CN114727364A

CN114727364A - Method and apparatus relating to UE and network behaviour during and after a network disaster

Info

Publication number: CN114727364A
Application number: CN202111624742.8A
Authority: CN
Inventors: 马各·纳耶米; 林元傑; 皇甫建君
Original assignee: MediaTek Singapore Pte Ltd
Current assignee: MediaTek Singapore Pte Ltd
Priority date: 2021-01-07
Filing date: 2021-12-28
Publication date: 2022-07-08

Abstract

Methods and apparatus related to User Equipment (UE) and network behavior during and after network disasters in mobile communications are presented. An apparatus embodied in or as a UE determines whether a disaster condition is satisfied with respect to a first Public Land Mobile Network (PLMN). The apparatus then selects a second PLMN according to information listing one or more PLMNs allowed to be selected by the UE when the disaster condition is satisfied. The apparatus also attempts to register in a second PLMN. Methods and apparatus relating to user equipment and network behavior during and after a network disaster provided in accordance with the present invention can indicate disaster-free accessibility to one or more UEs from other PLMNs, and can register with a disaster-free roaming PLMN when a disaster condition occurs in one PLMN.

Description

Method and apparatus relating to UE and network behaviour during and after a network disaster

Cross Reference to Related Applications

The present invention is priority of U.S. provisional patent application No. 63/134,603, filed on 7/1/2021, the contents of which are incorporated by reference in their entirety.

Technical Field

The present invention relates generally to mobile communications, and more particularly, to User Equipment (UE) and network behavior during and after a network disaster in mobile communications.

Background

Unless the invention is stated otherwise, the approaches described in this section are not prior art to the claims listed and are not admitted to be prior art by inclusion in this section.

In wireless communications such as mobile communications according to the 3rd Generation Partnership Project (3 GPP) specifications, support for Minimization of service Interruption (MINT) is a work item of release 17 (Rel-17) of the 3GPP specifications. In a highly connected society, it is important to ensure that interruptions in communication services are minimized. When a network fails to provide one or more communication services for its users (e.g., UEs connected to the network) due to certain events (e.g., fire or some natural disaster), it is necessary to minimize the time that the users leave one or more communication services and minimize additional impact on other networks. In the event of a disaster, one or more neighboring networks may provide assistance to the network users affected by the disaster. While one network may provide assistance to its neighboring networks, the impact on its home users should be minimized when a large number of users request access to the network. Other aspects include one or more restrictions imposed on the UE to select one or more other networks (e.g., when the UE was previously denied connection to one or more other networks before the event/disaster occurred). Therefore, solutions are needed for UE and network behavior at and after network disasters in mobile communications.

Disclosure of Invention

The following summary is illustrative only and is not intended to be in any way limiting. That is, the following summary is provided to introduce concepts, points, benefits and advantages of the novel and non-obvious techniques described herein. Selected embodiments are further described below in the detailed description. Thus, the following summary is not intended to identify essential features of the claimed subject matter, nor is it intended for use in determining the scope of the claimed subject matter.

It is an object of the present invention to propose solutions, designs, concepts, techniques, methods, systems and devices that solve the above problems. In particular, various proposed schemes according to the present invention relate to UE and network behavior at and after network disasters in mobile communications.

In one aspect, a method may include a UE determining that a disaster condition is satisfied with respect to a first Public Land Mobile Network (PLMN). The method may also include the UE selecting the second PLMN in accordance with information listing one or more PLMNs permitted to be selected by the UE when the disaster condition is satisfied. The method may also include the UE attempting to register in the second PLMN.

In another aspect, a method may include the UE determining from the received message that the first PLMN has recovered from the disaster condition. The method may also include, in response to the determination, the UE performing a PLMN search.

In yet another aspect, an apparatus that may be implemented in a UE may include a transceiver and a processor coupled to the transceiver. The transceiver may be configured for wireless communication. The processor may be configured to perform certain operations including: (i) determining that a disaster condition is satisfied with respect to the first PLMN; (ii) selecting a second PLMN according to information listing one or more PLMNs allowed to be selected by the UE when the disaster condition is satisfied; (iii) registration in the second PLMN is attempted.

