Network selection method and device, equipment, storage medium and program product

Abstract

The invention discloses a network selection method and device, equipment, a storage medium and a program product, and relates to the technical field of communication. The method comprises: an access layer sending first information to an upper layer, the first information being used for indicating a PLMN whose signal quality is greater than a threshold value (310). According to the embodiment of the invention, the PLMN with the better signal quality is indicated to the high layer through the access layer, so that the high layer can select the target PLMN from the PLMNs with the better signal quality when selecting the PLMNs, the finally selected target PLMN is ensured to be the PLMN with the better signal quality, and the communication quality is improved.

Description

Network selection method, device, equipment, storage medium and program product Technical Field

[0001] The embodiments of the present application relate to the field of communication technology, and in particular to a network selection method, apparatus, device, storage medium, and program product. Background Art

[0002] When a phone is powered on or enters idle mode, it selects a PLMN (Public Land Mobile Network). When selecting a PLMN, the phone's chipset's NAS (Non-access Stratum) triggers the access layer to read system information from surrounding cells and obtain the PLMN identifiers of the surrounding cells. The access layer then reports these PLMN identifiers to the NAS layer, which then selects the final PLMN.

[0003] In related technologies, when selecting a PLMN, the NAS layer prioritizes the PLMN's priority and selects the corresponding HPLMN (Home Public Land Mobile Network) or EHPLMN (Equivalent Home Public Land Mobile Network). Therefore, even if the signal quality of a high-priority PLMN is poor, it will still be selected, resulting in poor communication quality.

[0004] Summary of the Invention

[0005] The embodiments of the present application provide a network selection method, apparatus, device, storage medium, and program product. The technical solution is as follows:

[0006] According to one aspect of an embodiment of the present application, a network selection method is provided. The method is performed by a terminal device, the terminal device including an access layer and a high layer, and the method includes:

[0007] The access layer sends first information to the higher layer, where the first information is used to indicate a PLMN whose signal quality is greater than a threshold.

[0008] According to one aspect of an embodiment of the present application, a network selection device is provided, the device being arranged in a terminal device, the terminal device including an access layer and a high layer, the device comprising:

[0009] The first sending module is configured to send first information to the higher layer through the access layer, where the first information is used to indicate a PLMN whose signal quality is greater than a threshold.

[0010] According to one aspect of an embodiment of the present application, a terminal device is provided, comprising a processor and a memory, wherein a computer program is stored in the memory, and the processor executes the computer program to implement the above-mentioned network selection method.

[0011] According to one aspect of an embodiment of the present application, a computer-readable storage medium is provided, in which a computer program is stored. The computer program is configured to be executed by a processor to implement the above-mentioned network selection method.

[0012] According to one aspect of an embodiment of the present application, a chip is provided, which includes a programmable logic circuit and / or program instructions, and when the chip is running, is used to implement the above-mentioned network selection method.

[0013] According to one aspect of an embodiment of the present application, a computer program product is provided, which includes computer instructions stored in a computer-readable storage medium. A processor reads and executes the computer instructions from the computer-readable storage medium to implement the above-mentioned network selection method.

[0014] The technical solutions provided by the embodiments of the present application may have the following beneficial effects:

[0015] The first information is sent to the upper layer through the access layer, and the PLMN whose signal quality is greater than the threshold value is indicated to the upper layer through the first information. In simple terms, it can be understood that the PLMN with better signal quality is indicated to the upper layer through the access layer, so that when the upper layer selects the PLMN, it can select the target PLMN from these PLMNs with better signal quality, ensuring that the target PLMN finally selected is the PLMN with better signal quality, thereby improving the communication quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG1 is a schematic diagram of a network architecture provided by an embodiment of the present application;

[0017] FIG2 is a schematic diagram of an HPLMN provided by an embodiment of the present application;

[0018] FIG3 is a flow chart of a network selection method provided by an embodiment of the present application;

[0019] FIG4 is a flow chart of a network selection method provided by another embodiment of the present application;

[0020] FIG5 is a flow chart of a network selection method provided by another embodiment of the present application;

[0021] FIG6 is a flow chart of a network selection method provided by another embodiment of the present application;

[0022] FIG7 is a block diagram of a network selection device provided by an embodiment of the present application;

[0023] FIG8 is a block diagram of a network selection device provided by another embodiment of the present application;

[0024] FIG9 is a schematic structural diagram of a terminal device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0026] The network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. A person skilled in the art will appreciate that, with the evolution of the network architecture and the emergence of new business scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0027] The network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. A person skilled in the art will appreciate that, with the evolution of the network architecture and the emergence of new business scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0028] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: Global System of Mobile communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, Advanced Long Term Evolution (LTE-A) system, New Radio (NR) system, NR system evolution system, LTE on unlicensed spectrum (LTE-U) system, NR on unlicensed spectrum (NR-U) system, Non-Terrestrial Networks (NTN) system, Universal Mobile Telecommunication System (UMTS), Wireless Local Area Networks (WLAN), Wireless Fidelity (Wireless Fidelity) system. Fidelity, WiFi), fifth-generation communication (5th-Generation, 5G) system or other communication systems, etc.

[0029] Generally speaking, traditional communication systems support a limited number of connections and are easy to implement. However, with the development of communication technology, mobile communication systems will not only support traditional communications, but will also support, for example, device-to-device (D2D) communication, machine-to-machine (M2M) communication, machine-type communication (MTC), vehicle-to-vehicle (V2V) communication, or vehicle-to-everything (V2X) communication, etc. The embodiments of the present application can also be applied to these communication systems.

[0030] The communication system in the embodiment of the present application can be applied to a carrier aggregation (CA) scenario, a dual connectivity (DC) scenario, and a standalone (SA) networking scenario.

[0031] The communication system in the embodiment of the present application can be applied to an unlicensed spectrum, where the unlicensed spectrum can also be considered as a shared spectrum; or, the communication system in the embodiment of the present application can also be applied to an authorized spectrum, where the authorized spectrum can also be considered as an unshared spectrum.

[0032] The embodiments of the present application can be applied to non-terrestrial networks (NTN) systems, and can also be applied to terrestrial networks (TN) systems.

[0033] Please refer to FIG1 , which shows a schematic diagram of a network architecture 100 provided by an embodiment of the present application. The network architecture 100 may include: a terminal device 10 , an access network device 20 , and a core network device 30 .

[0034] The terminal device 10 may refer to a UE (User Equipment), an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a wireless communication device, a user agent, or a user apparatus. Optionally, the terminal device 10 may also be a cellular phone, a cordless phone, a SIP (Session Initiation Protocol) phone, a WLL (Wireless Local Loop) station, a PDA (Personal Digital Assistant), a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, an in-vehicle device, a wearable device, a terminal device in a 5GS (5th Generation System) or a terminal device in a future-evolved PLMN (Public Land Mobile Network), etc., but the embodiments of the present application are not limited thereto. For ease of description, the above-mentioned devices are collectively referred to as terminal devices. The number of terminal devices 10 is generally multiple, and one or more terminal devices 10 may be distributed in each cell managed by an access network device 20. In the embodiments of the present application, “terminal device” and “UE” are often used interchangeably, but those skilled in the art will understand that the two generally express the same meaning.

[0035] Access network equipment 20 is a device deployed in an access network to provide wireless communication capabilities for terminal device 10. Access network equipment 20 may include various forms of macro base stations, micro base stations, relay stations, access points, and the like. In systems employing different wireless access technologies, the names of devices that provide access network equipment functions may vary. For example, in 5G NR systems, they are referred to as gNodeBs or gNBs. As communication technologies evolve, the term "access network equipment" may change. For ease of description, in the embodiments of this application, the aforementioned devices that provide wireless communication capabilities for terminal device 10 are collectively referred to as access network equipment. Optionally, a communication relationship can be established between terminal device 10 and core network equipment 30 through access network equipment 20. For example, in an LTE (Long Term Evolution) system, access network equipment 20 may be an Evolved Universal Terrestrial Radio Access Network (EUTRAN) or one or more eNodeBs within EUTRAN. In a 5G NR system, access network equipment 20 may be a Radio Access Network (RAN) or one or more gNBs within the RAN. In the embodiment of the present application, unless otherwise specified, the "network device" refers to the access network device 20, such as a base station.

