Method and apparatus for updating locations of dormant mobile stations

• US 20040179492A1
• Filed: 01/07/2004
• Published: 09/16/2004
• Est. Priority Date: 01/08/2003
• Status: Active Grant

• Current Assignee: Ericsson AB (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Li, Jun, Wang, Chung-Ching, Wu, Geng, Zhang, Hang, Jang, Ke-Chi, Fong, Mo-Han, Chen, Xixian, Weisert, James
• Granted Patent: US 7,236,764 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 60/02 by periodical registration
• CPC Class Codes: H04W 60/04 using triggered events
• CPC Class Codes: H04W 68/04 multi-step notification using statistical or historical mobility data

Abstract

In code division multiple access communication systems, there are three levels for updating locations of dormant mobile stations (MSs) and setting up fast call. In sector and are levels, the dormant MS send a layer 2 message containing a message type and MS identifier to a base transceiver station (BTS). Since the message is associated with the sector where the MS is located, the network is aware of the MS'"'"'s location from the updated location. The dormant MS sends to the BTS a reconnect message containing a message type and an MS identifier. The MS'"'"'s dormant to active state transition is initiated by the MS. In the communication network, sub-packet zone ID is broadcasted in the overhead message. The MS reports its location change on R-CSCH and the network with the BSC level control can page the MS within the zone where the MS sends the report.

Claims

1. A method for determining when a location update message is sent from a mobile station (MS) to a base transceiver station (BTS) when the MS is in a dormant state, the method comprising the steps of:

starting a first timer when the MS enters a dormant state;

starting a second timer when the first timer reaches a predefined value T1;

while the first timer is counting and prior to its reaching said predefined value T1, sending a layer 2 location update message whenever the MS performs an idle handoff indicating that the strongest pilot signal strength has changed from one sector to another sector,

while the second timer is counting and prior to its reaching a predefined value T2, sending a layer 2 location update message whenever a further criterion is met; and

after the second timer has reached said predefined value T2, sending no further layer 2 location update messages.

2. The method of claim 1, wherein said further criterion includes a time period.

3. The method of claim 1, wherein said further criterion includes the MS having traveled a predetermined distance since the previous location update message was sent.

4. The method of claim 1, wherein said further criterion includes counting a predefined number of idle handoffs.

5. The method of claim 1, further comprising predefining the starting value for the first timer to said predefined value T1.

6. The method of claim 1, further comprising predefining the starting value of the second timer to said predefined value T2.

7. The method of claim 4, further comprising predefining the starting value of the second timer to said predefined value T2.

15. The method of claim 1, wherein said layer 2 location update message includes identification of the two strongest pilot signals being received by the MS.

21. The method of claim 1, wherein the step of sending a layer 2 location update message while the first timer is counting includes the step of:

sending by the MS to the BTS a layer 2 location update message containing a message type and an MS identifier, whereby the network updating the location of the MS.

22. The method of claim 21, further comprising the step of:

in response to the layer 2 location update message from the MS, sending by the BTS to the MS a location update acknowledgement message containing a message type and an MS identifier.

23. The method of claim 1, further comprising the steps of:

sending by the MS in the dormant state to the BTS a reconnect message containing a message type and an MS identifier; and

sending by the BTS to the MS a channel assignment message, whereby the MS initiates an MS'"'"'s dormant to active state transition.

24. The method of claim 1, further comprising the steps of:

sending by the MS to the BTS a layer 2 location update message containing a message type and an MS identifier;

sending by the BTS to the MS a location update acknowledgement message containing a message type and an MS identifier; and

sending by the BTS to the MS a message informing MS'"'"'s active set, wherein the BTS initiates an MS'"'"'s dormant to active state transition.

25. The method of claim 1, further comprising the steps of:

sending by the MS to the BTS a layer 2 location update message containing a message type and an MS identifier;

sending by the BTS to the MS a location update acknowledgement message containing a message type and an MS identifier,

sending by the BTS to the MS a message informing MS'"'"'s active set;

sending by the BTS to the MS a data burst message; and

sending by the MS to the BTS a data burst acknowledgement message containing a message type and an MS identifier.

