Signal level enhanced network selection

Abstract

Embodiments herein include methods, systems, and apparatus for performing automatic network selection based on operator-controlled signal thresholds. The signal threshold file may be available on a global subscriber identity module (USIM). The signal threshold file may include one or more operator controlled signal thresholds. A user equipment (UE) may perform a signal threshold-based public land mobile network (PLMN) selection procedure using the operator-controlled signal threshold.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Indian Patent Application No. 202211045610 filed on August 10, 2022, which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present application relates generally to wireless communication systems that include an automatic public land mobile network search process based on operator controlled signal thresholds. Background Art

[0004] Wireless mobile communication technologies use various standards and protocols to send data between base stations and wireless communication devices. Wireless communication system standards and protocols may include, for example, the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) (e.g., 4G), 3GPP New Radio (NR) (e.g., 5G), and the IEEE 802.11 standard for wireless local area networks (WLANs) (commonly referred to within industry organizations as WLANs). ).

[0005] As envisioned by 3GPP, different wireless communication system standards and protocols may use various radio access networks (RANs) to communicate between base stations of the RAN (which may also sometimes be referred to as RAN nodes, network nodes, or simply nodes) and wireless communication devices referred to as user equipment (UE). 3GPP RANs may include, for example, Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and / or Next Generation Radio Access Network (NG-RAN).

[0006] Each RAN may use one or more radio access technologies (RATs) to perform communications between base stations and UEs. For example, GERAN implements GSM and / or EDGE RAT, UTRAN implements Universal Mobile Telecommunications System (UMTS) RAT or other 3GPP RAT, E-UTRAN implements LTE RAT (sometimes referred to as LTE), and NG-RAN implements NR RAT (sometimes referred to herein as 5G RAT, 5G NR RAT, or NR). In some deployments, E-UTRAN may also implement NR RAT. In some deployments, NG-RAN may also implement LTE RAT.

[0007] The base stations used by the RAN may correspond to the RAN. An example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (also commonly denoted as an evolved Node B, enhanced Node B, eNodeB, or eNB). An example of an NG-RAN base station is a Next Generation Node B (sometimes also referred to as a g-Node B or gNB).

[0008] The RAN provides its communication services with external entities through its connection to the Core Network (CN). For example, E-UTRAN may utilize the Evolved Packet Core (EPC) while NG-RAN may utilize the 5G Core Network (5GC). BRIEF DESCRIPTION OF THE DRAWINGS

[0009] To easily identify the discussion of any particular element or action, the most significant digit(s) in a reference number refers to the drawing number that first introduces the element.

[0010] Figure 1 A flow chart of a method for enabling a fixed IoT UE to perform automatic PLMN selection during power-up or resume according to some embodiments is shown.

[0011] Figure 2 A flow chart of a method for a fixed IoT UE to perform automatic PLMN selection during periodic scanning while on an RPLMN according to some embodiments is shown.

[0012] Figure 3 An essential document specifying access technologies and associated operator controlled signals according to some embodiments is shown.

[0013] Figure 4 Basic files specifying location, access technology, and associated operator controlled signals are shown according to some embodiments.

[0014] Figure 5 An example architecture of a wireless communication system according to embodiments disclosed herein is shown.

[0015] Figure 6 A system for performing signaling between a wireless device and a network device according to embodiments disclosed herein is shown. DETAILED DESCRIPTION

[0016] Various embodiments are described with reference to user equipment (UE). However, reference to UE is provided for illustrative purposes only. The example embodiments may be used with any electronic component that can establish a connection with a network and is configured with hardware, software and / or firmware for exchanging information and data with the network. Therefore, UE as described herein is used to represent any suitable electronic component.

[0017] Internet of Things (IoT) devices (also referred to herein as IoT UEs) include hardware configured for certain applications that can transmit data over a network. For example, an IoT device may include sensors or actuators to monitor environmental conditions. The use cases for fixed IoT devices are growing exponentially. For example, fixed IoT devices may be used in water meters, may be used to monitor the power grid, or may be used for temperature measurement.

[0018] Sometimes, when deployed outdoors, these devices cannot be easily reached. For example, IoT devices may be placed in remote locations. In addition, sometimes the local coverage conditions in the deployed location may be very challenging. Fixed IoT UEs do not move and are often in permanent roaming situations. The permanent roaming situation may be caused by the IoT UE being deployed in a country different from the country where the Global Subscriber Identity Module (USIM) is provided, or because a global USIM is used for the IoT use case.

[0019] Since IoT UEs are fixed, IoT UEs constantly remain in almost the same coverage conditions. Some of these IoT UEs experience unstable conditions, and since they do not move, these IoT UEs always experience these unstable conditions. One of the sources of unstable conditions is the selection process.

[0020] During the network selection process (e.g., Public Land Mobile Network (PLMN) selection), sometimes the IoT UE selects a visited PLMN (VPLMN) on which the IoT UE can hardly attach and stay. Due to changing radio conditions (e.g., fading, absorption, etc.), establishing a data bearer occasionally or almost always fails. For example, the IoT UE may be programmed to try to send temperature measurements every hour. However, the IoT UE may fail to transmit data due to a poor connection with the selected VPLMN.

[0021] It can be difficult for the operator of the PLMN to detect such problems. During the initial installation of the IoT UE, it may appear that the connection is successfully established. Moreover, once such a situation occurs, manual intervention on site is required to identify and fix the problem. Manual intervention will affect operating expenses and deployment because these IoT UEs are often in remote and difficult to reach locations. Therefore, even if these problems are detected, they are often ignored and the problem persists.

[0022] One of the main reasons why IoT UEs select VPLMN cells with poor coverage is attributed to the current network selection process that affects how VPLMNs are selected. During the initial steps of selecting a network after switching on or recovery, the signal levels of available cells are not considered. Instead, the IoT UE considers only the cell selection criteria broadcast by the PLMN and the priority of the network. This may affect the IoT UE not only during the initial selection, but also during recovery from coverage loss and during the periodic reselection steps. Therefore, the IoT UE may select a PLMN based on priority rather than signal level.

[0023] Thus, the IoT UE selects or stays on a network with poor coverage at that particular location because the selected PLMN has a higher priority than other PLMNs. Under the current network selection process, the IoT UE will select a PLMN based on priority even if the selected PLMN has worse coverage than other available PLMNs with lower priority that have much better local coverage.

[0024] For typical consumer UEs (e.g., cellular phones), this is usually not a problem because the mobility of typical consumer UEs causes conditions to change rapidly and there are users who are aware of the problem and can react. For example, the user may change the location of the UE, or the user may apply manual PLMN selection. This selection behavior may be desirable as part of roaming guidance and to avoid frequent changes of networks. However, for fixed devices without supervision by the user, the network selection behavior may be a big problem.