[0036] The core network device 30 is a device deployed in the core network. The functions of the core network device 30 are mainly to provide user connections, user management, and service bearer, and to provide an interface to the external network as a bearer network. For example, the core network devices in the 5G NR system may include devices such as the AMF (Access and Mobility Management Function) entity, the UPF (User Plane Function) entity, and the SMF (Session Management Function) entity.

[0037] In some embodiments, the access network device 20 and the core network device 30 communicate with each other via an air interface technology, such as the NG interface in the 5G NR system. The access network device 20 and the terminal device 10 communicate with each other via an air interface technology, such as the Uu interface.

[0038] The "5G NR system" in the embodiments of the present application may also be referred to as a 5G system or an NR system, but those skilled in the art will understand its meaning. The technical solutions described in the embodiments of the present application may be applicable to LTE systems, 5G NR systems, subsequent evolution systems of 5G NR systems, and other communication systems such as NB-IoT (Narrow Band Internet of Things) systems, and this application does not limit this.

[0039] In an embodiment of the present application, the network device can provide services for a cell, and the terminal device communicates with the network device through the transmission resources (for example, frequency domain resources, or spectrum resources) on the carrier used by the cell. The cell can be a cell corresponding to the network device (for example, a base station). The cell can belong to a macro base station or a base station corresponding to a small cell. The small cells here may include: metro cell, micro cell, pico cell, femto cell, etc. These small cells have the characteristics of small coverage and low transmission power, and are suitable for providing high-speed data transmission services.

[0040] Before introducing the technical solutions of this application, we first introduce and explain some of the background technologies involved in this application. The following related technologies can be combined with the technical solutions of the embodiments of this application as optional solutions, and they all fall within the scope of protection of the embodiments of this application. The embodiments of this application include at least some of the following contents.

[0041] A terminal device (such as a mobile phone) will select a PLMN when it is just turned on or enters an idle state.

[0042] When PLMN selection is required, the terminal device's chip reads files such as "HPLMN Selector with Access Technology", "User Controlled PLMN Selector with Access Technology", "Forbidden PLMNs", "Equivalent HPLMN (EHPLMN)", and "Operator controlled PLMN Selector with Access Technology" from the SIM (Subscriber Identity Module) card.

[0043] The chip's NAS layer triggers the access layer to read system information from surrounding cells and obtain the PLMN IDs (PLMN Identifiers) of the surrounding cells from this system information. The access layer then reports these PLMN IDs to the NAS layer, which selects the final PLMN. The access layer also reports the signal quality of any PLMN below -110dB to the NAS layer, specifically the PLMN ID and signal quality.

[0044] The NAS layer selects a PLMN in the following order:

[0045] (1) either the HPLMN (if the EHPLMN list is not present or is empty) or the highest priority EHPLMN (equivalent HPLMN) that is available (if the EHPLMN list is present).

[0046] The HPLMN ID (HPLMN Identifier) ​​can be found in the SIM card's IMSI (International Mobile Subscriber Identity). As shown in Figure 2, the HPLMN is the MCC + MNC (Mobile Country Code and Mobile Network Code) in the IMSI.

[0047] At the same time, the SIM card contains the HPLMN Selector with Access Technology, as shown in Table 1. The higher the order in the table, the higher the priority.

[0048] For example, if a mobile 4G card is configured with LTE (Long Term Evolution) > 2G, the UE will select the mobile 4G network + LTE access technology when selecting a PLMN. When there is no 4G network coverage nearby, the UE will select PLMN + 2G.

[0049] It can be considered that the EHPLMN and the HPLMN provide the same services to the UE and have the same functions as the HPLMN. Therefore, the RAT (Radio Access Type) priorities in Table 1 also apply to the EHPLMN.

[0050] (2) each PLMN / access technology combination in the "User Controlled PLMN Selector with Access Technology" data file in the SIM (in priority order), that is, each PLMN / access technology combination in the "User Controlled PLMN Selector with Access Technology" data file in the SIM card (in priority order).

[0051] (3) each PLMN / access technology combination in the "Operator Controlled PLMN Selector with Access Technology" data file in the SIM (in priority order) or stored in the ME (Management Engine) (in priority order), that is, each PLMN / access technology combination is in the "Operator Controlled PLMN Selector with Access Technology" data file in the SIM (in priority order) or stored in the ME (Management Engine) (in priority order).

[0052] Operator Controlled PLMN Selector with Access Technology is shown in Table 2. Each PLMN is followed by a RAT. The higher the order in the table, the higher the priority.

[0053] (4) other PLMN / access technology combinations with received high quality signal in random order, that is, other PLMN / access technology combinations can receive high quality signals in random order.

[0054] (5) Other PLMN / access technology combinations in order of decreasing signal quality, that is, other PLMN / access technology combinations are arranged in order of decreasing signal quality.

[0055] Table 1: RAT priority for HPLMN Selector with Access Technology

[0056]

[0057] Table 2: RAT priority for Operator Controlled PLMN Selector with Access Technology

[0058]

[0059] The order of PLMN selection above shows that the UE prioritizes the PLMN's priority and only considers signal quality in the final step. This means that even if the signal quality of a high-priority PLMN is poor, the UE will still select that PLMN, and communication quality cannot be guaranteed.

[0060] Please refer to Figure 3, which shows a flow chart of a network selection method provided by an embodiment of the present application. The method can be executed by a terminal device, which includes an access layer and a high layer. The method may include the following steps:

[0061] Step 310: The access layer sends first information to a higher layer, where the first information is used to indicate a PLMN whose signal quality is greater than a threshold.

[0062] The access stratum (AS) refers to the functional layer in the wireless communication protocol stack that directly faces user connection or access.

[0063] In a wireless communication protocol stack, a high layer located above the access layer refers to a functional layer located above the access layer. In some embodiments, the high layer may be a NAS layer. In some embodiments, the high layer may also be an application layer or a non-standard functional layer, which is not limited in this embodiment of the present application.

[0064] In some embodiments, the upper layer indicates to the access layer a threshold value provided by the operator. For example, the upper layer sends indication information indicating the threshold value to the access layer. The indication information can be the threshold value itself or any information that can determine the threshold value, which is not limited in this application.

[0065] In some embodiments, the threshold value is configured in the USIM (Universal Subscriber Identity Module) of the terminal device. For example, the threshold value is configured in the SIM card of the terminal device, and the upper layer can obtain the threshold value from the SIM card. By configuring the threshold value provided by the operator in the USIM, the terminal device can obtain the threshold value even when it has not yet connected to the network, and then filter out PLMNs with better signal quality based on the threshold value.

[0066] In some embodiments, the signal quality can be represented by RSRP (Reference Signal Receiving Power), or the signal quality can also be represented by other parameters such as RSRQ (Reference Signal Receiving Quality) or SINR (Signal to Interference plus Noise Ratio), which is not limited in this application.

[0067] The technical solution provided in this embodiment sends first information to the upper layer through the access layer, and indicates to the upper layer through the first information the PLMN whose signal quality is greater than the threshold value. Simply put, it can be understood that the access layer indicates to the upper layer the PLMN with better signal quality, so that when the upper layer selects the PLMN, it can select the target PLMN from these PLMNs with better signal quality, ensuring that the target PLMN finally selected is the PLMN with better signal quality, thereby improving the communication quality.

[0068] Please refer to Figure 4, which shows a flow chart of a network selection method provided by another embodiment of the present application. The method can be executed by a terminal device, which includes an access layer and a high layer. The method may include at least one of the following steps 410 to 450:

[0069] Step 410: The upper layer sends a first request to the access layer, where the first request is used to request the access layer to report an available PLMN.

[0070] Available PLMN refers to the PLMN that can be selected by the higher layer.

[0071] In some embodiments, the upper layer indicates to the access layer a threshold value provided by the operator. In addition, the indication information for indicating the threshold value can be carried in the first request or sent separately from the first request, which is not limited in this application.

