Paging enhancement for extended DRX in cellular systems

Patent metadata

Field	Value
Publication number	US-10455505-B2
Application number	US-201515566201-A
Country	US
Kind code	B2
Filing date	Dec 24, 2015
Priority date	May 11, 2015
Publication date	Oct 22, 2019
Grant date	Oct 22, 2019

Abstract

Technology described herein relates to systems, methods, and computer readable media to implement extended Discontinuous Reception (eDRX) for user equipments (UEs). A Mobility Management Entity (MME) can be aware of the starting time and length of an eDRX cycle of a UE so that the MME can send a paging message for the UE to an evolved Node B (eNB) shortly ahead of a Paging Occasion (PO). In some examples, more than one PO can be included within an eDRX cycle. An eDRX timer can be used to control the duration of waking times and, if desired, to maintain legacy compatibility. Additional examples provide a way for the MME to update calculations regarding the starting time and length of eDRX cycle of the UE such that the MME will continue to be apprised of when the UE will be reachable when the UE moves between cells.

First claim

What is claimed is:

1. A user equipment (UE) capable of applying extended discontinuous reception (eDRX) to reduce energy consumption at the UE, the UE comprising,
one or more processors configured to:
signal transceiver circuitry at the UE to send an eDRX-request communication to a mobility management entity (MIME) via a wireless connection to a cellular base station, wherein the eDRX-request communication indicates that the UE requests to use eDRX for an idle mode of the UE;
identify an eDRX-response communication received from the MME via the wireless connection to the cellular base station, wherein the eDRX-response communication includes an absolute time reference (T ref );
identify an eDRX timer value (T eDRX ) to be applied, wherein the T eDRX specifies a duration of an eDRX cycle;
switch the UE into a power-saving state that applies the eDRX cycle;
switch the UE from the power-saving state into the idle mode, which applies a normal DRX cycle, before a periodic time instant T N ;
monitor a paging occasion (PO) for a paging communication from the MME for at least a predefined period of time;
switch the UE back into the power-saving state; and
use the T ref and the T eDRX to identify paging occasions (POs) that are to be monitored at the UE; and

a memory configured to communicate with the one or more processors.

2. The UE of claim 1 , wherein the T eDRX is sent in the eDRX-request communication.

3. The UE of claim 1 , wherein the T eDRX is received in the eDRX-response communication.

4. The UE of claim 1 , wherein the T ref is based on Coordinated Universal Time (UTC) and the T ref is encoded as a five-octet integer value.

5. The UE of claim 1 , wherein the one or more processors are further configured to:
switch the UE from the power-saving state into the idle mode before the periodic time instant T N , where T N is defined as T ref +N*T eDRX , where N is a non-negative integer;
monitor (PO) for a paging communication from the MME for at least the predefined period of time; and
switch the UE back into the power-saving state.

6. The UE of claim 5 , wherein the eDRX-response communication includes a number of normal discontinuous reception (DRX) repetitions (N DRX ) and the predefined period of time is defined as N DRX *T DRX , wherein T DRX specifies a duration of a normal DRX cycle.

7. The UE of claim 1 , wherein the one or more processors are further configured to:
switch the UE from the power-saving state into the idle mode before the periodic time instant T N , where T N is defined by the equation T N =T rlsUu +T Offset +N*T eDRX , wherein N is a positive integer, T rlsUu is a time instant when a Radio Resource Control (RRC) connection release procedure has been completed at the UE, and T Offset is a time offset value received at the UE in an RRC connection release message;
monitor the paging occasion (PO) for the paging communication from the MME for at least the predefined period of time; and
switch the UE back into the power-saving state.

8. The UE of claim 1 , wherein the one or more processors are further configured to use a Tracking Area Update or an Attach Procedure to receive an eDRX configuration from the MME.

9. A Mobility Management Entity (MME) comprising:
one or more processors configured to:
identify a request message received from a user equipment (UE) via an evolved Node B (eNB), wherein the request message indicates that the UE wishes to use extended discontinuous reception (eDRX) for an idle mode of the UE;
send an enhanced S1 Application Protocol (S1-AP) paging message to the eNB before a periodic time instant T N ; and
signal the eNB to send a response message to the UE, wherein the response message includes an absolute time reference (T ref ); and

a memory configured to communicate with the one or more processors.

