WO2016120419A2

WO2016120419A2 - Paging enhancement for low complexity user equipment and/or user equipment in coverage enhancement mode

Info

Publication number: WO2016120419A2
Application number: PCT/EP2016/051867
Authority: WO
Inventors: Yan Ji ZHANG; Rapeepat Ratasuk
Original assignee: Nokia Solutions And Networks Oy
Priority date: 2015-01-30
Filing date: 2016-01-29
Publication date: 2016-08-04
Also published as: WO2016120419A3

Abstract

Various communication systems may benefit from information regarding devices that are communicating in the system. Thus, for example, certain wireless communication systems may benefit from paging enhancement for Release 13 low complexity user equipment and/or user equipment in coverage enhancement mode. A method can include determining, at a mobility management entity, a latest coverage enhancement level of a user equipment. The method can also include providing the latest coverage enhancement level to an access point.

Description

DESCRIPTION:

Paging Enhancement for Low Complexity User Equipment and/or User Equipment in Coverage Enhancement Mode

CROSS-REFERENCE TO RELATED APPLICATION:

[0001 ] This application is related to and claims the benefit and priority of U.S. Provisional Patent Application No. 62/109,961 filed January 30, 2015, the entirety of which is hereby incorporated herein by reference.

BACKGROUND:

Field:

[0002] Various communication systems may benefit from information regarding devices that are communicating in the system. Thus, for example, certain wireless communication systems may benefit from paging enhancement for Release 13 low complexity user equipment and/or user equipment in coverage enhancement mode.

Description of the Related Art:

[0003] Conventionally, tracking area updating procedures are always initiated by the UE and can be used for various purposes. The most common triggers include normal and periodic tracking area updating. Additionally, certain UE specific parameters in the network can also be updated by TAU procedure.

[0004] The tracking area updating procedure initiated in evolved packet system (EPS) mobility management (EMM)-I DLE mode may request the network to re-establish the radio and S1 bearers for all active EPS bearer contexts during the procedure.

[0005] Third generation partnership project (3GPP) release 13 (Rel-13) includes a work item entitled "Further LTE Physical Layer Enhancements for MTC," see 3GPP RP- 141660, which is incorporated herein by reference in its entirety. This work item aims to specify a new low-complexity user equipment (UE) for machine type communication (MTC) operation in long term evolution (LTE), to support coverage enhancement (CE) for both Rel-13 low-complexity UE and UE operating in coverage enhancement compared to existing LTE networks and to reduce power consumption.

[0006] In order to support paging for the new type of Rel-13 UE, a paging message intended for Rel-13 low-complexity UE and/or UE operating CE may need to support physical downlink shared channel (PDSCH) subframe bundling/repetition with multiple bundle sizes/repetition levels. [0007] Additionally, the network may need to differentiate the new type of Rel-13 UE from other category UEs. Furthermore, the evolved Node B (eNB) may need knowledge that the UE to be paged is a Rel-13 low-complexity UE and/or is a UE that is to be paged using CE. Moreover, the eNB may need to have knowledge on the required amount of coverage enhancement during paging message transmission.

[0008] Therefore, the eNB may need to be informed of the required bundle

sizes/repetition levels for Rel-13 low-complexity UE and/or UE with coverage

enhancement. As the subframe bundling/repetition may be intended to improve the downlink coverage of PDSCH, the bundle sizes/repetition levels can referred to interchangeable with the coverage enhancement (CE) level herein.

SUMMARY:

[0009] According to a first embodiment, a method can include determining, at a network entity, a coverage enhancement level of a user equipment. The method can also include providing the coverage enhancement level to an access point.

[0010] In a variant, the network entity may be a mobility management entity.

[001 1 ] In a variant, the access point may be a base station or evolved Node B.

[0012] In a variant, a mobility management entity can store in user equipment context a coverage enhancement level reported by either the access point or UE, wherein determination of the latest coverage enhancement level can include referring to the stored reported coverage enhancement level.

[0013] In a variant, provision of the latest coverage enhancement level can include, during a paging procedure, extracting the latest coverage enhancement level from the user equipment context and including the latest coverage enhancement level in an S1 paging message.

[0014] According to a second embodiment, a method can include detecting, by a user equipment, a coverage enhancement level for the user equipment. The method can also include notifying a network regarding the coverage enhancement level.

[0015] In a variant, the detecting the coverage enhancement level can include detecting a change of the coverage enhancement level.