[0072] Step 420: When the access layer searches for a PLMN whose signal quality is greater than the threshold value, the access layer sends first information to the upper layer, where the first information includes a first PLMN list and a second PLMN list; wherein the first PLMN list includes the identifier of at least one PLMN whose signal quality is greater than the threshold value, and the second PLMN list includes the identifier of at least one PLMN whose signal quality is less than the threshold value.

[0073] The terminal device can search for PLMNs (PLMNs) around it through the access layer and measure the signal quality of each searched PLMN. Based on the threshold, the terminal device selects PLMNs with signal quality exceeding the threshold from the searched PLMNs. Based on the relationship between the signal quality of each searched PLMN and the threshold, the access layer constructs a first PLMN list and a second PLMN list. The first PLMN list includes the identifier of at least one PLMN with signal quality exceeding the threshold, and the second PLMN list includes the identifier of at least one PLMN with signal quality below the threshold.

[0074] It should be noted that, in some embodiments, if the signal quality of each PLMN searched by the access stratum is greater than a threshold value, or if the access stratum does not search for a PLMN with a signal quality less than the threshold value, then the second PLMN list does not exist or is empty. In this case, the first information may not include the second PLMN list, or the second PLMN list included in the first information may be empty.

[0075] In addition, if the signal quality of each PLMN searched by the access layer is less than the threshold value, or the access layer does not search for a PLMN with a signal quality greater than the threshold value, the access layer executes the following step 430.

[0076] Step 430: If the access layer fails to search for a PLMN with a signal quality greater than the threshold, the access layer sends first information to the upper layer. The first information includes a second PLMN list. The second PLMN list includes an identifier of at least one PLMN with a signal quality less than the threshold.

[0077] In addition, if the access layer of the terminal device does not search for any PLMN, the access layer may send indication information indicating that the PLMN was not searched to the higher layer.

[0078] After receiving the first information sent by the access layer, the upper layer executes the following step 440 or 450 according to the first information to select a PLMN.

[0079] Step 440: If the first information includes a first PLMN list and a PLMN meeting the conditions exists in the first PLMN list, the higher layer selects a target PLMN from the first PLMN list.

[0080] Step 450: If the first information does not include the first PLMN list or there is no PLMN meeting the conditions in the first PLMN list, the higher layer selects a target PLMN from the second PLMN list.

[0081] In some embodiments, the PLMN that meets the conditions includes at least one of the following: HPLMN, EHPLMN.

[0082] In some embodiments, if the first information includes a first PLMN list and a PLMN that meets the conditions exists in the first PLMN list, the upper layer selects the PLMN with the highest priority from the PLMNs that meet the conditions in the first PLMN list as the target PLMN. The method for determining the priority of the PLMN may adopt the method described above or other methods, and this application is not limited thereto.

[0083] In some embodiments, if the first information does not include the first PLMN list or there is no PLMN meeting the conditions in the first PLMN list, the higher layer selects a PLMN meeting the conditions with the best signal quality in the second PLMN list as the target PLMN.

[0084] In some embodiments, the second PLMN list further includes signal quality corresponding to each PLMN included in the second PLMN list.

[0085] Exemplarily, the PLMNs searched by the access layer include PLMN1, PLMN2, PLMN3, PLMN4 and PLMN5.

[0086] For example, if the signal quality of PLMN1, PLMN2, and PLMN3 found by the access layer is greater than a threshold, and the signal quality of PLMN4 and PLMN5 is less than a threshold, the first information includes a first PLMN list and a second PLMN list. The first PLMN list contains the IDs of PLMN1, PLMN2, and PLMN3, and the second PLMN list contains the IDs of PLMN4 and PLMN5 and their corresponding signal qualities. If a HPLMN and / or EHPLMN exists among PLMN1, PLMN2, and PLMN3, the higher layer selects the PLMN with the highest priority among the HPLMN and / or EHPLMN as the target PLMN. If none of PLMN1, PLMN2, and PLMN3 is an HPLMN or EHPLMN, the higher layer selects the PLMN with the highest signal quality among the HPLMN or EHPLMN among PLMN4 and PLMN5 as the target PLMN.

[0087] For example, if the signal qualities of PLMN1, PLMN2, PLMN3, PLMN4, and PLMN5 searched by the access layer are all less than a threshold, the first information only includes the second PLMN list (excluding the first PLMN list), and the second PLMN list includes the IDs of PLMN1, PLMN2, PLMN3, PLMN4, and PLMN5 and the signal qualities corresponding to these PLMNs. The upper layer selects the PLMN with the highest signal quality from the HPLMN and EHPLMN included in the second PLMN list as the target PLMN.

[0088] In addition, after selecting the target PLMN, the upper layer may initiate a request to the target PLMN to request access to the target PLMN.

[0089] In some embodiments, if a first PLMN list exists, the access layer sends a first message including only the first PLMN list to a higher layer, and the higher layer selects a PLMN that meets the conditions in the first PLMN list. If no PLMN that meets the conditions exists in the first PLMN list, the higher layer sends a second request to the access layer, and the access layer sends a second message including a second PLMN list to the higher layer. If the first PLMN list does not exist, the access layer sends the first message including only the second PLMN list to the higher layer. If the access layer does not search for any PLMN, the access layer may send an indication to the higher layer that no PLMN was found. This helps to reduce the amount of data required for the first message.

[0090] In some embodiments, if there is a first PLMN list and there is a PLMN that meets the conditions in the first PLMN list, the access layer sends a first message to the upper layer, and the first message only includes the first PLMN list; if there is no PLMN that meets the conditions in the first PLMN list, and there is a PLMN that meets the conditions in the second PLMN list, the access layer sends a first message to the upper layer that only includes the second PLMN list; if the access layer does not search for any PLMN, or the access layer does not search for any PLMN that meets the conditions, the access layer may send an indication message to the upper layer that the PLMN was not searched.

[0091] It should be noted that in the embodiment of the present application, before the access layer sends the first information to the higher layer in step 420 and / or step 430, the higher layer sends the first request to the access layer in step 410; and before the access layer sends the first information to the higher layer in step 420 and / or step 430, the access layer also searches for available PLMNs. Step 410, in which the higher layer sends the first request to the access layer, may be performed before the access layer searches for available PLMNs (for example, the access layer searches for available PLMNs after receiving the first request sent by the higher layer), or after the access layer searches for available PLMNs; this application does not limit this.

[0092] The technical solution provided by this embodiment is that, when the received first PLMN list contains PLMNs that meet the requirements, the upper layer selects the PLMN with the highest priority from the PLMNs that meet the requirements in the first PLMN list as the target PLMN. Specifically, when the signal quality of all selectable PLMNs exceeds a threshold, the upper layer selects the PLMN based on priority, thereby enabling the upper layer to select a PLMN with good signal quality and a high priority. If the received first LMN list does not contain PLMNs that meet the requirements, or if the first PLMN list is not received, the upper layer selects the PLMN with the best signal quality from the PLMNs that meet the requirements in the second PLMN list as the target PLMN. Specifically, when the signal quality of all selectable PLMNs falls below a threshold, the upper layer selects the PLMN based on signal quality, ensuring the signal quality of the PLMN and improving communication quality.

[0093] Please refer to Figure 5, which shows a flow chart of a network selection method provided by another embodiment of the present application. The method can be executed by a terminal device, which includes an access layer and a high layer. The method may include at least one of the following steps 510 to 580:

[0094] Step 510: The upper layer sends a second request to the access layer, where the second request is used to request the access layer to report a PLMN whose signal quality is greater than a threshold.

[0095] In some embodiments, the upper layer indicates to the access layer a threshold value provided by the operator. In addition, the indication information for indicating the threshold value can be carried in the above-mentioned second request or sent separately from the second request, which is not limited in this application.

[0096] Step 520: When the access layer searches for a PLMN with a signal quality greater than a threshold, the access layer sends first information to a higher layer. The first information includes a first PLMN list. The first PLMN list includes an identifier of at least one PLMN with a signal quality greater than a threshold.

[0097] The terminal device can search for PLMNs around it through the access layer, measure the signal quality of each searched PLMN, and, based on the threshold, screen out PLMNs with signal quality greater than the threshold from the searched PLMNs. The access layer constructs a first PLMN list based on the relationship between the signal quality of each searched PLMN and the threshold. The first PLMN list includes an identifier of at least one PLMN with signal quality greater than the threshold.

