Method for controlling non-access stratum (NAS) timer at or after intermittent coverage and method for declaring user equipment state at and after end of intermittent coverage

Abstract

Methods of controlling a non-access stratum (NAS) timer at or after intermittent coverage and declaring a user equipment state at and after the end of intermittent coverage are provided. A method of controlling a non-access stratum (NAS) timer at or after intermittent coverage includes the following steps. Unavailable cycles due to intermittent coverage are activated. All NAS timers, except for exceptional timers, are stopped. And stopping the related program. A method of declaring a user equipment (UE) state at and after the end of intermittent coverage comprises the following steps. And the UE returns to the currently registered tracking area (TA) coverage after losing the coverage due to the intermittent coverage. And the UE operates or starts an intermittent coverage maximum time offset timer. The UE enters a specific xMM state. The UE performs an xMM procedure upon expiration of the intermittent coverage maximum time offset timer. The specific xMM state comprises the condition that the xMM is registered, and the condition that the xMM-REGISTERED. ATTEMPTNG-REGISTRATION-UPDATE state is being attempted to be updated and registered is carried out on the condition that the xMM-REGISTERED.

Description

Technical Field

[0001] The present application generally relates to a method for performing 5G NR operation in intermittent coverage, and more specifically, to a method for controlling a non-access stratum (NAS) timer during or after intermittent coverage and declaring a user equipment status at and after the end of intermittent coverage. Background Art

[0002] Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims and are not admitted to be prior art by inclusion in this section.

[0003] In current technology, deployment options for satellite E-UTRAN or NG-RAN access are provided, where a short satellite E-UTRAN or NG-RAN access radio coverage period is followed by a longer satellite E-UTRAN or NG-RAN access coverage gap. During the coverage gap, the access layer may be deactivated. These coverage gaps are called intermittent coverage.

[0004] When the user equipment UE enters intermittent satellite coverage, it is unclear what happens to the ongoing timers of NAS such as T3412, T3410, T3346, etc.

[0005] When the UE leaves the intermittent coverage situation or activates the access layer after intermittent coverage, the UE shall start a random timer (running within the range of the stored intermittent coverage maximum NAS signaling waiting time value). During the timer running window, the UE EMM / 5GMM state is undefined, that is, the UE shall transition to the EMM / 5GMM state after leaving intermittent coverage. Summary of the invention

[0006] A simplified summary of one or more aspects is presented below to provide a basic understanding of these aspects. This summary is not a comprehensive overview of all intended aspects, and is neither intended to identify key or important elements of all aspects, nor to delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that is presented later.

[0007] According to one embodiment, a method for controlling non-access stratum (NAS) timers during or after intermittent coverage is provided. The method is applied to user equipment (UE). The method includes the following steps. An unavailable period is activated due to intermittent coverage. All NAS timers are stopped except for exception timers. Related procedures are terminated. The exception timers include T3412, T3346, T3396, T3447, any backoff timer, T3247, and timers that control periodic searches for a home public land mobile network (HPLMN) or an equivalent HPLMN (EPLMN) or a higher priority PLMN.

[0008] According to another embodiment, a method for declaring a user equipment (UE) state at and after the end of intermittent coverage is provided. The method is applied to a user equipment (UE). The method includes the following steps. The UE returns to the currently registered tracking area (TA) coverage after losing coverage due to intermittent coverage. The UE runs or starts an intermittent coverage maximum time offset timer. The UE enters a specific xMM state. The UE executes an xMM procedure when the intermittent coverage maximum time offset timer expires. The specific xMM state includes the xMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE state.

[0009] According to another embodiment, a user equipment (UE) is provided. The UE includes a processor. The processor activates an unavailable period due to intermittent coverage, stops all non-access stratum (NAS) timers, and terminates related procedures except for exception timers. The processor returns to the currently registered tracking area (TA) coverage after losing coverage due to intermittent coverage, runs or starts an intermittent coverage maximum time offset timer, enters a specific xMM state, and executes an xMM procedure when the intermittent coverage maximum time offset timer expires. The specific xMM state includes the xMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE state.