Methods and apparatus relating to user equipment and network behavior during and after a network disaster provided in accordance with the present invention can indicate disaster-free accessibility to one or more UEs from other PLMNs, and can register with a disaster-free roaming PLMN when a disaster condition occurs in one PLMN.

It is noted that although the description provided by the present invention may be in the context of certain Radio Access technologies, networks and Network topologies, such as 5th Generation (5G)/New Radio (NR) mobile networking and NTN communications, the proposed concepts, schemes and any variants/derivatives thereof may be implemented in, for, and by other types of wireless and wireline communication technologies, networks and Network topologies, such as, but not limited to, ethernet, Evolved Packet System (EPS), Universal Terrestrial Radio Access Network (UTRAN), Evolved UTRAN (E-UTRAN), E-UTRAN, Global System for Mobile communications (GSM), General Packet Radio Service (GPRS)/EDGE Radio Access Network (EDGE) Enhanced Data rates for GERAN, Long Term Evolution (LTE), LTE-Advanced Pro, Internet of Things (IoT), narrowband Internet of Things (Narrow Band Internet of Things (IoT)), Industrial Internet of Things (IIoT), and any future-developed networking technologies. Accordingly, the scope of the invention is not limited to the examples described herein.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. It is to be understood that the figures are not necessarily to scale, since some features may be shown out of proportion to the dimensions in an actual implementation in order to clearly illustrate the concepts of the invention.

FIG. 1 is a diagram of an exemplary network environment in which various solutions and schemes according to the present invention may be implemented.

FIG. 2 is a diagram of an example scenario under a proposed scheme according to an embodiment of the invention.

FIG. 3 is a diagram of an example scenario under a proposed scheme according to an embodiment of the invention.

FIG. 4 is a diagram of an example scenario under a proposed scheme according to an embodiment of the present invention.

FIG. 5 is a diagram of an example scenario under a proposed scheme according to an embodiment of the invention.

FIG. 6 is a diagram of an example scenario under a proposed scheme according to an embodiment of the invention.

Fig. 7 is a block diagram of an example communication system according to an embodiment of the present invention.

FIG. 8 is a flow diagram of an example process according to an embodiment of the invention.

FIG. 9 is a flow diagram of an example process according to an embodiment of the invention.

Detailed Description

Detailed embodiments and implementations of the claimed subject matter are disclosed. However, it is to be understood that the disclosed embodiments and implementations are merely illustrative of the claimed subject matter, which can be embodied in various forms. This invention may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments and implementations set forth herein. Rather, these exemplary embodiments and implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the following description, details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the presented embodiments and implementations.

SUMMARY

Embodiments according to the present invention relate to various techniques, methods, schemes and/or solutions relating to UE and network behavior during and after network disasters in mobile communications. According to the invention, a plurality of possible solutions can be implemented individually or jointly. That is, although these possible solutions may be described separately below, two or more of these possible solutions may be implemented in one combination or another.

Fig. 1 illustrates an example network environment 100 in which various solutions and schemes according to this invention may be implemented. Referring to fig. 1, a network environment 100 may include a UE110 that may establish wireless communication with a wireless network 120 (e.g., part of a 5G NR mobile network) that is part of a communication network via a network node 125 (e.g., a base station, eNB, gNB, or transmit/receive point (TRP)). In network environment 100, UE110 and network 120 (via network node 125) may implement various aspects related to UE and network behavior at and after a network disaster in mobile communications according to the present invention, as described below with reference to fig. 2-6. It is noted that throughout the present invention and in fig. 2-6, the term "PLMN D" refers to a PLMN in which a disaster or an applied disaster condition occurs. Further, the term "PLMN a" refers to a PLMN that allows selection (e.g., selectable by a UE) when a disaster or disaster condition occurs in PLMN D and applies to PLMN D, such that UE D initially connected to the PLMN may switch to PLMN a (e.g., by registering and connecting with PLMN a).