10. The MME of claim 9 , wherein the request message includes an eDRX timer value (T eDRX ) to be applied by the one or more processors at the UE and the response message includes either a verification that the T eDRX is acceptable or an indication of an alternative T eDRX .

11. The MME of claim 9 , wherein the response message includes an eDRX timer value (T eDRX ) to be applied by the one or more processors at the UE.

12. The MME of claim 11 , wherein the one or more processors are further configured to send the enhanced S1 Application Protocol (S1-AP) paging message to the eNB before the periodic time instant T N , wherein T N is defined by the equation T N =T ref +N*T eDRX , where N is a positive integer.

13. The MME of claim 12 , wherein the enhanced S1-AP paging message includes a number of normal discontinuous reception (DRX) repetitions (N DRX ) to be applied by the one or more processors at the UE.

14. The MME of claim 11 , wherein the one or more processors are further configured to:
send an enhanced S1 Application Protocol (S1-AP) UE context release message to the eNB, wherein the S1-AP UE context release message includes a time offset value (T Offset ); and
send an S1 Application Protocol (S1-AP) paging message to the eNB before a periodic time instant T N , where T N is defined by the equation T N =T rlsS1 +T Offset +N*T eDRX , wherein N is a positive integer and T rlsS1 is a time instant when an S1 release procedure for the UE has been completed at the MME.

15. The MME of claim 9 , wherein the one or more processors are further configured to provide an eDRX configuration to the UE via a tracking area update or via an attach procedure.

16. The UE of claim 9 , wherein the one or more processors are further configured to select the T ref that is sent in the response message in a UE-specific manner in order to stagger paging cycles of a plurality of UEs in order to prevent access-related congestion.

17. An evolved node B (eNB) comprising:
one or more processors configured to:
identify a request message received from a user equipment (UE) for a Mobility Management Entity (MME), wherein the request message indicates that the UE requests to use extended discontinuous reception (eDRX) for an idle mode of the UE;
send the request message to the MME via an S1 interface;
receive a response message for the UE from the MME, wherein the response message includes an absolute time reference (T ref );
receive an enhanced S1 Application Protocol (S1-AP) paging message for a user equipment (UE) when the UE is in an idle mode, wherein the enhanced S1-SP paging message includes a number of normal discontinuous reception (DRX) repetitions (N DRX ); and
signal transceiver circuitry at the eNB to send the response message to the UE via an air interface; and

a memory configured to communicate with the one or more processors.

18. The eNB of claim 17 , wherein the one or more processors are further configured to signal the transceiver circuitry at the eNB to send a paging communication to the UE on N DRX paging occasions (POs).

19. The eNB of claim 17 , wherein the one or more processors are further configured to receive an enhanced S1 Application Protocol (S1-AP) UE context release message for the UE when the UE is in a connected mode, wherein the enhanced S1-AP UE context release message includes a time offset value (T Offset ) to be applied by the UE.

20. The eNB of claim 19 , wherein the one or more processors are further configured to signal the transceiver circuitry at the eNB to send a Radio Resource Control (RRC) Connection Release message to the UE, wherein the RRC Connection Release message includes the T Offset .

Assignees

• Intel Ip Corp

Inventors

• Bangolae Sangeetha
• Stojanovski Alexandre
• Tarradell Marta Martinez
• Burbidge Richard
• Jain Puneet

Classifications

• H04W52/0216 Primary

  using a pre-established activity schedule, e.g. traffic indication frame · CPC title

• H04W76/28

  Discontinuous transmission [DTX]; Discontinuous reception [DRX] · CPC title

• H04W68/02

  Arrangements for increasing efficiency of notification or paging channel · CPC title

• H04W52/0229

  where the received signal is a wanted signal · CPC title

• Y02D70/142

  Cross-Sectional Technologies · mapped topic