[0098] Optionally, the access layer further constructs a second PLMN list based on the relationship between the signal quality of each searched PLMN and the threshold value, where the second PLMN list includes an identifier of at least one PLMN whose signal quality is less than the threshold value.

[0099] Optionally, the access layer further constructs a third PLMN list based on each searched PLMN, where the third PLMN list includes identifiers of all PLMNs searched by the access layer.

[0100] Step 530: If the access layer fails to search for a PLMN with a signal quality greater than the threshold, the access layer sends first information to a higher layer, where the first information indicates that no PLMN with a signal quality greater than the threshold is found.

[0101] Step 540: If the first information includes a first PLMN list and there is a PLMN meeting the conditions in the first PLMN list, the higher layer selects a target PLMN from the first PLMN list.

[0102] In some embodiments, the PLMN that meets the conditions includes at least one of the following: HPLMN, EHPLMN.

[0103] In some embodiments, if the first information includes a first PLMN list and a PLMN that meets the conditions exists in the first PLMN list, the upper layer selects the PLMN with the highest priority from the PLMNs that meet the conditions in the first PLMN list as the target PLMN. The method for determining the priority of the PLMN may adopt the method described above or other methods, and this application is not limited thereto.

[0104] Step 550: If the first information does not include the first PLMN list or there is no PLMN meeting the conditions in the first PLMN list, the upper layer sends a third request to the access layer, where the third request is used to request the access layer to report the PLMN whose signal quality is less than the threshold.

[0105] In step 560, the access layer sends second information to the upper layer, where the second information is used to indicate the PLMNs whose signal quality is less than the threshold value, such as the second information includes a second PLMN list or a third PLMN list; wherein the second PLMN list includes the identifier of at least one PLMN whose signal quality is less than the threshold value, and the third PLMN list includes the identifiers of all PLMNs searched by the access layer.

[0106] In some embodiments, the second information further includes: the signal quality corresponding to each PLMN included in the second PLMN list; or the signal quality corresponding to each PLMN included in the third PLMN list. For example, if the second information includes the second PLMN list, the second information further includes the signal quality corresponding to each PLMN included in the second PLMN list. If the second information includes the third PLMN list, the second information further includes the signal quality corresponding to each PLMN included in the third PLMN list.

[0107] In addition, after receiving the third request from the higher layer, the access layer may directly use the second PLMN list or third PLMN list determined by the previously searched PLMNs (i.e., the second PLMN list or third PLMN list constructed in the introduction to step 520 above) to send the second information containing the second PLMN list or third PLMN list to the higher layer. Alternatively, after receiving the third request from the higher layer, the access layer may again search for the PLMNs surrounding it, generate the second PLMN list or third PLMN list based on the new search results, and then send the second information containing the second PLMN list or third PLMN list to the higher layer.

[0108] Step 570: If the second information includes a second PLMN list, the higher layer selects a target PLMN from the second PLMN list.

[0109] In some embodiments, if the second information includes a second PLMN list, the higher layer selects a PLMN in the second PLMN list that has the best signal quality and meets the conditions as the target PLMN.

[0110] Step 580: If the second information includes a third PLMN list, the higher layer selects a target PLMN from the third PLMN list.

[0111] In some embodiments, if the second information includes a second PLMN list, the higher layer selects a PLMN in the third PLMN list that has the best signal quality and meets the conditions as the target PLMN.

[0112] In addition, if the access layer of the terminal device does not search for any PLMN, the access layer may send indication information indicating that the PLMN was not searched to the higher layer.

[0113] Exemplarily, the PLMNs searched by the access layer include PLMN1, PLMN2, PLMN3, PLMN4 and PLMN5.

[0114] For example, if the signal quality of PLMN1, PLMN2, and PLMN3 found by the access layer is greater than a threshold, and the signal quality of PLMN4 and PLMN5 is less than a threshold, then the first PLMN list includes the IDs of PLMN1, PLMN2, and PLMN3; the second PLMN list includes the IDs of PLMN4 and PLMN5 and their corresponding signal qualities; and the third PLMN list includes the IDs of PLMN1, PLMN2, PLMN3, PLMN4, and PLMN5 and their corresponding signal qualities. If PLMN1, PLMN2, and PLMN3 include an HPLMN or EHPLMN, the upper layer selects the PLMN with the highest priority among the HPLMN and / or EHPLMN as the target PLMN. If none of PLMN1, PLMN2, and PLMN3 is an HPLMN or EHPLMN, the upper layer sends a third request to the access layer. After receiving the third request from the upper layer, the access layer sends a second message to the upper layer. The second message includes the second PLMN list or the third PLMN list. If the second information includes a second PLMN list, the higher layer selects the PLMN with the best signal quality from the HPLMN and / or EHPLMN in the second PLMN list as the target PLMN. If the second information includes a third PLMN list, the higher layer selects the PLMN with the best signal quality from the HPLMN and / or EHPLMN in the third PLMN list as the target PLMN.

[0115] In some embodiments, if there is a first PLMN list and there is a PLMN that meets the conditions in the first PLMN list, the access layer sends first information to the upper layer, and the first information only includes the first PLMN list; if there is no PLMN that meets the conditions in the first PLMN list, and there is a PLMN that meets the conditions in the second PLMN list, the access layer sends an indication message to the upper layer that no PLMN with a signal quality greater than a threshold value is searched, and the access layer sends a second information to the upper layer that only includes the second PLMN list or the third PLMN list; if the access layer does not search for any PLMN, or the access layer does not search for any PLMN that meets the conditions, the access layer may send an indication message to the upper layer that no PLMN is searched.

[0116] It should be noted that in this embodiment of the present application, before the access layer sends the first information to the higher layer in step 520, the higher layer sends the first request to the access layer in step 510; and before the access layer sends the first information to the higher layer in step 520, the access layer also searches for available PLMNs. Step 510, in which the higher layer sends the first request to the access layer, may be performed before the access layer searches for available PLMNs (for example, the access layer searches for available PLMNs after receiving the first request from the higher layer), or after the access layer searches for available PLMNs; this application does not limit this.

[0117] This embodiment provides a technical solution in which, when the access layer searches for a PLMN with signal quality greater than a threshold, the access layer only sends first information containing a first PLMN list to the upper layer. The upper layer then selects the PLMN with the highest priority from the qualifying PLMNs in the first PLMN list as the target PLMN. This ensures that the upper layer selects a PLMN with good signal quality and high priority, while reducing the amount of data the upper layer must receive and alleviating its data processing pressure. If no qualifying PLMNs exist in the first PLMN list, or if the access layer fails to search for a PLMN with signal quality greater than the threshold, the access layer sends second information to the PLMN. The second information includes a second PLMN list or a third PLMN list. The second PLMN list contains at least one PLMN with signal quality less than the threshold. The third PLMN list contains all PLMNs searched by the access layer. The upper layer selects the PLMN with the highest signal quality from the qualifying PLMNs in the second or third PLMN list as the target PLMN, ensuring the signal quality of the target PLMN and improving communication quality.

[0118] Please refer to Figure 6, which shows a flow chart of a network selection method provided by another embodiment of the present application. The method can be executed by a terminal device, which includes an access layer and a high layer. The method may include at least one of the following steps 610 to 630:

[0119] Step 610: The access layer searches for available PLMNs according to a search cycle, or the access layer searches for available PLMNs according to a second triggering event.

[0120] In some embodiments, the search period is indicated by a higher layer to the access layer, or is agreed upon by a protocol, or is a period of background scanning, or is configured in the USIM of the terminal device.

[0121] In some embodiments, the second trigger event includes at least one of the following: the terminal device reselects a cell, the terminal device loses network coverage, the terminal device is powered on, the terminal device exits power saving mode, or before or when the terminal device's discontinuous reception paging transmission window arrives.

[0122] In some embodiments, step 610 is also applicable to the embodiments shown in FIG. 4 and FIG. 5 .

