell from the searched cells meeting the first preset condition, so that the terminal device can be ensured to be resident in the cells smoothly, and the user experience is improved.

Optionally, when the bandwidth of the first candidate cell is less than or equal to a preset threshold, the terminal device marks the first candidate cell as a cell with the lowest priority in the current RAT, or marks the first candidate cell as a cell with the lowest priority in all RATs supported by the terminal device. The current RAT refers to the RAT corresponding to the cell where the current cell resides. Wherein, in general, one PLMN can support multiple RATs. For example, china mobile may support GSM, time division-synchronous code division multiple access (TD-SCDMA), and LTE.

For example, the terminal device may acquire the priority information of the first candidate cell through a system message. Alternatively, the priority of the cell from low to high may be represented by the numbers 0-7. If the bandwidth of the first candidate cell is less than or equal to the preset threshold. The terminal device may locally modify the priority information of the first candidate cell to be the cell with the lowest priority in the current RAT or to be the cell with the lowest priority in all RATs supported by the terminal device. For example, the lowest priority in the LTE standard is 5, and if the priority is modified in the current RAT, the priority of the first candidate cell may be modified to be 5. If the priority is modified within all RATs, the priority of the first candidate cell may be modified to 0. After modifying the priority, the terminal device may refer to the locally modified priority information to perform a subsequent cell reselection procedure.

In the embodiment of the application, the terminal device marks the cell with the bandwidth smaller than or equal to the preset threshold as the cell with the lowest priority locally, so that the terminal device can preferentially camp on the cell with the bandwidth larger than the preset threshold in the subsequent cell reselection process, and the user experience is improved.

Optionally, in a case that a priori information is locally stored, the terminal device searches the first candidate cell according to the priori information, where the priori information is used to indicate cell information of a history cell in which the terminal device resides. In some examples, the terminal device searches the first candidate cell in a full band without locally storing a priori information indicating cell information of a history of camping cells.

Optionally, in a case that no prior message is locally stored, the terminal device searches for the first candidate cell in a full frequency band, where the prior message is used to indicate cell information of a history camped cell.

As an example of the cell selection method, it is assumed that, in the coverage areas of the first cell a and the second cell B of the terminal device, both the first cell a and the second cell B meet a first preset condition. The bandwidth of the first cell A is smaller than a preset threshold, and the bandwidth of the second cell B is larger than the preset threshold. According to the cell selection process in the prior art, if the terminal device first searches for the first cell a, the terminal device will choose to reside in the first cell a, without considering the bandwidth factor, and due to the limitation of the bandwidth, the data transmission rate of the terminal device will be far lower than the expectation of the user, thereby resulting in poor user experience. In this embodiment, if the terminal device first searches the first cell a in the cell selection process, because the bandwidth of the first cell a is smaller than the preset threshold, the terminal device does not camp in the first cell a, but continues to search for other candidate cells meeting the first preset condition until the second cell B is searched. Because the bandwidth of the second cell B is greater than the preset threshold, the terminal device finally resides in the second cell B, thereby ensuring the data transmission rate of the terminal device and improving the user experience.

Fig. 3 is a diagram illustrating a cell selection method according to another embodiment of the present application. As shown in fig. 3, the cell selection method 300 includes the following.

S301, the NAS of the terminal device selects a PLMN and instructs the AS of the terminal device to execute a cell selection process.

Optionally, for specific contents of the cell selection procedure, refer to the related description of fig. 2, and details are not repeated here.

And S302, if the terminal equipment stores the prior information, executing a cell selection process with the stored information.

For example, if the terminal device searches for a candidate cell meeting a first preset condition, the terminal device determines whether the bandwidth of the candidate cell is greater than a preset threshold. And if the bandwidth of the candidate cell is larger than a preset threshold value, the candidate cell is resided on. If the bandwidth of the candidate cell is less than or equal to the preset threshold, the candidate cell may be marked as a cell with the lowest priority in the current RAT, or marked as a cell with the lowest priority in all RATs, and then the terminal device continues to perform the cell selection procedure with the stored information. If the bandwidths of all the candidate cells searched by the terminal device are smaller than the preset threshold, the terminal device may select one cell from the searched candidate cells as the resident cell.