8. A method for defining the region of a wireless network in which to page a dormant mobile station (MS) when the network determines that data is to be sent to that dormant MS, the method comprising the steps of:

starting a first timer when the MS enters a dormant state;

starting a second timer when the first timer reaches a predefined value T1;

while the first timer is counting and prior to its reaching said predefined value T1, sending an MS page to the sector indicated by the most recent layer 2 location update message received from the MS;

while the second timer is counting and prior to its reaching a predefined value T2, sending an MS page to the sectors surrounding the sector indicated in the most recently received layer 2 location update message consistent with the further criterion being used to trigger a location update messages being sent from the MS; and

after the second timer has reached said predefined value T2, sending an MS page to all network sectors.

9. The method of claim 8, wherein said further criterion includes a time period.

10. The method of claim 8, wherein said further criterion includes the MS having traveled a predetermined distance since the previous location update message was sent.

11. The method of claim 8, further comprising predefining the starting value for the first timer to said predefined value T1.

12. The method of claim 8, further comprising predefining the starting value of the second timer to said predefined value T2.

13. The method of claim 11, further comprising predefining the starting value of the second timer to said predefined value T2.

14. The method of claim 8, wherein said further criterion includes counting a predefined number of idle handoffs

16. A method for determining when a location update message needs to be sent from an MS to a base transceiver station (BTS) when the MS is in a dormant state, the method comprising the steps of:

determining if the MS has moved physically from one geographic region to another region served by a cell sector; and

sending a location update message to the network servicing the MS indicating that the two strongest pilot signals are received by the MS.

17. The method of claim 16, wherein the step of determining includes the step of:

determining if the MS has moved physically outside the geographic region served by a plurality of cell sectors defined in a sub-packet zone received previously from the network servicing the MS.

18. The method of claim 16, wherein the step of determining includes the step of:

determining if the MS has moved physically into the geographic region served by a cell sector not identified in a list of cell sectors in a sub-packet zone received previously from the network servicing the MS.

19. The method of claim 16, further comprising providing a delay between the determining step and the sending step whereby ping-ponging between sub-packet zones in prevented.

20. The method of claim 16, wherein the location update message is transmitted as a layer 2 message.

26. A method for tracking zone update to enable a communication network to page a mobile station (MS) in a smaller area, zones relating to base station controllers (BSCs) that control communications among the BTSs and the MSs, the zones being further defined as smaller zones that are registered for zone tracking, the method comprising the steps of:

defining the size of the tracking zones;

defining the zones of the BTSs;

broadcasting tracking zone identifiers; and

paging MSs in the tracking zones.

27. The method of claim 26, wherein the step of defining the zones of the BTSs includes the step of assigning the same value to the BTSs in the same tracking zone;

28. The method of claim 26, further comprising the step of reporting by the MS on change of location in the tracking zone.

29. The method of claim 28, wherein the step of reporting includes the step of reporting the location change on R-CSCH.

30. The method of claim 26, wherein the information on the performing of the tracking zone update are defined by values.

31. The method of claim 30, wherein the values are defined for:

the tracking zone identifier;

the tracking zone list which is a list of most recent tracking zone identifier received by the MS;

the number of tracking zone identifier to be maintained in the tracking zone list;

the maximum number of Radio Environment Report Messages that the MS is permitted to transmit before disabling tracking zone reporting; and

the BTS'"'"'s support of tracking zone reporting indicator.

32. The method of claim 26, wherein the tracking zone update is performed in the MS'"'"'s dormant state, the method further comprising the step of:

performing paging channel supervision when the MS enters the dormant state from the MS initialization state.

33. The method of claim 26, further comprising the steps of:

upon entering the MS dormant state from the MS control on the Traffic Channel state, performing by the MS, if the tracking zone update is enabled and the tracking zone timer is not enabled,

initializing the tracking zone list with the length of the number of the tracking zone identifier and adding the tracking zone identifier to the tracking zone list;

setting the tracking zone update timer at a certain value; and

enabling the tracking zone update timer.