[0016] In a variant, the notifying can include notifying the network regarding a change of the coverage enhancement level.

[0017] In a variant, the network can include at least one of a mobility management entity or an access point.

[0018] In a variant, notification to the network can include initiating a tracking area update, location area update, or routing area update procedure to report the change. [0019] In a variant, notification to the network can include initiating a random access procedure to report the change.

[0020] In a variant, notification to the network can occur conditionally.

[0021 ] In a variant, notification can occur conditional upon a coverage enhancement level falling below a threshold coverage enhancement level.

[0022] In a variant, notification can occur conditional upon availability of a periodical tracking area update procedure.

[0023] In a variant, notification can occur conditional on timer T3324.

[0024] In a variant, notification can occur conditional on a power save mode of the user equipment.

[0025] In a variant, notification can occur conditional upon a mobility of the user equipment.

[0026] In a variant, notification can occur conditional upon based on a power preference profile selected by the user equipment.

[0027] In a variant, notification can occur conditional upon a battery level of the user equipment.

[0028] In a variant, notification can occur conditional upon a service type or access type of the user equipment.

[0029] In a variant, notification can occur conditional upon network loading.

[0030] In a variant, initiation of the notification can be conditioned on the coverage enhancement level being worse than a previous coverage enhancement level.

[0031 ] In a variant, notification to the network can include notifying the network of an updated repetition level and/or bundle size.

[0032] In a variant, detection of the change can include monitoring a radio link condition.

[0033] In a variant, notification to the network can include providing an optional information element in a tracking area update request message.

[0034] In a variant, the optional information element, when present, can be configured to indicate a value of the coverage enhancement level of the user equipment.

[0035] In a variant, notification to the network can include providing an updated coverage enhancement level in an S1 message during a tracking area update procedure.

[0036] In a variant, the S1 message can be an S1 initial user equipment message.

[0037] According to a third embodiment, a method can include detecting, by an access point, a coverage enhancement level for a user equipment. The method can also include notifying a network regarding the coverage enhancement level. [0038] In a variant, the detecting the coverage enhancement level can include detecting a change of the coverage enhancement level.

[0039] In a variant, the notifying can include notifying the network regarding a change of the coverage enhancement level.

[0040] In a variant, the access point may be a base station or evolved Node B.

[0041 ] In a variant, the network can include a mobility management entity.

[0042] In a variant, the detecting can include deciding the coverage enhancement level based on repetition of a random access channel preamble sent by the user equipment.

[0043] In a variant, notification to the network can include uploading the changed coverage enhancement level to a mobility management entity via an S1 message.

[0044] In a variant, the detecting can include being informed by the user equipment that a random access procedure is for reporting an updated coverage enhancement level.

[0045] In a variant, information that the random access procedure is for reporting the updated coverage enhancement level can be an indication of an establishment cause in a radio resource control connection request message.

[0046] In a variant, the method can further include omitting normal radio resource control connection setup when the establishment cause indicates that the random access procedure is for reporting the updated coverage enhancement level.

[0047] According to fourth through sixth embodiments, an apparatus can include means for performing the method according to the first through third embodiments respectively, in any of their variants.

[0048] According to seventh through ninth embodiments, an apparatus can include at least one processor and at least one memory and computer program code. The at least one memory and the computer program code can be configured to, with the at least one processor, cause the apparatus at least to perform the method according to the first through third embodiments respectively, in any of their variants.

[0049] According to tenth through twelfth embodiments, a computer program product may encode instructions for performing a process including the method according to the first through third embodiments respectively, in any of their variants.

[0050] According to thirteenth through fifteenth embodiments, a non-transitory computer readable medium may encode instructions that, when executed in hardware, perform a process including the method according to the first through third embodiments respectively, in any of their variants.

[0051 ] According to tenth and eleventh embodiments, a system may include at least one apparatus according to the fourth or seventh embodiments in communication with at least one apparatus according to the fifth or eighth embodiments and further in communication with at least one apparatus according to the sixth or ninth embodiments, respectively in any of their variants. [0052] The above variants of each of the embodiments may be used in combination with one another and may be variously modified or augmented in view of the disclosure herein.

BRIEF DESCRIPTION OF THE DRAWINGS:

[0053] For proper understanding of the invention, reference should be made to the accompanying drawings, wherein:

[0054] Figure 1 illustrates indication of the CE level for paging towards UE, according to certain embodiments.