Alternatively, if the terminal device does not search for a candidate cell meeting the preset condition by executing the cell selection procedure with the stored information, S303 may be continuously executed.

S303, if the terminal device does not store the prior information or does not search the candidate cell through the cell selection procedure with the stored information, the terminal device executes the initial cell selection procedure.

In a specific example, the terminal device may search for candidate cells meeting the first preset condition in the full frequency band. And if the bandwidth of the candidate cell is larger than a preset threshold value, the candidate cell is resided on. If the bandwidth of the candidate cell is less than or equal to the preset threshold, the candidate cell may be marked as a cell with the lowest priority in the current RAT, or marked as a cell with the lowest priority in all RATs, and then the terminal device continues to perform the initial cell selection procedure. If the bandwidths of all the candidate cells searched by the terminal device are smaller than the preset threshold, the terminal device may select one cell from the searched candidate cells meeting the first preset condition as the resident cell, and the terminal device may start a periodic search for searching a cell having a cell bandwidth larger than the preset threshold.

In a specific example, if the terminal device does not search for the candidate cell through the initial cell selection procedure, the terminal device performs an arbitrary cell search (any cell search) procedure. The random cell search process refers to a process of attempting limited camping by the terminal device under the condition that the terminal device cannot acquire normal service. The serving cell, in which an arbitrary cell search procedure resides, provides only emergency service. The resident cell also needs to satisfy the following conditions: (1) is not a forbidden cell; (2) the basic cell residence criterion is met. Or, the terminal device may report the search failure and re-trigger the network selection process.

A method 400 for cell reselection according to an embodiment of the present application is described below with reference to fig. 4, where the method 400 includes the following.

S401, a terminal device receives a system message of a resident serving cell, wherein the system message comprises neighbor cell information, and the neighbor cell information comprises priority information and parameter information of a first candidate cell.

The parameter information of the first candidate cell may include a parameter for determining whether the cell meets a cell reselection condition. For example, for scenario (a) and scenario (c) of the cell reselection criteria in the foregoing, the parameter information may include parameters required for calculating Srxlev or Squal. For scenario (b) of the cell reselection criterion, the above parameter information may include parameters required for calculating Rs and Rn, and the like.

As an example, in the LTE system, the neighbor information may be located in system information block type 4 (SIB 4) information, system information block type 5 (SIB 5) information, and/or system information block type 6 (SIB 6) information in a system message.

S402, the terminal equipment determines that the first candidate cell meets a cell reselection condition according to the priority information and the parameter information of the first candidate cell.

For example, the terminal device may compare the priorities of the first candidate cell and the currently camped cell according to the priority information of the first candidate cell to determine which of scenarios (a) - (c) applies to the cell reselection criterion. And then, further judging whether the first candidate cell meets the cell reselection condition or not according to the cell measurement result and the parameter information.

For specific contents of the cell reselection criteria in the above scenarios (a) - (c), reference may be made to the related description in the foregoing, and details are not repeated here for brevity.

S403, the terminal device receives a system message of the first candidate cell, where the system message of the first candidate cell includes bandwidth information of the first candidate cell, and the bandwidth information is used to indicate a bandwidth of the first candidate cell.

For example, the terminal device may acquire frequency point information of the first candidate cell according to the neighboring cell information, perform cell synchronization with the first candidate cell according to the frequency point information of the first candidate cell, and then receive the system message of the first candidate cell. As one example, in the LTE system, the Bandwidth information may be dl-Bandwidth information in a Master Information Block (MIB) message in a system message.

S404, under the condition that the bandwidth of the first candidate cell is larger than a preset threshold value, the terminal equipment is switched from the service cell to the first candidate cell.

Optionally, the currently camped serving cell may also be referred to as a source cell, and the first candidate cell may also be referred to as a capable cell (capable cell). In the case where the terminal device determines to handover to the first candidate cell, the first candidate cell may be referred to as a target cell.