[0123] In step 620, the access layer sends first information to the upper layer according to a reporting period, or the access layer sends first information to the upper layer according to a first trigger event; wherein the first information includes a first PLMN list and a second PLMN list, or the first information includes a third PLMN list, the first PLMN list includes an identifier of at least one PLMN whose signal quality is greater than a threshold value, the second PLMN list includes an identifier of at least one PLMN whose signal quality is less than the threshold value, and the third PLMN list includes identifiers of all PLMNs searched by the access layer.

[0124] In some embodiments, the reporting period is indicated by the higher layer to the access layer, or is agreed upon by the protocol, or is the period of background scanning, or is configured in the USIM of the terminal device.

[0125] In some embodiments, the first trigger event includes at least one of the following: a change in the first PLMN list, a cell reselection by the terminal device, or a loss of network coverage by the terminal device.

[0126] In step 630, if the first information includes a first PLMN list and a PLMN that meets the conditions exists in the first PLMN list, the higher layer selects the target PLMN from the first PLMN list; or, if the first information does not include the first PLMN list or a PLMN that meets the conditions does not exist in the first PLMN list, and the first information includes a second PLMN list, the higher layer selects the target PLMN from the second PLMN list; or, if the first information includes a third PLMN list, the higher layer selects the target PLMN from the third PLMN list.

[0127] In some embodiments, the PLMN that meets the conditions includes at least one of the following: HPLMN, EHPLMN.

[0128] In some embodiments, if the first information includes a first PLMN list and a PLMN that meets the conditions exists in the first PLMN list, the upper layer selects the PLMN with the highest priority from the PLMNs that meet the conditions in the first PLMN list as the target PLMN. The method for determining the priority of the PLMN may adopt the method described above or other methods, and this application is not limited thereto.

[0129] In some embodiments, if the first information does not include the first PLMN list or there is no PLMN meeting the conditions in the first PLMN list, the higher layer selects a PLMN meeting the conditions with the best signal quality in the second PLMN list as the target PLMN.

[0130] In some embodiments, if the first information does not include the first PLMN list or there is no PLMN meeting the conditions in the first PLMN list, the higher layer selects a PLMN meeting the conditions with the best signal quality in the third PLMN list as the target PLMN.

[0131] Exemplarily, the PLMNs searched by the access layer include PLMN1, PLMN2, PLMN3, PLMN4 and PLMN5.

[0132] For example, if the signal quality of PLMN1, PLMN2, and PLMN3 found by the access layer search is greater than a threshold, and the signal quality of PLMN4 and PLMN5 is less than a threshold, then the first PLMN list includes the IDs of PLMN1, PLMN2, and PLMN3, the second PLMN list includes the IDs of PLMN4 and PLMN5 and the corresponding signal quality of these five PLMNs, and the third PLMN list includes the IDs of PLMN1, PLMN2, PLMN3, PLMN4, and PLMN5 and the corresponding signal quality of these five PLMNs.

[0133] Exemplarily, the access layer searches for available PLMNs according to a search period indicated by the higher layer (or agreed upon by the protocol, or a background scan period, or configured in the USIM of the terminal device), and then sends first information to the higher layer according to a reporting period indicated by the higher layer (or agreed upon by the protocol, or a background scan period, or configured in the USIM of the terminal device). The first information includes a first PLMN list and a second PLMN list, or the first information includes a third PLMN list. When the first information includes the first PLMN list and the second PLMN list, if PLMN1, PLMN2, and PLMN3 include an HPLMN or an EHPLMN, the higher layer selects the PLMN with the highest priority from the HPLMN and / or EHPLMN included in the first PLMN list as the target PLMN. If none of PLMN1, PLMN2, and PLMN3 is an HPLMN or EHPLMN, the higher layer selects the PLMN with the best signal quality from the HPLMN and / or EHPLMN included in the second PLMN list as the target PLMN. When the first information includes the third PLMN list, the higher layer selects a PLMN with the best signal quality from the HPLMN and / or EHPLMN included in the third PLMN list as the target PLMN.

[0134] Exemplarily, the access layer searches for available PLMNs when a terminal device undergoes cell reselection (or the terminal device loses network coverage, or the terminal device is turned on, or the terminal device exits power saving mode, or before or when the paging transmission window for discontinuous reception of the terminal device arrives), and sends a first message to the upper layer when the first PLMN list changes (or the terminal device undergoes cell reselection, or the terminal device loses network coverage). The first information includes the first PLMN list and the second PLMN list, or the first information includes the third PLMN list. When the first information includes the first PLMN list and the second PLMN list, if PLMN1, PLMN2, and PLMN3 include HPLMN or EHPLMN, the upper layer selects the PLMN with the highest priority from the HPLMN and / or EHPLMN included in the first PLMN list as the target PLMN. If none of PLMN1, PLMN2, and PLMN3 is HPLMN or EHPLMN, the upper layer selects the PLMN with the best signal quality from the HPLMN and / or EHPLMN included in the second PLMN list as the target PLMN. When the first information includes the third PLMN list, the higher layer selects a PLMN with the best signal quality from the HPLMN and / or EHPLMN included in the third PLMN list as the target PLMN.

[0135] In the technical solution provided by this embodiment, the access layer searches for the PLMN according to the search cycle or the second trigger event, and reports the first information to the upper layer according to the reporting cycle or the first trigger event, thereby realizing periodic updating of the PLMN information in the upper layer and being able to periodically reselect the PLMN. When the first trigger event and the second trigger event occur, the PLMN can also be reselected in time, so that the signal quality of the PLMN is dynamically guaranteed, thereby improving the user communication quality.

[0136] The following are device embodiments of the present application, which can be used to implement the method embodiments of the present application. For details not disclosed in the device embodiments of the present application, please refer to the method embodiments of the present application.

[0137] Please refer to Figure 7, which shows a block diagram of a network selection device provided by one embodiment of the present application. This device has the functionality to implement the aforementioned method examples. This functionality can be implemented in hardware or by hardware executing corresponding software. This device can be the terminal device described above, or it can be provided within a terminal device; the terminal device includes an access layer and a higher layer. As shown in Figure 7, the device 700 includes a first sending module 710.

[0138] The first sending module 710 is configured to send first information to the higher layer through the access layer, where the first information is used to indicate a PLMN whose signal quality is greater than a threshold.

[0139] In some embodiments, when the access layer searches for a PLMN whose signal quality is greater than a threshold value, the first information includes: a first PLMN list and a second PLMN list; the first PLMN list includes an identifier of at least one PLMN whose signal quality is greater than the threshold value; the second PLMN list includes an identifier of at least one PLMN whose signal quality is less than the threshold value.

[0140] In some embodiments, when the access layer fails to search for the PLMN with a signal quality greater than a threshold, the first information includes the second PLMN list.

[0141] In some embodiments, referring to FIG. 8 , the apparatus 700 further includes: a first selection module 720 or a second selection module 730 .

[0142] The first selection module 720 is configured to select a target PLMN from the first PLMN list through the higher layer if the first information includes the first PLMN list and there is a PLMN meeting the conditions in the first PLMN list.

[0143] The second selection module 730 is configured to select a target PLMN from the second PLMN list through the higher layer if the first information does not include the first PLMN list or there is no PLMN meeting the conditions in the first PLMN list.

[0144] In some embodiments, referring to FIG. 8 , the apparatus 700 further includes: a first request module 740 configured to send a first request to the access layer through the higher layer, wherein the first request is configured to request the access layer to report an available PLMN.

[0145] In some embodiments, when the access layer searches for the PLMN whose signal quality is greater than the threshold, the first information includes: a first PLMN list; the first PLMN list includes an identifier of at least one PLMN whose signal quality is greater than the threshold.

[0146] In some embodiments, when the access layer fails to search for the PLMN whose signal quality is greater than the threshold, the first information is used to indicate that the PLMN whose signal quality is greater than the threshold is not searched.

[0147] In some embodiments, referring to FIG8 , the apparatus 700 further includes: a second request module 750 for sending a second request to the access layer through the higher layer, wherein the second request is for requesting the access layer to report the PLMN whose signal quality is greater than a threshold value.

[0148] In some embodiments, referring to FIG. 8 , the apparatus 700 further includes: a first selection module 720 or a third request module 760 .