[0025] Some embodiments herein provide improvements to the network selection process by allowing IoT UEs to consider the signal levels of available cells. Embodiments herein include methods of considering signal levels during the initial steps of network selection after switch-on, during recovery from coverage loss, and during the steps of periodic reselection.

[0026] The embodiments herein include any option or combination thereof in category M1 or M2 supporting narrowband (NB)-IoT, global system for mobile communications (GSM) enhanced data GSM evolution (EDGE) radio access network (GERAN) extended coverage (EC)-GSM-IoT, and evolved universal terrestrial radio access (E-UTRA). The embodiments herein may include a 5G system that supports a mechanism that enables the home operator to configure, update, or delete the operator-controlled signal threshold of the access technology on the USIM. When the "operator-controlled signal threshold of the access technology" is configured on the USIM, the automatic network selection process can be enhanced. The allowed range of the operator-controlled signal threshold of the access technology can be between the cell selection criteria and the high-quality signal as defined in the technical specification (TS) (e.g., TS23.122).

[0027] The embodiments herein consider various aspects of signal level enhancement network selection. For example, various aspects of the embodiments include how to configure the signal threshold controlled by the operator of the access technology. In addition, various aspects of the embodiments consider the allowable range of the signal threshold controlled by the operator of the access technology. In addition, some embodiments consider specific impacts on the USIM. Some embodiments consider enhancements to the non-access stratum (NAS) automatic network selection process. Some embodiments consider enhancements to the NAS periodic network selection process. Some embodiments consider the impact of cell selection criteria.

[0028] 3GGP TS23.122 defines various aspects of the automatic network selection process. The automatic network selection process occurs after power-up, after recovery from lack of coverage, at user request, and periodically in the background. Each network broadcasts cell selection criteria (e.g., signal level and quality criteria). Only cells that meet these criteria are considered for further steps.

[0029] In addition, cells with signal levels better than the following are marked as high quality: 85 decibel milliwatts (dBm) for GSM; 95dBm for UTRAN frequency division duplex (FDD); 84dBm for UTRAN time division duplex (TDD); and 110dBm for LTE, NB-IoT, and NR. A list of cells marked as high quality or marked with signal level is provided to the NAS (in the UE) for network selection. However, these high quality designations are generally not considered in automatic network processes.

[0030] Typically, the IoT UE looks for the last registered PLMN (RPLMN) and selects this PLMN. As an option controlled by the Home PLMN (HPLMN), the IoT UE may first try to find an equivalent (E)HPLMN. If those PLMNs are not available, the IoT UE then traverses the various lists in priority order. Currently, the IoT UE selects a network based on high quality indication / signal level only if there is no RPLMN or higher priority PLMN. All previous steps rely only on cell selection criteria.

[0031] 3GPP TS23.122 includes the following steps for automatic network selection:

[0032] 4.4.3.1.1 Automatic network selection mode process

[0033] The mobile station (MS) selects other PLMN / access technology combinations (if available and allowed for item numbers i, ii, iii, iv, v) in the following order and attempts to register on them:

[0034] i) the HPLMN (if the EHPLMN list does not exist or is empty) or the highest priority EHPLMN available (if the EHPLMN list exists);

[0035] ii) each PLMN / access technology combination in the “Subscriber Controlled PLMN Selector for Linked Access Technology” data file in the SIM (in order of priority);

[0036] iii) each PLMN / access technology combination in the SIM (in order of priority) or in the “Operator controlled PLMN selector with access technology” data file stored in the ME (in order of priority);

[0037] iv) other PLMN / access technology combinations with received high quality signals in random order;

[0038] NOTE 1: High quality signals are defined in the appropriate AS technical specifications.

[0039] v) Other PLMN / access technology combinations, sorted in descending order of signal quality.

[0040] As can be seen in steps 1-3, the PLMN is selected without considering signal quality. Signal quality is not considered until steps 4 and 5. Fixed IoT UEs usually do not proceed to steps 4 and 5 because it is usually the case that the IoT UE can find a PLMN that meets the requirements of steps 1-3. The embodiments herein address this problem of lack of signal quality consideration for the automatic network selection process.

[0041] The embodiments of this document allow operators to configure signal thresholds. The signal threshold is a value separate from the high quality value and can be configured according to the access technology. The threshold can be configured for category M1 or M2 of NB-IoT, GERAN EC-GSM-IoT, and E-UTRA. The threshold can be pre-defined in the data file in the USIM or pre-defined in the mobile equipment (ME). The threshold can be updated using the NAS roaming guidance (SoR) process. The operator-controlled signal threshold is delivered to the UE as part of the REGISTRATION ACCEPT message or DL ​​NAS TRANSPORT message in the SOR transparent container information element (IE) using NAS signaling (using the SoR process). The threshold can be updated using the SIM Toolkit that can trigger the SIMRefresh command to change the content of the SIM basic file (EF).

[0042] In some embodiments, the allowed range of the signal threshold controlled by the operator of the access technology is between the cell selection criteria and the high-quality signal level. The high-quality signal level can be set as defined in 3GPP TS23.122. For example, the high-quality signal level can be a cell with a signal level better than the following signal levels: 85dBm for GSM; 95dBm for UTRAN FDD; 84dBm for UTRAN TDD; and 110dBm for LTE, NB-IoT and NR. In other words, the signal threshold of the embodiments herein can be set to not exceed the high-quality signal level for the access technology. The signal threshold allows the operator to specify a lower range of acceptable signal levels.

[0043] In some embodiments, the signal threshold may be region specific. For example, the signal threshold may be specific to a geographic region and a PLMN. For example, one signal threshold may be set for parts of Asia, and a different signal threshold may be set for parts of Europe.

[0044] Three items may be provided in the data file for the IoT UE, namely, location identifier, access technology, and signal threshold. The value of the signal threshold may vary depending on the location identifier and access technology. The location identifier may include a PLMN identity and a tracking area code. The access technology may include one or more of NB-IoT, GERAN EC-GSM-IoT, and E-UTRA categories M1 or M2. The signal threshold may be set by the operator to a value that does not exceed the high quality signal level established in the standard.

[0045] Some embodiments herein use the value of the signal threshold to enhance the automatic network selection process. For example, the automatic PLMN search process (e.g., the process found in Section 4.4.3.1.1 of 3GPP TS23.122) may be updated as follows. In some embodiments, if the operator-controlled signal threshold according to the access technology data file is available on the USIM, the MS should select the network only if the network selection condition is met and the received signal quality of the candidate PLMN / access technology combination is equal to or higher than the signal strength in the operator-controlled signal threshold according to the access technology data file. According to some embodiments, if no candidate PLMN / access technology combination meets the operator-controlled signal threshold standard, the UE shall repeat the automatic network selection process without applying the operator-controlled signal threshold according to the access technology. Therefore, the UE can compare the received signal quality of the candidate PLMN with the operator-controlled signal threshold to determine a suitable PLMN candidate, and if no suitable candidate is found, the UE can perform the automatic network selection process without considering the operator-controlled signal threshold.