Optionally, on the basis that the first candidate cell satisfies the cell reselection condition, the terminal device further needs to determine whether the bandwidth of the first candidate cell is greater than a preset threshold, and the terminal device determines to switch to the first candidate cell only when the bandwidth of the first candidate cell is greater than the preset threshold. The terminal device may determine the bandwidth of the first candidate cell according to the bandwidth information acquired in S403.

In the embodiment of the application, the terminal device selects and switches to the cell with the bandwidth larger than the preset threshold value in the cell reselection process, so that the data transmission rate can not be reduced due to the bandwidth, and the user experience is improved.

In some examples, the terminal device determines to continue camping on the current serving cell if the bandwidth of the first candidate cell is less than or equal to the preset threshold.

In some examples, the terminal device may locally mark the first candidate cell as a forbidden cell if the bandwidth of the first candidate cell is less than or equal to the preset threshold. And after the first candidate cell is marked as the forbidden cell, prohibiting the terminal equipment from residing on the first candidate cell within a preset time period. The duration of the preset time period may be determined according to practice, and is not limited in the embodiment of the present application.

For example, when the bandwidth of a first candidate cell is less than or equal to a preset threshold, the first candidate cell may be added to a forbidden cell list (cell barred list for limited bandwidth) for limiting the bandwidth so as to be forbidden to camp on the first candidate cell, and then the cell reselection procedure is ended. Or, instead of processing the first candidate cell, it may be determined that the cell reselection fails, so as to continue camping on the current serving cell.

As an example of a cell reselection method, it is assumed that a terminal device currently resides in a second cell B, and a first cell a is a neighbor cell of the terminal device. According to the system message, the first cell a has a higher priority than the second cell B, and the first cell a is compliant with the conditions of cell reselection in the prior art (see scenario (a) of cell reselection criteria above). The bandwidth of the first cell A is smaller than a preset threshold value, and the bandwidth of the second cell B is larger than the preset threshold value. If the terminal device is handed over to the first cell a according to the existing cell reselection scheme, the data transmission rate of the terminal device will be much lower than the user's expectation due to the limitation of the bandwidth, thereby resulting in poor user experience. In the embodiment of the present application, since the bandwidth of the first cell a is smaller than the preset threshold, the terminal device does not switch to the first cell a, but continues to camp on the second cell B.

In addition, if the terminal device searches for the first cell a in the previous cell selection or cell reselection process, the first cell a is marked as the cell with the lowest priority locally, so that the first cell a is not considered preferentially in the cell reselection process, thereby ensuring the data transmission rate of the terminal device and improving the user experience.

Fig. 5 is a flowchart illustrating a cell reselection method according to another embodiment of the present application. As shown in fig. 5, the flow of the cell reselection method 500 is as follows.

S501, the terminal equipment resides in a source cell.

S502, the terminal device performs cell measurement on the candidate cell, and determines to start a cell reselection process according to a cell measurement result.

S503, if the candidate cell meets the cell reselection condition, the terminal equipment acquires the bandwidth information of the candidate cell.

The cell reselection conditions are as described above, and are not described herein again.

Alternatively, the terminal device may determine whether it stores bandwidth information of the candidate cell. If the bandwidth information of the candidate cell is not stored, the terminal device may obtain the bandwidth information of the candidate cell by receiving a system message of the candidate cell, where the system message of the candidate cell includes the bandwidth information.

Optionally, if the candidate cell does not satisfy the cell reselection condition, the terminal device continues to perform the cell measurement and cell reselection process.

S504, the terminal device determines whether to switch from the source cell to the candidate cell according to the bandwidth information of the candidate cell.

For example, if the bandwidth of the candidate cell is greater than the preset threshold, the terminal device switches from the source cell to the candidate cell.

For example, if the bandwidth of the candidate cell is less than or equal to the preset threshold, the terminal device resides in the source cell. Optionally, the terminal device may add the candidate cell to a forbidden cell list of the limited bandwidth, and end the cell reselection procedure. In this case, the terminal device is prohibited from camping on the candidate cell for a period of time. Or the terminal device may not perform any special processing on the candidate cell, but determine that the cell reselection fails and continue to camp on the source cell.

Fig. 6 is a flowchart illustrating a method for cell selection and cell reselection according to another embodiment of the present application. Fig. 6 shows a detailed flow of cell selection and cell reselection. As shown in fig. 6, the method includes:

s601, the terminal equipment selects a PLMN.