[0055] Figure 2 illustrates CE level notification NAS TAU request message, according to certain embodiments.

[0056] Figure 3 illustrates CE Level notification via an S1 initial UE message, according to certain embodiments.

[0057] Figure 4 illustrates CE level notification via a new S1 message and simplified RA procedure, according to certain embodiments.

[0058] Figure 5 illustrates a method according to certain embodiments.

[0059] Figure 6 illustrates another method according to certain embodiments.

[0060] Figure 7 illustrates a further method according to certain embodiments.

[0061 ] Figure 8 illustrates a system according to certain embodiments.

DETAILED DESCRIPTION :

[0062] The eNB may need to be informed of the required bundle sizes/repetition levels for Rel-13 low-complexity UE and/or UE operating in coverage enhancement. Without accurate knowledge of the amount of bundle sizes/repetition level required for the UE upon paging, DL overhead may increase, degrading the spectrum efficiency. Furthermore, this absence of knowledge may also cause unreliable reception of the paging message.

[0063] Currently it is assumed that the UE specific bundle size/repetition level may be determined by UE for preamble transmission or eNB for DL transmission, according to the radio link quality. This could be realized by reporting the measurement result from UE, when UE is in connected mode. Such reporting is not conventionally feasible for the UE in IDLE mode. In addition, the application of the last repetition level/bundle size when UE leaves the connected mode is not conventionally viewed as desirable, because the radio link situation might change which may lead to variation of the expected amount of the coverage enhancement. [0064] Certain embodiments provide a solution for the eNB to get the required repetition level/bundle size upon paging towards a Rel-13 low complexity UE and/or the UE in coverage enhancement mode.

[0065] Certain embodiments may include various features. For example, certain embodiments may enhance existing TAU procedure to notify the network of an updated repetition level/bundle size. One modification to the existing TAU procedure may be that a new event may be defined for initiating TAU from UE - the update of coverage level of UE. The modification may be that when the CE level of the UE changes, the UE shall initiate the normal TAU procedure to report the updated CE level. Alternatively, the UE may initiate this procedure only when the CE level is worse than previously, such as when the UE may require or expect to require additional amount of repetition.

[0066] Another enhancement to existing TAU procedures may that a new optional information element (IE) may be added in TAU Request message. The meaning of this IE may be that when the I E is absent, normal UE or no CE required or no CE update, whereas the presence of the IE may indicate the CE level of the Rel-13 low complexity UE and/or the UE in coverage enhancement mode.

[0067] Alternatively, the updated CE level may be indicated in the S1 message during the TAU procedure. The interpretation of this S1 message may be similar to that of the optional IE. For example, if the S1 message is absent, the UE may be considered to be a normal UE or no CE required or no CE update. By contrast, the presence of the S1 message may indicate the CE level of the Rel-13 low complexity UE and/or the UE in coverage enhancement mode

[0068] The mobility management entity (MME) can indicate the required CE level in the S1 paging message upon the paging towards the Rel-13 low complexity UE and/or the UE in coverage enhancement mode.

[0069] 3GPP TS 23.401 specifies that the tracking area update could occur when the UE Network Capability and/or MS Network Capability and/or UE Specific DRX Parameters of the UE change.

[0070] In certain embodiments, the existing TAU procedure can be updated to support an additional CE level update for Rel-13 low complexity UE and/or UE in coverage enhancement mode. For example, when the UE detects a change of a CE level to reflect radio link condition, the UE can initiate the normal TAU procedure to report the updated CE level mapped with the measured radio link quality either by NAS EMM message or S1 message. The change of CE level and/or radio link condition may be due, for example, to movement of the UE.

[0071 ] The reported CE level can be stored in MME and can be used for inclusion in S1 paging. Figure 1 illustrates indication of the CE level for paging towards Rel-13 low complexity UE and/or UE in coverage enhancement mode, according to certain embodiments. [0072] Some MME operations may take place prior to the illustrated steps. For example, the MME can store the CE level in UE context if the CE level is reported either by an eNB or by the UE.

[0073] Then, as shown in Figure 1 , during paging procedure, MME can extract the latest CE level from the UE context and can include the CE level in the S1 paging message. The eNB can then apply the latest CE level for paging message transmission and can page the UE accordingly.

[0074] At least two approaches can be used to notify the MME of the updated CE level. According to a first approach, the new CE level can be reported by network access stratum (NAS) TAU request message.