[0046] In addition, in some embodiments, the periodic network selection process can be updated in a similar manner to the automatic PLMN search process. In addition, if the registration fails on the newly selected PLMN for some reason, the UE can revert to the old PLMN selection process. That is, the UE can repeat the automatic network selection process without applying the operator-controlled signal threshold according to the access technology.

[0047] The enhanced automatic network selection process may only be applicable to fixed UEs. It may not be desirable to affect consumer cellular devices that can move to an area with better coverage at any time. Therefore, the embodiments herein specifically deal with fixed UEs. The UE may apply the enhanced automatic network selection process only at a specific location identified by the operator. If the UE moves to another location, the UE may not have to follow the threshold set in the USIM, because the threshold may no longer apply, or the entire process may have to be evaluated and applied again.

[0048] In some embodiments, the cell selection criteria may be updated based on the signal threshold. For example, when the operator-controlled signal threshold according to the access technology data file is available on the USIM, the criteria may be updated so that the MS should select the network only if the signal quality of the candidate access technology is equal to or higher than the signal strength in the operator-controlled signal threshold according to the access technology data file. In addition, in some embodiments, the criteria should only apply to a specific cell or tracking area for a specific access technology, rather than to the entire PLMN.

[0049] Figure 1A flow chart of a method 100 for enabling a fixed IoT UE to perform automatic PLMN selection during power-on or resume is shown. As shown, the IoT UE initiates this method 100 during a power-on or resume event 102. The method 100 is an updated PLMN selection process when an operator-controlled signal threshold according to an access technology data file is available on the USIM.

[0050] The IoT UE determines 104 whether the operator-controlled signal threshold according to the access technology data file is available on the USIM. The threshold can be configured for category M1 or M2 of NB-IoT, GERAN EC-GSM-IoT and E-UTRA. The threshold can be pre-defined in the data file in the USIM or pre-defined in the ME. The threshold can be updated using the NAS SoR procedure. The operator-controlled signal threshold is delivered to the UE as part of the REGISTRATION ACCEPT message or DL ​​NAS TRANSPORT message in the SOR transparent container IE using NAS signaling (using the SoR procedure). The threshold can be updated using the SIM Toolkit that can trigger the SIM Refresh command to change the content of the SIM EF. The signal threshold sets a minimum value for the PLMN. In some embodiments, the IoT UE can additionally determine whether the current location matches the location associated with the signal threshold.

[0051] If the IoT UE determines 104 that there is an available signal threshold, the IoT UE performs 106 PLMN selection with signal strength sequence (PLMN selection process based on signal threshold). The PLMN selection with signal strength sequence is based on the operator controlled signal threshold. The signal strength sequence considers whether the received signal strength of the candidate PLMN is greater than or equal to the operator controlled signal threshold in the USIM.

[0052] For example, the IoT UE may use the following steps to determine the available PLMNs. The IoT UE may perform these steps until a match is found or all steps are completed. In the first step, the IoT UE may attempt to determine a PLMN that is either the HPLMN (if the EHPLMN list does not exist or is empty) or the highest priority EHPLMN available (if the EHPLMN list exists). The PLMN identified in the first step must have a received signal quality equal to or higher than the signal strength in the operator controlled signal threshold.

[0053] If no PLMN meets this condition in the first step, the IoT UE may proceed to the second step. In the second step, the IoT UE may attempt to determine each PLMN / access technology combination (in order of priority) in the "User-controlled PLMN selector for contact access technology" data file in the SIM. As in the first step, any PLMN identified in the second step must have a received signal quality equal to or higher than the signal strength in the operator-controlled signal threshold.

[0054] If no PLMN meets this condition in the second step, the IoT UE may proceed to the third step. In the third step, the IoT UE may attempt to determine each PLMN / access technology combination in the "operator-controlled PLMN selector for contact access technology" data file in the SIM (in order of priority) or stored in the ME (in order of priority). As in the previous steps, any PLMN identified in the second step must have a received signal quality equal to or higher than the signal strength in the operator-controlled signal threshold.

[0055] If no PLMN meets the condition in the third step, the IoT UE may proceed to the fourth step. In the fourth step, the IoT UE may try to determine other PLMN / access technology combinations with high quality received signals in a random order. A high quality signal will be greater than or equal to a signal threshold controlled by the operator.

[0056] If no PLMN meets the condition in the fourth step, the IoT UE may proceed to the fifth step. In the fifth step, the IoT UE may try to determine other PLMN / access technology combinations in order of decreasing signal quality. Any PLMN identified in the fifth step must have a received signal quality equal to or higher than the signal strength in the operator-controlled signal threshold.

[0057] The IoT UE determines 108 whether there is a PLMN that matches these conditions in the PLMN selection using signal strength sequence. If there is a match, the IoT UE may select 110 the PLMN that matches these conditions. The IoT UE selects a PLMN that matches these conditions and meets or exceeds the operator controlled signal threshold in the order of steps outlined above for PLMN selection using signal strength sequence and attempts to register on that PLMN.

[0058] If the IoT UE determines 104 that there is no operator-controlled signal threshold, the operator-controlled signal threshold is not applicable to the current location, or if the PLMN selection using the signal strength sequence does not determine 108 a PLMN match, the IoT UE may perform 112 PLMN selection without a signal strength sequence (a PLMN selection process not based on a signal threshold). For example, the IoT UE may perform steps i) to v) in automatic network selection to find a PLMN without applying the operator-controlled threshold in the USIM, wherein steps i) to v) include: the IoT UE selects other PLMN / access technology combinations (if available and allowed for item numbers i, ii, iii, iv, v) in the following order and attempts to register on them:

[0059] i) the HPLMN (if the EHPLMN list does not exist or is empty) or the highest priority EHPLMN available (if the EHPLMN list exists);

[0060] ii) each PLMN / access technology combination in the “Subscriber Controlled PLMN Selector for Linked Access Technology” data file in the SIM (in order of priority);

[0061] iii) each PLMN / access technology combination in the SIM (in order of priority) or in the “Operator controlled PLMN selector with access technology” data file stored in the ME (in order of priority);

[0062] iv) other PLMN / access technology combinations with received high quality signals in random order;

[0063] NOTE 1: High quality signals are defined in the appropriate AS technical specifications.

[0064] v) Other PLMN / access technology combinations, sorted in descending order of signal quality.