[0010] To accomplish the foregoing and related ends, the features included in one or more aspects and specifically pointed out in the claims are fully described below. The following description and the accompanying drawings set forth in detail certain illustrative features of the one or more aspects. However, these features are indicative of several of the various ways of employing the principles of the various aspects, and this description is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A flow chart showing a method of controlling a non-access stratum (NAS) timer during or after intermittent coverage according to certain embodiments of the present invention is shown;

[0012] Figure 2 A flow chart showing a method of declaring a user equipment (UE) status at and after the end of intermittent coverage according to certain embodiments of the present invention is shown;

[0013] Figure 3 It is shown that according to some embodiments of the present invention, Figure 2 Flowchart of a method for declaring UE status at and after the end of intermittent coverage;

[0014] Figure 4 A schematic diagram of a communication system 400 according to some embodiments of the present invention is shown. DETAILED DESCRIPTION

[0015] The technical terms in this specification are used in the technical field. If there is an explanation or definition of certain technical terms in this specification, the technical terms in this part will take precedence over the explanation or definition elsewhere. The present invention of each embodiment has one or more technical features. Where possible, a person of ordinary skill in the art can selectively implement some or all of the technical features of the present invention, or selectively combine these technical features of the present invention.

[0016] Figure 1 A flow chart of a method for controlling a non-access stratum NAS timer during or after intermittent coverage is shown, according to some embodiments of the present invention. The method for controlling a NAS timer during or after intermittent coverage is applied to a user equipment UE. In some embodiments, the UE may be, for example, a laptop, a tablet computer, a smart phone, a smart watch, etc., but the present invention is not limited thereto. Figure 1 As shown, the method for controlling NAS timers includes the following steps. An unavailable period is activated due to intermittent coverage (step S100). All NAS timers are stopped except for the exception timer (step S102). The related program is terminated (step S104). In some embodiments, the exception timer includes T3412, T3346, T3396, T3447, any back-off timer, T3247, and a timer for controlling periodic search for the home public land mobile network HPLMN or equivalent HPLMN (EHPLMN) or a higher priority PLMN, but the present invention is not limited thereto.

[0017] In some embodiments, the unavailable period in step S100 includes periods of intermittent coverage and / or periods when the UE's access stratum is deactivated. Prior to performing step S100, the UE and the network may support satellite E-UTRAN access with CIoT EPS optimization in WB-S1 mode or NB-S1 mode. Support for satellite E-UTRAN is specified in 3GPP TS 36.300

[20] . The network's mobility management entity (MME) may determine that the UE is using satellite E-UTRAN access to access the network and may enforce mobility restrictions for the UE as specified in 3GPP TS23.401. If the unavailable period is activated due to intermittent coverage ( Figure 1 In step S100), as described in 3GPP TS23.401, all NAS timers are stopped except for the exception timers ( Figure 1 Step S102 in ) and terminate the relevant procedures (as described in 3GPP TS23.122) ( Figure 1 , or step S104 in the above procedure.

[0018] In some embodiments, when there is an EPLMN list, the related procedures are suspended except for the EPLMN. In some embodiments, if an unavailable period is activated due to intermittent coverage, the UE may deactivate the access stratum.

[0019] Figure 2 A flow chart of a method for declaring the status of a user equipment UE at and after the end of intermittent coverage is shown, according to some embodiments of the present invention. The method is applied to the UE. In some embodiments, the UE can be, for example, a laptop, a tablet computer, a smart phone, a smart watch, etc., but the present invention is not limited thereto.

[0020] like Figure 2As shown, the method includes the following steps. After losing coverage due to intermittent coverage, the UE returns to the currently registered tracking area (TA) coverage (step S200). The UE runs or starts an intermittent coverage maximum time offset timer (step S202). The UE enters a specific xMM state. The specific xMM state includes an xMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE state (step S204). When the intermittent coverage maximum time offset timer expires, the UE executes an xMM procedure (step S206). In some embodiments, the xMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE state is a 5GMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE state or an EMM-REGISTERED.ATTEMPTING-TO-UPDATE state.