[0149] The first selection module 720 is configured to select a target PLMN from the first PLMN list through the higher layer if the first information includes the first PLMN list and there is a PLMN meeting the conditions in the first PLMN list.

[0150] The third request module 760 is configured to send a third request to the access layer through the higher layer if the first information does not include the first PLMN list or there is no PLMN that meets the conditions in the first PLMN list. The third request is configured to request the access layer to report the PLMN whose signal quality is less than a threshold value.

[0151] In some embodiments, referring to FIG8 , the apparatus further includes: a second sending module 770 configured to send second information to the higher layer through the access layer, where the second information is used to indicate the PLMN whose signal quality is less than a threshold.

[0152] In some embodiments, the second information includes: a second PLMN list or a third PLMN list; wherein the second PLMN list includes the identifier of at least one PLMN whose signal quality is less than the threshold value, and the third PLMN list includes the identifiers of all PLMNs searched by the access layer.

[0153] In some embodiments, referring to FIG. 8 , the apparatus 700 further includes: a second selection module 730 or a third selection module 780 .

[0154] The second selection module 730 is configured to select a target PLMN from the second PLMN list through the higher layer if the second information includes the second PLMN list.

[0155] The third selection module 780 is configured to select a target PLMN from the third PLMN list through the higher layer if the second information includes the third PLMN list.

[0156] In some embodiments, the first information includes a first PLMN list and a second PLMN list, or the first information includes a third PLMN list;

[0157] The first PLMN list includes an identifier of at least one PLMN whose signal quality is greater than the threshold;

[0158] The second PLMN list includes an identifier of at least one PLMN whose signal quality is less than the threshold;

[0159] The third PLMN list includes identifiers of all PLMNs searched by the access layer.

[0160] In some embodiments, the first sending module 710 is configured to send the first information to the higher layer through the access layer according to a reporting period;

[0161] Alternatively, the first sending module 710 is configured to send the first information to the higher layer through the access layer according to a first triggering event.

[0162] In some embodiments, the reporting period is indicated by the higher layer to the access layer, or is agreed upon by the protocol, or is a period of background scanning, or is configured in the USIM of the terminal device.

[0163] In some embodiments, the first triggering event includes at least one of the following:

[0164] The first PLMN list changes;

[0165] The terminal device undergoes cell reselection;

[0166] The terminal device loses network coverage.

[0167] In some embodiments, the apparatus 700 further includes a search module (not shown in the figure) configured to:

[0168] Searching for available PLMNs through the access layer according to a search period;

[0169] or,

[0170] An available PLMN is searched for according to a second triggering event through the access layer.

[0171] In some embodiments, the search period is indicated by the higher layer to the access layer, or is agreed upon by a protocol, or is a period of background scanning, or is configured in the USIM of the terminal device.

[0172] In some embodiments, the second triggering event includes at least one of the following:

[0173] The terminal device undergoes cell reselection;

[0174] The terminal device loses network coverage;

[0175] Turning on the terminal device;

[0176] The terminal device exits the power saving mode;

[0177] Before or when the paging transmission window of the discontinuous reception of the terminal device arrives.

[0178] In some embodiments, referring to FIG. 8 , the apparatus 700 further includes: a first selection module 720 , or a second selection module 730 , or a third selection module 780 .

[0179] The first selection module 720 is configured to select a target PLMN from the first PLMN list through the higher layer if the first information includes the first PLMN list and there is a PLMN meeting the conditions in the first PLMN list.

[0180] The second selection module 730 is configured to select a target PLMN from the second PLMN list through the higher layer if the first information does not include the first PLMN list or there is no PLMN meeting the conditions in the first PLMN list, and the first information includes the second PLMN list.

[0181] The third selection module 780 is configured to select a target PLMN from the third PLMN list through the higher layer if the first information includes the third PLMN list.

[0182] In some embodiments, the first selection module 720 is configured to select, through the higher layer, a PLMN with the highest priority from the PLMNs meeting the conditions in the first PLMN list as the target PLMN, where the PLMN meeting the conditions includes at least one of the following: HPLMN and EHPLMN.

[0183] In some embodiments, the second selection module 730 is configured to select, through the higher layer, a PLMN with the best signal quality and meeting the conditions in the second PLMN list as the target PLMN, where the PLMN meeting the conditions includes at least one of the following: HPLMN and EHPLMN.

[0184] In some embodiments, the third selection module 780 is configured to select, through the higher layer, a PLMN with the best signal quality and meeting the conditions in the third PLMN list as the target PLMN, where the PLMN meeting the conditions includes at least one of the following: HPLMN and EHPLMN.

[0185] In some embodiments, the second PLMN list further includes: signal quality corresponding to each PLMN included in the second PLMN list.

[0186] In some embodiments, the third PLMN list further includes: signal quality corresponding to each PLMN included in the third PLMN list.

[0187] In some embodiments, the apparatus 700 further includes: a threshold value indicating module (not shown in the figure), configured to indicate the threshold value provided by the operator to the access layer through the higher layer.

[0188] In some embodiments, the threshold value is configured in the USIM of the terminal device.

[0189] In some embodiments, the upper layer is a non-access layer.

[0190] It should be noted that, when the device provided in the above embodiment realizes its function, it only uses the division of the above-mentioned functional modules as an example. In actual application, the above-mentioned functions can be assigned to different functional modules according to actual needs, that is, the content structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0191] Regarding the apparatus in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0192] Please refer to FIG9 , which shows a schematic diagram of the structure of a terminal device provided by an embodiment of the present application. The terminal device 900 may include: a processor 901 , a transceiver 902 , and a memory 903 .

[0193] The processor 901 includes one or more processing cores. The processor 901 executes various functional applications and information processing by running software programs and modules.

[0194] The transceiver 902 may include a receiver and a transmitter. For example, the receiver and the transmitter may be implemented as the same wireless communication component, which may include a wireless communication chip and a radio frequency antenna.

[0195] The memory 903 may be connected to the processor 901 and the transceiver 902 .

[0196] The memory 903 may be used to store a computer program executed by the processor, and the processor 901 is used to execute the computer program to implement the various steps performed by the terminal device in the above method embodiment.

[0197] In addition, the memory 903 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, and the volatile or non-volatile storage device includes but is not limited to: a magnetic disk or an optical disk, an electrically erasable programmable read-only memory, an erasable programmable read-only memory, a static access memory, a read-only memory, a magnetic memory, a flash memory, and a programmable read-only memory.

[0198] In some embodiments, the terminal device includes an access layer and a higher layer, and the processor 901 is configured to send first information to the higher layer through the access layer, where the first information is used to indicate a PLMN whose signal quality is greater than a threshold.

[0199] For details not described in detail in this embodiment, please refer to the above embodiments and will not be described in detail here.

[0200] An embodiment of the present application further provides a computer-readable storage medium, wherein the storage medium stores a computer program, and the computer program is configured to be executed by a processor of a terminal device to implement the above-mentioned network selection method.

[0201] Optionally, the computer-readable storage medium may include: ROM (Read-Only Memory), RAM (Random-Access Memory), SSD (Solid State Drives), or an optical disk, etc. Among them, the random access memory may include ReRAM (Resistance Random Access Memory) and DRAM (Dynamic Random Access Memory).

[0202] An embodiment of the present application further provides a chip, which includes a programmable logic circuit and / or program instructions. When the chip runs on a terminal device, it is used to implement the above-mentioned network selection method.

[0203] An embodiment of the present application also provides a computer program product, which includes computer instructions stored in a computer-readable storage medium. The processor of the terminal device reads and executes the computer instructions from the computer-readable storage medium to implement the above-mentioned network selection method.

[0204] It should be understood that the "indication" mentioned in the embodiments of this application can be a direct indication, an indirect indication, or an indication of an association. For example, "A indicates B" can mean that A directly indicates B, for example, B can be obtained through A; it can also mean that A indirectly indicates B, for example, A indicates C, and B can be obtained through C; it can also mean that there is an association between A and B.

[0205] In the description of the embodiments of the present application, the term "corresponding" may indicate a direct or indirect correspondence between the two, or an association relationship between the two, or a relationship between indication and being indicated, configuration and being configured, etc.

