Method for transmitting traffic indication message in wireless communication system, base station thereof, method for receiving the same, terminal thereof and message structure thereof

• US 20060009267A1
• Filed: 06/20/2005
• Published: 01/12/2006
• Est. Priority Date: 06/19/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Sung-Wook, Kim, Jin-A, Lee, Kang-Gyu, Kim, Yun-Sung
• Granted Patent: US 7,573,841 B2
• Time in Patent Office: Days
• US Class Current: 455/574
• CPC Class Codes: H04W 68/025 Indirect paging
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]

Abstract

Disclosed are methods for transmitting/receiving a traffic indication message in a wireless communication system. In the wireless communication system, a base station (BS) groups a plurality of sleep mode IDs, and broadcasts a traffic indication message that includes first bitmap information indicating whether traffic corresponding to respective the sleep mode ID groups exists as well as second bitmap information indicating whether traffic indicators with respect to the respective sleep mode IDs that belong to the sleep mode ID groups exists. A mobile subscriber station (MS) which is allocated with any one of the plurality of sleep mode IDs, determines whether the traffic occurs in the sleep mode ID group to which the MS itself belongs using the first bitmap information if the MS receives the traffic indication message, and checks the traffic indicator of the terminal itself using the second bitmap information if the traffic occurs in the sleep mode ID group to which the MS belongs.

Claims

1. A wireless communication system, comprising:

a base station for grouping a plurality of sleep mode IDs, and broadcasting a traffic indication message that includes first bitmap information indicating whether traffic exists with respect to the sleep mode ID groups, and second bitmap information indicating whether the traffic exists corresponding to the respective sleep mode IDs of the sleep mode ID groups; and

a terminal, which is allocated with any one of the plurality of sleep mode IDs, for determining whether the traffic exists in a sleep mode ID group to which the terminal itself belongs using the first bitmap information if the terminal receives the traffic indication message, and determining whether the traffic exists in the terminal itself using the second bitmap information if the traffic exists in the sleep mode ID group to which the terminal belongs.

2. The wireless communication system as claimed in claim 1, wherein the traffic indication message further includes third bitmap information indicating traffic states with respect to the respective sleep mode IDs of the sleep mode ID group.

3. The wireless communication system as claimed in claim 1, wherein the traffic indication message further includes fourth bitmap information indicating that the number of sleep mode IDs in which the traffic exists in the sleep mode ID group is equal to or larger than a predetermined number.

4. The wireless communication system as claimed in claim 3, wherein the base station includes the traffic indicators for all the sleep mode IDs that belong to the sleep mode ID group in the third bitmap information if the number of sleep mode IDs in which the traffic exists in the sleep mode ID group is larger than the predetermined number.

5. The wireless communication system as claimed in claim 3, wherein the base station includes only the traffic indicators for the sleep mode IDs in which the traffic exists among all the sleep mode IDs that belong to the sleep mode ID group in the second bitmap information if the number of sleep mode IDs in which the traffic exists in the sleep mode ID group is equal to or smaller than the predetermined number.

6. A method of transmitting a traffic indication message through a base station in a wireless communication system, the method comprising the steps of:

forming sleep mode ID groups by grouping a plurality of sleep mode IDs;

setting first bitmap information that indicates whether traffic exists corresponding to the respective sleep mode IDs of the sleep mode ID groups;

setting second bitmap information that indicates traffic indicators with respect to the respective sleep mode IDs that belong to the sleep mode ID groups; and

broadcasting a traffic indication message that includes the first and second bitmap information.

7. The method as claimed in claim 6, further comprising the step of setting third bitmap information that indicates traffic states with respect to the respective sleep mode IDs of a sleep mode ID group.

8. The method as claimed in claim 6, further comprising the step of setting fourth bitmap information that indicates that the number of sleep mode IDs in which the traffic exists in a sleep mode ID group is equal to or larger than a predetermined number.

9. The method as claimed in claim 7, further comprising the step of including the traffic indicators for all the sleep mode IDs that belong to the sleep mode ID group in the third bitmap information, if the number of sleep mode IDs in which the traffic exists in the sleep mode ID group is larger than a predetermined number.