[0021] In some embodiments, if the UE has stored the maximum time offset for intermittent coverage as described in subclauses 5.4.4.3, 5.5.1.2.4 and 5.5.1.3.4, and returns to the currently registered tracking area (TA) coverage after losing coverage due to intermittent coverage, and in the last registration acceptance REGISTRATION ACCEPT message, the unavailable period end report is set to "UE needs to report the end of the unavailable period", then the UE starts a maximum time offset for intermittent coverage timer with a random value (i.e., the random timer in step S202), which random value contains at most the maximum time offset for intermittent coverage stored for this PLMN and NR satellite access.

[0022] The UE enters the 5GMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE state and does not start any NAS signaling on the NR satellite access and PLMN while the intermittent coverage maximum time offset timer (i.e., the intermittent coverage maximum time offset timer in step S202) is running. If the UE receives a paging message, has pending emergency services, is establishing an emergency PDU session, or is performing an emergency service fallback procedure, or when the UE enters a TAI outside the registration area, the UE stops the intermittent coverage maximum time offset timer and starts NAS signaling. When the intermittent coverage maximum time offset timer expires, the UE performs a registration procedure for mobility registration update.

[0023] In some embodiments, upon entering, during or after a random timer running state, the UE does not initiate any 5GMM procedures, except emergency services. The UE remains in the same 5GMM state, such as the NO-Cell state, until the random timer expires.

[0024] Figure 3 It shows some embodiments according to the present invention. Figure 2 A flowchart of a method for declaring a UE status at and after the end of intermittent coverage in FIG. The method is applied to a UE. In some embodiments, the UE may be, for example, a laptop, a tablet computer, a smart phone, a smart watch, etc., but the present invention is not limited thereto. Figure 3 As shown, the method comprises the following steps: storing a specific xMM state before entering the intermittent coverage situation or before deactivating the access layer due to intermittent coverage (step S300). Selecting the specific xMM state once the UE leaves the intermittent coverage and the intermittent coverage maximum time offset timer is started or running (step S302).

[0025] In some embodiments, when the unavailability period is activated, all NAS timers are stopped and related procedures are aborted, except timers T3512, T3346, T3447, T3396, T3584, T3585, any back-off timer, T3247 and timer T that controls the periodic search for HPLMN or EHPLMN or higher priority PLMN. In some embodiments, when the UE activates the unavailability period using the registration procedure without providing the start of the unavailability period, then after the procedure is successfully completed, the UE enters the 5GMM-REGISTERED.NO-CELL-AVAILABLE state. Otherwise, if the UE provides the start of the unavailability period in the registration procedure, the UE enters the 5GMM-REGISTERED.NO-CELL-AVAILABLE state only after activating the unavailability period. In some embodiments, when the UE activates the unavailability period using the deregistration procedure, then after the procedure is successfully completed, the UE enters the 5GMM-DEREGISTERED.NO-CELL-AVAILABLE state.

[0026] In some embodiments, the specific xMM state may also be the 5GMM-DEREGISTERED.NORMAL-SERVICE state, and / or the 5GMM-DEREGISTERED.ATTEMPTING-REGISTRATION state, and / or a new state, such as the 5GMM-DEREGISTERED.DISCONTINUOUS-COVERAGE-WAITING state, and / or the 5GMM-DEREGISTERED.INITIAL-REGISTRATION-NEEDED state, and / or the 5GMM-REGISTERED.NORMAL-SERVICE state, and / or the 5GMM-REGISTERED.UPDATE-NEEDED state, and / or a new state, such as the 5GMM-REGISTERED.DISCONTINUOUS-COVERAGE-WAITING state.

[0027] In some embodiments, the specific xMM state may also be the EMM-DEREGISTERED.NORMAL-SERVICE state in the deregistered state, and / or the EMM-DEREGISTERED.ATTEMPTING-TO-ATTACH state, and / or a new state, such as the EMM-DEREGISTERED.DISCONTINUOUS-COVERAGE-WAITING state, and / or the EMM-DEREGISTERED.ATTACH-NEEDED state, and / or the EMM-REGISTERED.NORMAL-SERVICE state, and / or the EMM-REGISTERED.UPDATE-NEEDED state, and / or a new state, such as the EMM-REGISTERED.DISCONTINUOUS-COVERAGE-WAITING state.