FIG. 2 illustrates an example scenario 200 under a proposed scheme according to an embodiment of the present invention. According to the proposed solution shown in fig. 2, two problems can be solved, including: (1) notifying one or more UEs of the disaster condition (e.g., in PLMN D), and (2) PLMN selection of the UE when the "disaster condition" applies. In scenario 200, a UE (e.g., UE110) may determine that a disaster condition is satisfied (or applies the disaster condition) with respect to a first PLMN (e.g., PLMN D) based on one or more of: (i) NAS signaling indicates that the UE is deregistered due to a catastrophic condition in the first PLMN; (ii) RRC signaling indicates that an N2 interface, which is a control plane interface between the access network and a 5th Generation Core (5 GC), is unavailable or UL messages over an N2 interface are not routable; (iii) UE-determined (self-determined) disaster condition occurs; (iv) the broadcast information from the cell of the second PLMN (e.g., PLMN a) indicates a disaster condition in the first PLMN. When it is determined that "disaster conditions" apply to the first PLMN, the UE may store a disaster indication of "disaster conditions apply to PLMN D" in a memory of the UE. Thus, the UE may need cell selection (or reselection) to connect to a PLMN (e.g., PLMN a) that is allowed to be selected. In the event that one or more allowed PLMNs are available, the UE may perform PLMN selection using the disaster indication stored in the memory. In the case that one or more non-allowed (non-allowed) PLMNs are available, the UE may select cells of the PLMN from those PLMNs in a priority order by using the following information: (a) configuring (or pre-configuring) allowed disaster roaming PLMNs, (b) providing recommended disaster roaming PLMNs. In case no cell is available, the UE may enter a restricted (limited) service state.

FIG. 3 illustrates an example scenario 300 under a proposed scheme according to an embodiment of the present invention. According to the proposed solution shown in fig. 3, two problems can be solved, including: (1) indicating disaster-free accessibility to one or more UEs from other PLMNs, and (2) registering with a disaster-free roaming PLMN when a disaster condition occurs in PLMN D. The scenario 300 may be considered a continuation of the scenario 200 in that in the scenario 300, a UE (e.g., UE110) may select cells as described above with respect to the scenario 200 (e.g., cells of PLMNs are selected in order of priority in those PLMNs by using (a) configuring (or pre-configuring) allowed disaster roaming PLMNs, and (b) providing recommended disaster roaming PLMNs. The UE may then determine whether there is any broadcast information from the selected PLMN indicating "accept disaster inbound roamers (inbound roamers) from PLMN D subscriber". In the event of a positive determination (e.g., such broadcast information is present), the UE may determine whether registration with the selected PLMN was successful. If the registration is successful, the UE may receive one or more normal services through disaster indication stored in memory. If the registration is unsuccessful, the UE may select another cell. In the case of a negative determination (e.g., no broadcast information), the UE may determine whether one or more other cells are present (e.g., selectable by the UE) that are allowed to be selected. The UE may enter a limited service state without other allowed cells. In the case where selection of at least one other cell is allowed, the UE may select one or more allowed cells.

Notably, the broadcast information may also indicate a timestamp and a validity period. Further, the broadcast information may be integrity protected by a PLMN with a catastrophic condition (e.g., PLMN D). Further, the private key used to decrypt the broadcast information may be based on a predefined number N of Home PLMNs (HPLMNs) or pre-Registered PLMNs (RPLMNs) of the UE.

FIG. 4 illustrates an example scenario 400 under a proposed scheme according to an embodiment of the present invention. According to the proposed scheme shown in fig. 4, one problem that may be solved may include notifying one or more UEs that the disaster condition is no longer applicable (e.g., no longer applicable to PLMN D). Scenario 400 may be considered a continuation of scenario 300 because, in scenario 400, a UE (e.g., UE110) may receive one or more normal services through disaster indications stored in memory while in idle mode or connected mode. The UE may then receive a message or signal indicating that the disaster condition is no longer applicable (e.g., no longer applicable to PLMN D). For example, the UE may receive broadcast information (e.g., from PLMN a or another PLMN or cell) indicating that the disaster condition in the first PLMN is no longer applicable. In response, the UE may deregister from PLMN a and remove the stored disaster indication from its memory. Further, the UE may perform a PLMN search (e.g., a high priority PLMN search). Furthermore, the disaster roaming PLMNs may be restored to their normal priority in PLMN selection (e.g., normal PLMN selection rules may be applied so that the disaster roaming PLMNs may be set back to the forbidden PLMN list).