For example, the NAS of the terminal device selects a network from a pre-stored PLMN list, and selects one PLMN. For example, the terminal device may select a PLMN from the PLMN list according to a priority ranking. After selecting the PLMN, the NAS of the terminal device may indicate the RAT related to the selected PLMN to the AS and instruct the AS of the terminal device to perform a cell selection procedure. The AS of the terminal equipment executes a cell selection flow with stored information or an initial cell selection flow according to whether the cell information corresponding to the PLMN is stored or not, wherein the cell information comprises prior information.

And S602, if the terminal equipment stores the cell information corresponding to the PLMN, executing a cell selection process with the stored information.

The cell selection process is used for searching candidate cells meeting the first preset condition. For example, the terminal device may search for a candidate cell meeting the first preset condition according to the frequency point information of the history resident cell in the prior information. Alternatively, if the candidate cell meeting the first preset condition is not searched according to the cell selection process with the stored information, the terminal device executes S603.

S603, if the terminal device does not store the cell information corresponding to the PLMN, or the candidate cell meeting the first preset condition is not searched in the cell selection process with the stored information, executing the initial cell selection process.

The initial cell selection process searches for a candidate cell meeting a first preset condition in a full frequency band.

S604, if the candidate cell meeting the first preset condition is searched, the terminal equipment judges whether the bandwidth of the candidate cell is larger than a preset threshold value.

If the candidate cell meeting the preset condition is searched through S602 or S603, the terminal device determines whether the bandwidth of the candidate cell is greater than a preset threshold. And if the bandwidth of the candidate cell is larger than a preset threshold value, residing in the candidate cell. If the bandwidth of the candidate cell is smaller than the preset threshold, the process returns to S602 or S603 to continue the cell selection process.

The terminal device may obtain the bandwidth information of the candidate cell through the system message. For example, the Bandwidth information of the candidate cell may be dl-Bandwidth information in a MIB message in a system message.

Alternatively, in the case that the bandwidth of the candidate cell is greater than the preset threshold, if the terminal device is rejected due to some reasons (home calls) when performing NAS registration in the selected PLMN, any cell selection procedure in step S608 may be performed.

S605, if the terminal device searches for one or more candidate cells meeting the first preset condition in S603 and S604, but bandwidths of all the searched candidate cells are less than or equal to a preset threshold, the terminal device selects one cell from the candidate cells to camp on. If the terminal device does not search for a candidate cell meeting the first preset condition in S603 and S604, the terminal device performs an arbitrary cell selection procedure in S608.

S606, the terminal device may execute the cell selection procedure after leaving the connected state when returning to the idle state or the inactive state from the connected state. The terminal device first searches for a last resident cell, determines whether a first preset condition is met, and executes S604. If the last resident cell does not meet the first preset condition, the terminal device executes the cell selection procedure with the stored information in S602.

For example, the terminal device leaves the idle state and/or the inactive state and is in the connected state after camping on the cell. When the terminal device returns to the idle state and/or the inactive state from the connected state, the terminal device may perform a cell selection procedure after leaving the connected state. In the cell selection process after leaving the connected state, the terminal device preferentially attempts to camp in the last camped serving cell, and if the terminal device cannot camp, searches other cells and attempts to camp.

S607, after the terminal device resides in the serving cell, when detecting a candidate cell meeting the cell reselection condition, the cell reselection process may be triggered.

For the cell reselection condition, reference may be made to the foregoing description about the cell reselection rule, which is not described herein again. After searching for a candidate cell meeting the cell reselection condition, the terminal device may execute the step S604 to determine whether to handover from the camped source cell to the candidate cell. If the bandwidth of the candidate cell is less than or equal to the preset threshold, the cell reselection procedure may be ended, and the cell may be re-camped in the source cell. Alternatively, if no candidate cell meeting the reselection condition is found, any cell selection procedure in S608 may be performed.

S608, the terminal device executes an arbitrary cell selection procedure.