[0028] In some embodiments, the UE stores a specific EMM state before entering an intermittent coverage situation or before deactivating the access stratum due to intermittent coverage. Once the UE leaves intermittent coverage and a random timer starts or runs, the UE selects a specific EMM state.

[0029] In some embodiments, the UE does not initiate any EMM procedures except emergency services in the state when entering, during or after the random timer is running. The same EMM state includes the NO-Cell state.

[0030] Figure 4 4 shows a schematic diagram of a communication system 400 according to some embodiments of the present invention. Figure 4As shown, the communication system 400 includes a user equipment UE 402, a network 404, and a base station 406. In some embodiments, the UE 402 may be a laptop, a tablet, a smart phone, or a smart watch, but the present invention is not limited thereto. In some embodiments, the UE 402 can access the network 404 through the base station 406. The UE 402 is connected to the base station 406 via Radio Resource Control (RRC) signaling, but the present invention is not limited thereto. In some embodiments, the base station 406 may be a gNB, but the present invention is not limited thereto.

[0031] In some embodiments, UE 402 includes an antenna 412, a transceiver 408, and a processor 410. The transceiver 408 is electrically connected between the antenna 412 and the processor 410. The processor 410 may be a modem, but the present invention is not limited thereto. In some embodiments, UE 402 further includes a memory (not shown) storing a plurality of codes. The processor 410 reads the code stored in the memory to perform the following steps. In some embodiments, the processor 410 activates an unavailable period due to intermittent coverage, stops all non-access stratum (NAS) timers, except for exception timers, and terminates related programs. In some embodiments, the exception timers include T3412, T3346, T3396, T3447, any back-off timer, T3247, and a timer that controls periodic search for a home public land mobile network (HPLMN) or an equivalent HPLMN (EHPLMN) or a higher priority PLMN. Unavailable periods include periods of intermittent coverage and / or periods when the access stratum of UE 402 is deactivated.

[0032] In some embodiments, after the processor 410 suspends related procedures except T3412, T3346, T3396, T3447, any back-off timer, T3247, and the timer controlling the periodic search for HPLMN or EHPLMN or higher priority PLMN, the processor 410 deactivates the access layer. In some embodiments, when there is an EHPLMN list, related procedures except EHPLMN are suspended.

[0033] In some embodiments, the processor 410 returns to the currently registered tracking area (TA) coverage after losing coverage due to intermittent coverage, runs or starts the intermittent coverage maximum time offset timer, enters a specific xMM state, and executes an xMM program when the intermittent coverage maximum time offset timer expires. The specific xMM state includes the xMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE state. In some embodiments, the xMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE state is the 5GMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE state or the EMM-REGISTERED.ATTEMPTING-TO-UPDATE state.

[0034] In some embodiments, the xMM procedure is a registration procedure for mobility registration update or a tracking area update procedure. In some embodiments, the processor 410 stores a specific xMM state before entering an intermittent coverage situation or before deactivating the access layer due to intermittent coverage, and selects the specific xMM state when the UE leaves intermittent coverage and the intermittent coverage maximum time offset timer is started or running.

[0035] In some embodiments, the processor 410 receives the last REGISTRATION ACCEPT message from the network. The last REGISTRATION ACCEPT message includes reporting that the unavailable period has ended. Reporting that the unavailable period has ended means that "the UE does not need to report the end of the unavailable period". The processor 410 selects an appropriate 5GMM-REGISTERED substate when returning to the tracking area identity (TAI) coverage of the current registration area. Since the unavailable period has ended, the processor 410 does not perform the registration procedure for mobility registration update when returning to the TAI coverage of the current registration area.

[0036] In some embodiments, the processor 410 does not initialize any 5GMM program in the state entered when or after the random timer runs, except for emergency services. The processor 410 remains in the same 5GMM state until the random timer expires. The same 5GMM state includes the NO-Cell state.

