WO2020102831A1

WO2020102831A1 - Methods and apparatus for mobile roaming services

Info

Publication number: WO2020102831A1
Application number: PCT/US2020/022375
Authority: WO
Inventors: Zhixian Xiang; Jianning Liu; Yan Li
Original assignee: Futurewei Technologies, Inc.
Priority date: 2019-04-30
Filing date: 2020-03-12
Publication date: 2020-05-22
Also published as: CN113455027A; CN113455027B

Abstract

A method includes receiving from a home network of a user equipment, one or more service change network selection lists (SCNSLs); detecting a service change occurred indicator associated with the home network is set to a first specified value, and based thereon: switching from using a network selection list to using a SCNSL in accordance with its selection policy; scanning for suitable networks that are in the SCNSL; receiving identifiers from one or more networks that are in the SCNSL; determining a network selection priority in accordance with the SCNSL; and selecting one of the one or more networks in the SCNSL in accordance with the network selection priority.

Description

Methods and Apparatus for Mobile Roaming Services

This application claims the benefit of U.S. Provisional Application No. 62/840,922, filed on April 30, 2019, entitled "System and Method for Mobile Roaming Service Interruption Minimization," which application is hereby incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to methods and apparatus for digital

communications, and, in particular embodiments, to methods and apparatus for mobile roaming services.

BACKGROUND

Regional regulatory authorities strive to provide measures to minimize the impact of a communications interruption on peoples’ daily lives, regardless of cause. For example, recently, the Korean government announced measures to enhance communications service resilience in disastrous situations. One of these measures is to provide access to communications service through cooperation among regional operators in unexpected situations. As society becomes ever more hyper-connected, these types of regulatory requirements should be efficiently supported.

When a network cannot provide communications service to its users due to certain events (e.g., disasters (such as fire, earthquake, inclement weather, etc.), oversubscribed services due to too many users (such as concerts, special events, and so on), and so forth), the amount of time that users are out of communications services and the additional impact on other networks should be minimized. To better achieve these aspects, there is a need for methods and apparatus for mobile roaming services.

SUMMARY

According to a first aspect, a method implemented by a user equipment (UE) is provided. The method comprising: receiving, by the UE, from a home network of the UE, one or more service change network selection lists (SCNSLs); detecting, by the UE, a service change occurred indicator associated with the home network is set to a first specified value, and based thereon: switching, by the UE, from using a network selection list to using a SCNSL in accordance with its selection policy; scanning, by the UE, for suitable networks that are in the SCNSL; receiving, by the UE, identifiers from one or more networks that are in the SCNSL; determining, by the UE, a network selection priority in accordance with the SCNSL; and selecting, by the UE, one of the one or more networks in the SCNSL in accordance with the network selection priority.

In a first implementation form of the method according to the first aspect as such, the one or more SCNSLs being different from the network selection list.

In a second implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, the network selection priority comprising at least one of a service for the UE, a subscription level of the UE, a current time of day, an expected service time and period, a trigger event restriction, or services offered by the one or more networks.

In a third implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, the network selection priority further comprising a location of the UE, and a time and period of a service which the UE is expected to receive.

In a fourth implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, further comprising determining, by the UE, the location of the UE, and a time and period of a service which the UE is expected to receive.

In a fifth implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, further comprising accessing, by the UE, the one of the one or more networks.

In a sixth implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, further comprising: detecting, by the UE, the service change occurred indicator associated with the home network is set to a second specified value, and based thereon: switching, by the UE, to using the network selection list; scanning, by the UE, for suitable second networks that are in the network selection list; receiving, by the UE, identifiers from one or more second networks that are in the network selection list; and selecting, by the UE, one of the one or more second networks in accordance with the network selection list.

In a seventh implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, the service change indicator being received from a network with coverage that includes the UE. In an eighth implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, the UE being capable of receiving information from the network.

In a ninth implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, further comprising accessing, by the UE, the one of the one or more second networks.

In a tenth implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, further comprising: receiving, by the UE, an identifier of the home network; and accessing, by the UE, the home network.

In an eleventh implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, the service change occurred indicator being set to the first specified value indicates that a service change event has occurred in the home network.

According to a second aspect, a method implemented by a network entity is provided. The method comprising: detecting, by the network entity, an occurrence of a service change event at a network; and sending, by the network entity, a service change occurred indicator associated with the network, the service change occurred indicator being set to a first specified value.

In a first implementation form of the method according to the second aspect as such, the network entity receiving the service change event from a centralized management entity.

In a second implementation form of the method according to the second aspect as such or any preceding implementation form of the second aspect, the service change event comprising at least one of an emergency occurring in the network, or a special event occurring in the network.

In a third implementation form of the method according to the second aspect as such or any preceding implementation form of the second aspect, the service change occurred indicator being transmitted in a broadcast message, or unicast message responsive to a query.

In a fourth implementation form of the method according to the second aspect as such or any preceding implementation form of the second aspect, further comprising: detecting, by the network entity, a resolution of the service change event, and based thereon, transmitting, by the network entity, the service change occurred indicator set to a second specified value.

In a fifth implementation form of the method according to the second aspect as such or any preceding implementation form of the second aspect, the second specified value indicating that the service change event has been resolved.

In a sixth implementation form of the method according to the second aspect as such or any preceding implementation form of the second aspect, the first specified value indicating an occurrence of the service change event. According to a third aspect, a UE is provided. The UE comprising: a non-transitoiy memory storage comprising instructions; and one or more processors in communication with the memory storage, wherein the one or more processors execute the instructions to: receive, from a home network of the UE, one or more SCNSLs; detect a service change occurred indicator associated with the home network is set to a first specified value, and based thereon: switch from using a network selection list to using a SCNSL in accordance with its selection policy; scan for suitable networks that are in the SCNSL; receive identifiers from one or more networks that are in the SCNSL; determine a network selection priority in accordance with the SCNSL; and select one of the one or more networks in the SCNSL in accordance with the network selection priority.

In a first implementation form of the UE according to the third aspect as such, the network selection priority comprising at least one of a service for the UE, a subscription level of the UE, a current time of day, an expected service time and period, a trigger event restriction, or services offered by the one or more networks.

In a second implementation form of the UE according to the third aspect as such or any preceding implementation form of the third aspect, the network selection priority further comprising a location of the UE, and a time and period of a service which the UE is expected to receive.

In a third implementation form of the UE according to the third aspect as such or any preceding implementation form of the third aspect, the one or more processors further executing the instructions to determine the location of the UE, and a time and period of a service which the UE is expected to receive. In a fourth implementation form of the UE according to the third aspect as such or any preceding implementation form of the third aspect, the one or more processors further executing the instructions to access the one of the one or more networks.

