Method and apparatus for power saving operations in wireless network elements

• US 9,693,299 B2
• Filed: 11/30/2009
• Issued: 06/27/2017
• Est. Priority Date: 11/30/2009
• Status: Expired due to Fees

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Technologies Oy (Nokia Corporation)
• Inventors: Doppler, Klaus Franz, Kneckt, Jarkko Lauri Sakari, Ribeiro, Cassio Barboza, Korhonen, Juha Sakari
• Primary Examiner(s): Mian, Omer S
• Application Number:
  US12/627,103
• Publication Number:
  US 20110128865A1
• Time in Patent Office: 2,766 Days
• Field of Search: 370311
• CPC Class Codes: H04W 36/0088 Scheduling hand-off measurements
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

In accordance with an example embodiment of the present invention, a method comprises determining at a base station an activity level, and selecting an availability mode based at least in part on the activity level, wherein the availability mode is one of a full-availability mode, a semi-availability mode and a minimum-availability mode. The method also comprises configuring radio resources for at least the minimum-availability mode and switching to the selected availability mode.

Claims

1. A method, comprising:

determining at a base station an activity level in a current radio frame;

selecting, by the base station, an availability mode for the base station based at least in part on the activity level, wherein the availability mode is one of a full-availability mode, a semi-availability mode and a minimum-availability mode, wherein each of the full-availability mode, semi-availability mode and minimum-availability mode is defined by different numbers of receiving-on periods, within a beacon interval, of the base station;

configuring radio resources for and the selected availability mode;

scheduling discontinuous reception (DRx) cycles for the selected availability mode;

switching to the selected availability mode and indicating the selected availability mode to a plurality of active user equipments (UEs); and

transmitting and receiving data in the selected availability mode,

wherein the full-availability mode has a higher number of receive-on periods than the semi-availability mode, and is selected when at least the activity level is higher than a maximum activity level defined to be supported by the semi-availability mode, wherein the minimum-availability mode has a lower number of receive-on periods than the semi-availability mode, and is selected when at least the activity level is lower than a minimum activity level defined to be supported by the semi-availability mode,

wherein the configuring radio resources comprises allocating primary broadcast channels (PBCHs) for the selected availability mode by consolidating the PBCHs over multiple radio frames into a single radio frame, increasing power of synchronization channel in the single radio frame, and selecting maximum available number of random access channel (RACH) locations,

wherein the scheduling DRx cycles for the selected availability mode comprises synchronizing receive-on periods of the DRx cycles of the base station in the current radio frame with the receive-on period of a radio frame next in time to the current radio frame by signaling offsets to active UEs associated with the base station, and

wherein the selection of the availability mode is further based on an amount of receiving resources needed.

2. A method of claim 1 wherein determining the activity level further comprises determining the activity level based on lengths of DRx cycles requested by at least one active UE.

3. A method of claim 1 wherein switching to the selected availability mode further comprises switching to a lesser availability mode and signaling each of the active UEs on the selected availability mode by sending to the active UE one of a unicast signaling message and a broadcast signaling message that includes at least an indicator of the selected availability mode, wherein in the lesser availability mode the base station is less available than a current availability mode.

4. A method of claim 3 wherein switching to the semi-availability mode further comprises switching off power supply to a plurality of components of the base station during the receiving-off period, the plurality of components including a digital processing module;

and wherein switching to the minimum-availability mode comprises switching off power supply to a second plurality of components of the base station during the receiving-off period, the second plurality of components including the digital processing module and at least an analog processing module.

5. A method of claim 1, wherein scheduling the DRx cycles for one of the full-availability mode and the semi-availability mode, further comprises at least one of

scheduling for each of active UEs a plurality of DRx cycles in such way that the DRx cycles are evenly distributed over radio frames to achieve an even traffic distribution;

configuring at least one of a length of a PBCH DRx cycle, a periodicity of the PBCH DRx, a length of RACH DRx cycle and a periodicity of RACH DRx cycle in such a way that the PBCH DRx cycle and the RACH DRx cycle are multiples of the DRx cycles for the active UE.

6. A method of claim 1, further comprising:

transmitting data to at least one active UE when data is ready for transmission; and

resuming a current availability mode after transmitting the data.

12. A method of claim 2 wherein determining the activity level further comprises determining the activity level based on the number of active user equipments (UEs) associated with the base station.

7. An apparatus, comprising:

a base station configured to

determine an activity level in a current radio frame;

select an availability mode, for the apparatus, based at least in part on the activity level, wherein the availability mode is one of a full-availability mode, a semi-availability mode and a minimum-availability mode,

wherein each of the full-availability mode, semi-availability mode and minimum-availability mode is defined by different numbers of receiving-on periods, within a beacon interval, of a base station;

configure radio resources for the selected availability mode;

schedule discontinuous reception (DRx) cycles for the selected availability mode;

switch to the selected availability mode; and

indicate the selected availability mode to a plurality of user equipments (UEs); and

transmit and receive data in the selected availability mode,

wherein the full-availability mode has a higher number of receive-on periods than the semi-availability mode, and is selected when at least the activity level is higher than a maximum activity level defined to be supported by the semi-availability mode,

wherein the minimum-availability mode has a lower number of receive-on periods than the semi-availability mode, and is selected when at least the activity level is lower than a minimum activity level defined to be supported by the semi-availability mode,

wherein the configuring radio resources comprises allocating primary broadcast channels (PBCHs) for the selected availability mode by consolidating the PBCHs over multiple radio frames into a single radio frame, increasing power of synchronization channel in the single radio frame, and selecting maximum available number of random access channel (RACH) locations,

wherein the scheduling DRx cycles for the selected availability mode comprises synchronizing receive-on periods of the DRx cycles of the base station in the current radio frame with the receive-on period of a radio frame next in time to the current radio frame by signaling offsets to active UEs associated with the base station, and

wherein the selection of the availability mode is further based on an amount of receiving resources needed.

8. An apparatus of claim 7 wherein scheduling the DRx cycles for one of the full-availability mode and the semi-availability mode further comprises performing at least one of

scheduling for each of the active UEs a plurality of DRx cycles in such way that the DRx cycles are evenly distributed over radio frames to achieve an even traffic distribution;

configuring a length of PBCH DRx cycle and a length of a RACH DRx cycle in such a way that the PBCH DRx cycle and the RACH DRx cycle are multiples of the DRx cycles of the active UE.

9. An apparatus of claim 7 wherein

the full-availability mode indicates that the apparatus is available for receiving data for an entire radio frame;

the semi-availability mode indicates that the apparatus is available for receiving data for part of the radio frame; and

the minimum-availability mode indicates that the apparatus is available for receiving data for a minimum part of the radio frame.

10. An apparatus of claim 7, wherein the power control module is further configured to cause to

transmit beacon signals in the minimum-availability mode wherein an interval between the beacon signals is configurable;

and

transmit a resource allocation map that includes the selected availability mode, wherein the resource allocation map is part of the main information block.

11. An apparatus of claim 7 wherein the activity level is determined based at least in part on one of the number of active UEs, a current cell-wide traffic load, a scheduled cell-wide traffic load, a type of power source, lengths of DRx cycles requested by the active UEs, a delay requirement of the active UE, and an amount of resource used by the UEs;

and wherein the apparatus is one of a base station, and a LTE-compatible access point.