COMMUNICATION METHOD IN WIRELESS LOCAL AREA NETWORK SYSTEM

• US 20140153469A1
• Filed: 07/19/2012
• Published: 06/05/2014
• Est. Priority Date: 07/19/2011
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Park, Jong Hyun, You, Hyang Sun, Kim, Eun Sun, Seok, Yong Ho
• Granted Patent: US 9,560,586 B2
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H04W 52/0203 in the radio access network or backbone network of wireless communication networks
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: H04W 84/047 using dedicated repeater stations
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A communication method performed by a target station in a WLAN system is provided. The method includes receiving a relayed TIM message from a relay station, the TIM message comprising a relayed TIM field indicating whether there is buffered traffic intended to be transmitted from an AP to the target station, determining whether there is the buffered traffic based on the relayed TIM field, receiving a data frame related to the buffered traffic, if the relayed TIM field indicates that there is the buffered traffic, and switching to a doze state, if the relayed TIM field indicates that there is no buffered traffic. The relayed TIM field is determined based on a TIM element transmitted from the AP to the relay station. The TIM element is transmitted in a first period, and the relayed TIM message is transmitted in a second period.

Claims

1. A communication method performed by a target station in a Wireless Local Area Network (WLAN) system, the communication method comprising:

receiving a relayed Traffic Indication Map (TIM) message from a relay station, wherein the TIM message comprises a relayed TIM field indicating whether or not there is buffered traffic intended to be transmitted from an Access Point (AP) to the target station;

determining whether or not there is the buffered traffic based on the relayed TIM field;

receiving a data frame related to the buffered traffic, if the relayed TIM field indicates that there is the buffered traffic; and

switching to a doze state, if the relayed TIM field indicates that there is no buffered traffic,

wherein the relayed TIM field is determined based on a TIM element transmitted from the AP to the relay station,

the TIM element is transmitted in a first period in which communication between the relay station and the AP is permitted, and

the relayed TIM message is transmitted in a second period in which communication between the relay station and the target station is permitted.

2. The communication method of claim 1, wherein:

the relayed TIM field comprises a bitmap sequence, and

the bitmap sequence indicates whether or not there is the buffered traffic intended to be transmitted from the AP in relation to each station whose communication with the relay station is permitted for the second period.

3. The communication method of claim 2, wherein determining whether or not there is the buffered traffic based on the relayed TIM field comprises,

determining whether a relevant bit of a bitmap sequence corresponding to the target station indicates the buffered traffic or not.

4. The communication method of claim 3, further comprising:

transmitting a TIM relay request message requesting the relay station to transmit the relayed TIM message, to the relay station; and

receiving a TIM relay response message from the relay station in response to the TIM relay request message.

5. The communication method of claim 4, wherein:

the TIM relay response message comprises a relay identification information field, and

the relay identification information field comprises identification information about the target station related to order of the relevant bit in the bitmap sequence.

6. The communication method of claim 5, wherein:

the TIM relay request message comprises a requester identification information field, and

the requester identification information field comprises an Association IDentifier (AID) allocated when the target station is associated with the AP.

7. The communication method of claim 6, wherein the identification information of the target station is determined based on the AID.

8. The communication method of claim 1, wherein the data frame is received from the AP.

9. The communication method of claim 8, wherein the data frame is received from the relay station.

10. The communication method of claim 9, wherein the data frame is received by the relay station from the AP for the first period and is relayed to the target station for the second period.

11. The communication method of claim 1, further comprising receiving a beacon frame from the AP,

wherein the beacon frame comprises information indicating the first period and the second period.

12. The communication method of claim 1, wherein the relayed TIM message and the data frame are transmitted through a direct link set up between the target station and the relay station.

13. The communication method of claim 1, wherein maximum transmit power permitted for the second period is lower than maximum transmit power permitted for the first period.

14. A wireless apparatus operated in a Wireless Local Area Network (WLAN) system, the wireless apparatus comprising:

a transceiver configured to transmit and receive radio signals; and

a processor functionally connected to the transceiver, wherein the process is configured to;

receive a relayed Traffic Indication Map (TIM) message from a relay station, wherein the TIM message comprises a relayed TIM field indicating whether or not there is buffered traffic intended to be transmitted from an Access Point (AP) to the wireless apparatus;

determine whether or not there is the buffered traffic based on the relayed TIM field;

receive a data frame related to the buffered traffic, if the relayed TIM field indicates that there is the buffered traffic; and

switch to a doze state, if the relayed TIM field indicates that there is no buffered traffic,

wherein the relayed TIM field is determined based on a TIM element transmitted from the AP to the relay station,

the TIM element is transmitted in a first period in which communication between the relay station and the AP is permitted, and

the relayed TIM message is transmitted in a second period in which communication between the relay station and the wireless apparatus is permitted.