[0065] Thereafter, the IoT UE may select 110 the PLMN identified by the PLMN selection without the signal strength selection sequence.

[0066] Figure 2 A flow chart of a method 200 of a fixed IoT UE performing automatic PLMN selection during periodic scanning when on an RPLMN is shown. As shown, the IoT UE initiates this method 200 during a periodic scan 202. The method 200 is an updated PLMN selection process when an operator-controlled signal threshold according to an access technology data file is available on the USIM.

[0067] The IoT UE determines 204 whether the operator-controlled signal threshold according to the access technology data file is available on the USIM. The threshold can be configured for category M1 or M2 of NB-IoT, GERAN EC-GSM-IoT and E-UTRA. The threshold can be pre-defined in the data file in the USIM or pre-defined in the ME. The threshold can be updated using the NAS SoR procedure. The operator-controlled signal threshold is delivered to the UE as part of the REGISTRATION ACCEPT message or DL ​​NAS TRANSPORT message in the SOR transparent container IE using NAS signaling (using the SoR procedure). The threshold can be updated using the SIM Toolkit that can trigger the SIM Refresh command to change the content of the SIM EF. The signal threshold sets a minimum value for the PLMN. In some embodiments, the IoT UE can additionally determine whether the current location matches the location associated with the signal threshold.

[0068] If the IoT UE determines 204 that there is an available signal threshold, the IoT UE performs 206 PLMN selection with signal strength sequence (PLMN selection process based on signal threshold). The PLMN selection with signal strength sequence is based on the operator controlled signal threshold. The signal strength sequence considers whether the received signal strength of the candidate PLMN is greater than or equal to the operator controlled signal threshold in the USIM.

[0069] For example, the IoT UE may use the following steps to determine the available PLMNs. The IoT UE may perform these steps until a match is found or all steps are completed. In the first step, the IoT UE may attempt to determine a PLMN that is either the HPLMN (if the EHPLMN list does not exist or is empty) or the highest priority EHPLMN available (if the EHPLMN list exists). The PLMN identified in the first step must have a received signal quality equal to or higher than the signal strength in the operator controlled signal threshold.

[0070] If no PLMN meets this condition in the first step, the IoT UE may proceed to the second step. In the second step, the IoT UE may attempt to determine each PLMN / access technology combination (in order of priority) in the "User-controlled PLMN selector for contact access technology" data file in the SIM. As in the first step, any PLMN identified in the second step must have a received signal quality equal to or higher than the signal strength in the operator-controlled signal threshold.

[0071] If no PLMN meets this condition in the second step, the IoT UE may proceed to the third step. In the third step, the IoT UE may attempt to determine each PLMN / access technology combination in the "operator-controlled PLMN selector for contact access technology" data file in the SIM (in order of priority) or stored in the ME (in order of priority). As in the previous steps, any PLMN identified in the second step must have a received signal quality equal to or higher than the signal strength in the operator-controlled signal threshold.

[0072] If no PLMN meets the condition in the third step, the IoT UE may proceed to the fourth step. In the fourth step, the IoT UE may try to determine other PLMN / access technology combinations with high quality received signals in a random order. A high quality signal will be greater than or equal to a signal threshold controlled by the operator.

[0073] If no PLMN meets the condition in the fourth step, the IoT UE may proceed to the fifth step. In the fifth step, the IoT UE may try to determine other PLMN / access technology combinations in order of decreasing signal quality. Any PLMN identified in the fifth step must have a received signal quality equal to or higher than the signal strength in the operator-controlled signal threshold.

[0074] The IoT UE determines 208 whether there is a PLMN that matches these conditions in the PLMN selection using signal strength sequence. If there is a match, the IoT UE may select 210 the PLMN that matches these conditions. The IoT UE follows the order of steps outlined above for PLMN selection using signal strength sequence to select a PLMN that matches these conditions and meets or exceeds the operator controlled signal threshold and attempts to register on that PLMN.

[0075] If the IoT UE determines 204 that there is no operator-controlled signal threshold, the operator-controlled signal threshold is not applicable to the current location, or if the PLMN selection using the signal strength sequence does not determine 208 a PLMN match, the IoT UE may perform 212 PLMN selection without a signal strength sequence (a PLMN selection process not based on a signal threshold). For example, the IoT UE may perform steps i) to v) in the automatic network selection to find a PLMN without applying the operator-controlled threshold in the USIM, wherein steps i) to v) include: the IoT UE selects other PLMN / access technology combinations (if available and allowed for item numbers i, ii, iii, iv, v) in the following order and attempts to register on them:

[0076] i) the HPLMN (if the EHPLMN list does not exist or is empty) or the highest priority EHPLMN available (if the EHPLMN list exists);

[0077] ii) each PLMN / access technology combination in the “Subscriber Controlled PLMN Selector for Linked Access Technology” data file in the SIM (in order of priority);

[0078] iii) each PLMN / access technology combination in the SIM (in order of priority) or in the “Operator controlled PLMN selector with access technology” data file stored in the ME (in order of priority);

[0079] iv) other PLMN / access technology combinations with received high quality signals in random order;

[0080] NOTE 1: High quality signals are defined in the appropriate AS technical specifications.

[0081] v) Other PLMN / access technology combinations, sorted in descending order of signal quality.

[0082] Thereafter, if a match better than the RPLMN is determined 214, the IoT UE may select 210 the PLMN identified by the PLMN selection without the signal strength selection sequence. Otherwise, the IoT UE may stay 216 on the RPLMN.

[0083] Methods 100 and 200 may be implemented as follows according to the standard section "Automatic Network Selection Mode Procedure" (e.g., Section 4.4.3.1.1 of the updated TS23.122). The MS selects other PLMN / access technology combinations (if available and allowed for item numbers i, ii, iii, iv, v) and attempts to register on them in the following order:

[0084] i) the HPLMN (if the EHPLMN list does not exist or is empty) or the highest priority EHPLMN available (if the EHPLMN list exists);

[0085] ii) each PLMN / access technology combination in the “Subscriber Controlled PLMN Selector for Linked Access Technology” data file in the SIM (in order of priority);

[0086] iii) each PLMN / access technology combination in the SIM (in order of priority) or in the “Operator controlled PLMN selector with access technology” data file stored in the ME (in order of priority);

[0087] iv) other PLMN / access technology combinations with received high quality signals in random order;

[0088] NOTE 1: High quality signals are defined in the appropriate AS technical specifications.

[0089] v) Other PLMN / access technology combinations, sorted in descending order of signal quality.

