Power saving methods for wireless systems

• US 8,711,747 B2
• Filed: 07/06/2010
• Issued: 04/29/2014
• Est. Priority Date: 07/07/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Fong, Mo-Han, Zhang, Hang
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Huang, Weibin
• Application Number:
  US12/831,052
• Publication Number:
  US 20110261739A1
• Time in Patent Office: 1,393 Days
• Field of Search: 370/310, 370/311, 340/7.32, 340/7.33, 340/7.35, 340/7.36, 455/130, 455/334, 455/343.1, 455/343.2, 455/343.3, 455/343.4
• US Class Current: 370/311
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Methods for saving power and facilitating transitions from power-saving states back to active states in mobile stations are provided. A base station transmits indication of a periodic interval at which system configuration information is to be transmitted, periodically transmits a current version of system configuration information and in advance of an action time of a new version of system configuration information, periodically transmits the new version of system configuration information at the periodic interval; and transmits a flag indicating whether the new version of system configuration information is available. In respect of each of at least one mobile station in a power-saving state, in which the mobile station (MS) is configured on a per-MS basis to periodically wake up and check for the presence of an information block relevant to the MS, the base station transmits an information block presence indicator indicative of whether the information block is present.

Claims

1. A method in a network node, the method comprising:

transmitting an indication of a periodic interval at which system configuration information is to be transmitted;

periodically transmitting a current version of system configuration information at the periodic interval; and

in advance of an action time of a new version of system configuration information;

periodically transmitting the new version of system configuration information at the periodic interval; and

transmitting a flag indicating whether the new version of system configuration information is available.

2. The method of claim 1, further comprising:

transmitting a system configuration information presence indicator indicative of whether system configuration information is present including an indication of length and type of system configuration information; and

transmitting a current system configuration information identifier indicative of the version of system configuration information currently in effect.

3. The method of claim 2, wherein periodically transmitting the new version of system configuration information at the periodic interval comprises periodically transmitting:

the system configuration identifier for the new version of system configuration information; and

the action time of the new version of system configuration information.

4. The method of claim 2, wherein transmitting the indication of the periodic interval at which system configuration information is to be transmitted, transmitting the flag indicating whether the new version of system configuration information is available, transmitting a system configuration information presence indicator and transmitting a current system configuration information identifier comprise broadcasting the indication of the periodic interval at which system configuration information is to be transmitted, the flag indicating whether the new version of system configuration information is available, the system configuration information presence indicator and the current system configuration information identifier in a broadcast channel.

5. The method of claim 1, further comprising:

after the action time of the new version of system configuration information, stopping transmission of the flag indicating the new version of system configuration information is available to indicate that a newer version of system configuration information is not yet available.

6. The method of claim 1, further comprising:

in respect of each of at least one mobile station in a power-saving state, in which the mobile station (MS) is configured on a per-MS basis to periodically wake up and check for the presence of an information block relevant to the MS, transmitting an information block presence indicator indicative of whether the information block is present.

7. The method of claim 6, wherein the information block presence indicator is transmitted as part of a broadcast channel in a superframe header together with the indication of the periodic interval at which system configuration information is to be transmitted and the flag indicating whether the new version of system configuration information is available.

8. The method of claim 7, wherein the MS is configured to wake up at a multiple N of the periodic interval at which system configuration information is to be transmitted, N≧

1.

9. The method of claim 6, wherein transmitting an information block presence indicator indicative of whether the information block is present comprises at least one of:

in respect of each of at least one MS in a sleep state, transmitting a traffic indication information block presence indicator indicative of whether a traffic indication information block (TFIB) is present; and

in respect of each of at least one MS in an idle state, transmitting a paging information block presence indicator indicative of whether a paging indication information block (PGIB) is present.

10. The method of claim 9, wherein location and modulation and coding scheme (MCS) of the TFIB and PGIB are predefined.

11. A network node comprising:

at least two antennas;

transmit and receive circuitry;

a processor configured to;

transmit an indication of a periodic interval at which system configuration information is to be transmitted;

periodically transmit a current version of system configuration information at the periodic interval; and

in advance of an action time of a new version of system configuration information;

periodically transmit the new version of system configuration information at the periodic interval; and

transmit a flag indicating whether the new version of system configuration information is available.

12. A method in a mobile station (MS), the method comprising:

in a power-saving state;

periodically waking up;

receiving an indication of a periodic interval at which system configuration information is to be transmitted;

waking up at a multiple N of the periodic interval at which system configuration information is to be transmitted, N≧

1;

receiving a flag indicating whether a new version of system configuration information is available; and

upon determining that a new version of system configuration information is available and has not been previously received, attempting to receive the new version of system configuration information.

13. The method of claim 12, further comprising:

receiving a system configuration information presence indicator indicative of whether system configuration information is present including an indication of length and type of system configuration information; and

receiving a current system configuration information identifier indicative of the version of system configuration information currently in effect,

wherein attempting to receive the new version of system configuration information comprises checking the system configuration information indicator and the current system configuration information identifier.

14. The method of claim 13, wherein:

system configuration information comprises a system configuration identifier indicative of the version of the system configuration information and an action time identifier identifying when the associated version of system configuration information will take effect; and

determining that a new version of system configuration information is available and has not been previously received comprises;

comparing the system configuration information identifier for the new version of system configuration information with the current system configuration information identifier for the version of system configuration information currently in effect and the system configuration information identifier for any previously received version of system configuration information.

15. The method of claim 13, wherein periodically waking up to receive:

an indication of the periodic interval at which system configuration information is to be transmitted, a flag indicating whether a new version of system configuration information is available, a system configuration information presence indicator and a current system configuration information identifier comprises periodically waking up to receive a broadcast channel (BCH) containing the indication of the periodic interval at which system configuration information is to be transmitted, the flag indicating whether the new version of system configuration information is available, the system configuration information presence indicator and the current system configuration information identifier.

16. The method of claim 15, wherein periodically waking up to receive a broadcast channel comprises periodically waking up at a MS-specific interval to decode a superframe header containing the BCH.

17. The method of claim 12, further comprising:

in the power-saving state, periodically waking up to check for the presence of an information block presence indicator indicative of whether an information block relevant to the MS is present.

18. The method of claim 17, further comprising receiving the information block presence indicator in a broadcast channel (BCH) in a superframe header together with the indication of the periodic interval at which system configuration information is to be transmitted and the flag indicating whether the new version of system configuration information is available.

19. The method of claim 17, wherein in the power-saving state, periodically waking up to check for the presence of an information block presence indicator indicative of whether an information block relevant to the MS is present comprises at least one of:

in a sleep state, periodically waking up to check for the presence of a traffic indication information block presence indicator indicative of whether a traffic indication information block (TFIB) is present; and

in an idle state, periodically waking up to check for the presence of a paging information block presence indicator indicative of whether a paging indication information block (PGIB) is present.

20. A mobile station comprising:

at least one antenna;

transmit and receive circuitry;

a processor configured to;

in a power-saving state;

periodically wake up;

receive an indication of a periodic interval at which system configuration information is to be transmitted;

wake up at a multiple N of the periodic interval at which system configuration information is to be transmitted, N≧

1;

receive a flag indicating whether a new version of system configuration information is available; and

upon determining that a new version of system configuration information is available and has not been previously received, attempt to receive the new version of system configuration information.