In a fifth implementation form of the UE according to the third aspect as such or any preceding implementation form of the third aspect, the one or more processors further executing the instructions to detect the service change occurred indicator associated with the home network is set to a second specified value, and based thereon: switch to using the network selection list; scan for suitable second networks that are in the network selection list; receive identifiers from one or more second networks that are in the network selection list; and select one of the one or more second networks in accordance with the network selection list.

In a sixth implementation form of the UE according to the third aspect as such or any preceding implementation form of the third aspect, the one or more processors further executing the instructions to receive an identifier of the home network; and access the home network.

According to a fourth aspect, a network entity is provided. The network entity comprising: a non-transitoiy memory storage comprising instructions; and one or more processors in communication with the memory storage, wherein the one or more processors execute the instructions to: detect an occurrence of a service change event at a network; and send a service change occurred indicator associated with the network, the service change occurred indicator being set to a first specified value.

In a first implementation form of the network entity according to the fourth aspect as such, the one or more processors further executing the instructions to receive the service change event from a centralized management entity.

In a second implementation form of the network entity according to the fourth aspect as such or any preceding implementation form of the fourth aspect, the service change event comprising at least one of an emergency occurring in the network, or a special event occurring in the network.

In a third implementation form of the network entity according to the fourth aspect as such or any preceding implementation form of the fourth aspect, the one or more processors further executing the instructions to detect a resolution of the service change event, and based thereon, transmit the service change occurred indicator set to a second specified value.

An advantage of a preferred embodiment is that users impacted by a service change situation can obtain service in networks ordinarily unavailable to them. Therefore, the users can receive important information in emergency situations or maintain user satisfaction in non-emergency situations.

Yet another advantage of a preferred embodiment is that once the service change situation clears, the users can return to their normal networks, even if the users miss the indication that the service change situation has cleared.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

Figure t illustrates an example communication system too for communicating data;

Figure 2A illustrates a communication system with three public land mobile networks (PLMNs);

Figure 2B illustrates a communication system, highlighting a situation where an emergency disables a home PLMN (HPLMN);

Figure 2C illustrates a communication system, highlighting a situation where a special event causes service disruption;

Figure 3A illustrates a first example service change PLMN selection list according to example embodiments presented herein;

Figure 3B illustrates a second example service change PLMN selection list according to example embodiments presented herein;

Figure 4 illustrates a diagram of messages exchanged and processing occurring at devices or networks participating in example operations occurring in response to an occurrence of a service change event according to example embodiments presented herein; Figure 5 illustrates a flow diagram of example operations occurring in a UE in response to an occurrence of a service change event according to example embodiments presented herein;

Figure 6 illustrates a flow diagram of example operations occurring in a network entity in response to an occurrence of a service change event according to example embodiments presented herein;

Figure 7 illustrates a flow diagram of example operations occurring in a UE recovering upon a resolution of a service change event according to example embodiments presented herein;

Figure 8 illustrates a detailed view of a communication system highlighting the configuration of a service change PLMN list according to example embodiments presented herein;

Figure 9 illustrates an example communication system according to example

embodiments presented herein;

Figures 10A and 10B illustrate example devices that may implement the methods and teachings according to this disclosure; and

Figure 11 is a block diagram of a computing system that may be used for implementing the devices and methods disclosed herein.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The structure and use of disclosed embodiments are discussed in detail below. It should be appreciated, however, that the present disclosure provides many applicable concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific structure and use of embodiments, and do not limit the scope of the disclosure.

Figure 1 illustrates an example communication system too for communicating data. Communication system too includes an access point (AP) 110 having a coverage area 111, a plurality of mobile devices (such as mobile devices 120 and 122), and a backhaul network 130. AP 110 may comprise any component capable of providing wireless access by, among other things, establishing uplink (dashed line) and/or downlink (solid line) connections with the mobile devices. In a first operating mode, communications to and from a mobile device passes through AP 110. In a second operating mode, communications to and from a mobile device do not pass through AP no, however, AP no typically allocates resources used by the mobile device to communicate when specific conditions are met.

APs may also be commonly referred to as Node Bs, evolved Node Bs (eNBs), next generation (NG) Node Bs (gNBs), master eNBs (MeNBs), secondary eNBs (SeNBs), master gNBs (MgNBs), secondary gNBs (SgNBs), network controllers, control nodes, base stations, access nodes, transmission points (TPs), transmission-reception points (TRPs), cells, carriers, macro cells, femtocells, pico cells, and so on, while mobile devices may also be commonly referred to as mobile stations, mobiles, terminals, users, subscribers, stations, user equipments (UEs), and the like. APs may provide wireless access in accordance with one or more wireless communication protocols, e.g., the Third Generation Partnership Project (3GPP) long term evolution (LTE), LTE advanced (LTE- A), 5G, 5G LTE, 5G NR, High Speed Packet Access (HSPA), the IEEE 802.11 family of standards, such as 802.na/b/g/n/ac/ad/ax/ay/be, etc. While it is understood that communications systems may employ multiple APs capable of communicating with a number of mobile devices, only one AP and two mobile devices are illustrated for simplicity.

Backhaul network 130 may be any component or collection of components that allow data to be exchanged between the AP and a remote end. In some embodiments, backhaul network 130 may comprise various other wireless devices, such as relays, low power nodes, etc. Public land mobile networks (PLMNs) are mobile wireless networks that offer a combination of wireless services in a specific region. A PLMN is typically operated by a single operator. There may be multiple PLMNs within an area, with some overlapping coverage. Home public land mobile networks (HPLMNs) and visited public land mobile networks (VPLMNs) in communication system too may have the same overlapping coverage areas or different coverage areas from each other.

The 3GPP Technical Specification Group on Service and System Aspects: Services (SAt) has created a new item to study how to enhance roaming between operators to provide service in case of a disastrous situation. Potential aspects to be addressed to derive relevant potential service requirements include, for example:

- The scenarios, scales or causes of interruption of communication service;

- Allowing impacted users to override restriction, e.g., forbidden PLMN due to prior access before disaster occurs;

- Allowing impacted users to obtain missed warning messages from the out- of-service period; and - Giving different treatment to the refugee users than the native home users (e.g., access control differentiation), and for which types of services (e.g., voice, data, etc.) the differentiation applies.