FIG. 5 illustrates an example scenario 500 under a proposed solution according to an embodiment of the present invention. One problem that may be solved according to the proposed solution shown in fig. 5 may include preventing signalling overload in PLMNs (in order to avoid overloading such PLMNs) without catastrophic conditions. Scenario 500 may be considered an extension or extension of scenario 300 because, in scenario 500, a UE (e.g., UE110) may wait a random time before registering after receiving broadcast information from a selected PLMN indicating "accept disaster inbound roamers from PLMN D subscribers". Alternatively or additionally, the UE may determine from its load that the currently connected PLMN (e.g., PLMN a) is open and closed access in time. The UE may then determine whether registration with the selected PLMN was successful. If the registration is successful, the UE may receive one or more normal services through disaster indication stored in memory. If the registration is unsuccessful, the UE may select another cell. In the case of a negative determination (e.g., no broadcast information), the UE may determine whether one or more other cells are present that are allowed to be selected (e.g., selectable by the UE). The UE may enter a limited service state if no other cells are allowed to be selected. The UE may select one or more cells that are allowed if there is at least one other cell allowed to be selected.

FIG. 6 illustrates an example scenario 600 under a proposed scheme according to an embodiment of the present invention. According to the proposed scheme shown in fig. 6, one problem that may be solved may include preventing signaling overload by returning multiple UEs to a previous PLMN with a catastrophic condition (e.g., PLMN D). Scenario 600 may be considered an extension or extension of scenario 400, because in scenario 600, after removing the stored disaster indication and performing PLMN selection, the UE (e.g., UE110) may start a random timer (e.g., having a range of values 1-10 seconds) in response to receiving broadcast information indicating that the disaster condition in the first PLMN (e.g., PLMN D) is no longer applicable. In addition, the UE may attempt registration to the highest priority PLMN from PLMN search upon expiration of the random timer. The UE may also receive one or more normal services if the registration is successful.

Illustrative embodiments

Fig. 7 illustrates an example communication system 700 having at least an example apparatus 710 and an example apparatus 720 in accordance with an embodiment of the present invention. Each of the apparatus 710 and the apparatus 720 may perform various functions to implement the schemes, techniques, processes and methods described herein relating to UE and network behavior at and after network disaster in mobile communications, including the various schemes of the designs, concepts, schemes, systems described above with respect to various proposals and the methods described above, including the network environment 100 and the multiple processes described below.

Each of the apparatus 710 and the apparatus 720 may be part of an electronic apparatus, which may be a network apparatus or UE (e.g., UE110), such as a portable or mobile apparatus, a wearable apparatus, a vehicle-mounted device or vehicle, a wireless communication device, or a computing device. For example, each of the apparatus 710 and the apparatus 720 may be implemented in a smartphone, a smart watch, a personal digital assistant, an Electronic Control Unit (ECU) in a vehicle, a digital camera, or a computing device such as a tablet, laptop, or notebook computer. Each of the apparatus 710 and the apparatus 720 may also be part of a machine type device, which may be an internet of things device, such as a non-mobile or fixed device, a household device, a roadside unit (RSU), a wired communication device, or a computing device. For example, each of the device 710 and the device 720 may be implemented in a smart thermostat, a smart refrigerator, a smart door lock, a wireless speaker, or a home control center. When implemented in or as a network device, the apparatus 710 and/or the apparatus 720 may be implemented in an eNodeB in an LTE, LTE-Advanced, or LTE-Advanced Pro network or in a gNB or TRP in a 5G network, NR network, or IoT network.

In some embodiments, each of the devices 710 and 720 may be implemented in the form of one or more integrated-circuit (IC) chips, such as, but not limited to, one or more single-core processors, one or more multi-core processors, one or more reduced-instruction-set computing (RISC) processors, or one or more complex-instruction-set computing (CISC) processors. In the various aspects described above, each of the apparatus 710 and the apparatus 720 may be implemented in or as a network apparatus or a UE. Each of the apparatus 710 and the apparatus 720 may include at least some of those components shown in fig. 7. For example, in FIG. 7, there are processor 712 and processor 722, respectively. Each of the apparatus 710 and the apparatus 720 may further include one or more other components not relevant to the proposed solution of the invention (e.g., an internal power supply, a display device, and/or a user interface device), and thus, such components) neither the apparatus 710 nor the apparatus 720 are shown in fig. 7, nor are described below for simplicity and brevity.