[0075] Figure 2 illustrates CE level notification NAS TAU request message, according to certain embodiments. As shown in Figure 2, the UE can determine the CE level based on measurement of radio link quality. The UE can report an updated value via NAS EMM TAU Request message to the MME. The MME can store such information in the EMM context. Subsequently, the MME can extract the relevant paging information and includes it in the S1 AP paging message to the eNB upon paging.

[0076] The UE can trigger the TAU procedure after detecting a change of radio quality. The UE thus can perform a random access (RA) procedure in order to subsequently initiate an NAS procedure. Then, the new CE level can be reported in a TAU Request message

[0077] The NAS procedure can be modified to include an optional IE added in TAU Request message for indicating the change of the CE level of the UE. The absence of this IE can indicate a normal TAU procedure triggered by other conditions. The presence of this IE can indicate the CE level of the Rel-13 low complexity UE and/or the UE in coverage enhancement mode.

[0078] According to a second approach, the updated CE level can be reported by an S1 initial UE message during the TAU procedure.

[0079] During the TAU Request procedure, the eNB can decide the CE level of the UE based on the repetition of the RACH Preamble sent by UE and can upload the CE level to MME via S1 initial UE message, so that the MME can store the CE level. At paging, the MME can include the paging information in the S1 AP paging message to the eNB.

[0080] Figure 3 illustrates CE Level notification via an S1 initial UE message, according to certain embodiments. As shown in Figure 3, the UE can trigger the TAU procedure after detecting a change of radio quality. Thus, the UE can perform an RA procedure and then initiate an NAS procedure.

[0081 ] The eNB can determine the CE level of the UE based on the repetition level of the PRACH preamble received from UE and can include the CE level in the initial UE message which carries the NAS TAU Request message.

[0082] One optional IE can be added in an S1 initial UE message for indicating the change of the CE level of the UE. The absence of this IE can indicate that the CE level is unchanged. The presence of this I E can indicate the CE level of the Rel-13 low complexity UE and/or the UE in coverage enhancement mode.

[0083] According to a third approach, in certain embodiments an updated CE level can be reported by a newly defined S1 message with simplified RA procedure.

[0084] As the UE stays in I DLE mode, there may be no need to establish the RRC connection just for reporting the updated CE level. In order to reduce the signaling exchange over the Uu interface and S1 interface required for the normal TAU procedure, the procedure described with reference to Figure 4.

[0085] Figure 4 illustrates CE level notification via a new S1 message and simplified RA procedure, according to certain embodiments. As shown in Figure 4, the UE can trigger an RA procedure after detecting a change of the radio quality.

[0086] The UE can inform the eNB that the RA procedure is for reporting the updated CE level by applying a new establishmentCause in RRCConnectionRequest message (Msg3)

[0087] Meanwhile, the eNB can determine the CE level of the UE based on the repetition level of the PRACH preamble received from UE. When the eNB gets the UE identity and the establishmentCause from the RRCConnectionRequest message, there may be no need for a normal RRCConnectionSetup message to follow. The eNB can report the CE level and UE identity associated in the new S1 AP message.

[0088] For certain embodiments, a new establishmentCause (CE level update) can be defined to inform the eNB that the RRC connection request is for updating the CE level and that any immediately subsequent RRCConnectionSetup message can be ignored with respect to actually setting up such a connection.

[0089] Moreover, a new S1 AP message can be used to indicate the change of the CE level of UE. This message can include the CE level and UE identity associated therewith. The new S1 AP may also include the CE level of multiple UEs if each of the UEs updates is respective CE level within the same time duration.

[0090] Certain embodiments may have various benefits and/or advantages. For example, the eNB may get the appropriate CE level to transfer paging message towards the Rel-13 low complexity UE and/or the UE in coverage enhancement mode to achieve the optimized system performance and ensure the successful paging procedure.

[0091 ] Power consumption may increase in certain embodiments, because the UE may now have to send information regarding CE level when in idle mode. However, this procedure may be configurable by the eNB. Furthermore, there are several methods that may reduce the number of TAU/access requests. Some examples are as follows. For example, the eNB can configure the UE to report the CE level only when it fall below a threshold CE level. Furthermore, a UE which is using Power Saving Mode can determine whether to report the CE level only when T3324 is greater than a threshold, as upon expiry of the timer T3324, the UE may activate PSM during which the UE could not be paged. [0092] A UE may adopt PSM for reducing the UE's own power consumption. PSM can be a mode similar to power-off, but in PSM the UE can remain registered with the network. Thus, in PSM there may be no need to re-attach or re-establish PDN connections. A UE in PSM may not be immediately reachable for mobile terminating services. A UE using PSM, however, may be available for mobile terminating services for the period of an Active Time after a mobile originated event like data transfer or signaling, for example after a periodic TAU/RAU procedure.