If the terminal device does not search for a candidate cell meeting the first preset condition in the cell selection process, or does not search for a cell meeting the cell reselection condition in the cell reselection process, or searches for a candidate cell meeting the first preset condition but rejects the NAS registration, any cell selection procedure may be performed. The arbitrary cell selection procedure may also be referred to as an arbitrary cell search procedure, and refers to a process in which the terminal device attempts a restricted camping when the terminal device cannot acquire normal service. The relevant content of any cell search procedure can refer to the relevant description in fig. 3, and is not described herein again.

Fig. 7 is a schematic structural diagram of a terminal device 700 according to an embodiment of the present application. The terminal device 700 may be configured to perform the cell selection method or steps performed by the terminal device in the method embodiment of the present application. As shown in fig. 7, the terminal device 700 includes: a search unit 710, a receiving unit 720 and a processing unit 730.

The searching unit 710 is configured to search for a first candidate cell. The receiving unit 720 is configured to receive a system message of the first candidate cell, where the system message of the first candidate cell includes information indicating: the PLMN of the first candidate cell is a PLMN selected by a non-access stratum (NAS), or the PLMN of the first candidate cell is a registered PLMN, or the PLMN of the first candidate cell is a PLMN in an equivalent PLMN list; the first candidate cell is a cell that is not barred; the TAI of the first candidate cell is not a TAI in a roaming-forbidden tracking area list; parameter information of the first candidate cell; bandwidth information of the first candidate cell, the bandwidth information indicating a bandwidth of the first candidate cell; the processing unit 730 is configured to determine, according to the cell measurement value and the parameter information of the first candidate cell, a cell selection reception level value Srxlev and a cell selection quality value Squal of the first candidate cell, and determine Srxlev >0 and Squal > 0; the processing unit 730 is further configured to determine that the terminal device is camped on the first candidate cell if the bandwidth of the first candidate cell is greater than a preset threshold.

Fig. 8 is a schematic structural diagram of a terminal device 800 according to an embodiment of the present application. The terminal device 800 may be configured to perform the method or steps of cell reselection performed by the terminal device in the method embodiment of the present application. As shown in fig. 8, the terminal apparatus 800 includes: a receiving unit 810 and a determining unit 820.

The receiving unit 810 is configured to receive a system message of a camped serving cell, where the system message includes neighboring cell information, and the neighboring cell information includes priority information and parameter information of a first candidate cell. The determining unit 820 is configured to determine that the first candidate cell satisfies a cell reselection condition according to the priority information and the parameter information of the first candidate cell. The receiving unit 810 is further configured to receive a system message of the first candidate cell, where the system message of the first candidate cell includes bandwidth information of the first candidate cell, and the bandwidth information is used to indicate a bandwidth of the first candidate cell. The determining unit 820 is further configured to determine that the terminal device is handed over from the serving cell to the first candidate cell if the bandwidth of the first candidate cell is greater than a preset threshold.

Fig. 9 is a schematic structural diagram of a terminal device 900 according to another embodiment of the present application. The terminal device 900 may be configured to perform the methods or steps performed by the terminal device in the method embodiments of the present application. As shown in fig. 9, the terminal apparatus 900 includes:

A transceiver 910;

a memory 920 for storing programs;

a processor 930 for executing programs in the memory 920.

In one example, processor 930, when the program is executed, is configured to search for a first candidate cell; receiving, by the transceiver 910, a system message of the first candidate cell, the system message of the first candidate cell including information indicating: the PLMN of the first candidate cell is a NAS selected PLMN, or the PLMN of the first candidate cell is a registered PLMN, or the PLMN of the first candidate cell is a PLMN in an equivalent PLMN list; the first candidate cell is a cell that is not barred; the TAI of the first candidate cell is not a TAI in a roaming-forbidden tracking area list; parameter information of the first candidate cell; bandwidth information of the first candidate cell, the bandwidth information indicating a bandwidth of the first candidate cell; determining a cell selection receiving grade value Srxlev and a cell selection quality value Squal of the first candidate cell according to the cell measurement value and the parameter information of the first candidate cell, and determining that Srxlev is greater than 0 and the Squal is greater than 0; and determining that the terminal device resides in the first candidate cell when the bandwidth of the first candidate cell is greater than a preset threshold.