In an aspect, each of the processors 712 and 722 may be implemented in the form of one or more single-core processors, one or more multi-core processors, one or more RISC processors, or one or more CISC processors. That is, even though the singular term "processor" is used in this disclosure to refer to the processor 712 and the processor 722, each of the processor 712 and the processor 722 may include multiple processors in some embodiments and a single processor in other embodiments according to the present disclosure. In another aspect, each of the processors 712 and 722 may be implemented in hardware (and optionally firmware) with electronic components including, for example and without limitation, one or more transistors, one or more diodes, one or more capacitors, one or more resistors, one or more inductors, one or more memristors, and/or one or more varactors configured and arranged to achieve certain objectives in accordance with the present disclosure. In other words, in at least some embodiments, each of the processors 712 and 722 is a dedicated machine specifically designed, arranged, and configured to perform specific tasks, including tasks related to UE and network behavior at and after network disasters in mobile communications, according to various embodiments of the present invention.

In some implementations, the apparatus 710 can also include a transceiver 716 coupled to the processor 712. The transceiver 716 is capable of wirelessly transmitting and receiving data. In some implementations, the transceiver 716 can wirelessly communicate with different types of wireless networks of different Radio Access Technologies (RATs). In some implementations, the transceiver 716 can be equipped with multiple antenna ports (not shown), such as four antenna ports. That is, the transceiver 716 may be equipped with multiple transmit antennas and multiple receive antennas for multiple-input multiple-output (MIMO) wireless communication. In some implementations, the apparatus 720 can also include a transceiver 726 coupled to the processor 722. The transceiver 726 may include a transceiver capable of wirelessly transmitting and receiving data. In some embodiments, the transceiver 726 is capable of wireless communication with different types of UEs/wireless networks of different RATs. In some implementations, the transceiver 726 can be equipped with multiple antenna ports (not shown), for example four antenna ports. That is, the transceiver 726 may be equipped with multiple transmit antennas and multiple receive antennas for MIMO wireless communication.

In some implementations, the apparatus 710 can also include a memory 714 coupled to the processor 712 and capable of being accessed by the processor 712 and storing data therein. In some embodiments, the apparatus 720 may also include a memory 724 coupled to the processor 722 and capable of being accessed by the processor 722 and storing program instructions and data therein. Each of memory 714 and memory 724 may include a type of random-access memory (RAM), such as Dynamic RAM (DRAM), static RAM (static RAM, SRAM), thyristor RAM (T-RAM), and/or zero-capacitor RAM (Z-RAM). Alternatively, or in addition, each of memory 314 and memory 324 may include a type of read-only memory (ROM), such as a mask ROM, a Programmable ROM (PROM), an Erasable Programmable ROM (EPROM), and/or an Electrically Erasable Programmable ROM (EEPROM). Alternatively or additionally, each of memory 314 and memory 324 may include a type of non-volatile random-access memory (NVRAM), such as flash memory, solid-state memory, ferroelectric RAM (FeRAM), Magnetoresistive RAM (MRAM), and/or phase change memory.

Each of the devices 710 and 720 may be communication entities capable of communicating with each other using various proposed schemes according to the present invention. For illustrative purposes, and not by way of limitation, the following description of the capability of apparatus 710 as a UE (e.g., UE110) and apparatus 720 as a network node (e.g., network node 125) of a wireless network (e.g., network 120 such as a 5G/NR mobile network) is provided.

Under various proposals in accordance with this disclosure relating to UE and network behavior at and after a network disaster in mobile communications, processor 712 of apparatus 710 implemented in or as UE110 may determine, via transceiver 716, whether a disaster condition with respect to the first PLMN is satisfied. Further, the processor 712 may select the second PLMN via the transceiver 716 according to information listing one or more PLMNs allowed to be selected by the UE when the disaster condition is satisfied. Further, processor 712 may attempt registration with the second PLMN via transceiver 716.

In some embodiments, the UE may be allowed to select one or more PLMNs within the duration of the disaster condition being met and not outside (e.g., one or more available PLMNs may only be selected by the UE for the duration of the disaster condition being met).