[0090] When following the above procedure, the following requirements apply: If the operator controlled signal threshold according to the access technology data file is available on the USIM, the MS shall select the network only if the network selection condition is met and the received signal quality of the candidate PLMN / access technology combination is equal to or higher than the signal strength in the operator controlled signal threshold according to the access technology data file. According to some embodiments, if no candidate PLMN / access technology combination meets the operator controlled signal threshold criteria, the UE shall repeat the automatic network selection process without applying the operator controlled signal threshold according to the access technology.

[0091] In addition, the cell selection criteria can be modified to include the cell signal threshold configured by the operator for the access technology. For example, as part of the cell selection criteria, the IoT UE can determine whether the measured cell RX level value (RSRP) is greater than or equal to the cell signal threshold configured by the operator for the access technology.

[0092] In some embodiments, the UE will use one of the following two cell selection processes: a) initial cell selection; and b) stored information cell selection. During the initial cell selection, this process does not require prior knowledge of which RF channels are E-UTRA carriers or NB-IoT carriers. The UE will scan all RF channels in the E-UTRA band to find a suitable cell based on its capabilities. On each carrier frequency, the UE only needs to search for the strongest cell. Once a suitable cell is found, this cell will be selected. During the stored information cell selection, this process requires information about the stored carrier frequency and optional information about cell parameters, which comes from previously received measurement control information elements or from previously detected cells. Once the UE has found a suitable cell, the UE will select the cell. If a suitable cell is not found, the initial cell selection process should be started.

[0093] In some embodiments, if the measurement is performed using RSS as specified in 3GPP TS 36.133, the cell selection criterion S under normal coverage is met when Srxlev>0. Otherwise, the cell selection criterion S under normal coverage is met when Srxlev>0 and Squal>0. If the operator-controlled signal threshold according to the access technology data file is available on the USIM, the cell selection criterion S under normal coverage is met when Srxlev>0 and Squal>0 and Qrxlevmeas>=QUSIM.

[0094] Where: Srxlev = Qrxlevmeas - (Qrxlevmin + Qrxlevminoffset) - Pcompensation - Qoffsettemp

[0095] Sequal = Qqualmeas - (Qqualmin + Qqualminoffset) - QoffsettempQrxlevemeas: measured cell RX level value (RSRP)

[0096] QUSIM: Operator-configured cell RX signal threshold for access technology, and wherein Table 1 provides additional parameters.

[0097]

[0098]

[0099] Table 1

[0100] Similarly, the cell selection criteria for NB-IoT can be modified to include operator-configured cell signal thresholds for access technologies. In some embodiments, if measurements are performed on a non-anchor carrier and the UE meets the requirements specified in TS36.133, the cell selection criterion S is met when Srxlev>0. Otherwise, the cell selection criterion S is met when Srxlev>0 and Squal>0. If the operator-controlled signal threshold according to the access technology data file is available on the USIM, the cell selection criterion S under normal coverage is met when Srxlev>0 and Squal>0 and Qrxlevmeas>=QUSIM.

[0101] in:

[0102] Srxlev=Q rxlevmeas -(Q rxlevmin +Q rxlevminoffset )-Pcompensation-Qoffset temp

[0103] Squal=Q qualmeas -(Q qualmin +Q qualminoffset )-Qoffset temp

[0104] In addition, the USIM may be updated to include information about operator-controlled signal thresholds according to access technology. For example, in some embodiments, the USIM may include an access technology identifier and a corresponding signal strength threshold. In some embodiments, the USIM may also include a location (e.g., location area identifier, tracking area) to which the corresponding signal strength threshold may apply. In addition, the basic file (EF) for the USIM service table (EF ) may be updated. ust ). EF ust Indicates which services are available. If a service is not indicated as available in the USIM, the ME will not select this service. ust One of the services in may be service n° 145: Operator controlled signal threshold per access technology. This service may be a way for a network node to indicate to an IoT UE that operator controlled signal threshold per access technology is available.

[0105] Another USIM update may include an additional EF for operator-controlled signal thresholds per access technology (EF OCSIGHRESHACT ).For example, Figure 3 and Figure 4 shows the possible EF OCSIGHRESHACT structure.

[0106] Specifically, Figure 3 EF diagram illustrating an access technology and associated operator controlled signal thresholds according to some embodiments OCSIGHRESHACT 300. In some embodiments, if service n°145 is "available", this file (ie, EF OCSIGHRESHACT 300) should exist.

[0107] EF OCSIGHRESHACT 300 includes encoding for several (n) access technologies, where n is determined by the operator. For example, the first record 302 specifies the first access technology using the first access technology identifier 304 and specifies the associated operator-controlled signal threshold for the access technology using the first signal strength threshold 306.

[0108] The access technology identifier and signal strength threshold can be EF OCSIGHRESHACT 300 can be configured by the operator. These fields can provide information to the IoT UE that can be used during network selection. For example, when trying to use Figure 1Method 100 or Figure 2 When registering a PLMN using method 200, you can use EF OCSIGHRESHACT 400.

[0109] The access technology identifier may be two bytes that specify the access technology. For example, the EF (EF) of the PLMN selector controlled by the user for the associated access technology may be used to identify the access technology. PLMNwACT ) to encode the access technology identifier. The signal strength threshold may be four bytes that specify the operator-controlled signal threshold for the associated access technology.

[0110] Figure 4 EF diagram illustrating a signal threshold indicating location, access technology, and associated operator control according to some embodiments OCSIGHRESHACT 400. In some embodiments, if service n°145 is "available", this file (ie, EF OCSIGHRESHACT 400) should exist.

[0111] EF OCSIGHRESHACT 400 includes encoding for several location area codes / tracking area codes (LAC / TAC), access technologies, and associated operator-controlled signal thresholds for the access technologies. For example, a first record 402 specifies a first LAC / TAC (e.g., a first location area identifier / tracking area identifier 404), a first access technology (e.g., a first access technology identifier 406), and an associated operator-controlled signal threshold for the access technology at the LAC / TAC (e.g., a first signal strength threshold 408).

[0112] Location area identifier / tracking area identifier, access technology identifier and signal strength threshold can be EF OCSIGHRESHACT 300 can be configured by the operator. These fields can provide information to the IoT UE that can be used during network selection. For example, when trying to use Figure 1 Method 100 or Figure 2 When registering a PLMN using method 200, you can use EF OCSIGHRESHACT 400.

[0113] The location area identifier / tracking area identifier may be nine bytes including information about an area associated with a signal strength threshold. The location area identifier may include an MCC (Mobile Country Code), an MNC (Mobile Network Code), and a LAC. The tracking area identifier may include an MCC, an MNC, and a TAC. The encoding of the location area identifier / tracking area identifier may be done according to other aspects of the standard. For example, the PLMN may be according to TS24.501 / 24.008 / 24.301. A "BCD" value of "D" in any of the MCC and / or MNC digits may be used to indicate a "wild" value for the corresponding MCC / MNC digit. TAC may be encoded according to TS.24.501 for NG-RAN and according to 24.008 / 24.301 for other LAC / TACs. Two values ​​of TAC / LAC may be stored, thereby allowing a range of TAC / LAC values ​​for a specified PLMN, where the access technology identifier and signal strength threshold should apply. If only 2 bytes are used for the TAC / LAC, the unused bytes may be set to FF.