[0037] It should be understood that the specific order or hierarchy of the blocks in the disclosed process / flowchart is an illustration of an exemplary method. It should be understood that the specific order or hierarchy of the blocks in the process / flowchart may be rearranged based on design preferences. In addition, some blocks may be combined or omitted. The accompanying method claims present the elements of the various blocks in an example order and are not intended to be limited to the specific order or hierarchy presented.

[0038] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. Therefore, the claims are not intended to be limited to the various aspects shown herein, but should be given a full scope consistent with the claims text, wherein unless explicitly stated, the reference to the elements in the singular form is not intended to represent "one and only one", but to represent "one or more". The word "exemplary" is used herein to represent "used as an example, instance or illustration". Any aspect described as "exemplary" herein is not necessarily interpreted as being preferred or advantageous over other aspects. Unless otherwise explicitly stated, the term "some" refers to one or more. Combinations such as "at least one of A, B or C", "one or more of A, B or C", "at least one of A, B and C", "one or more of A, B and C" and "A, B, C or any combination thereof" include any combination of A, B and / or C, and may include multiple A, multiple B or multiple C. Specifically, phrases such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" may be only A, only B, only C, A and B, A and C, B and C, or A and B and C, wherein any such combination may include one or more members of A, B, or C. All structural and functional equivalents of the elements throughout the various aspects of the description of the present invention that are known or will later be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by the claims. In addition, regardless of whether such disclosure is expressly recited in the claims, nothing disclosed herein is intended to be dedicated to the public. The terms "module," "mechanism," "element," "device," and the like may not replace the term "device." Therefore, unless a claim element is expressly recited using the phrase "device for...", no claim element should be interpreted as a device plus function.

Claims

1. A method for controlling a non-access stratum NAS timer during or after intermittent coverage, applied to a user equipment UE, characterized in that: include: Activate an unavailable period due to an intermittent coverage; Stop all NAS timers except one; as well as Terminate the relevant program.

2. The method according to claim 1, characterized in that The exception timers include T3412, T3346, T3396, T3447, any back-off timer, T3247, and a timer for controlling periodic search for the home public land mobile network HPLMN or equivalent HPLMN EHPLMN or higher priority PLMN.

3. The method according to claim 1, characterized in that Further including: Deactivate an access layer.

4. The method according to claim 1, characterized in that The unavailable period includes an intermittent coverage period or a period during which the access stratum of the UE is deactivated.

5. A method for declaring the status of a user equipment (UE) at and after the end of intermittent coverage, applied to the UE, characterized in that: include: Return to the currently registered tracking area TA coverage after losing coverage due to an intermittent coverage; Run or start an intermittent coverage maximum time offset timer; Entering a specific xMM state; and Execute an xMM procedure when the intermittent coverage maximum time offset timer expires; The specific xMM status includes an xMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE status.

6. The method according to claim 5, characterized in that The xMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE state is 5GMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE state or EMM-REGISTERED.ATTEMPTING-TO-UPDATE state.

7. The method according to claim 5, characterized in that The xMM procedure is a registration procedure or a tracking area update procedure for mobility registration update.

8. The method according to claim 5, characterized in that Further including: storing the specific xMM state prior to entering an intermittent coverage condition or prior to deactivating an access layer due to the intermittent coverage; and The specific xMM state is selected once the UE leaves the intermittent coverage and the intermittent coverage maximum time offset timer starts or runs.

9. The method according to claim 5, characterized in that Further including: No xMM procedures are initialized in the state entered while or after the intermittent coverage maximum time offset timer is running, except for emergency services.

10. A user equipment UE, characterized in that: include: a processor configured to activate an unavailable period due to an intermittent coverage, stop all non-access stratum NAS timers, and suspend related procedures except for exception timers; or wherein the processor is configured to return to the currently registered tracking area TA coverage after losing coverage due to the intermittent coverage, run or start an intermittent coverage maximum time offset timer, enter a specific xMM state, and execute an xMM program when the intermittent coverage maximum time offset timer expires; and The specific xMM state includes the xMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE state.

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