Periodic ranging in a wireless access system for mobile station in sleep mode

• US 7,672,696 B2
• Filed: 05/21/2009
• Issued: 03/02/2010
• Est. Priority Date: 08/09/2004
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Ryu, Ki-Seon, Kim, Beum-Joon, Lee, Chang-Jae
• Primary Examiner(s): ZEWDU, MELESS NMN
• Application Number:
  US12/470,188
• Publication Number:
  US 20090233654A1
• Time in Patent Office: 285 Days
• Field of Search: 455418-420, 455423-425, 4553431-3435, 455/466, 455/550.1, 455/561, 455/574, 455/67.11, 455/67.16, 455/434, 455502-503, 455/517, 713/300, 713/310, 713/320, 713/321, 340 731- 733, 370/311, 370/350, 370/395.62, 375/354, 375/358, 375/360, 375/362, 375/365
• US Class Current: 455/574
• CPC Class Codes: H04W 52/0235 where the received signal is a power saving command
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method of performing a ranging process between a base station and a mobile station in sleep mode in a wireless access system, wherein the base station provides the mobile station with an initial notification of a periodic ranging time that occurs during a sleep time interval and during which the mobile station is to perform the ranging process, the initial notification included in a first message, the first message indicating whether the mobile station should terminate sleep mode to receive downlink data, and wherein the base station provides the mobile station with subsequent notifications of periodic ranging times that occur during the sleep time interval, the subsequent notifications indicated in a second message, the second message transmitted to the mobile station as part of the ranging process such that the mobile station performs a plurality of ranging processes within the sleep time interval.

Claims

1. A method of determining when to terminate a sleep mode between a base station and a mobile station in a wireless access system, comprising:

receiving a traffic indication message during a listening interval from the base station;

receiving a ranging response message from the base station in response to a ranging request message transmitted to the base station through uplink resources allocated by the base station, wherein the ranging response message comprises a next periodic ranging time;

checking whether or not the traffic indication message indicates that a downlink traffic exists;

checking whether or not the ranging response message indicates that the downlink traffic exists;

maintaining a sleep mode if the traffic indication message indicates that the downlink traffic does not exist;

terminating the sleep mode and receiving data if the traffic indication message indicates that the downlink traffic exists;

when the next periodic ranging time has been reached, transmitting another ranging request message to the base station through the uplink resources allocated by the base station if the ranging response message indicates that the downlink traffic does not exist; and

terminating the sleep mode and receiving data if the ranging response message indicates that the downlink traffic exists.

2. The method of claim 1, wherein the ranging response message indicates that the downlink traffic exists by having a value of the next periodic ranging time set to zero.

3. The method of claim 1, the next periodic ranging time in the ranging response message has a type length value (TLV) form.

4. A mobile subscriber station of a wireless communication system, the mobile subscriber station configured to perform the following functions while in a sleep mode:

receive a traffic indication message during a listening interval from a base station;

receive a ranging response message from the base station in response to a ranging request message transmitted to the base station through uplink resources allocated by the base station, wherein the ranging response message comprises a next periodic ranging time;

check whether or not the traffic indication message indicates that a downlink traffic exists;

check whether or not the ranging response message indicates that the downlink traffic exists;

maintain a sleep mode if the traffic indication message indicates that the downlink traffic does not exist;

terminate the sleep mode and receiving data if the traffic indication message indicates that the downlink traffic exists;

when the next periodic ranging time has been reached, transmit another ranging request message to the base station through the uplink resources allocated by the base station if the ranging response message indicates that the downlink traffic does not exist; and

terminate the sleep mode and receiving data if the ranging response message indicates that the downlink traffic exists.

5. The mobile subscriber station of claim 4, wherein the ranging response message indicates that the downlink traffic exists by having a value of the next periodic ranging time set to zero.

6. The mobile subscriber station of claim 4, wherein the next periodic ranging time in the ranging response message has a type length value (TLV) form.