[0206] In some embodiments of the present application, "predefined" may be implemented by pre-storing corresponding codes, tables, or other methods that can be used to indicate relevant information in a device (e.g., including a terminal device and a network device), and the present application does not limit the specific implementation method. For example, predefined may refer to information defined in a protocol.

[0207] In some embodiments of the present application, the "protocol" may refer to a standard protocol in the field of communications, for example, it may include an LTE protocol, a NR protocol, and related protocols used in future communication systems, and this application does not limit this.

[0208] In this document, "plurality" refers to two or more. "And / or" describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. The character " / " generally indicates an "or" relationship between the associated objects.

[0209] In addition, the step numbers described in this document only illustrate a possible execution order between the steps. In some other embodiments, the above steps may not be executed in the order of the numbers, such as two steps with different numbers are executed at the same time, or two steps with different numbers are executed in the opposite order of the diagram. The embodiments of the present application are not limited to this.

[0210] In addition, the embodiments provided herein may be arbitrarily combined to form new embodiments, which are all within the scope of protection of this application.

[0211] Those skilled in the art will appreciate that in one or more of the above examples, the functions described in the embodiments of the present application can be implemented using hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any media that facilitates the transmission of computer programs from one place to another. The storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0212] The above description is merely an exemplary embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A network selection method, characterized in that: The method is performed by a terminal device, the terminal device includes an access layer and a high layer, and the method includes: The access layer sends first information to the higher layer, where the first information is used to indicate a public land mobile network PLMN whose signal quality is greater than a threshold.

2. The method according to claim 1, characterized in that In the case where the access layer searches for the PLMN whose signal quality is greater than a threshold, the first information includes: a first PLMN list and a second PLMN list; The first PLMN list includes an identifier of at least one PLMN whose signal quality is greater than the threshold; The second PLMN list includes an identifier of at least one PLMN whose signal quality is less than the threshold.

3. The method according to claim 2, characterized in that In a case where the access layer fails to search for the PLMN with a signal quality greater than a threshold, the first information includes the second PLMN list.

4. The method according to claim 2 or 3, characterized in that After the access layer sends the first information to the higher layer, the method further includes: If the first information includes the first PLMN list and a PLMN meeting the conditions exists in the first PLMN list, the higher layer selects a target PLMN from the first PLMN list; or, If the first information does not include the first PLMN list or there is no PLMN meeting the conditions in the first PLMN list, the higher layer selects a target PLMN from the second PLMN list.

5. The method according to any one of claims 2 to 4, characterized in that Before the access layer sends the first information to the higher layer, the method further includes: The higher layer sends a first request to the access layer, where the first request is used to request the access layer to report an available PLMN.

6. The method according to claim 1, wherein In the case where the access layer searches for the PLMN whose signal quality is greater than a threshold, the first information includes: a first PLMN list; The first PLMN list includes an identifier of at least one PLMN whose signal quality is greater than the threshold.

7. The method according to claim 6, characterized in that In a case where the access layer fails to search for the PLMN whose signal quality is greater than the threshold, the first information is used to indicate that the PLMN whose signal quality is greater than the threshold is not searched for.

8. The method according to claim 6 or 7, characterized in that Before the access layer sends the first information to the higher layer, the method further includes: The higher layer sends a second request to the access layer, where the second request is used to request the access layer to report the PLMN whose signal quality is greater than a threshold.

9. The method according to any one of claims 6 to 8, characterized in that After the access layer sends the first information to the higher layer, the method further includes: If the first information includes the first PLMN list and a PLMN meeting the conditions exists in the first PLMN list, the higher layer selects a target PLMN from the first PLMN list; or, If the first information does not include the first PLMN list or there is no PLMN that meets the conditions in the first PLMN list, the upper layer sends a third request to the access layer, where the third request is used to request the access layer to report the PLMN whose signal quality is less than the threshold value.

10. The method according to claim 9, characterized in that After the upper layer sends the third request to the access layer, the method further includes: The access layer sends second information to the higher layer, where the second information is used to indicate the PLMN whose signal quality is less than a threshold.

11. The method according to claim 10, characterized in that The second information includes: a second PLMN list, the second PLMN list including an identifier of at least one PLMN whose signal quality is less than the threshold; or, A third PLMN list, wherein the third PLMN list includes identifiers of all PLMNs searched by the access layer.

12. The method according to claim 11, characterized in that After the access layer sends the second information to the higher layer, the method further includes: If the second information includes the second PLMN list, the higher layer selects a target PLMN from the second PLMN list; or, If the second information includes the third PLMN list, the higher layer selects a target PLMN from the third PLMN list.

13. The method according to claim 1, wherein The first information includes a first PLMN list and a second PLMN list, or the first information includes a third PLMN list; The first PLMN list includes an identifier of at least one PLMN whose signal quality is greater than the threshold; The second PLMN list includes an identifier of at least one PLMN whose signal quality is less than the threshold; The third PLMN list includes identifiers of all PLMNs searched by the access layer.

14. The method according to claim 13, characterized in that The access layer sends first information to the higher layer, including: The access layer sends the first information to the higher layer according to a reporting period; or, The access layer sends the first information to the higher layer according to a first triggering event.

15. The method according to claim 14, characterized in that The reporting period is indicated by the higher layer to the access layer, or is agreed upon by the protocol, or is a period of background scanning, or is configured in the universal subscriber identity module USIM of the terminal device.

16. The method according to claim 14 or 15, characterized in that The first triggering event includes at least one of the following: The first PLMN list changes; The terminal device undergoes cell reselection; The terminal device loses network coverage.

17. The method according to any one of claims 13 to 16, characterized in that The method further comprises: The access layer searches for available PLMNs according to a search period; or, The access layer searches for available PLMNs according to the second triggering event.

18. The method according to claim 17, characterized in that The search period is indicated by the higher layer to the access layer, or is agreed upon by the protocol, or is a period of background scanning, or is configured in the USIM of the terminal device.

19. The method according to claim 17 or 18, characterized in that The second triggering event includes at least one of the following: The terminal device undergoes cell reselection; The terminal device loses network coverage; Turning on the terminal device; The terminal device exits the power saving mode; Before or when the paging transmission window of the discontinuous reception of the terminal device arrives.

20. The method according to any one of claims 13 to 19, characterized in that After the access layer sends the first information to the higher layer, the method further includes: If the first information includes the first PLMN list and a PLMN meeting the conditions exists in the first PLMN list, the higher layer selects a target PLMN from the first PLMN list; or, If the first information does not include the first PLMN list or the first PLMN list does not contain a PLMN that meets the conditions, and the first information includes the second PLMN list, the higher layer selects a target PLMN from the second PLMN list; or, If the first information includes the third PLMN list, the higher layer selects a target PLMN from the third PLMN list.

21. The method according to any one of claims 4, 9 and 20, characterized in that The higher layer selects a target PLMN from the first PLMN list, including: The upper layer selects a PLMN with the highest priority as the target PLMN from the PLMNs that meet the conditions in the first PLMN list, where the PLMNs that meet the conditions include at least one of the following: a home public land mobile network HPLMN and an equivalent home public land mobile network EHPLMN.

22. The method according to any one of claims 4, 12 and 20, characterized in that The higher layer selects a target PLMN from the second PLMN list, including: The higher layer selects a PLMN with the best signal quality and meeting the conditions in the second PLMN list as the target PLMN, and the PLMN meeting the conditions includes at least one of the following: HPLMN and EHPLMN.

23. The method according to claim 12 or 20, characterized in that The higher layer selects a target PLMN from the third PLMN list, including: The higher layer selects a PLMN with the best signal quality and meeting the conditions in the third PLMN list as the target PLMN, and the PLMN meeting the conditions includes at least one of the following: HPLMN and EHPLMN.

24. The method according to any one of claims 2 to 5 and 11 to 20, characterized in that The second PLMN list further includes: signal quality corresponding to each PLMN included in the second PLMN list.

25. The method according to any one of claims 11 to 20, characterized in that The third PLMN list further includes: signal quality corresponding to each PLMN included in the third PLMN list.