Issues associated with enhanced roaming between operations in case of a disastrous situation include:

- UE selection during the disaster situation, e.g., allowing impacted users to override a restriction, e.g., forbidden PLMN due to prior access before disaster occurs; and

- Preventing a VPLMN from being flooded with UEs from the PLMN experiencing the disaster.

Figure 2A illustrates a communication system 200 with three PLMNs. Communication system 200 includes three PLMNs: a HPLMN 205, a PLMN_t 210, and a PLMN_2 212. Operating within HPLMN 205 are UEs 220 and 225. HPLMN 205 is the home PLMN of UEs 220 and 225. UE 220 is operating within the coverage areas of HPLMN 205 and PLMN_t 210, while UE 225 is operating within the coverage areas of HPLMN 205, PLMN_t 210 and PLMN_2 212. As such, it is possible for UE 220 to connect to HPLMN 205 or PLMN_t 210, and UE 225 to connect to HPLMN 205, PLMN_t 210, or PLMN_2 212.

Figure 2B illustrates communication system 200, highlighting a situation where an emergency disables HPLMN 205. Because HPLMN 205 is disabled, UEs 220 and 225 are unable to obtain service through HPLMN 205. However, if there is a service agreement between HPLMN 205 and PLMN_t 210 or PLMN_2 212, it may be possible for UE 220 or UE 225 to obtain service through PLMN_t 210 or PLMN_2 212. If HPLMN 205 does not have a service agreement with PLMN_t 210 or PLMN_2 212, then it is possible for UE 220 or UE 225 to be without service.

Figure 2C illustrates communication system 200, highlighting a situation where a special event causes service disruption. As shown in Figure 2C, UE 225 is located in region 250, which may correspond to the location of a special event, such as a concert, a convention, a sporting event, etc. In general, a special event may be an event or occurrence that causes a HPLMN to suspend service for its users for a period of time. Therefore, for the duration of the special event, the HPLMN expects the users to move to another network for the period of time. For discussion purposes, consider a situation where there are so many users in region 250 that it is not possible for HPLMN 205 to provide services for all of its users. In such a situation, UE 225 may be without service. Therefore, there is a need for methods and apparatus for mobile roaming services in scenarios that arise from service change situations. As discussed above, in a disastrous or emergency situation, or in the occurrence of a special event, there may be a need for moving UEs from one PLMN to another PLMN to enable the UEs to continue receiving service. In these service change situations, existing service agreements between PLMNs may not be able to ensure that the UEs continue to receive service. As an example, in an emergency situation, the only available PLMN may not have a service agreement with the HPLMN of the UE, hence, the UE will not be able to obtain service through the only available PLMN. As another example, at a convention, the convention organizer has a service agreement with a PLMN that does not have a service agreement with the HPLMN of a UE. The UE would be unable to access services that help to ensure a successful convention, such as services that augment the attendee experience.

According to an example embodiment, a network selection mechanism for selecting a VPLMN in a service change event is provided. The network selection mechanism enables a UE to obtain services through PLMNs that the HPLMN of the UE may not ordinarily have a service agreement with or the HPLMN of the UE may not ordinarily have a service agreement with at the subscription level of the UE. Hence, without the network selection mechanism, the UE may be unable to obtain services in the occurrence of a service change event. As discussed previously, service change events, which include emergencies, disastrous events, special events, etc., are extraordinary events that usually do not occur daily and would fall outside the scope of an ordinary PLMN selection list. The ordinary PLMN selection list may provide a list of PLMNs with service agreements with the HPLMN of the UE and services that the UE may be able to obtain through the PLMNs in the event that the UE roams outside of the coverage of the HPLMN. The ordinary PLMN selection list typically includes no information regarding how to handle the occurrence of a service change event, which may include loss of connectivity from the HPLMN.

According to an example embodiment, a multi-policy based network selection mechanism to access VPLMNs while the HPLMN of the UE is unavailable is provided. In the event that the HPLMN is unavailable, e.g., the HPLMN is unavailable due to a disastrous event or emergency, or the HPLMN is unavailable due to a special agreement between the HPLMN and one or more other PLMNs exists to provide services at a special event, the network selection mechanism enables the selection of PLMNs based one multiple policies. Examples of the policies include, but are not limited to: time of day, location, service type, subscription type, service change event restrictions, UE

subscription level, PLMN selection criteria, expected service time and period, or combinations thereof. Although the discussion presented herein focusses primarily on disasters or emergencies, the example embodiments presented herein are operable in other situations. As an example, during a special event, such as a concert, a convention, an athletic event, etc., the number of users operating within a particular area may exceed the capability of a single PLMN, e.g., the HPLMN. In such a situation, the HPLMN may make arrangements with one or more other PLMNs to allow at least some of the users to migrate to the one or more other PLMNs, to alleviate the congestion caused by the large number of users for the duration of the special event. In other words, there is a collaborative arrangement between the HPLMN and the one or more other PLMNs to establish inter-operator roaming operations outside of normal roaming relationships that exist in normal conditions. The arrangement would supersede existing roaming relationships that may or may not exist between the various PLMNs. Therefore, the discussion of disasters or emergencies should not be construed as being limiting on the scope of the example embodiments.

According to an example embodiment, a service change event PLMN selection mechanism for a UE whose HPLMN is unable to provide service is provided. In a situation when the HPLMN of a UE is unable to provide service to the UE, such as after occurrence of a service change event, the UE will need to obtain service from an alternative PLMN. Due to the typically unexpected nature of service change events, the ordinary PLMN selection list does not include information regarding where the UE is to obtain service when the service change event occurs.

In an embodiment, a service change PLMN selection list is provided. The service change PLMN selection list may be separate from the ordinary PLMN selection list. In an embodiment, the service change PLMN selection list is provisioned by the HPLMN and provided to the UE. As an example, the service change PLMN selection list is provided to the UE when the UE attaches to the HPLMN. In an embodiment, multiple service change PLMN selection lists are provided to the UE, with the multiple service change PLMN selection lists being applicable to different service change events, different UE locations, different subscription levels, service time and period, etc., for example.

Additionally, the service change PLMN selection list may be provided to the UE when there is a change to the service change PLMN selection list. For example, when the HPLMN establishes an agreement with a PLMN, impacting the service change PLMN selection list, an updated version of the service change PLMN selection list is generated and provided to the UE. As another example, when an agreement between the HPLMN and any PLMN with which the HPLMN has a service agreement changes, the HPLMN updates the service change PLMN selection list and provides the updated service change PLMN selection list to the UE. As another example, when the subscription level of the UE changes and if a different version of the service change PLMN selection list is warranted, the HPLMN provides the different version of the service change PLMN selection list to the UE.