In some implementations, the determination that the disaster condition is satisfied can be based on one or more of: (a) NAS signaling indicates that the UE is deregistered; (b) RRC signaling indicates that an N2 interface, which is a control plane interface between the access network and the 5GC, is unavailable or that UL messages over an N2 interface are not routable; (c) occurrence of a UE-determined disaster condition; (d) the broadcast information from the second PLMN indicates that the disaster condition applies to the first PLMN.

In some embodiments, the information listing the one or more PLMNs allowed to be selected by the UE when the disaster condition is met may be pre-configured in the UE or received from the network.

In some embodiments, the information may indicate that one or more PLMNs are accepting a disaster inbound roamer from a first PLMN.

In some implementations, the processor 712 may perform additional operations. For example, the processor 712 may determine that registration in the second PLMN was unsuccessful. Further, the processor 712 can select an additional PLMN in the information via the transceiver 716. Alternatively, the processor 712 may enter the limited service state in response to no other PLMN in the information being allowed to be selected.

In some implementations, the processor 712 may perform additional operations. For example, the processor 712 may determine that the registration in the second PLMN is successful. Further, processor 712 may enter a registered normal service state with a disaster indication.

In some embodiments, the registration attempt in the second PLMN may be triggered by one or both of: (a) a specific period of time has elapsed; (b) allowing selection of the second PLMN. In some embodiments, the specific time period may be controlled by a random timer.

Under various proposed aspects in accordance with the present invention relating to UE and network behavior at and after a network disaster in mobile communications, processor 712 of apparatus 710 implemented in or as UE110 may determine, via transceiver 716, that the first PLMN recovered from the disaster condition in accordance with the received message. Further, the processor 712 may perform a PLMN search in response to the determination. In some embodiments, the received message may include broadcast information or a logoff message.

In some implementations, the processor 712 may perform additional operations. For example, the processor 712 may de-register the apparatus 710 as a UE from the second PLMN. Further, processor 712 may remove the stored disaster indication associated with the first PLMN.

In some implementations, the processor 712 may perform additional operations. For example, the processor 712 may attempt to register in a third PLMN selected from the PLMN search results in response to a lapse of a certain period of time. In some embodiments, the specific time period may be controlled by a random timer and may be initiated in response to the determination. In some embodiments, the third PLMN may be a highest priority PLMN allowed to be selected among the plurality of PLMNs from the results of the PLMN search.

Illustrative Process

FIG. 8 illustrates an example process 800 according to an embodiment of the invention. Process 800 may represent one aspect of a design, concept, scheme, system, and method that partially or fully implements the various proposals described above, including those related to those descriptions above. More specifically, process 800 may represent one aspect of the proposed concepts and schemes related to UE and network behavior at and after network disasters in mobile communications. Process 800 may include one or more operations, actions, or functions as indicated by one or more of

blocks

810, 820, and 830. Although shown as discrete blocks, the individual blocks of process 800 may be divided into additional blocks, combined into fewer blocks, or eliminated, depending on the desired implementation. Further, the blocks/sub-blocks of process 800 may be performed in the order shown in FIG. 8, or alternatively, in a different order. Further, one or more of the blocks/sub-blocks of process 800 may be performed iteratively. The process 800 may be implemented by or in the apparatus 710 and the apparatus 720 and any variation thereof. For purposes of illustration only and not to limit scope, process 800 is described below in the context of apparatus 710 as a UE (e.g., UE110) and apparatus 720 as a communication entity, such as a network node or base station of a mobile communication network (e.g., network node 125). Process 800 may begin at block 810.

At 810, process 800 may include processor 712 of apparatus 710 determining whether a disaster condition is satisfied with respect to the first PLMN. Process 800 may proceed from 810 to 820.

At 820, process 800 can include processor 712 selecting a second PLMN according to information listing one or more PLMNs allowed to be selected by the UE when the disaster condition is satisfied. Process 800 may proceed from 820 to 830.

At 830, process 800 may include processor 712 attempting to register with the second PLMN.

In some embodiments, the information listing the one or more PLMNs allowed to be selected by the UE when the disaster condition is met may be pre-configured in the UE or received from a configuration message from the network.