[0093] The network can accept the use of PSM by providing a specific value for timer T3324 when accepting the attach or tracking area updating procedure. The UE may use PSM only if the network has provided the T3324 value IE during the last attach or tracking area updating procedure with a value different from "deactivated." Upon expiry of the timer T3324, the UE may deactivate the AS layer and activate PSM.

[0094] In another option, the UE may determine not to trigger the regular CE level report if timer T3412 is less than a threshold, as the update CE level could be reported by the periodical TAU procedure triggered by the expiry of the timer T3412. The eNB can determine which UE will report the CE level based on mobility information. For example, a UE with no or limited mobility may not be required to report CE level when in idle mode.

[0095] In a further option, the eNB can determine which UE will report the CE level based on power preference profile selected by the UE. For example, a UE with a power indication bit set may not be required to report CE level when in idle mode. The power indication bit may indicate a preference for power saving mode.

[0096] In an additional option, the eNB can determine which UE will report the CE level based on battery level of the UE. For instance, a message may be introduced for UE to report the UE's battery level, which may enable the eNB to determine the proper configuration.

[0097] The eNB can determine which UEs will report CE level based on service or access types. For example, UEs with mostly UE-initiated data transmission, such as sensors or meters, may rarely be paged. Therefore, there may be no need to report CE level in idle mode. The network, for example the MME, may be able to obtain this information from a MTC application server.

[0098] Furthermore, the eNB can turn off CE level reporting in idle mode when the system is lightly loaded. In this case, there may be no need to conserve paging resources. Thus, the eNB may always use the maximum number of repetitions for paging messages.

[0099] Figure 5 illustrates a method according to certain embodiments. As shown in Figure 5, a method can include, at 510, determining, at a mobility management entity, a latest coverage enhancement level of a user equipment. The method can also include providing, at 520, the latest coverage enhancement level to an access point. The access point may be a base station or evolved Node B.

[0100] The method can also include, at 502, receiving a report of coverage enhancement level of the user equipment from the user equipment or from an access point. The method can further include, at 504, the mobility management entity storing the reported coverage enhancement level in a user equipment context. In such a case, determination of the latest coverage enhancement level can include referring to the stored reported coverage enhancement level.

[0101 ] In a variant, provision of the latest coverage enhancement level can include, during a paging procedure, extracting the latest coverage enhancement level from the user equipment context and including the latest coverage enhancement level in an S1 paging message.

[0102] Figure 6 illustrates another method according to certain embodiments. As shown in Figure 6, a method can include, at 610, detecting, by a user equipment, a change of a coverage enhancement level for the user equipment. In a variant, detection of the change can include monitoring a radio link condition at 602.

[0103] The method can also include, at 620, notifying a network regarding the change of the coverage enhancement level. The network can include a mobility management entity. Notification of the network can include notifying the network of an updated repetition level and/or bundle size.

[0104] Notification of the network can include initiating a tracking area update, location area update, or routing area update procedure to report the change, at 622. Any similar procedure can be used to report the change. For example, notification to the network can include initiating a random access procedure to report the change. The tracking area update can be conditioned on the coverage enhancement level being worse than a previous coverage enhancement level.

[0105] In a variant, notification of the network can include providing, at 624, an optional information element in a tracking area update request message. The optional information element, when present, can be configured to indicate a value of the coverage

enhancement level of the user equipment.

[0106] In a variant, notification of the network can include, at 626, providing an updated coverage enhancement level in an S1 message during a tracking area update procedure. The S1 message can be an S1 initial user equipment message.

[0107] Figure 7 illustrates a further method according to certain embodiments. As shown in Figure 7, a method can include, at 710 detecting, by an access point, a change of a coverage enhancement level for a user equipment. The method can also include, at 720, notifying a network regarding the change of the coverage enhancement level.

[0108] The access point may be a base station or evolved Node B, while the network can include a mobility management entity.

[0109] The detecting can include, at 702, deciding the coverage enhancement level based on repetition of a random access channel preamble sent by the user equipment.