An example service change PLMN selection list may include a prioritized list of VPLMNs that lists either candidate VPLMNs or disaster consortium identifiers (IDs) for the UEs to access, along with the time, location, service type, roaming trigger event restrictions, subscription type or level (e.g., gold, silver, bronze, etc., where gold is higher than silver, which is higher than bronze, for example), and other PLMN selection policies, on which the UE uses to select the VPLMN to obtain service. The UE uses the information in the service change PLMN selection list to generate a policy or restrictions on which it bases the selection of the VPLMN to obtain service.

An example service change PLMN selection list entry may specify that a UE searching for voice service is permitted to access a third VPLMN when the UE located in a third location because the service change event is a fire emergency. Another example service change PLMN selection list may specify that a UE searching for video service while located in a second location is permitted to access a second VPLMN. Yet another example service change PLMN selection list entry may specify that a first UE with a high grade subscription type (e.g., a gold subscription level) is permitted to access a second VPLMN while located at a particular location, while a second UE with a lower grade subscription type (e.g., a bronze subscription level) is permitted to access a third VPLMN while located at the particular location, where the second VPLMN offers greater bandwidth, less latency, higher quality of service (QoS) requirements, fewer number of UEs, etc., than the third VPLMN (in other words, the second VPLMN is a premium VPLMN, while the third VPLMN is not). Additional examples of service change PLMN selection lists and associated entries are provided below.

Figure 3A illustrates a first example service change PLMN selection list 300. As shown in Figure 3A, service change PLMN selection list 300 includes entries for a plurality of PLMNs. As an example, entries 306 are associated with HPLMN 305, entries 311 are associated with VPLMN_t 310, entries 316 are associated with VPLMN_2 315, and so on. The entries in service change PLMN selection list 300 may be prioritized. As an example, a UE utilizing service change PLMN selection list 300 may select an entry that is highest in service change PLMN selection list 300 meeting its requirements (e.g., service, time, location, subscription level, service change event restrictions, service time and period, etc.).

Entries 306 includes two entries: entry 307 indicating that HPLMN 305 provides video services in locations 1, 2, and 3 24 hours a day, while entry 308 indicating that HPLMN 305 provides audio services in all locations 24 hours a day. Entries 311 includes three entries: entry 312 indicating that VPLMN_t 310 provides video service in location 1 between the hours of 8AM-7PM, entry 313 indicating that VPLMN_t 310 provides audio service in location 2 24 hours a day, and entry 314 indicating that VPLMN_t 310 provides E911 service in all locations 24 hours a day. Entries 316 includes three entries: entry 317 indicating that VPLMN_2 315 provides video service in location 2 between the hours of 7PM-5AM, entry 318 indicating that VPLMN_2 315 provides audio service in location 1 24 hours a day, and entry 319 indicating that VPLMN_2 315 provides E911 service in all locations 24 hours a day.

Figure 3B illustrates a second example service change PLMN selection list 350. As shown in Figure 3B, service change PLMN selection list 350 includes entries grouped based on selection priority. As an example, entries 356 are associated with location criteria 355, entries 361 are associated with service criteria 360, and so on. The entries in service change PLMN selection list 350 may be prioritized. As an example, a UE utilizing service change PLMN selection list 350 may select an entry based on selection criteria that matches the requirements of the UE. As an example, the UE utilizing service change PLMN selection list 350 may select an entry that matches its location with highest priority, and an entry that matches its service requirement with next highest priority.

Entries 356 includes two entries: entry 357 indicating for location 1, an ordered list of PLMNs comprises HPLMN, VPLMN_2, and VPLMN_i, and entry 358 indicating for location 2, an ordered list of PLMNs comprises HPLMN, VPLMN_i, and VPLMN 3. Entries 361 includes two entries: entry 362 indicating that for location 1, an ordered list of PLMNs comprises HPLMN, VPLMN_2, and VPLMN_i, and entry 363 indicating that for location 2, an ordered list of PLMNs comprises HPLMN, VPLMN_i, and VPLMN 3.

The entries shown in Figures 3A and 3B are for illustrative purposes and are not intended to illustrate all of the information that may be included in the service change PLMN selection list. As an example, service change event restrictions and subscription type are not shown in Figures 3A and 3B. Therefore, the information shown in Figures 3A and 3B should not be construed as being limiting to the scope of the example embodiments. In an embodiment, the service change PLMN selection list is activated and used by the UE when a service change event occurs. In normal operations, when a service change event has not occurred, the UE uses the ordinary PLMN selection list. However, when a service change event occurs, the UE switches to the service change PLMN selection list and uses the service change PLMN selection list to select a PLMN to obtain service.

In an embodiment, when the service change event completes, the service change PLMN selection list is deactivated. When the service change event completes, such as when recovery from the disastrous event or emergency event is achieved or when the special event is over, the UE switches to the ordinary PLMN selection list and resumes normal operation.

In an embodiment, a service change occurred indicator indicates the occurrence of a service change event. As an example, the service change occurred indicator comprises a one-bit or longer indicator and an identifier field, that when the indicator is set to a first value indicates that a service change event has occurred in a PLMN with identifier conveyed in the identifier field. Furthermore, when the indicator is set to a second value, the service change occurred indicator indicates that the PLMN (with identifier conveyed in the identifier field) has recovered from the service change event or the service change event is over. As another example, the service change occurred indicator may be an identifier field that, when set to the identifier of a PLMN, implicitly indicates that a service change event has occurred in the PLMN with identifier conveyed in the identifier field. When the PLMN has recovered from the service change event or the service change event is over, another service change occurred indicator may be sent, implicitly indicating that recovery has occurred or the service change event is over.

Figure 4 illustrates a diagram 400 of messages exchanged and processing occurring at devices or networks participating in example operations occurring in response to an occurrence of a service change event. Diagram 400 illustrates messages exchanged and processing occurring at a PLMN_t 405, a network entity 407, a PLMN_2 409, a first UE (UE_i) 411, a second UE (UE_2) 413, and a PLMN 3415.

At PLMN_t 405, a service change condition is met (block 420). If an emergency or disastrous event has occurred, a failure may be detected at one or more network entities of PLMN_t 405, for example. As an example, an earthquake may have disabled one or more access nodes of PLMN_t 405. As another example, in a situation where the network change event is a special event, the special event may be detected based on a time and location associated with the special event. Network entity 407 sends a service change notification (event 422). The service change notification may be a network level message intended for PLMNs operating in the vicinity of PLMN_t 405 to notify them that a service change event has occurred in PLMN_t 405. The service change notification may be may be a message with an identifier of PLMN_t 405, for example. Network entity 407 may be a network entity of PLMN_t 405. Alternatively, network 407 may be a network entity of any other PLMN that is able to detect the occurrence of the service change event in PLMN_t 405.