34. The method of claim 26, further comprising the steps of performing by the MS, if the tracking zone update is enabled,

if the tracking identifier is not equal to any entry in the tracking zone list, sending a Radio Environment Report Message by performing the Mobile Station Message Transmission Operation in an update overhead information substate;

if the tracking zone update timer of any entry in the tracking zone list has expired, deleting that entry; and

if the tracking zone update timer expires, disabling the tracking zone update timer to disable the tracking zone update.

35. The method of claim 26, further comprising the step of:

enabling the tracking zone update at a different time than the radio environment report.

36. The method of claim 35, wherein the step of enabling includes the steps of performing by the MS, upon expiration of the radio environment report timer, if the tracking zone reporting information included indicator is equal to “

1”

;

enabling the tracking zone update;

initializing the tracking zone list with the length of the number of tracking zone identifier and adding the tracking zone identifier to the tracking zone list;

setting the tracking zone update timer at a certain value; and

enabling the tracking zone update timer.

37. The method of claim 32, further comprising the steps of performing by the MS, in response to an Extended System Parameters Message received on the Paging Channel,

storing the MS initiated position location determination supported indicator;

if the MS supports tracking zone, storing the tracking zone supported indicator;

if the tracking zone update is enabled and the tracking zone update timer is not enabled,

initializing the tracking zone list with the length of the number of tracking zone identifier and adding the tracking zone identifier to the tracking zone list;

setting the tracking zone update timer to a certain value; and

enabling the tracking zone update timer.

38. The method of claim 26, further comprising the steps of performing by the MS:

if the MS supports tracking zone,

storing the tracking zone supported indicator,

if the indicator is equal to ‘

1’

, storing the tracking zone identifier;

if the tracking zone update is enabled and the tracking zone update timer is not enabled, performing;

initializing the tracking zone list with the length of the number of the tracking zone identifier and adding the tracking zone identifier to the tracking zone list;

setting the tracking zone update timer to a certain value; and

enabling the tracking zone update timer.

39. The method of claim 26, wherein:

the MS supports the Mobile Station Message Transmission Operation, the operation being performed when the user directs the MS to transmit a Data Burst Message, or when the MS detects a change in the hook status since the last time when the MS sent hook status information; and

the MS supports the Device Information Message on the R-CSCH, or when the MS detects that a Radio Environment Report Message is required to be transmitted on the R-CSCH,

wherein when the MS detects that a Radio Environment Report Message is required to be transmitted on the R-CSCH, the method includes the steps of performing by the MS;

if RER_ENABLED is set to YES, entering the Update Overhead Information Substate of the System Access State with a radio environment report indication within a certain period of time;

otherwise, if the tracking zone update is enabled, entering the Update Overhead Information Substate of the System Access State with a tracking zone report indication within a certain period of time.

40. The method of claim 26, further comprising the step of updating the information wherein if the Updated Overhead Information Substate is entered with a tracking zone report indication, the MS enters the Mobile Station Message Transmission Substate with a tracking zone report indication.

41. The method of claim 26, wherein in the Mobile Station Message Transmission Substate, the MS sends a Data Burst Message, a Device Information Message, or a Radio Environment Report Message, wherein the method includes the steps of performing by the MS;

upon entering the Mobile Station Message Transmission Substate with a radio environment report indication, transmitting the Radio Environment Report Message to the BTS;

if RER_ENABLED is set to NO and the tracking zone reporting information included indicator is equal to ‘

1’

,

enabling the tracking zone update;

initializing the tracking zone list with the length of the number of tracking zone identifier and adding the tracking zone identifier to the tracking zone list;

setting the tracking zone update timer to a certain value; and

enabling the tracking zone update timer,

if the MS enters the Mobile Station Message Transmission Substate with a tracking zone report indication,

transmitting the Radio Environment Report Message to the BTS;

if the MS receives confirmation of delivery of Radio Environment Report Message, adding the tracking zone update identifier to the tracking zone list and starting the tracking zone update timer for the tracking zone update identifier, wherein the tracking zone list is full, the entry with active tracking zone update timer with smallest remaining tracking zone update timer value is removed from the list before adding the new entry;

incrementing the tracking zone update count upon receiving confirmation of delivery, wherein if, after incrementing, the count is equal to the maximum number of Radio Environment Report Messages, the MS disables the tracking zone update timer.