[0114] When TAC is 3 bytes, the value "000000" stored in bytes 4 to 6 and the value "FFFFFE" can be used to indicate the entire range of TACs for a given PLMN. When TAC is 2 bytes, the value "FF0000" stored in bytes 4 to 6 and the value "FFFFFE" can be used to indicate the entire range of TACs for a given PLMN. If bytes 4 to 6 are the same as the values ​​stored in bytes 7 to 9 for a given PLMN, they can indicate a specific TAC for this PLMN, where this access technology identifier and signal strength threshold should apply. (If only 2-byte TAC / LAC is used, byte 4 and byte 7 should be set to FF). In order to indicate a range of TAC values, for a given PLMN, the value stored in bytes 4 to 6 should be the beginning of the TAC range and the value stored in bytes 7 to 9 should be the end of the TAC range. If only 2-byte TAC / LAC is used, byte 4 and byte 7 can be set to FF.

[0115] The access technology identifier may be two bytes that specify the access technology. For example, the EF (EF) of the PLMN selector controlled by the user for the associated access technology may be used to identify the access technology. PLMNwACT ) to encode the access technology identifier. The signal strength threshold may be four bytes that specify the operator-controlled signal threshold for the associated access technology.

[0116] Figure 5An example architecture of a wireless communication system 500 according to an embodiment disclosed herein is shown. The description provided below is for an example wireless communication system 500 operating in conjunction with the LTE system standard and / or the 5G or NR system standard provided in the 3GPP technical specifications.

[0117] like Figure 5 As shown, wireless communication system 500 includes UE 502 and UE 504 (however, any number of UEs may be used). In this example, UE 502 and UE 504 are shown as smartphones (e.g., handheld touch screen mobile computing devices capable of connecting to one or more cellular networks), but may also include any mobile or non-mobile computing device configured for wireless communication.

[0118] UE 502 and UE 504 may be configured to be communicatively coupled to RAN 506. In an embodiment, RAN 506 may be NG-RAN, E-UTRAN, etc. UE 502 and UE 504 utilize connections (or channels) (shown as connection 508 and connection 510, respectively) with RAN 506, each of which includes a physical communication interface. RAN 506 may include one or more base stations (such as base station 512 and base station 514) that implement connection 508 and connection 510.

[0119] In this example, connection 508 and connection 510 are the air interfaces used to enable such communicative coupling and may conform to the RAT used by RAN 506, such as, for example, LTE and / or NR.

[0120] In some embodiments, UE 502 and UE 504 may also directly exchange communication data via side link interface 516. UE 504 is illustrated as being configured to access an access point (illustrated as AP 518) via connection 520. For example, connection 520 may include a local wireless connection, such as a connection conforming to any IEEE 802.11 protocol, wherein AP 518 may include In this example, AP 518 can connect to another network (eg, the Internet) without going through CN 524.

[0121] In an embodiment, UE 502 and UE 504 may be configured to communicate with each other or with base station 512 and / or base station 514 over a multi-carrier communication channel using orthogonal frequency division multiplexing (OFDM) communication signals according to various communication techniques, such as, but not limited to, orthogonal frequency division multiple access (OFDMA) communication techniques (e.g., for downlink communication) or single carrier frequency division multiple access (SC-FDMA) communication techniques (e.g., for uplink and ProSe or sidelink communication), although the scope of the embodiment is not limited in this respect. The OFDM signal may include multiple orthogonal subcarriers.

[0122] In some embodiments, all or part of the base station 512 or the base station 514 may be implemented as one or more software entities running on a server computer as part of a virtual network. In addition, or in other embodiments, the base station 512 or the base station 514 may be configured to communicate with each other via the interface 522. In an embodiment where the wireless communication system 500 is an LTE system (e.g., when the CN 524 is an EPC), the interface 522 may be an X2 interface. The X2 interface may be defined between two or more base stations (e.g., two or more eNBs, etc.) connected to the EPC and / or between two eNBs connected to the EPC. In an embodiment where the wireless communication system 500 is an NR system (e.g., when the CN 524 is a 5GC), the interface 522 may be an Xn interface. The Xn interface is defined between two or more base stations (e.g., two or more gNBs, etc.) connected to the 5GC, between the base station 512 (e.g., gNB) and the eNB connected to the 5GC, and / or between two eNBs connected to the 5GC (e.g., CN 524).

[0123] RAN 506 is illustrated as being communicatively coupled to CN 524. CN 524 may include one or more network elements 526 configured to provide various data and telecommunication services to customers / subscribers (e.g., UE 502 and users of UE 504) connected to CN 524 via RAN 506. Components of CN 524 may be implemented in one physical device or separate physical devices including components for reading and executing instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium).

[0124] In an embodiment, CN 524 may be an EPC, and RAN 506 may be connected to CN 524 via an S1 interface 528. In an embodiment, S1 interface 528 may be divided into two parts: an S1 user plane (S1-U) interface, which carries communication traffic data between base station 512 or base station 514 and a serving gateway (S-GW); and an S1-MME interface, which is a signaling interface between base station 512 or base station 514 and a mobility management entity (MME).

[0125] In an embodiment, CN 524 may be a 5GC, and RAN 506 may be connected to CN 524 via an NG interface 528. In an embodiment, NG interface 528 may be divided into two parts: an NG user plane (NG-U) interface, which carries communication service data between base station 512 or base station 514 and a user plane function (UPF); and an S1 control plane (NG-C) interface, which is a signaling interface between base station 512 or base station 514 and an access and mobility management function (AMF).

[0126] In general, the application server 530 may be an element that provides applications that use Internet Protocol (IP) bearer resources with the CN 524 (e.g., packet-switched data services). The application server 530 may also be configured to support one or more communication services (e.g., VoIP sessions, group communication sessions, etc.) for the UE 502 and UE 504 via the CN 524. The application server 530 may communicate with the CN 524 via an IP communication interface 532.

[0127] Figure 6 A system 600 for performing signaling 634 between a wireless device 602 and a network device 618 according to an embodiment disclosed herein is shown. The system 600 can be part of a wireless communication system as described herein. The wireless device 602 can be, for example, a UE of a wireless communication system. The network device 618 can be, for example, a base station (e.g., an eNB or a gNB) of a wireless communication system.