The PLMNs receiving the service change notification (e.g., PLMN_2 409 and PLMN .3 415) transmit service change occurred indicators (events 424 and 426). As an example, the service change occurred indicator includes a one-bit or longer indicator and an identifier field, where the indicator is set to a value indicating that a service change event has occurred and the identifier field is set to the identifier of PLMN_t 405. As another example, the service change occurred indicator includes an identifier field that is set to the identifier of PLMN_t 405. The service change occurred indicator may be broadcast so that any UE may able to receive the service change occurred indicator. The service change occurred indicator may also be groupcast or unicast. As an example, the service change occurred indicator may be groupcast (to a UE group) or unicast (to a UE) in response to a query from a member of the UE group or the UE. The query may be a network status query, for example. As an alternative to the service change occurred indicator being transmitted in a message that is broadcast, groupcast, or unicast over- the-air to the UE, the service change occurred indicator may be transmitted by other means, such as over the Internet or a wireline network, to the UE.

As shown in Figure 4, first UE 411 and second UE 413 receive the service change occurred indicator. First UE 411 and second UE 413 switch to their respective service change PLMN selection lists (which maybe different), initiate service change selections, and select PLMNs that meet their respective selection priorities (blocks 428 and 430). For discussion purposes, first UE 411 selects PLMN_2 409 and second UE 413 selects PLMN 3415. However, a UE selects a PLMN in accordance with its requirements (e.g., service, time, location, subscription level, service change event restrictions, service time and period, etc.). First UE 411 accesses PLMN_2 409 (event 432) and second UE 413 accesses PLMN 3 415 (event 434. Accessing a PLMN may include transmitting one or more messages to attach to the PLMN. The UE may also receive one or more messages from the PLMN.

In a situation where a service change event has already occurred in PLMN_t 405, once the service change event has resolved or the service change event is over, the messages exchanged and processing shown in Figure 4 are also applicable to the resumption of normal activity at PLMN_i 405 and UEs served by PLMN_i 405. As an example, once the service change event has resolved or is over, network entity 407 sends a service change notification indicating that the service change event has resolved or is over. PLMN_2 409 and PLMN_3 415 may transmit service change occurred indicators indicating that the service change event has resolved or is over. First UE 411 and second UE 413 may then switch back to their respective ordinary PLMN selection lists and select PLMNs in accordance with the ordinary PLMN selection lists. Alternatively, PLMN_i 405 may resume operations and the UEs served by PLMN_i 405, upon detection of such transmissions, may switch back to PLMN_i 405 and resume normal operations. A detailed discussion of switching based on HPLMN transmissions is provided below.

Figure 5 illustrates a flow diagram of example operations 500 occurring in a UE in response to an occurrence of a service change event. Operations 500 may be indicative of operations occurring in a UE as the UE responds to an occurrence of a service change event. The service change event may be a disastrous or emergency event or a special event.

Operations 500 begin with the UE receiving a service change occurred indicator (block 505). The service change occurred indicator may indicate the occurrence of a service change event in a PLMN with an identifier included in the service change occurred indicator. As an example, a service change event occurred in the HPLMN of the UE. The service change occurred indicator may be received in a broadcast message, a message transmitted to a UE group that includes the UE, or a message specifically addressed to the UE. The service change occurred indicator may also be received in a message transmitted over the Internet or a wireline network. The UE switches to the service change PLMN selection list (block 507). The UE switches from the ordinary PLMN selection list to the service change PLMN selection list after the UE receives the service change occurred indicator indicating the occurrence of a service change event.

The UE optionally determines its current location (block 509). As an example, the UE may measure position reference signals transmitted by access nodes located near the UE and determine its current location based on the measurements. As another example, the UE transmits position reference signals and access nodes located near the UE measures the position reference signals to determine the current location of the UE. The current location of the UE may be helpful in selecting a PLMN, but it may not be necessary to update the current location of the UE. A previously determined location of the UE may be used instead of the current location. In addition to determining its current location, the UE may also determine a time and period of the service that it is expecting to receive. The additional knowledge regarding the time and period of the service that the UE is expecting to receive may further assist the UE in considering PLMNs. As an example, if the UE is expecting to utilize video services, the UE will not consider PLMNs that are not offering video services.

The UE scans for suitable PLMNs (block 511). The UE scans for signals transmitted by access nodes of PLMNs located near the UE. The signals received by the UE may be used to identify the PLMNs, as well as potentially identifying the relative signal strength and quality of the PLMNs, for example.

The UE determines a network selection priority (block 513). The network selection priority may be determined in accordance with the service change PLMN selection list and information included therein. Furthermore, the network selection priority may be determined in accordance with the service that the UE intends to use, as well as the location of the UE, the subscription level of the UE, the time of the day, service time and period, and so forth. An example network selection priority may be as follows: PLMN 3, voice, access time 4pm - 10pm; PLMN 4, video, access time 12pm - 10pm; and PLMN 2, voice, access time 4pm- 10pm.

The UE selects a PLMN (block 515). The UE selects a PLMN from the PLMNs that the UE was able to detect in the scan performed in block 511. The selection of the PLMN may be in accordance with the network selection priority and the service change PLMN selection list. In a situation when there is more than one possible PLMN to select from, the UE may select the PLMN with a stronger signal (or better performance guarantees, better performance history, lower error rates, etc.), for example. The UE accesses the selected PLMN (block 517). Accessing the selected PLMN may include transmitting one or more messages to attach to the selected PLMN. The UE may also receive one or more messages from the selected PLMN.

Figure 6 illustrates a flow diagram of example operations 600 occurring in a network entity in response to an occurrence of a service change event. Operations 600 may be indicative of operations occurring in a network entity as the network entity responds to an occurrence of a service change event. The service change event may be a disastrous or emergency event or a special event. The network entity may be in the PLMN that is experiencing the service change event or in a PLMN in the vicinity of the PLMN that is experiencing the service change event. The network entity may be an access node or any other entity in a PLMN that is capable of detecting the service change event and communicating with other network entities. Operations 6oo begin with the network entity detecting the occurrence of a network change event (block 605). As an example, the network entity may detect failure in one or more network entities of the PLMN where the service change event occurs. As another example, in a situation where the network change event is a special event, the network entity may detect the occurrence of the service change event based on a time and location associated with the special event. The network entity sends a service change notification (block 607). The service change notification may be a network level message intended for PLMNs operating in the vicinity of the PLMN where the service change event occurred to notify them that a service change event has occurred in the PLMN. The service change notification may be a message with an identifier of the PLMN where the service change event occurred, for example.