In another example, when the program is executed, processor 930 is configured to receive, via transceiver 910, a system message of a camped serving cell, where the system message includes neighbor cell information, and the neighbor cell information includes priority information and parameter information of a first candidate cell; determining that the first candidate cell meets a cell reselection condition according to the priority information and the parameter information of the first candidate cell; and receiving, by the transceiver 910, a system message of the first candidate cell, where the system message of the first candidate cell includes bandwidth information of the first candidate cell, and the bandwidth information is used to indicate a bandwidth of the first candidate cell; and determining that the terminal device is switched from the serving cell to the first candidate cell when the bandwidth of the first candidate cell is greater than a preset threshold.

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

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

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

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

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

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

Claims

1. A method of cell selection, comprising:

the terminal equipment searches a first candidate cell;

the terminal equipment receives the system message of the first candidate cell, wherein the system message of the first candidate cell comprises information used for indicating the following contents: the public land mobile network, PLMN, of the first candidate cell is a PLMN that is not selected by the access stratum, NAS, or the PLMN of the first candidate cell is a registered PLMN, or the PLMN of the first candidate cell is a PLMN in an equivalent PLMN list; the first candidate cell is a cell that is not barred; the tracking area identity, TAI, of the first candidate cell is not a TAI in a list of roaming forbidden tracking areas; parameter information of the first candidate cell; bandwidth information of the first candidate cell, the bandwidth information indicating a bandwidth of the first candidate cell;

the terminal equipment determines a cell selection receiving grade value Srxlev and a cell selection quality value Squal of the first candidate cell according to the cell measurement value and the parameter information of the first candidate cell, and determines that Srxlev is greater than 0 and the Squal is greater than 0;

and the terminal equipment resides in the first candidate cell under the condition that the bandwidth of the first candidate cell is larger than a preset threshold value.

2. The method of claim 1, wherein the method further comprises: and the terminal equipment does not reside in the first candidate cell under the condition that the bandwidth of the first candidate cell is less than or equal to the preset threshold value.

3. The method of claim 1, wherein the terminal device determines the cells to camp on among the candidate cells meeting the first preset condition when the bandwidths of all the candidate cells meeting the first preset condition, which are searched by the terminal device, are less than or equal to the preset threshold;

the first preset condition includes:

the PLMN of the candidate cell is a NAS selected PLMN, or the PLMN of the candidate cell is a registered PLMN, or the PLMN of the candidate cell is a PLMN in an equivalent PLMN list; the candidate cell is a cell that is not barred; the TAI of the candidate cell is not a TAI in a roaming forbidden tracking area list; srxlev >0, and Squal > 0.

4. The method of any of claims 1 to 3, further comprising: and under the condition that the bandwidth of the first candidate cell is less than or equal to a preset threshold, the terminal equipment marks the first candidate cell as a cell with the lowest priority in the current Radio Access Technology (RAT), or marks the first candidate cell as a cell with the lowest priority in all RATs supported by the terminal equipment.

5. The method of any of claims 1 to 4, wherein the terminal device searching for the first candidate cell comprises:

under the condition that prior information is locally stored, the terminal equipment searches the first candidate cell according to the prior information, wherein the prior information is used for indicating cell information of a historical resident cell.

6. The method of claim 5, wherein the terminal device searches for a first candidate cell, further comprising:

and under the condition that the first candidate cell is not searched according to the prior message, the terminal equipment determines the first candidate cell through full-band search.

7. The method of any of claims 1 to 4, wherein the terminal device searching for the first candidate cell comprises:

and under the condition that no prior message is stored locally, the terminal equipment searches the first candidate cell in the full frequency band, wherein the prior message is used for indicating the cell information of the historical resident cell.

8. A method of cell reselection, the method comprising:

the method comprises the steps that terminal equipment receives a system message of a resident serving cell, wherein the system message comprises neighbor cell information, and the neighbor cell information comprises priority information and parameter information of a first candidate cell;

The terminal equipment determines that the first candidate cell meets cell reselection conditions according to the priority information and the parameter information of the first candidate cell;

the terminal equipment receives a system message of the first candidate cell, wherein the system message of the first candidate cell comprises bandwidth information of the first candidate cell, and the bandwidth information is used for indicating the bandwidth of the first candidate cell;

and under the condition that the bandwidth of the first candidate cell is larger than a preset threshold value, the terminal equipment is switched from the serving cell to the first candidate cell.