[0128] The wireless device 602 may include one or more processors 604. The processor 604 may execute instructions to perform various operations of the wireless device 602 as described herein. The processor 604 may include one or more baseband processors implemented using, for example, a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0129] The wireless device 602 may include a memory 606. The memory 606 may be a non-transitory computer-readable storage medium storing instructions 608 (which may include, for example, instructions executed by the processor 604). The instructions 608 may also be referred to as program code or a computer program. The memory 606 may also store data used by the processor 604 and results calculated by the processor.

[0130] The wireless device 602 may include one or more transceivers 610, which may include radio frequency (RF) transmitter and / or receiver circuitry that uses an antenna 612 of the wireless device 602 to facilitate signaling (e.g., signaling 634) to and / or from the wireless device 602 with other devices (e.g., network device 618) in accordance with a corresponding RAT.

[0131] The wireless device 602 may include one or more antennas 612 (e.g., one, two, four, or more). For embodiments with multiple antennas 612, the wireless device 602 may utilize the spatial diversity of such multiple antennas 612 to transmit and / or receive multiple different data streams on the same time-frequency resources. This behavior may be referred to as, for example, multiple-input multiple-output (MIMO) behavior (referring to the multiple antennas used at each of the transmitting device and the receiving device to implement this aspect). MIMO transmission by the wireless device 602 may be implemented based on precoding (or digital beamforming) applied to the wireless device 602, which multiplexes the data streams between the antennas 612 based on known or assumed channel characteristics, so that each data stream is received with appropriate signal strength relative to the other streams and at a desired location in the spatial domain (e.g., the location of the receiver associated with the data stream). Certain embodiments may use a single-user MIMO (SU-MIMO) approach (where data streams are all directed to a single receiver) and / or a multi-user MIMO (MU-MIMO) approach (where separate data streams may be directed to separate (different) receivers in different locations in the spatial domain).

[0132] In certain embodiments with multiple antennas, wireless device 602 may implement analog beamforming techniques whereby the phases of signals transmitted by antennas 612 are relatively adjusted so that the (joint) transmissions of antennas 612 may be directed (this is sometimes referred to as beam steering).

[0133] The wireless device 602 may include one or more interfaces 614. The interface 614 may be used to provide input to the wireless device 602 or provide output from the wireless device. For example, a wireless device 602 as a UE may include an interface 614, such as a microphone, a speaker, a touch screen, buttons, etc., to allow a user of the UE to input and / or output to the UE. Other interfaces of such a UE may be composed of transmitters, receivers, and other circuit systems (e.g., in addition to the transceiver 610 / antenna 612 already described), which allow the UE to communicate with other devices and may communicate according to known protocols (e.g., etc.) to perform the operation.

[0134] The wireless device 602 may include a network selection module 616. The network selection module 616 may be implemented via hardware, software, or a combination thereof. For example, the network selection module 616 may be implemented as a processor, circuit, and / or instructions 608 stored in the memory 606 and executed by the processor 604. In some examples, the network selection module 616 may be integrated within the processor 604 and / or the transceiver 610. For example, the network selection module 616 may be implemented by a combination of software components (e.g., executed by a DSP or general purpose processor) and hardware components (e.g., logic gates and circuit systems) within the processor 604 or the transceiver 610.

[0135] The network selection module 616 may be used in various aspects of the present disclosure, for example, Figure 1-4 The network selection module 616 is configured to perform PLMN selection using an operator controlled signal strength threshold.

[0136] The network device 618 may include one or more processors 620. The processor 620 may execute instructions to perform various operations of the network device 618 as described herein. The processor 620 may include one or more baseband processors implemented using, for example, a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0137] The network device 618 may include a memory 622. The memory 622 may be a non-transitory computer-readable storage medium storing instructions 624 (which may include, for example, instructions executed by the processor 620). The instructions 624 may also be referred to as program code or a computer program. The memory 622 may also store data used by the processor 620 and results calculated by the processor.

[0138] The network device 618 may include one or more transceivers 626, which may include RF transmitter and / or receiver circuitry that uses an antenna 628 of the network device 618 to facilitate signaling (e.g., signaling 634) transmitted or received by the network device 618 with other devices (e.g., wireless device 602) according to a corresponding RAT.

[0139] The network device 618 may include one or more antennas 628 (e.g., one, two, four, or more). In embodiments with multiple antennas 628, the network device 618 may perform MIMO, digital beamforming, analog beamforming, beam steering, etc. as described above.

[0140] The network device 618 may include one or more interfaces 630. The interface 630 may be used to provide input to or output from the network device 618. For example, the network device 618 as a base station may include an interface 630 composed of a transmitter, a receiver, and other circuit systems (e.g., in addition to the transceiver 626 / antenna 628 described above), which enables the base station to communicate with other equipment in the core network and / or enables the base station to communicate with external networks, computers, databases, etc., in order to achieve the purpose of performing operations, management, and maintenance of the base station or other equipment operably connected thereto.

[0141] The network device 618 may include a network selection module 632. The network selection module 632 may be implemented by hardware, software, or a combination thereof. For example, the network selection module 632 may be implemented as a processor, circuit, and / or instructions 624 stored in the memory 622 and executed by the processor 620. In some examples, the network selection module 632 may be integrated within the processor 620 and / or the transceiver 626. For example, the network selection module 632 may be implemented by a combination of software components (e.g., executed by a DSP or general purpose processor) and hardware components (e.g., logic gates and circuit systems) within the processor 620 or the transceiver 626.

[0142] The network selection module 632 may be used in various aspects of the present disclosure, for example, Figure 1-4 The network selection module 632 is configured to support the UE in selecting a PLMN.

[0143] Embodiments contemplated herein include an apparatus comprising a method for performing Figure 1 Method 100 and Figure 2 The apparatus may be, for example, an apparatus of a UE (such as the wireless device 602 as a UE, as described herein).

[0144] Embodiments contemplated herein include one or more non-transitory computer-readable media including instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform Figure 1 Method 100 and Figure 2 One or more elements of the method 200 of . The non-transitory computer-readable medium may be, for example, a memory of a UE (such as the memory 606 of the wireless device 602 as a UE, as described herein).

[0145] Embodiments contemplated herein include an apparatus comprising a method for performing Figure 1 Method 100 and Figure 2 Logic, modules, or circuitry of one or more elements of the method 200. The apparatus may be, for example, an apparatus of a UE (such as the wireless device 602 as a UE, as described herein).

[0146] Embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform Figure 1 Method 100 and Figure 2 The apparatus may include one or more elements of the method 200. The apparatus may be, for example, an apparatus of a UE (such as the wireless device 602 as a UE, as described herein).