According to an example embodiment, the network selection mechanism for selecting a VPLMN in an occurrence of a service change event is also operable when recovery from the service change event is achieved or the service change event ends. In other words, the network selection mechanism for selecting a VPLMN in the occurrence of a service change event is also operable when resolution of the service change event is achieved.

In an embodiment, when resolution of the service change event is achieved or the service change event ends, a network entity (upon detecting the recovery from the service change event or ending of the service change event) sends a service change notification indicating that the PLMN has resumed normal operation. The service change notification may follow the format of the service change notification indicating the occurrence of the service change event, for example.

In an embodiment, PLMNs, receiving the service change notification indicating that the PLMN has resumed normal operation, transmit service change occurred indicators indicating that the service change event has been resolved (e.g., the service change event is over) in the PLMN identified in the identifier field. The service change occurred indicators may follow the format of the service change occurred indicators indicating the occurrence of the service change event, for example.

In an embodiment, UEs, utilizing their respective service change PLMN selection lists, receiving the service change notification indicating that the PLMN has resumed normal operation, switch back to normal operation. The UE may resume normal operation by switching back to the ordinary PLMN selection list, for example.

According to an example embodiment, the organization of the service change PLMN selection list enables a UE to switch back to normal operation even in the situation where the UE do not receive the service change notification indicating that the PLMN has resumed normal operation. In an embodiment, the service change PLMN selection list is organized so that information related to the HPLMN of the UE, including the services offered by the HPLMN, the locations of the HPLMN, subscription type, etc., is assigned the highest priority. With the HPLMN assigned the highest priority, the UE will select the HPLMN whenever the UE is able to detect the HPLMN.

Figure 7 illustrates a flow diagram of example operations 700 occurring in a UE recovering upon a resolution of a service change event. Operations 700 may be indicative of operations occurring in a UE as the UE recovers due to a resolution of a service change event.

Operations 700 begin with the UE performing a check to determine if it has received a service change occurred indicator indicating that the service change event has been resolved (block 705). The service change occurred indicator indicating that the service change event has been resolved may be in a format similar to the service change occurred indicator indicating that the service change event has occurred, but with the indicator set to a different value, for example. If the UE has received such a service change occurred indicator, the UE resumes normal operation by deactivating service change PLMN selection (block 707) and switching back to the ordinary PLMN selection list (block 709).

However, even if the UE has not received the service change occurred indicator indicating that the service change event has been resolved, the UE may still switch back to normal operation when the UE detects transmissions of its HPLMN (block 711).

Because the service change PLMN selection list is organized so that its HPLMN is given the highest priority, if the UE detects transmissions from its HPLMN, the UE determines that the service change event has resolved and the UE resumes normal operation by deactivating service change PLMN selection (block 707) and switching back to the ordinary PLMN selection list (block 709).

Figure 8 illustrates a detailed view of a communication system 800 highlighting the configuration of a service change PLMN list. Communication system 800 includes a UE 805 that is connected to network functions 810 by way of a network side interface 815. Network functions 810 may be implemented in one or more network entities, stand alone or collocated. Network functions 810 configure an ordinary PLMN selection list and a service change PLMN selection list for UE 805. UE 805 may store the ordinary PLMN selection list and the service change PLMN selection list in a memory 807. As an example, the ordinary PLMN selection list is stored in memory 807 as ordinary PLMN selection list 808, while the service change PLMN selection list is stored in memory are service change PLMN selection list 809. In a situation where multiple service change PLMN selection lists are configured for UE 805, the multiple service change PLMN selection lists may be stored in memory 807.

Figure 9 illustrates an example communication system 900. In general, the system 900 enables multiple wireless or wired users to transmit and receive data and other content. The system 900 may implement one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), or non-orthogonal multiple access (NOMA).

In this example, the communication system 900 includes electronic devices (ED) 910a- 910c, radio access networks (RANs) 92oa-92ob, a core network 930, a public switched telephone network (PSTN) 940, the Internet 950, and other networks 960. While certain numbers of these components or elements are shown in Figure 9, any number of these components or elements may be included in the system 900.

The EDs 9ioa-9ioc are configured to operate or communicate in the system 900. For example, the EDs 9ioa-9ioc are configured to transmit or receive via wireless or wired communication channels. Each ED 9ioa-9ioc represents any suitable end user device and may include such devices (or may be referred to) as a user equipment or device (UE), wireless transmit or receive unit (WTRU), mobile station, fixed or mobile subscriber unit, cellular telephone, personal digital assistant (PDA), smartphone, laptop, computer, touchpad, wireless sensor, or consumer electronics device.

The RANs 92oa-92ob here include base stations 970a-970b, respectively. Each base station 970a-970b is configured to wirelessly interface with one or more of the EDs 910a- 910c to enable access to the core network 930, the PSTN 940, the Internet 950, or the other networks 960. For example, the base stations 970a-970b may include (or be) one or more of several well-known devices, such as a base transceiver station (BTS), a Node- 15 (NodeB), an evolved NodeB (eNodeB), a Next Generation (NG) NodeB (gNB), a Home NodeB, a Home eNodeB, a site controller, an access point (AP), or a wireless router. The EDs 9ioa-9ioc are configured to interface and communicate with the Internet 950 and may access the core network 930, the PSTN 940, or the other networks 960.

In the embodiment shown in Figure 9, the base station 970a forms part of the RAN 920a, which may include other base stations, elements, or devices. Also, the base station 970b forms part of the RAN 920b, which may include other base stations, elements, or devices. Each base station 970a-970b operates to transmit or receive wireless signals within a particular geographic region or area, sometimes referred to as a“cell.” In some embodiments, multiple-input multiple-output (MIMO) technology maybe employed having multiple transceivers for each cell.

The base stations 970a-970b communicate with one or more of the EDs 9ioa-9ioc over one or more air interfaces 990 using wireless communication links. The air interfaces 990 may utilize any suitable radio access technology.

It is contemplated that the system 900 may use multiple channel access functionality, including such schemes as described above. In particular embodiments, the base stations and EDs implement 5G New Radio (NR), LTE, LTE-A, or LTE-B. Of course, other multiple access schemes and wireless protocols may be utilized.