10. The method as claimed in claim 8, further comprising the step of including only the traffic indicators for the sleep mode IDs in which the traffic exists among all the sleep mode IDs that belong to the sleep mode ID group in the third bitmap information, if the number of sleep mode IDs in which the traffic exists in the sleep mode ID group is equal to or smaller than the predetermined number.

11. A traffic indication message structure for informing a plurality of terminals of an existence of traffic in a wireless communication system including a plurality of terminals that are in a sleep mode, the message structure comprising:

a first bitmap for grouping a plurality of sleep mode IDs and indicating whether traffic exists with respect to sleep mode ID groups; and

a second bitmap for indicating whether the traffic exists corresponding to the respective sleep mode IDs of the the sleep mode ID groups.

12. The message structure as claimed in claim 11, further comprising a third bitmap for indicating traffic states with respect to the respective sleep mode IDs of the sleep mode ID groups.

13. The message structure as claimed in claim 11, further comprising a fourth bitmap for indicating that the number of sleep mode IDs in which the traffic exists in a sleep mode ID group is equal to or larger than a predetermined number.

14. The message structure as claimed in claim 13, wherein the third bitmap includes the traffic indicators for all the sleep mode IDs that belong to the sleep mode ID groups, if the number of sleep mode IDs in which the traffic exists in the sleep mode ID groups is larger than the predetermined number.

15. The message structure as claimed in claim 13, wherein the third bitmap includes only the traffic indicators for the sleep mode IDs in which the traffic exists from among the sleep mode IDs that belong to the sleep mode ID group, if the number of sleep mode IDs in which the traffic exists in the sleep mode ID group is equal to or smaller than the predetermined number.

16. The message structure as claimed in claim 11, wherein the traffic indication message is dynamically sized according to an amount of traffic buffered until a terminal'"'"'s entering into a listening interval of the sleep mode in order to provide quick traffic indication information to at least one terminal which is in a sleep mode.

17. A base station that transmits a traffic indication message in a wireless communication system, the base station comprising:

means for forming sleep mode ID groups (SLPID-Groups) by grouping a plurality of sleep mode IDs;

means for setting a first bitmap that indicates whether traffic exists with respect to the SLPID-Groups;

means for setting a second bitmap that indicates traffic indicators with respect to the respective sleep mode IDs that belong to the SLPID-Groups; and

means for broadcasting a traffic indication message that includes the first bitmap and the second bitmap.

18. The base station as claimed in claim 17, wherein the second bitmap is set with respect to the SLPID-Group in which the traffic exists.

19. The base station as claimed in claim 18, wherein the second bitmap is a set of traffic indicators which indicate traffic states of the respective sleep mode IDs of a SLPID-Group.

20. The base station as claimed in claim 18, wherein the traffic indicators of the second bitmap are allocated in an ascending order of their SLPID values of the SLPID-Groups in which the traffic exists.

21. The base station as claimed in claim 19, wherein the traffic indicators have either a value indicating an existence of the traffic or a value indicating a non-existence of the traffic.

22. The base station as claimed in claim 21, wherein the traffic indicator comprises a single bit.

23. The base station as claimed in claim 22, wherein the traffic indicator has a length of a multiple of the number of sleep mode IDs that belong to a SLPID-Group.

24. A terminal that receives a traffic indication message in a wireless communication system, the terminal comprising:

means for being allocated with any one of a plurality of sleep mode IDs (SLPIDs) and calculating SLPID-Groups to which the SLPID allocated to the means belongs;

means for receiving the traffic indication message which includes a first bitmap indicating whether a traffic exists with respect to the SLPID-Groups and a second bitmap indicating traffic indicators for the respective SLPIDs that belong to the SLPID-Groups from a base station;

means for determining whether the traffic occurs in a SLPID-Group to which the means belongs using the second bitmap, if the traffic indication message is received; and

means for checking a traffic indicator of the second bitmap, if the traffic exists in the SLPID-Group.