[01 10] Notification of the network can include, at 722, uploading the changed coverage enhancement level to a mobility management entity via an S1 message. [01 1 1 ] The detecting can include being informed, at 704, by the user equipment that a random access procedure is for reporting an updated coverage enhancement level.

Information that the random access procedure is for reporting the updated coverage enhancement level can be an indication of an establishment cause in a radio resource control connection request message.

[01 12] The method can further include omitting normal radio resource control connection setup when the establishment cause indicates that the random access procedure is for reporting the updated coverage enhancement level.

[01 13] Figure 8 illustrates a system according to certain embodiments of the invention. In one embodiment, a system may include multiple devices, such as, for example, at least one UE 810, at least one access point 820, which may be an eNB or other base station or access point, and at least one MME 830 or other core network element.

[01 14] Each of these devices may include at least one processor, respectively indicated as 814, 824, and 834. At least one memory can be provided in each device, and indicated as 815, 825, and 835, respectively. The memory may include computer program instructions or computer code contained therein. The processors 814, 824, and 834 and memories 815, 825, and 835, or a subset thereof, can be configured to provide means corresponding to the various blocks of any of Figures 5 through 7.

[01 15] As shown in Figure 8, transceivers 816, 826, and 836 can be provided, and each device may also include an antenna, respectively illustrated as 817, 827, and 837. Other configurations of these devices, for example, may be provided. For example, MME 830 may be configured for wired communication only, and in such a case antenna 837 can illustrate any form of communication hardware, without requiring a conventional antenna.

[01 16] Transceivers 816, 826, and 836 can each, independently, be a transmitter, a receiver, or both a transmitter and a receiver, or a unit or device that is configured both for transmission and reception.

[01 17] Processors 814, 824, and 834 can be embodied by any computational or data processing device, such as a central processing unit (CPU), application specific integrated circuit (ASIC), or comparable device. The processors can be implemented as a single controller, or a plurality of controllers or processors.

[01 18] Memories 815, 825, and 835 can independently be any suitable storage device, such as a non-transitory computer-readable medium. A hard disk drive (HDD), random access memory (RAM), flash memory, or other suitable memory can be used. The memories can be combined on a single integrated circuit as the processor, or may be separate from the one or more processors. Furthermore, the computer program instructions stored in the memory and which may be processed by the processors can be any suitable form of computer program code, for example, a compiled or interpreted computer program written in any suitable programming language.

[01 19] The memory and the computer program instructions can be configured, with the processor for the particular device, to cause a hardware apparatus such as UE 810, access point 820, and MME 830, to perform any of the processes described herein (see, for example, any of Figures 5 through 7). Therefore, in certain embodiments, a non- transitory computer-readable medium can be encoded with computer instructions that, when executed in hardware, perform a process such as one of the processes described herein. Alternatively, certain embodiments of the invention can be performed entirely in hardware.

[0120] Furthermore, although Figure 8 illustrates a system including a UE, throughput guidance entity, and information receiver, embodiments of the invention may be applicable to other configurations, and configurations involving additional elements. For example, not shown, additional UEs may be present, and additional core network elements may be present.

[0121 ] One having ordinary skill in the art will readily understand that the invention as discussed above may be practiced with steps in a different order, and/or with hardware elements in configurations which are different than those which are disclosed. Therefore, although the invention has been described based upon these preferred embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of the invention.

[0122] List of Abbreviations

[0123] CE Coverage Enhancement

[0124] EMM EPS Mobility Management

[0125] eNB Evolved Node B

[0126] MME Mobility Management Entity

[0127] MTC Machine Type Communication

[0128] NAS Non Access Stratum

[0129] PRACH Physical Random Access CHannel

[0130] RAR Random Access Response

[0131 ] RRC Radio Resource Control

[0132] S1 AP Signaling Radio Bearer

[0133] TAU Tracking Area Update

[0134] UE User Equipment

Claims

WE CLAIM:

1 . A method, comprising:

determining, at a network entity, a coverage enhancement level of a user equipment; and providing the coverage enhancement level to an access point.

2. The method of claim 1 , wherein the network entity comprises a mobility management entity.

3. The method of claim 1 , wherein the access point comprises a base station or an evolved Node B.

4. The method of claim 1 , wherein a mobility management entity stores in user equipment context a coverage enhancement level reported by either the access point or the user equipment, wherein determination of the latest coverage enhancement level comprises referring to the stored reported coverage enhancement level.