42. The method of claim 26, wherein in the Traffic Channel Substate, the MS exchanges Traffic Channel frames with the BTS, the method includes the steps of performing by the MS:

while in the Traffic Channel Substate, disabling the tracking zone update, setting the tracking zone list to null, and disabling the tracking zone update timer.

43. The method of claim 26, wherein in the procedure for the exiting the Release Substate, if the MS receives an Extended Release Message with the field of the tracking zone reporting information included indicator set to ‘

1’ and

the BTS support of tracking zone reporting indicator is equal to ‘

1’

, the method includes the steps of performing by the MS;

setting the tracking zone count to 0; and

storing the values of;

the number of the tracking zone identifier to be maintained in the tracking zone list;

the tracking zone update timer;

the maximum allowed number of tracking zone reports; and

the tracking zone update period;

if RER_INFO_INCL is equal to ‘

0’

, enabling the tracking zone update;

if RER_INFO_INCL is equal to ‘

1’

, setting the tracking zone reporting information included indicator.

44. The method of claim 39, wherein the Mobile Station Message Transmission Operation supported by the MS, the method further comprising the step of:

providing on the R-CSCH messages containing the Radio Environment Report Message.

45. The method of claim 44, wherein the step of providing includes the step of:

providing the Radio Environment Report Message containing the field of the tracking zone report indicator and its length.

46. The method of claim 45, wherein the step of providing includes the step of:

providing the Radio Environment Report Message containing the field of the tracking zone report indicator of one bit.

47. The method of claim 46, further comprising the steps of:

setting the field to ‘

1’

if the Radio Environment Report Message is sent for tracking zone report; and

otherwise, setting the field to ‘

0’

.

48. The method of claim 44, further comprising the step of:

providing a message field containing;

a radio environment reporting supported indicator; and

a tracking zone supported indicator.

49. The method of claim 48, wherein the step of providing includes the step of:

setting the field of the tracking zone supported indicator to ‘

1’

if it supports tracking zone reporting on the R-CSCH; and

otherwise, setting the filed to ‘

0’

.

50. The method of claim 44, further comprising the step of:

providing an Extended System Parameters Message containing fields of a tracking zone supported indicator and a tracking zone identifier.

51. The method of claim 50, wherein the step of providing includes the step of:

providing an Extended System Parameters Message containing fields of a tracking zone supported indicator of one bit and a tracking zone identifier of zero or eight bits

52. The method of claim 51, wherein the BTS sets the field of the tacking zone supported indicator to ‘

1’

if the tracking zone is supported and otherwise to ‘

0’

.

53. The method of claim 50, wherein the BTS sets the field of the tacking zone identifier to ‘

1’

if the field of the tacking zone supported indicator is set to ‘

1’ and

otherwise, the BTS omits the field of the tracking zone identifier.

54. The method of claim 44, further comprising the step of:

providing an ANSI-41 System Parameters Message containing fields of a tracking zone supported indicator and a tracking zone identifier.

55. The method of claim 54, wherein the step of providing includes the step of:

providing an ANSI-41 System Parameter Message containing fields of a tracking zone supported indicator of one bit and a tracldng zone identifier of zero or eight bits.

56. The method of claim 54, wherein the BTS sets the field of the tracking zone supported indicator to ‘

1’

if the tracking zone is supported and otherwise, the BTS sets the field of the tracking zone supported indicator to ‘

0’

.

57. The method of claim 54, wherein if the field of the tracking zone supported indicator is set to ‘

1’

the BTS sets the field of the tracking zone identifier to its tracking zone identifier and otherwise, the BTS omits the field of the tracking zone identifier.

58. The method of claim 44, further comprising the step of:

providing an Extended Release-Message containing fields of a tracking zone reporting information included indicator, a maximum number of tracking zone reporting index, a tracking zone update period, a tracking zone list length and a tracking zone timer.