9. The method of claim 8, wherein the method further comprises: and under the condition that the bandwidth of the first candidate cell is less than or equal to the preset threshold, the terminal equipment determines to continuously reside in the current serving cell.

10. The method of claim 8, wherein the terminal device marks the first candidate cell as a forbidden cell if the bandwidth of the first candidate cell is less than or equal to the preset threshold.

11. The method according to any one of claims 8 to 10, wherein the determining, by the terminal device, that the first candidate cell satisfies the cell reselection condition according to the priority information and the parameter information of the first candidate cell comprises:

The terminal equipment determines that the priority of the first candidate cell is greater than that of the serving cell according to the priority information of the first candidate cell;

the terminal equipment determines a cell selection receiving grade value Srxlev of the first candidate cell according to the cell measurement value of the first candidate cell and the parameter information of the first candidate cell;

the terminal equipment determines that Srxlev of the first candidate cell is larger than a first threshold value within a preset time period; and

the terminal device determines to camp on the serving cell for more than one second.

12. The method according to any one of claims 8 to 10, wherein the determining, by the terminal device, that the first candidate cell satisfies the cell reselection condition according to the priority information and the parameter information of the first candidate cell comprises:

the terminal equipment determines that the priority of the first candidate cell is equal to the priority of the serving cell according to the priority information of the first candidate cell;

the terminal equipment determines a cell ranking criterion Rn of the first candidate cell according to the parameter information of the first candidate cell;

the terminal device determines that Rn is greater than Rs, which represents a cell ranking criterion for the serving cell.

13. The method according to any one of claims 8 to 10, wherein the determining, by the terminal device, that the first candidate cell satisfies the cell reselection condition according to the priority information and the parameter information of the first candidate cell comprises:

the terminal equipment determines that the priority of the first candidate cell is smaller than the priority of the serving cell according to the priority information of the first candidate cell;

the terminal device determines that the Srxlev of the first candidate cell is larger than a second threshold value and the Srxlev of the serving cell is smaller than a third threshold value within a preset time period; and

determining that the terminal device is camped on the serving cell for more than one second.

14. A chip, comprising:

a processor for calling a computer program from a memory, the computer program, when executed, causing a terminal device in which the chip is installed to perform the steps of:

searching a first candidate cell;

receiving a system message of the first candidate cell, wherein the system message of the first candidate cell comprises information for indicating the following: the public land mobile network, PLMN, of the first candidate cell is a PLMN that is not selected by the access stratum, NAS, or the PLMN of the first candidate cell is a registered PLMN, or the PLMN of the first candidate cell is a PLMN in an equivalent PLMN list; the first candidate cell is a cell that is not barred; the tracking area identity, TAI, of the first candidate cell is not a TAI in a list of roaming forbidden tracking areas; parameter information of the first candidate cell; bandwidth information of the first candidate cell, the bandwidth information indicating a bandwidth of the first candidate cell;

According to the cell measurement value and the parameter information of the first candidate cell, determining a cell selection receiving level value Srxlev and a cell selection quality value Squal of the first candidate cell, and determining that Srxlev is greater than 0 and the Squal is greater than 0;

and determining that the terminal equipment is resided in the first candidate cell under the condition that the bandwidth of the first candidate cell is greater than a preset threshold value.

15. The chip of claim 14, wherein the computer program, when executed, causes a terminal device in which the chip is installed to determine that the terminal device is not camped on the first candidate cell if a bandwidth of the first candidate cell is less than or equal to the preset threshold.