5. The method of claim 1 , wherein provision of the latest coverage enhancement level comprises, during a paging procedure, extracting the latest coverage enhancement level from the user equipment context and including the latest coverage enhancement level in an S1 paging message.

6. A method, comprising:

detecting, by a user equipment, a coverage enhancement level for the user equipment; and

notifying a network regarding the coverage enhancement level.

7. The method of claim 6, wherein the detecting the coverage enhancement level comprises detecting a change of the coverage enhancement level.

8. The method of claim 6, wherein the notifying comprises notifying the network regarding a change of the coverage enhancement level.

9. The method of claim 6, wherein the network comprises at least one of a mobility management entity or an access point.

10. The method of claim 6, wherein notification to the network comprises initiating a tracking area update, location area update, or routing area update procedure to report the change.

1 1 . The method of claim 6, wherein notification to the network comprises initiating a random access procedure to report the change.

12. The method of claim 6, wherein notification to the network occurs conditionally.

13. The method of claim 6, wherein notification occurs conditional upon a coverage enhancement level falling below a threshold coverage enhancement level.

14. The method of claim 6, wherein notification occurs conditional upon availability of a periodical tracking area update procedure.

15. The method of claim 6, wherein notification occurs conditional on timer T3324.

16. The method of claim 6, wherein notification occurs conditional on a power save mode of the user equipment.

17. The method of claim 6, wherein notification occurs conditional upon a mobility of the user equipment.

18. The method of claim 6, wherein notification occurs conditional upon based on a power preference profile selected by the user equipment.

19. The method of claim 6, wherein notification occurs conditional upon a battery level of the user equipment.

20. The method of claim 6, wherein notification occurs conditional upon a service type or access type of the user equipment.

. The method of claim 6, wherein notification occurs conditional upon network loading.

22. The method of claim 6, wherein initiation of the notification is conditioned on the coverage enhancement level being worse than a previous coverage enhancement level.

23. The method of claim 6, wherein notification to the network comprises notifying the network of an updated repetition level and/or bundle size.

24. The method of claim 6, wherein detection of the change comprises monitoring a radio link condition.

25. The method of claim 6, wherein notification to the network comprises providing an optional information element in a tracking area update request message.

26. The method of claim 25, wherein the optional information element, when present, is configured to indicate a value of the coverage enhancement level of the user equipment.

27. The method of claim 6, wherein notification to the network comprises providing an updated coverage enhancement level in an S1 message during a tracking area update procedure.

28. The method of claim 27, wherein the S1 message comprises an S1 initial user equipment message.

29. A method, comprising:

detecting, by an access point, a coverage enhancement level for a user equipment; and notifying a network regarding the coverage enhancement level.

30. The method of claim 29, wherein the detecting the coverage enhancement level comprises detecting a change of the coverage enhancement level.

31 . The method of claim 29, wherein the notifying comprises notifying the network regarding a change of the coverage enhancement level.

32. The method of claim 29, wherein the access point comprises a base station or evolved Node B.

33. The method of claim 29, wherein the network comprises a mobility management entity.

34. The method of claim 29, wherein the detecting comprises deciding the coverage enhancement level based on repetition of a random access channel preamble sent by the user equipment.

35. The method of claim 29, wherein notification to the network comprises uploading the changed coverage enhancement level to a mobility management entity via an S1 message.

36. The method of claim 29, wherein the detecting comprises being informed by the equipment that a random access procedure is for reporting an updated coverage enhancement level.

37. The method of claim 29, wherein information that the random access procedure is for reporting the updated coverage enhancement level comprises an indication of an establishment cause in a radio resource control connection request message.

38. The method of claim 29, further comprising: omitting normal radio resource control connection setup when the establishment cause indicates that the random access procedure is for reporting the updated coverage enhancement level.

39. An apparatus, comprising:

means for performing the method according to any of claims 1-37.

40. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code,

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to perform the method according to any of claims 1 -37.

41. A computer program product encoding instructions for performing a process, the process comprising the method according to any of claims 1-37.

42. A non-transitory computer readable medium encoded with instructions that, when executed in hardware, perform a process, the process comprising the method according to any of claims 1-37.

43. A system comprising:

a first apparatus comprising means for performing the method according to any of claims 1-5;

a second apparatus comprising means for performing the method according to any of claims 6-27; and

a third apparatus comprising means for performing the method according to any of claims 28-37,

wherein the first apparatus is in communication with the second apparatus and further in communication with the third apparatus.