59. The method of claim 58, wherein the step of providing includes the step of:

providing an Extended Release Message containing fields of a tracking zone reporting information included indicator of one bit, a maximum number of tracking zone reporting index of zero or three bits, a tracking zone update period of zero or four bits, a tracking zone list length of zero or four bits and a tracking zone timer of zero or eight bits.

60. The method of claim 58, further comprising the steps of performing by the BTS based on the channel indication bits of channels processed by the MS:

setting the field of the racking zone reporting information included indicator to ‘

1’

if the tracking zone reporting related fields are included in the extended release message and otherwise to ‘

0’

.

61. The method of claim 58, wherein if the tracking zone reporting information included indicator is set to ‘

0’

, the BTS omits the field of the maximum number of tracking zone reporting index and otherwise, the BTS includes the field of the maximum number of tracking zone reporting index and set it as follows;

the BTS sets the field of the maximum number of tracking zone reporting index to the maximum number of tracking zone reports that the MS is allowed to transmit, expressed as 2<sup>MAX_—

NUM_—

TKZ_—

IDX</sup> where 0≦

MAX_NUM_TKZ_IDX≦

6, wherein if the MS is allowed to transmit an unlimited number of tracking zone reports, then the BTS sets the field of the maximum number of tracking zone reporting index to ‘

111’

.

62. The method of claim 58, wherein if the tracking zone reporting information included indicator is set to ‘

0’

, the BTS omits the field of the racking zone update period; and

otherwise, the BTS includes the field of the racking zone update period and set it as follows;

the BTS sets the field of the racking zone update period such that the desired tracking zone update timer value is 2<sup>TKZ_—

UPDATE_—

PRD+6</sup> seconds, wherein the value of the timer is infinite, then the BTS sets the field of the racking zone update period to ‘

1111’

.

63. The method of claim 58, wherein if the tracking zone reporting information included indicator is set to ‘

0’

, the BTS omits the filed of the tracking zone list length; and

otherwise, the BTS includes the filed of the tracking zone list length and set it as follows;

the BTS sets the filed of the tracking zone list length to the length of the tracking zone list minus one.

64. The method of claim 58, wherein if the tracking zone reporting information included indicator is set to ‘

0’

, the BTS omits the filed of the tracking zone timer; and

otherwise, the BTS includes the filed of the tracking zone timer and sets it as follows;

the BTS sets the filed of the tracking zone timer to the value of the tracking zone timer (in units of seconds) minus one.

65. The method of claim 44, wherein if the PDU on the R-CSCH corresponds to a Radio Environment Report Message and RER_ENABLED is set to YES, the MS generates a new set of pilots that includes the Active Set pilot and additional pilots with records included in the PDU that have the strongest pilot strength.

66. A system for tracking zone updates to a communication network to page a mobile station (MS) in a smaller area including zones relating to base station controllers (BSCs) that control communications among the BTSs and the MSs, the zones being further defined as smaller zones that are registered for zone tracking, the system comprising:

means for defining the size of the tracking zones;

means for defining the zones of the BTSs;

means for broadcasting tracking zone identifiers; and

means for paging MSs in the tracking zones.

67. The system of claim 66, wherein the means for defining the zones of the BTSs includes means for assigning the same value to the BTSs in the same tracking zone.

68. The system of claim 66, further including means for reporting by the MS on change of location in the tracking zone.

69. The system of claim 66, wherein the information on the performing of the tracking zone update are defined by values, said values being defined for:

the tracking zone identifier;

the tracking zone list which is a list of most recent tracking zone identifier received by the MS;

the number of tracking zone identifier to be maintained in the tracking zone list;

the maximum number of Radio Environment Report Messages that the MS is permitted to transmit before disabling tracking zone reporting; and

the BTS'"'"'s support of tracking zone reporting indicator.

70. A mobile station (MS) for communicating with a base transceiver station (BTS) and a base station controller (BSC) in wireless communication system, the MS in a dormant state sending a location update message, the MS comprising:

means for starting a first timer when the MS enters a dormant state;

means for starting a second timer when the first timer reaches a predefined value T1;

means for sending, while the first timer is counting and prior to its reaching said predefined value T1, a layer 2 location update message whenever the MS performs an idle handoff indicating that the strongest pilot signal strength has changed from one sector to another sector;

means for sending, while the second timer is counting and prior to its reaching a predefined value T2, a layer 2 location update message whenever a further criterion is met; and

means for sending, after the second timer has reached said predefined value T2, no further layer 2 location update messages.