26. The method according to any one of claims 1 to 25, characterized in that The method further comprises: The higher layer indicates to the access layer the threshold value provided by the operator.

27. The method according to any one of claims 1 to 26, characterized in that The threshold value is configured in the USIM of the terminal device.

28. The method according to any one of claims 1 to 27, characterized in that The high layer is the non-access layer.

29. A network selection device, characterized in that: The device is provided in a terminal device, the terminal device includes an access layer and a high layer, and the device includes: The first sending module is configured to send first information to the higher layer through the access layer, where the first information is used to indicate a public land mobile network PLMN whose signal quality is greater than a threshold.

30. The device according to claim 29, characterized in that In the case where the access layer searches for the PLMN whose signal quality is greater than a threshold, the first information includes: a first PLMN list and a second PLMN list; The first PLMN list includes an identifier of at least one PLMN whose signal quality is greater than the threshold; The second PLMN list includes an identifier of at least one PLMN whose signal quality is less than the threshold.

31. The device according to claim 29, characterized in that In a case where the access layer fails to search for the PLMN with a signal quality greater than a threshold, the first information includes the second PLMN list.

32. The device according to claim 30 or 31, characterized in that The device further comprises: a first selection module configured to select a target PLMN from the first PLMN list through the higher layer if the first information includes the first PLMN list and a PLMN meeting a condition exists in the first PLMN list; or, The second selection module is configured to select a target PLMN from the second PLMN list through the higher layer if the first information does not include the first PLMN list or there is no PLMN meeting the conditions in the first PLMN list.

33. The device according to any one of claims 30 to 32, characterized in that The device further comprises: The first request module is configured to send a first request to the access layer through the higher layer, where the first request is used to request the access layer to report an available PLMN.

34. The device according to claim 29, characterized in that In the case where the access layer searches for the PLMN whose signal quality is greater than a threshold, the first information includes: a first PLMN list; The first PLMN list includes an identifier of at least one PLMN whose signal quality is greater than the threshold.

35. The device according to claim 34, characterized in that In a case where the access layer fails to search for the PLMN whose signal quality is greater than the threshold, the first information is used to indicate that the PLMN whose signal quality is greater than the threshold is not searched for.

36. The device according to claim 34 or 35, characterized in that The device further comprises: The second request module is configured to send a second request to the access layer through the higher layer, where the second request is configured to request the access layer to report the PLMN whose signal quality is greater than a threshold.

37. The device according to any one of claims 34 to 36, characterized in that The device further comprises: a first selection module configured to select a target PLMN from the first PLMN list through the higher layer if the first information includes the first PLMN list and a PLMN meeting a condition exists in the first PLMN list; or, a third request module, configured to send a third request to the access layer through the higher layer if the first information does not include the first PLMN list or no PLMN meeting the conditions exists in the first PLMN list, wherein the third request is used to request the access layer to report the PLMN whose signal quality is less than a threshold value.

38. The device according to claim 37, characterized in that The device further comprises: The second sending module is configured to send second information to the higher layer through the access layer, where the second information is used to indicate the PLMN whose signal quality is less than a threshold.

39. The device according to claim 38, characterized in that The second information includes: a second PLMN list, the second PLMN list including an identifier of at least one PLMN whose signal quality is less than the threshold; or, A third PLMN list, wherein the third PLMN list includes identifiers of all PLMNs searched by the access layer.

40. The device according to claim 39, characterized in that The device further comprises: a second selection module, configured to select a target PLMN from the second PLMN list through the higher layer if the second information includes the second PLMN list; or, A third selection module is configured to select a target PLMN from the third PLMN list through the higher layer if the second information includes the third PLMN list.

41. The device according to claim 29, characterized in that The first information includes a first PLMN list and a second PLMN list, or the first information includes a third PLMN list; The first PLMN list includes an identifier of at least one PLMN whose signal quality is greater than the threshold; The second PLMN list includes an identifier of at least one PLMN whose signal quality is less than the threshold; The third PLMN list includes identifiers of all PLMNs searched by the access layer.

42. The device according to claim 41, characterized in that The first sending module is configured to send the first information to the higher layer through the access layer according to a reporting period; or, The first sending module is configured to send the first information to the higher layer through the access layer according to a first triggering event.

43. The device according to claim 42, characterized in that The reporting period is indicated by the higher layer to the access layer, or is agreed upon by the protocol, or is a period of background scanning, or is configured in the universal subscriber identity module USIM of the terminal device.

44. The device according to claim 42 or 43, characterized in that The first triggering event includes at least one of the following: The first PLMN list changes; The terminal device undergoes cell reselection; The terminal device loses network coverage.

45. The device according to any one of claims 41 to 44, characterized in that The device further includes a search module, configured to: Searching for available PLMNs through the access layer according to a search period; or, An available PLMN is searched for according to a second triggering event through the access layer.

46. ​​The device according to claim 45, characterized in that The search period is indicated by the higher layer to the access layer, or is agreed upon by the protocol, or is a period of background scanning, or is configured in the USIM of the terminal device.

47. The device according to claim 45 or 46, characterized in that The second triggering event includes at least one of the following: The terminal device undergoes cell reselection; The terminal device loses network coverage; Turning on the terminal device; The terminal device exits the power saving mode; Before or when the paging transmission window of the discontinuous reception of the terminal device arrives.

48. The device according to any one of claims 41 to 47, characterized in that The device further comprises: a first selection module configured to select a target PLMN from the first PLMN list through the higher layer if the first information includes the first PLMN list and a PLMN meeting a condition exists in the first PLMN list; or, a second selection module configured to select a target PLMN from the second PLMN list through the higher layer if the first information does not include the first PLMN list or there is no PLMN meeting the conditions in the first PLMN list, and the first information includes the second PLMN list; or, A third selection module is configured to select a target PLMN from the third PLMN list through the higher layer if the first information includes the third PLMN list.

49. The device according to any one of claims 32, 37 and 48, characterized in that The first selection module is configured to select, through the higher layer, a PLMN with the highest priority from the PLMNs that meet the conditions in the first PLMN list as the target PLMN, wherein the PLMNs that meet the conditions include at least one of the following: a home public land mobile network HPLMN and an equivalent home public land mobile network EHPLMN.

50. The device according to any one of claims 32, 40 and 48, characterized in that The second selection module is configured to select a PLMN with the best signal quality and meeting the conditions from the second PLMN list as the target PLMN through the higher layer, where the PLMN meeting the conditions includes at least one of the following: HPLMN and EHPLMN.

51. The device according to claim 40 or 48, characterized in that The device comprises: The third selection module is configured to select, through the higher layer, a PLMN with the best signal quality and meeting the conditions from the third PLMN list as the target PLMN, wherein the PLMN meeting the conditions includes at least one of the following: HPLMN and EHPLMN.

52. The device according to any one of claims 30 to 33 and 39 to 48, characterized in that The second PLMN list further includes: signal quality corresponding to each PLMN included in the second PLMN list.

53. The device according to any one of claims 39 to 48, characterized in that The third PLMN list further includes: signal quality corresponding to each PLMN included in the third PLMN list.

54. The device according to any one of claims 29 to 53, characterized in that The device further comprises: The threshold value indicating module is used to indicate the threshold value provided by the operator to the access layer through the higher layer.

55. The device according to any one of claims 29 to 54, characterized in that The threshold value is configured in the USIM of the terminal device.

56. The device according to any one of claims 29 to 55, characterized in that The high layer is the non-access layer.

57. A terminal device, characterized in that: The terminal device includes a processor and a memory, wherein a computer program is stored in the memory, and the processor executes the computer program to implement the method according to any one of claims 1 to 28.

58. A computer-readable storage medium, characterized in that The storage medium stores a computer program, which is configured to be executed by a processor to implement the method according to any one of claims 1 to 28.

59. A chip, characterized in that: The chip includes a programmable logic circuit and / or program instructions, and when the chip is running, is used to implement the method according to any one of claims 1 to 28.

60. A computer program product, characterized in that The computer program product includes computer instructions, which are stored in a computer-readable storage medium. A processor reads and executes the computer instructions from the computer-readable storage medium to implement the method according to any one of claims 1 to 28.

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