In some implementations, process 800 may include processor 712 performing additional operations. For example, process 800 may include processor 712 determining that registration in the second PLMN was unsuccessful. Further, process 800 may include processor 712 selecting an additional PLMN in the information. Alternatively, process 800 may include processor 712 entering the limited service state in response to no other PLMN in the information being allowed for selection.

In some implementations, process 800 may include processor 712 performing additional operations. For example, process 800 may include processor 712 determining that registration in the second PLMN is successful. Further, process 800 may include processor 712 entering a registered normal service state with a disaster indication.

In some embodiments, the registration attempt in the second PLMN may be triggered by either or both of: (a) the lapse of a certain period of time; (b) allowing selection of the second PLMN. In some embodiments, the specific time period may be controlled by a random timer.

FIG. 9 illustrates an example process 900 according to an embodiment of the invention. Process 900 may represent an aspect of a design, concept, scheme, system, and method that partially or fully implements the various proposals described above, including those related to those described above. More specifically, process 900 may represent one aspect of the proposed concepts and schemes related to UE and network behavior at and after network disasters in mobile communications. Process 900 may include one or more operations, actions, or functions as indicated by one or more of

blocks

910 and 920. Although shown as discrete blocks, the various blocks of process 900 may be divided into additional blocks, combined into fewer blocks, or eliminated, depending on the desired implementation. Further, the blocks/sub-blocks of process 900 may be performed in the order shown in FIG. 9, or alternatively, in a different order. Further, one or more of the blocks/sub-blocks of process 900 may be performed iteratively. Process 900 may be implemented by or in apparatus 710 and apparatus 720 and any variations thereof. For purposes of illustration only and not to limit scope, process 900 is described below in the context of apparatus 710 as a UE (e.g., UE110) and apparatus 720 as a communication entity, such as a network node or base station of a mobile communication network (e.g., network node 125). Process 900 may begin at block 910.

At 910, process 900 may include processor 712 of apparatus 710 determining from the received message that the first PLMN has recovered from the disaster condition. In some embodiments, the received message may include broadcast information or a logoff message. Process 900 may proceed from 910 to 920.

At 920, process 900 can include processor 712 performing a PLMN search in response to the determination.

In some embodiments, process 900 may include processor 712 performing additional operations. For example, process 900 may include processor 712 deregistering as a UE device 710 from the second PLMN. Further, process 900 may include processor 712 removing the stored disaster indication associated with the first PLMN.

In some embodiments, process 900 may include processor 712 performing additional operations. For example, process 900 may include processor 712 attempting to register in a third PLMN selected from the PLMN search results in response to a certain period of time elapsing. In some embodiments, the specific time period may be controlled by a random timer and may be initiated in response to the determination. In some embodiments, the third PLMN may allow a highest priority PLMN to be selected among the plurality of PLMNs from the results of the PLMN search.

Additional description

The subject matter described herein sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Hence, any two components of the invention combined to achieve a particular functionality can be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being "operably connected," or "operably coupled," to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being "operably couplable," to each other to achieve the desired functionality. Specific examples of operatively couplable include, but are not limited to: physically mateable and/or physically interacting components and/or wirelessly interactable and/or wirelessly interacting components and/or logically interacting and/or logically interactable components.

Further, with respect to the use of any plural and/or singular terms of the present invention, those having skill in the art may translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. For clarity, the invention may explicitly set forth various singular/plural reciprocity.

Moreover, those skilled in the art will understand that, in general, terms used in connection with the present invention, and especially in the appended claims (e.g., bodies of the appended claims) generally mean "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" introduced into the claim recitation. However, the use of such phrases should not be construed to imply that: the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, means at least two recitations, or two or more recitations). Further, in those cases where a convention similar to "A, B and at least one of C, etc." is used, in general, such an interpretation will be understood by those skilled in the art that this syntax means, for example: "a system having at least one of A, B and C" would include, but not be limited to, a system having A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B and C together, etc. In those cases where a convention analogous to "A, B or at least one of C, etc." is used, in general, such an interpretation will be understood by those skilled in the art to mean, for example: "a system having at least one of A, B or C" would include, but not be limited to, systems having A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B and C together, etc. It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "a or B" will be understood to include the possibility of "a" or "B" or "a and B".