71. The MS of claim 70, further including means for predefining the starting value for the first timer to said predefined value T1.

72. The method of claim 70, further including means for predefining the starting value of the second timer to said predefined value T2.

73. The MS of claim 70, further including means for sending the BTS a layer 2 location update message containing a message type and an MS identifier, whereby the network updating the location of the MS.

74. A communication network comprising base station controllers (BSCs) and base transceiver stations (BTSs) that communicate with mobile stations (MSs) in wireless communication system, the network paging a dormant MS when the network determines that data is to be sent to that dormant MS, the MS comprising:

means for starting a first timer when the MS enters a dormant state;

means for starting a second timer when the first timer reaches a predefined value T1;

means for sending, while the first timer is counting and prior to its reaching said predefined value T1, a layer 2 location update message whenever the MS performs an idle handoff indicating that the strongest pilot signal strength has changed from one sector to another sector;

means for sending, while the second timer is counting and prior to its reaching a predefined value T2, a layer 2 location update message whenever a further criterion is met; and

means for sending, after the second timer has reached said predefined value T2, no further layer 2 location update messages,

wherein the BTS includes;

means for receiving the layer 2 location update message;

means for sending a location update acknowledgement message to the MS.

75. The communication network of claim 74, wherein:

the MS further includes means for sending the BTS a layer 2 location update message containing a message type and an MS identifier, whereby the network updating the location of the MS; and

the BTS further include means for sending the MS a location update acknowledgment message containing a message type and an MS identifier.

76. The communication network of claim 74, wherein:

the MS in the dormant state includes means for sending the BTS a reconnect message containing a message type and an MS identifier; and

the BTS includes the MS a channel assignment message, whereby the MS initiates an MS'"'"'s dormant to active state transition.

77. The communication network of claim 74, wherein:

the MS includes means for sending the BTS a layer 2 location update message containing a message type and an MS identifier; and

the BTS includes;

means for sending the MS a location update acknowledgement message containing a message type and an MS identifier; and

means for sending the MS a message informing MS'"'"'s active set,

wherein the BTS initiates an MS'"'"'s dormant to active state transition.

78. The communication network of claim 74, wherein:

the MS includes means for sending the BTS a layer 2 location update message containing a message type and an MS identifier; and

the BTS includes;

means for sending the MS a location update acknowledgement message containing a message type and an MS identifier; and

means for sending the MS a message informing MS'"'"'s active set; and

means for sending the MS a data burst message,

wherein the MS further includes means for sending the BTS a data burst acknowledgement message containing a message type and an MS identifier.

79. A method for updating locations of mobile stations (MSs) in a dormant state in a wireless communication network wherein a Base Station Controller controls various operating aspects of the network and a Base Transceiver Station provides communication links between MSs and between the MSs and a wireline telephone network, the method comprising the steps of:

starting a timer when the MS enters a dormant state;

while the timer is counting and prior to its reaching a predefined value T1, sending by the MS to the BTS, whenever the MS performs an idle handoff, a message containing information on the location of the MS, the information being associated with the sector of the MS, thereby the network updating the location of the dormant MS at the sector level;

when the timer'"'"'s count reaches the value T1, restarting the timer to count until it reaches a predetermined value T2;

while the timer is counting and prior to its reaching the predefined value T2, sending by the MS to the BTS a message containing information on the location of the MS, the information being associated with the area of the MS, the area being greater than the sector, thereby the network updating the location of the dormant MS at the area level;

when the timer'"'"'s count reaches the value T2, sending no further message of location to the BTS.

80. The method of claim 79, further including the step of:

after the timer'"'"'s count reaches the value T2, sending an MS page to all network sectors.

81. The method of claim 79, wherein:

the step of sending a message prior to T1 includes the step of sending a layer 2 message containing a message type and an MS identifier; and

the step of sending a message prior to T2 includes the step of sending a layer 2 message containing a message type and an MS identifier.