[0147] Embodiments contemplated herein include Figure 1 Method 100 and Figure 2 A signal described in or related to one or more elements of method 200.

[0148] Embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution of the program by a processor causes the processor to perform Figure 1 Method 100 and Figure 2 The processor may be a processor of a UE (such as the processor 604 of the wireless device 602 as a UE, as described herein). These instructions may be located, for example, in a processor and / or in a memory of a UE (for example, the memory 606 of the wireless device 602 as a UE, as described herein).

[0149] For one or more embodiments, at least one of the components set forth in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, and / or methods as described herein. For example, a baseband processor as described herein in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples set forth herein. For another example, circuits associated with a UE, a base station, a network element, etc. as described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples set forth herein.

[0150] Unless otherwise expressly stated, any of the above embodiments may be combined with any other embodiment (or combination of embodiments). The foregoing description of one or more specific implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise form disclosed. In view of the above teachings, modifications and variations are possible or can be obtained from the practice of various embodiments.

[0151] Embodiments and implementations of the systems and methods described herein may include various operations that may be embodied in machine executable instructions to be executed by a computer system. A computer system may include one or more general or special purpose computers (or other electronic devices). A computer system may include hardware components that include specific logic components for performing operations; or may include a combination of hardware, software, and / or firmware.

[0152] It should be appreciated that the systems described herein include descriptions of specific embodiments. These embodiments may be combined into a single system, partially combined into other systems, separated into multiple systems, or otherwise divided or combined. In addition, it is contemplated that parameters, attributes, aspects, etc. of another embodiment may be used in one embodiment. For clarity, these parameters, attributes, aspects, etc. are described only in one or more embodiments, and it should be appreciated that these parameters, attributes, aspects, etc. may be combined with or substituted for parameters, attributes, aspects, etc. of another embodiment unless expressly stated herein.

[0153] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of the authorized use should be clearly stated to users.

[0154] Although the foregoing has been described in considerable detail for the sake of clarity, it will be apparent that certain changes and modifications may be made without departing from the principles of the invention. It should be noted that there are many alternative ways to implement both the processes and the apparatus described herein. Therefore, the embodiments of the present invention should be regarded as illustrative rather than restrictive, and the specification is not limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.

Claims

1. A method for a user equipment (UE), the method comprising: determining whether a signal threshold file is available on a universal subscriber identity module (USIM), wherein the signal threshold file includes operator controlled signal thresholds; performing a signal threshold based public land mobile network (PLMN) selection process using the operator controlled signal threshold when the signal threshold file is available; When the signal threshold file is not available, performing a public land mobile network (PLMN) selection process not based on signal threshold; as well as Register with the PLMN for communication.

2. The method of claim 1, further comprising performing PLMN selection not based on a signal threshold when no suitable PLMN is found using the PLMN selection based on a signal threshold. The method of claim 1 , wherein the operator-controlled signal threshold is configured according to access technology. The method of claim 1 , wherein the operator-controlled signal threshold is configured based on location.

5. The method of claim 1, wherein the signal threshold file comprises an elementary file having records, the records comprising corresponding location area identification and tracking area identification, access technology identifiers, and signal strength thresholds.

6. The method of claim 1, further comprising comparing received signal quality in a cell of a candidate PLMN to a signal threshold controlled by the operator.

7. The method of claim 6, wherein if the operator-controlled signal threshold is available, the UE shall select a network if a network selection condition is met and the received signal quality in the cell of the candidate PLMN is equal to or higher than the operator-controlled signal threshold.

8. A non-transitory computer-readable storage medium comprising instructions that, when executed by a user equipment (UE), cause the UE to: determining whether a signal threshold file is available on a universal subscriber identity module (USIM), wherein the signal threshold file includes operator controlled signal thresholds; performing a signal threshold based public land mobile network (PLMN) selection process using the operator controlled signal threshold when the signal threshold file is available; When the signal threshold file is not available, performing a public land mobile network (PLMN) selection process not based on signal threshold; as well as Register with the PLMN for communication.

9. The computer-readable storage medium of claim 8, wherein the instructions further configure the UE to perform non-signal threshold based PLMN selection when no suitable PLMN is found using the signal threshold based PLMN selection.

10. The computer-readable storage medium of claim 8, wherein the operator-controlled signal threshold is configured based on access technology.

11. The computer-readable storage medium of claim 8, wherein the operator-controlled signal threshold is configured based on location.

12. The computer-readable storage medium of claim 8, wherein the signal threshold file comprises an elementary file having records including corresponding location area identifications and tracking area identifications, access technology identifiers, and signal strength thresholds.

13. The computer-readable storage medium of claim 8, wherein the instructions further configure the UE to compare a received signal quality in a cell of a candidate PLMN to a signal threshold controlled by the operator.

14. The computer-readable storage medium of claim 13, wherein if the operator-controlled signal threshold is available, the UE should select a network if a network selection condition is met and a received signal quality in a cell of the candidate PLMN is equal to or higher than the operator-controlled signal threshold.

15. A user equipment (UE), the user equipment (UE) comprising: processor; as well as a memory storing instructions, which, when executed by the processor, configure the UE to: determining whether a signal threshold file is available on a universal subscriber identity module (USIM), wherein the signal threshold file includes operator controlled signal thresholds; performing a signal threshold based public land mobile network (PLMN) selection process using the operator controlled signal threshold when the signal threshold file is available; When the signal threshold file is not available, performing a public land mobile network (PLMN) selection process not based on signal threshold; as well as Register with the PLMN for communication.

16. The UE of claim 15, wherein the instructions further configure the UE to perform PLMN selection not based on signal threshold when no suitable PLMN is found using PLMN selection based on signal threshold.

17. The UE of claim 15, wherein the instructions further configure the UE to compare a received signal quality of a candidate PLMN with a signal threshold controlled by the operator.

18. The UE of claim 17, wherein if the operator-controlled signal threshold is available, the UE should select a network only if a network selection condition is met and the received signal quality of the candidate PLMN is equal to or higher than the operator-controlled signal threshold.

19. The UE of claim 15, wherein the signal threshold file comprises an elementary file having a record, the record comprising a corresponding location area identifier and tracking area identifier, an access technology identifier, and a signal strength threshold.

20. The UE of claim 15, wherein the UE is a fixed IoT device.

21. The UE of claim 15, wherein the operator controlled signal threshold is delivered to the UE as part of a REGISTRATION ACCEPT message in a SOR transparent container information element (IE) or a downlink (DL) NAS TRANSPORT message using non-access stratum (NAS) signaling, using a Steering of Roaming (SoR) procedure.

22. The UE of claim 21, wherein the operator controlled signal threshold can be updated in the USIM using a SIM toolkit that can trigger a SIM REFRESH command.

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