16. The chip of claim 14, wherein the computer program, when executed, causes a terminal device installed with the chip to determine a cell to camp on among all candidate cells meeting a first preset condition if the searched bandwidths of all candidate cells meeting the first preset condition are less than or equal to the preset threshold;

the first preset condition includes: the PLMN of the candidate cell is a NAS selected PLMN, or the PLMN of the candidate cell is a registered PLMN, or the PLMN of the candidate cell is a PLMN in an equivalent PLMN list; the candidate cell is a cell that is not barred; the TAI of the candidate cell is not a TAI in a roaming forbidden tracking area list; srxlev >0, and Squal > 0.

17. The chip of any one of claims 14 to 16, wherein the computer program, when executed, causes a terminal device in which the chip is installed to mark the first candidate cell as a current radio access technology, intra-RAT, lowest priority cell, or as a cell with lowest intra-RAT priority for all supported by the terminal device, if the bandwidth of the first candidate cell is less than or equal to a preset threshold.

18. The chip according to any of claims 14 to 17, wherein in searching for a first candidate cell, the computer program, when executed, causes a terminal device in which the chip is installed to search for the first candidate cell in accordance with a priori information indicating cell information of a historical camping cell, if the a priori information is stored locally.

19. The chip of claim 18, wherein in searching for a first candidate cell, the computer program, when executed, causes a terminal device on which the chip is installed to determine the first candidate cell through a full band search if the first candidate cell is not searched according to the a priori message.

20. The chip of any one of claims 14 to 17, wherein in searching for a first candidate cell, the computer program, when executed, causes a terminal device in which the chip is installed to search for the first candidate cell over a full frequency band without having a priori information stored locally, the a priori information indicating cell information of a historical camping cell.

21. A chip, comprising:

receiving a system message of a resident serving cell, wherein the system message comprises neighbor cell information, and the neighbor cell information comprises priority information and parameter information of a first candidate cell;

determining that the first candidate cell meets a cell reselection condition according to the priority information and the parameter information of the first candidate cell;

receiving a system message of the first candidate cell, wherein the system message of the first candidate cell comprises bandwidth information of the first candidate cell, and the bandwidth information is used for indicating the bandwidth of the first candidate cell;

And under the condition that the bandwidth of the first candidate cell is larger than a preset threshold value, determining that the terminal equipment is switched from the serving cell to the first candidate cell.

22. The chip of claim 21, wherein the computer program, when executed, causes a terminal device installed with the chip to determine that the terminal device continues to camp on a current serving cell if a bandwidth of the first candidate cell is less than or equal to the preset threshold.

23. The chip of claim 21, wherein the computer program, when executed, causes a terminal device in which the chip is installed to mark the first candidate cell as a forbidden cell if a bandwidth of the first candidate cell is less than or equal to the preset threshold.

24. The chip according to any of claims 21 to 23, wherein in respect of determining that the first candidate cell satisfies a cell reselection condition based on the priority information and parameter information of the first candidate cell, the computer program, when executed, causes a terminal device in which the chip is installed to perform the steps of:

determining that the priority of the first candidate cell is greater than the priority of the serving cell according to the priority information of the first candidate cell;

Determining a cell selection receiving grade value Srxlev of the first candidate cell according to the cell measurement value of the first candidate cell and the parameter information of the first candidate cell;

determining that Srxlev of the first candidate cell is greater than a first threshold within a preset time period; and

25. The chip according to any of claims 21 to 23, wherein in respect of determining that the first candidate cell satisfies a cell reselection condition based on the priority information and parameter information of the first candidate cell, the computer program, when executed, causes a terminal device in which the chip is installed to perform the steps of:

determining that the priority of the first candidate cell is equal to the priority of the serving cell according to the priority information of the first candidate cell;

determining a cell ranking criterion Rn of the first candidate cell according to the parameter information of the first candidate cell;

determining Rn is greater than Rs, which represents a cell ranking criterion for the serving cell.

26. The chip according to any of claims 21 to 23, wherein in respect of determining that the first candidate cell satisfies a cell reselection condition based on the priority information and parameter information of the first candidate cell, the computer program, when executed, causes a terminal device in which the chip is installed to perform the steps of:

Determining that the priority of the first candidate cell is smaller than the priority of the serving cell according to the priority information of the first candidate cell;

determining that the Srxlev of the first candidate cell is larger than a second threshold value and the Srxlev of the serving cell is smaller than a third threshold value within a preset time period; and