From the foregoing, it will be appreciated that various embodiments of the invention have been described herein for purposes of illustration, and that various modifications may be made without deviating from the scope and spirit of the invention. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims

1. A method of user equipment and network behavior at and after a network disaster, comprising:

determining, by a processor of a user equipment, whether a disaster condition is satisfied with respect to a first public land mobile network;

the processor selecting a second public land mobile network according to information listing one or more public land mobile networks allowed to be selected by the user equipment when a disaster condition is satisfied; and

attempting, by the processor, registration in the second public land mobile network.

2. The method of claim 1, wherein the user equipment is allowed to select the one or more public land mobile networks within a duration of time other than when the disaster condition is met.

3. The method of claim 1, wherein determining that the disaster condition is satisfied is based on one or more of:

non-access stratum signaling indicates the user equipment to logout;

radio resource control signaling indicates that an N2 interface, which is a control plane interface between an access network and a fifth generation core, is unavailable or that uplink messages over the N2 interface are not routable;

the occurrence of a self-determined disaster condition by the user equipment; and

broadcast information indicates that the disaster condition applies to the first public land mobile network.

4. The method of claim 1, wherein the information listing the one or more public land mobile networks that are allowed to be selected by the user equipment when the disaster condition is satisfied is pre-configured in the user equipment or received from a network.

5. The method of claim 1, wherein the information indicates that the one or more public land mobile networks are accepting a disaster inbound roamer from the first public land mobile network.

6. The method of claim 1, further comprising:

the processor determining that registration in the second public land mobile network is unsuccessful;

or performing, by a processor, one of:

selecting one other public land mobile network in the information; or

Entering a limited service state in response to no other public land mobile network in the information being allowed to be selected.

7. The method of claim 1, further comprising:

the processor determining that registration in the second public land mobile network was successful; and

entering, by the processor, a registered normal service state with a disaster indication.

8. The method of claim 1, wherein the attempt to register in the second public land mobile network is triggered by either or both of:

the lapse of a certain period of time; and

allowing selection of the second public land mobile network.

9. The method of claim 8, wherein the specific time period is controlled by a random timer.

10. A method of relating user equipment and network behavior at and after a network disaster, comprising:

determining, by a processor of the user equipment, that the first public land mobile network has recovered from the disaster condition based on the received message; and

performing, by the processor, a public land mobile network search in response to the determination.

11. The method of claim 10, further comprising:

the processor deregisters the user equipment from a second public land mobile network; and

removing, by the processor, a stored disaster indication associated with the first public land mobile network.

12. The method of claim 10, wherein the received message comprises a broadcast message or a logoff message.

13. The method of claim 10, further comprising:

in response to a lapse of a certain period of time, the processor attempts registration in a third public land mobile network selected from results of the public land mobile network search.

14. The method of claim 13, wherein the specific time period is controlled by a random timer and is initiated in response to the determination.

15. The method of claim 13, wherein the third public land mobile network is a highest priority public land mobile network allowed to be selected from results of a public land mobile network search.

16. An apparatus implementable in a user device for user device and network behavior at and after a network disaster, comprising:

a transceiver configured to communicate wirelessly; and

a processor coupled to the transceiver and configured to perform operations comprising:

determining whether a disaster condition is satisfied with respect to the first public land mobile network;

selecting a second public land mobile network in accordance with information listing one or more public land mobile networks that are allowed to be selected by the user equipment when a disaster condition is satisfied; and

attempting to register in the second public land mobile network.

17. The apparatus of claim 16, wherein the user equipment is allowed to select the one or more public land mobile networks within a duration of time other than when the disaster condition is met.

18. The apparatus of claim 16, wherein the disaster condition is determined to be satisfied based on one or more of:

non-access stratum signaling indicates the user equipment to logout;

19. The apparatus of claim 16, wherein the processor is further configured to:

determining that registration in the second public land mobile network is unsuccessful;

or performing an operation of:

selecting one other public land mobile network in the information; or

20. The apparatus of claim 16, wherein the processor is further configured to:

determining that registration with the second public land mobile network is successful; and

entering a registered normal service state with a disaster indication.

21. A non-transitory computer readable storage medium storing program instructions and data which, when executed by a processor of an apparatus implementable in user equipment regarding user equipment and network behavior at and after a network disaster, may cause the apparatus to perform operations of a method as recited in any of claims 1-15 above.