25. The terminal as claimed in claim 24, wherein the second bitmap is set with respect to the SLPID-Group in which the traffic exists.

26. The terminal as claimed in claim 24, wherein the traffic indicators of the second bitmap are allocated in an ascending order of their SLPID values of the SLPID-Group in which the traffic exists.

27. The terminal as claimed in claim 24, wherein the traffic indicators have either a value indicating an existence of the traffic or a value indicating a non-existence of the traffic.

28. The terminal as claimed in claim 27, wherein the traffic indicator comprises a single bit.

29. A method of receiving a traffic indication message through a terminal in a wireless communication system, the method comprising the steps of:

being allocated, by a means, with any one of a plurality of sleep mode IDs (SLPIDs) and calculating SLPID-Groups to which the SLPID allocated to the means belongs;

receiving the traffic indication message that includes a first bitmap indicating whether a traffic exists with respect to SLPID-Groups and a second bitmap indicating traffic indicators for the respective SLPIDs that belong to the SLPID-Groups from a base station;

determining whether the traffic exists in a SLPID-Group to which the means belongs using the second bitmap if the traffic indication message is received; and

checking the traffic indicator of the means using the second bitmap if the traffic exists in the SLPID-Group to which the means belongs.

30. A method of generating a traffic indication message for awakening a plurality of mobile terminals that are called at listening intervals of the terminals when a base station calls the terminals in a mobile communication system having a sleep interval for intercepting a data transmission/reception of the terminals and the listening interval for receiving the traffic indication message in order to reduce power consumption of the terminals located in an area occupied by the base station, the method comprising the steps of:

classifying a plurality of bits that the traffic indication message has into a plurality of groups, and generating first bitmap information so that the called terminals belong to the plurality of groups; and

generating second bitmap information for indicating sleep mode IDs (SLPIDs) of the called terminals by the plurality of bits in the classified groups.

31. The method as claimed in claim 30, wherein the second bitmap information is set with respect to a SLPID Group in which the traffic exists.

32. The method as claimed in claim 31, wherein the second bitmap information is a set of traffic indicators which indicate traffic states of the respective sleep mode IDs of a SLPID-Group.

33. The method as claimed in claim 31, wherein the traffic indicators of the second bitmap are allocated in an ascending order of their SLPID values of the SLPID-Groups in which the traffic exists.

34. The method as claimed in claim 30, wherein the traffic indicators have either a value indicating an existence of the traffic or a value indicating a non-existence of the traffic.

35. The method as claimed in claim 34, wherein the traffic indicator comprises a single bit.

36. The method as claimed in claim 35, wherein the traffic indicator has a length of a multiple of the number of sleep mode IDs that belong to a SLPID-Group.

37. A method for generating a message used when a base station informs each of mobile stations (MSs) in a sleep mode whether there is traffic to be transmitted to each of the MSs in a Broadband Wireless Access communication system having an awake mode where there is transmission data and the sleep mode where there is no transmission data, the method comprising the steps of:

allocating, by the base station, unique sleep identifiers to the MSs in the sleep mode;

grouping the sleep identifiers by a predetermined number, and generating a first indication bitmap by combining areas indicating the grouped sleep identifiers;

generating a second indication bitmap indicating the predetermined number of the sleep identifiers; and

generating a traffic indication message including the first indication bitmap and the second indication bitmap, and transmitting the generated traffic indication message to the MSs.

38. The method of claim 37, wherein the sleep identifiers are transmitted to the MS through a sleep response message.

39. The method of claim 37, wherein when there is traffic to be transmitted to at least one of the MSs, each bit of the first indication bitmap indicates the existence of transmission traffic.

40. The method of claim 37, further comprising the steps of:

detecting, by the MS, a bit corresponding to its location from the first indication bitmap, and determining whether there is traffic depending on the detected bit; and

detecting the second indication bitmap, only if it is determined that there is traffic.

41. The method of claim 40, wherein when the second indication bitmap is detected, the MS detects a bit corresponding to its location, and determines whether there is traffic depending on the detected bit.