Power status for wireless communications

• US 7,433,702 B2
• Filed: 01/10/2001
• Issued: 10/07/2008
• Est. Priority Date: 01/28/2000
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Lindskog, Jan, Almehag, Lorens, Malmgren, Göran, Sällström, Fredrik
• Primary Examiner(s): Urban; Edward
• Assistant Examiner(s): Dean; Raymond S.
• Application Number:
  US09/757,084
• Publication Number:
  US 20010031626A1
• Time in Patent Office: 2,827 Days
• Field of Search: 455/466, 455/41.2, 455/41.3, 455 631- 677, 455/574, 455/573, 455/572, 4553431-3436, 455/418, 455/423, 455/425, 455/426.1, 455/426.2, 455/452.2, 455/522, 455/561, 455/114.2, 455/226.1, 455/226.2, 455/226.3, 455/235.1, 455/245.1, 455/501
• US Class Current: 455/522
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: H04W 52/0219 where the power saving management affects multiple terminals
• CPC Class Codes: H04W 8/245 from a network towards a terminal
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A wireless local area network (LAN) is operated so that a mobile terminal (MT) transmits various power-related information over an air interface to a power status repository (PSR) of the wireless local area network (LAN). For example, in one aspect of the invention, the mobile terminal transmits power status information, the power status information having an indication of whether the mobile terminal is currently operating using battery power or line power. The power status information is transmitted at one of the following times: (1) upon power-up of the mobile terminal; (2) upon command issued from the power status repository; (3) upon establishment of a connection between the mobile terminal and the LAN; and (4) upon a change in power status for the mobile terminal. The power status repository (PSR) can take the form of an Access Point (AP) for an intranet, or another mobile terminal in the case of an ad hoc network. In differing embodiments, the power status information can either be transmitted as a dedicated message or in a message with other status information. In another aspect, the mobile terminal which transmits to the power status repository certain measurement capability information. The measurement capability information has an indication of whether the mobile terminal has a capacity to perform radio frequency measurements. For example, the measurement capability information can indicate one of low power of the mobile terminal or a power restriction on the mobile terminal. As another example, the measurement capability information can indicate a particular sleep mode of the mobile terminal. In accordance with yet another aspect of the invention, if the power status repository does not have sufficient measurements regarding radio frequency (in view, e.g., of power incapacitation by one or more mobile terminals (MTs) in its cell), the power status repository can modify (e.g., increase) a rate at which a frequency measurement command is transmitted to other mobile terminal(s) in the cell. In still another aspect of the invention, the mobile terminal determines a duration of a sleep cycle in accordance with the power status information of the mobile terminal.

Claims

1. A wireless local area network (LAN) comprising a mobile terminal which communicates over an air interface with a power status repository, wherein the mobile terminal transmits measurement capability information over the air interface to the power status repository, the measurement capability information having an indication of whether the mobile terminal has a power capacity to perform radio frequency measurements, wherein if the power status repository does not have sufficient measurements regarding radio frequency, the power status repository modifies a rate at which a frequency measurement command is transmitted to another mobile terminal.

2. The network of claim 1, wherein the power status repository increases a rate at which a frequency measurement command is transmitted to another mobile terminal.

3. A method of operating a wireless local area network (LAN) comprising a mobile terminal which communicates over an air interface with a power status repository;

the method comprising;

the mobile terminal transmitting measurement capability information over the air interface to the power status repository, the measurement capability information having an indication of whether the mobile terminal has a power capacity to perform radio frequency measurements;

the power status repository using the measurement capability information to determine whether to transmit a frequency measurement command to the mobile terminal to request the mobile terminal to make measurements regarding a radio frequency; and

if the power status repository does not have sufficient measurments regarding radio frequency, the power status repository modifying a rate at which a frequency measurement command is transmitted to another mobile terminal.

4. The method of claim 3, wherein the power status repository increases a rate at which a frequency measurement command is transmitted to another mobile terminal.

5. A wireless local area network (LAN) comprising:

a power status repository;

plural mobile terminals which communicate over an air interface with the power status repository;

wherein if the power status repository does not have sufficient measurements from the plural mobile terminals in view of incapacity of one or more of the plural mobile terminals to perform a frequency measurement regarding radio frequency, the power status repository modifies a rate at which a frequency measurement command is transmitted to any of the mobile terminals which have sufficient capacity to perform the frequency measurement.

6. The network of claim 5, wherein the, power status repository increases a rate at which a frequency measurement command is transmitted to the mobile terminals which have sufficient capacity to perform the frequency measurement.

7. The network of claim 5, wherein the power status repository is an access point of the wireless local area network.

8. The network of claim 5, wherein the wireless local area network is an ad hoc network and wherein the power status repository is another mobile terminal participating in the network.

9. A method of operating a wireless local area network (LAN) having plural mobile terminals which communicate over an air interface with a power status repository, the method comprising:

making a determination whether the power status repository has sufficient measurements from the plural mobile terminals in view of incapacity of one or more of the plural mobile terminals to perform a frequency measurement regarding radio frequency; and

if the determination is negative;

modifying a rate at which a frequency measurement command is transmitted from the power status repository to any of the mobile terminals which have sufficient capacity to perform the frequency measurement.

10. The method of claim 9, further comprising the power status repository increasing a rate at which a frequency measurement command is transmitted to the mobile terminals which have sufficient capacity to perform the frequency measurement if the determination is negative.

11. The method of claim 9, further comprising using an access point of the wireless local area network as the power status repository.

12. The method of claim 9, wherein the wireless local area network is an ad hoc network, and wherein the method further comprises using another mobile terminal participating in the network as the power status repository.