The RANs 920a-920b are in communication with the core network 930 to provide the EDs 9ioa-9ioc with voice, data, application, Voice over Internet Protocol (VoIP), or other services. Understandably, the RANs 920a-920b or the core network 930 may be in direct or indirect communication with one or more other RANs (not shown). The core network 930 may also serve as a gateway access for other networks (such as the PSTN 940, the Internet 950, and the other networks 960). In addition, some or all of the EDs 9ioa-9ioc may include functionality for communicating with different wireless networks over different wireless links using different wireless technologies or protocols. Instead of wireless communication (or in addition thereto), the EDs may communicate via wired communication channels to a service provider or switch (not shown), and to the Internet

950.

Although Figure 9 illustrates one example of a communication system, various changes may be made to Figure 9. For example, the communication system 900 could include any number of EDs, base stations, networks, or other components in any suitable configuration.

Figures 10A and 10B illustrate example devices that may implement the methods and teachings according to this disclosure. In particular, Figure 10A illustrates an example ED 1010, and Figure 10B illustrates an example base station 1070. These components could be used in the system 900 or in any other suitable system.

As shown in Figure 10A, the ED 1010 includes at least one processing unit 1000. The processing unit 1000 implements various processing operations of the ED 1010. For example, the processing unit 1000 could perform signal coding, data processing, power control, input/output processing, or any other functionality enabling the ED 1010 to operate in the system 900. The processing unit 1000 also supports the methods and teachings described in more detail above. Each processing unit 1000 includes any suitable processing or computing device configured to perform one or more operations. Each processing unit 1000 could, for example, include a microprocessor,

microcontroller, digital signal processor, field programmable gate array, or application specific integrated circuit.

The ED 1010 also includes at least one transceiver 1002. The transceiver 1002 is configured to modulate data or other content for transmission by at least one antenna or NIC (Network Interface Controller) 1004. The transceiver 1002 is also configured to demodulate data or other content received by the at least one antenna 1004. Each transceiver 1002 includes any suitable structure for generating signals for wireless or wired transmission or processing signals received wirelessly or by wire. Each antenna 1004 includes any suitable structure for transmitting or receiving wireless or wired signals. One or multiple transceivers 1002 could be used in the ED 1010, and one or multiple antennas 1004 could be used in the ED 1010. Although shown as a single functional unit, a transceiver 1002 could also be implemented using at least one transmitter and at least one separate receiver.

The ED 1010 further includes one or more input/output devices 1006 or interfaces (such as a wired interface to the Internet 950). The input/output devices 1006 facilitate interaction with a user or other devices (network communications) in the network. Each input/output device 1006 includes any suitable structure for providing information to or receiving information from a user, such as a speaker, microphone, keypad, keyboard, display, or touch screen, including network interface communications.

In addition, the ED 1010 includes at least one memory 1008. The memory 1008 stores instructions and data used, generated, or collected by the ED 1010. For example, the memory 1008 could store software or firmware instructions executed by the processing unit(s) 1000 and data used to reduce or eliminate interference in incoming signals. Each memory 1008 includes any suitable volatile or non-volatile storage and retrieval device(s). Any suitable type of memory may be used, such as random access memory (RAM), read only memory (ROM), hard disk, optical disc, subscriber identity module (SIM) card, memory stick, secure digital (SD) memory card, and the like.

As shown in Figure 10B, the base station 1070 includes at least one processing unit 1050, at least one transceiver 1052, which includes functionality for a transmitter and a receiver, one or more antennas 1056, at least one memory 1058, and one or more input/output devices or interfaces 1066. A scheduler, which would be understood by one skilled in the art, is coupled to the processing unit 1050. The scheduler could be included within or operated separately from the base station 1070. The processing unit 1050 implements various processing operations of the base station 1070, such as signal coding, data processing, power control, input/output processing, or any other functionality. The processing unit 1050 can also support the methods and teachings described in more detail above. Each processing unit 1050 includes any suitable processing or computing device configured to perform one or more operations. Each processing unit 1050 could, for example, include a microprocessor, microcontroller, digital signal processor, field programmable gate array, or application specific integrated circuit.

Each transceiver 1052 includes any suitable structure for generating signals for wireless or wired transmission to one or more EDs or other devices. Each transceiver 1052 further includes any suitable structure for processing signals received wirelessly or by wire from one or more EDs or other devices. Although shown combined as a transceiver 1052, a transmitter and a receiver could be separate components. Each antenna 1056 includes any suitable structure for transmitting or receiving wireless or wired signals. While a common antenna 1056 is shown here as being coupled to the transceiver 1052, one or more antennas 1056 could be coupled to the transceiver(s) 1052, allowing separate antennas 1056 to be coupled to the transmitter and the receiver if equipped as separate components. Each memory 1058 includes any suitable volatile or non-volatile storage and retrieval device(s). Each input/output device 1066 facilitates interaction with a user or other devices (network communications) in the network. Each input/output device 1066 includes any suitable structure for providing information to or receiving/providing information from a user, including network interface communications.

Figure 11 is a block diagram of a computing system 1100 that may be used for

implementing the devices and methods disclosed herein. For example, the computing system can be any entity of UE, access network (AN), mobility management (MM), session management (SM), user plane gateway (UPGW), or access stratum (AS). Specific devices may utilize all of the components shown or only a subset of the components, and levels of integration may vary from device to device. Furthermore, a device may contain multiple instances of a component, such as multiple processing units, processors, memories, transmitters, receivers, etc. The computing system 1100 includes a processing unit 1102. The processing unit includes a central processing unit (CPU) 1114, memory 1108, and may further include a mass storage device 1104, a video adapter 1110, and an I/O interface 1112 connected to a bus 1120. The bus 1120 may be one or more of any type of several bus architectures including a memory bus or memory controller, a peripheral bus, or a video bus. The CPU 1114 may comprise any type of electronic data processor. The memory 1108 may comprise any type of non-transitoiy system memory such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), read-only memory (ROM), or a combination thereof. In an embodiment, the memory 1108 may include ROM for use at boot-up, and DRAM for program and data storage for use while executing programs.

The mass storage 1104 may comprise any type of non-transitory storage device configured to store data, programs, and other information and to make the data, programs, and other information accessible via the bus 1120. The mass storage 1104 may comprise, for example, one or more of a solid state drive, hard disk drive, a magnetic disk drive, or an optical disk drive.

The video adapter 1110 and the I/O interface 1112 provide interfaces to couple external input and output devices to the processing unit 1102. As illustrated, examples of input and output devices include a display 1118 coupled to the video adapter 1110 and a mouse, keyboard, or printer 1116 coupled to the I/O interface 1112. Other devices may be coupled to the processing unit 1102, and additional or fewer interface cards may be utilized. For example, a serial interface such as Universal Serial Bus (USB) (not shown) may be used to provide an interface for an external device.

The processing unit 1102 also includes one or more network interfaces 1106, which may comprise wired links, such as an Ethernet cable, or wireless links to access nodes or different networks. The network interfaces 1106 allow the processing unit 1102 to communicate with remote units via the networks. For example, the network interfaces 1106 may provide wireless communication via one or more transmitt ers/transmit antennas and one or more receivers/ receive antennas. In an embodiment, the processing unit 1102 is coupled to a local-area network 1122 or a wide-area network for data processing and communications with remote devices, such as other processing units, the Internet, or remote storage facilities.

It should be appreciated that one or more steps of the embodiment methods provided herein may be performed by corresponding units or modules. For example, a signal may be transmitted by a transmitting unit or a transmitting module. A signal may be received by a receiving unit or a receiving module. A signal may be processed by a processing unit or a processing module. Other steps may be performed by a detecting unit or module, a switching unit or module, a scanning unit or module, a determining unit or module, an accessing unit or module, or a selecting unit or module. The respective units or modules may be hardware, software, or a combination thereof. For instance, one or more of the units or modules may be an integrated circuit, such as field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs). Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the scope of the disclosure as defined by the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A method implemented by a user equipment (UE), the method comprising: receiving, by the UE, from a home network of the UE, one or more service change network selection lists (SCNSLs);

detecting, by the UE, a service change occurred indicator associated with the home network is set to a first specified value, and based thereon:

switching, by the UE, from using a network selection list to using a SCNSL in accordance with its selection policy;

scanning, by the UE, for suitable networks that are in the SCNSL;

receiving, by the UE, identifiers from one or more networks that are in the

SCNSL;

determining, by the UE, a network selection priority in accordance with the SCNSL; and

selecting, by the UE, one of the one or more networks in the SCNSL in accordance with the network selection priority.

2. The method of claim l, the one or more SCNSLs being different from the network selection list.

3. The method of claim l, the network selection priority comprising at least one of a service for the UE, a subscription level of the UE, a current time of day, an expected service time and period, a trigger event restriction, or services offered by the one or more networks.

4. The method of any one of claims 1-3, the network selection priority further comprising a location of the UE, and a time and period of a service which the UE is expected to receive.

5. The method of claim 4, further comprising determining, by the UE, the location of the UE, and a time and period of a service which the UE is expected to receive.

6. The method of any one of claims 1-5, further comprising accessing, by the UE, the one of the one or more networks.

7. The method of any one of claims 1-6, further comprising:

detecting, by the UE, the service change occurred indicator associated with the home network is set to a second specified value, and based thereon:

switching, by the UE, to using the network selection list;

scanning, by the UE, for suitable second networks that are in the network selection list;

receiving, by the UE, identifiers from one or more second networks that are in the network selection list; and

selecting, by the UE, one of the one or more second networks in accordance with the network selection list.

8. The method of any one of claims 1-7, the service change indicator being received from a network with coverage that includes the UE.

9. The method of claim 8, the UE being capable of receiving information from the network.

10. The method of claim 7, further comprising accessing, by the UE, the one of the one or more second networks.

11. The method of any one of claims 1-6, further comprising:

receiving, by the UE, an identifier of the home network; and

accessing, by the UE, the home network.

12. The method of any one of claims 1-11, the service change occurred indicator being set to the first specified value indicates that a service change event has occurred in the home network.

13. A method implemented by a network entity, the method comprising:

detecting, by the network entity, an occurrence of a service change event at a network; and

sending, by the network entity, a service change occurred indicator associated with the network, the service change occurred indicator being set to a first specified value.

14. The method of claim 13, the network entity receiving the service change event from a centralized management entity.

15. The method of claim 13, the service change event comprising at least one of an emergency occurring in the network, or a special event occurring in the network.

16. The method of any one of claims 13-15, the service change occurred indicator being transmitted in a broadcast message, or unicast message responsive to a query.

17. The method of any one of claims 13-16, further comprising:

detecting, by the network entity, a resolution of the service change event, and based thereon, transmitting, by the network entity, the service change occurred indicator set to a second specified value.

18. The method of claim 17, the second specified value indicating that the service change event has been resolved.

19. The method of any one of claims 13-18, the first specified value indicating an occurrence of the service change event.

20. A user equipment (UE) comprising:

a non-transitory memory storage comprising instructions; and

one or more processors in communication with the memory storage, wherein the one or more processors execute the instructions to:

receive, from a home network of the UE, one or more service change network selection lists (SCNSLs);

detect a service change occurred indicator associated with the home network is set to a first specified value, and based thereon:

switch from using a network selection list to using a SCNSL in accordance with its selection policy;

scan for suitable networks that are in the SCNSL;

receive identifiers from one or more networks that are in the

SCNSL;

determine a network selection priority in accordance with the

SCNSL; and

select one of the one or more networks in the SCNSL in accordance with the network selection priority.

21. The UE of claim 20, the network selection priority comprising at least one of a service for the UE, a subscription level of the UE, a current time of day, an expected service time and period, a trigger event restriction, or services offered by the one or more networks.

22. The UE of any one of claims 20-21, the network selection priority further comprising a location of the UE, and a time and period of a service which the UE is expected to receive.

23. The UE of claim 22, the one or more processors further executing the instructions to determine the location of the UE, and a time and period of a service which the UE is expected to receive.

24. The UE of any one of claims 20-23, the one or more processors further executing the instructions to access the one of the one or more networks.

25. The UE of any one of claims 20-24, the one or more processors further executing the instructions to detect the service change occurred indicator associated with the home network is set to a second specified value, and based thereon:

switch to using the network selection list;

scan for suitable second networks that are in the network selection list;

receive identifiers from one or more second networks that are in the network selection list; and

select one of the one or more second networks in accordance with the network selection list.

26. The UE of any one of claims 20-24, the one or more processors further executing the instructions to receive an identifier of the home network; and access the home network.

27. A network entity comprising:

a non-transitory memory storage comprising instructions; and

detect an occurrence of a service change event at a network; and send a service change occurred indicator associated with the network, the service change occurred indicator being set to a first specified value.

28. The network entity of claim 27, the one or more processors further executing the instructions to receive the service change event from a centralized management entity.

29. The network entity of claim 27, the service change event comprising at least one of an emergency occurring in the network, or a special event occurring in the network.

30. The network entity of any one of claims 27-29, the one or more processors further executing the instructions to detect a resolution of the service change event, and based thereon, transmit the service change occurred indicator set to a second specified value.