System and method relating to packet data communication

• US 6,438,383 B1
• Filed: 03/17/1999
• Issued: 08/20/2002
• Est. Priority Date: 03/20/1998
• Status: Expired due to Fees

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Sundell, Hans-Olof, Karlsson, Johanna, Hall, Göran
• Primary Examiner(s): Le, Thanh Cong
• Assistant Examiner(s): Corsaro, Nick
• Application Number:
  US09/271,265
• Time in Patent Office: 1,252 Days
• Field of Search: 455/458, 455/515, 455/574, 455/466, 455/456, 455/435, 370/338, 370/352, 370/311
• US Class Current: 455/458
• CPC Class Codes: H04W 68/00 User notification, e.g. alerting and paging, for incoming communication, change of service or the like

Abstract

A cellular communication system supporting packet data communication includes a number of switching arrangements for switching speech and/or circuit switched data. It also includes a number of packet data nodes, each controlling/serving the packet data communication in a number of packet paging areas. In each cell, a number of packet data communication channel resources are used for packet data communication, and each packet data node includes mobile station information handling devices keeping information about mobile stations registered in the cells covered by the packet data node. Cell information handling devices are further provided keeping information about packet data communication channel resources in the cells covered by the packet data node. Devices are provided for calculating which packet data communication channels are to be used for mobile stations after updating of a cell. Furthermore, devices are provided for keeping information about which cells have been updated and when a cell is updated. Paging of a mobile station in a stand-by state is performed by sending a number of first paging messages from the packet data node using the calculated packet data communication channel resources in all cells within the packet paging area in which the mobile station is registered. If the mobile station is not found, a second paging message is sent out to all cells which have been updated, advantageously on all packet data communication channel resources of such cells.

Claims

1. A cellular communication system supporting packet data communication, comprising:

a number of switching arrangements for switching speech and/or circuit switched data,

a number of packet data nodes, each controlling/serving the packet data communication in a number of packet paging areas,

in each cell, a number of packet data communication channels being used for packet data communication, wherein each packet data node comprises mobile station information handling means keeping information about mobile stations registered in the cells covered by the packet paging areas covered by the packet data node and cell information handling means keeping information about packet data communication channels in the cells covered by the packet data node,

means for calculating which packet data communication channel resources are to be used for mobile stations after updating of a cell, and

means for keeping information about which cells have been updated,

wherein when a cell is updated, paging of a mobile station in a stand-by state is performed by sending a number of first paging messages from the packet data node using the calculated packet data communication channel resources in all cells within the packet paging area in which the mobile station is registered, and if the mobile station is not found, a second paging message is sent out to all cells which have been updated.

2. A system according to claim 1, wherein a mobile station, registered with the packet data node for packet data communication, is entered in a packet stand-by state when no packet data has been communicated to/from the mobile station for a predetermined time period, and the packet data node contains means for keeping information on such entry.

3. A system according to claim 1, wherein a packet data communication channel using one frequency comprises a number of functional channels, each functional channel corresponding to one time slot on said frequency.

4. A system according to claim 3, wherein a packet data communication channel is comprises one, two or three functional channels.

5. A system according to claim 3, wherein in the calculating means, a calculation is performed to calculate which packet data communication channel resource is to be used by a mobile station in stand-by state after a cell update, and said calculating means also calculates which functional channel(s) on said packet data communication channel which is/are to be used for paging messages.

6. A system according to claim 5, wherein the first paging message(s) is/are sent on the calculated functional channel(s) in all cells within the packet paging area.

7. A system according to claim 6, wherein the second paging message is sent on all functional channels of all packet data communication channels in all updated cells within the packet paging area.

8. A system according to claim 1, wherein the mobile station information handling means keeps information about data communication traffic events relating to transmission/reception of data packets and registration events by the mobile stations in the packet paging area and further includes means for keeping information about the times at which such events occur.

9. A system according to claim 8, wherein the mobile station information handling means includes time stamping means stamping the time of each data communication event, at least the time stamp of the last event is stored, and also information about the data communication channel resource used at the event is stored.

10. A system according to claim 1, wherein the cell information means keeps information about which packet data communication channels are used in each cell within the packet paging area, including information about which are the functional channels used by said packet data communication channels and the means further include cell time stamping means stamping the time when a cell is updated.

11. A system according to claim 10, wherein the cell information handling means contains a cell update flag which is set when a cell is updated, and said flag is cleared when a time period has elapsed, said time period being predetermined, fixed or reconfigurable.

12. A system according to claim 1, wherein the packet data node includes a paging timer for which a time interval is given, upon the expiration of which a second paging message is sent out, said paging timer being initiated upon sending out of a first paging message.

13. A system according to claim 9, wherein the cell information means keeps information about which packet data communication channels are used in each cell within the packet paging area, including information about which are the functional channels used by said packet data communication channels and the means further include cell time stamping means stamping the time when a cell is updated, the packet data node includes a paging timer for which a time interval is given, upon the expiration of which a second paging message is sent out, said paging timer being initiated upon sending out of a first paging message, the packet data node includes comparing means for comparing the time stamp of each cell and the time stamp of the mobile station, and the second paging message is sent out to all cells for which the cell time stamp shows a later time than the mobile station time stamp.

14. A system according to claim 9, wherein the cell information handling means contains a cell update flag which is set when a cell is updated, said flag is cleared when a time period has elapsed, said time period being predetermined, fixed or reconfigurable, the packet data node includes a paging timer for which a time interval is given, upon the expiration of which a second paging message is sent out, said paging timer being initiated upon sending out of a first paging message, the cell time stamp of the cells for which a flag is set is compared to the time stamp of the mobile station, and the second paging message is sent to those cells for which the time stamp shows a time which is later than the time stamp of the mobile station.

15. A system according to claim 11, wherein the cell information handling means includes means for holding information about the identities of all cells, cell update time stamps, cell update flags, the packet paging areas to which the cells belong and about which functional channels the packet data communication channels, used by the cells, comprise.

16. A system according to claim 3, wherein a second paging message is sent on all functional channels of all packet data communication channels of all updated cells except for the cell in which the mobile station is registered, in which cell, if updated, the paging message is sent on the packet data communication channel on which a mobile station is registered and on the calculated packet data communication channel resource(s).

17. A system according to claim 16, wherein if the mobile station is not found by the second paging message, a third paging message is sent out, preferably upon expiration of a timer, said third message being sent out in the cell in which the mobile station is registered at least on the channel resources on which the second paging message was not sent.

18. An arrangement for paging a mobile station in a stand-by state in a cellular communication system supporting packet data communication, the arrangement comprising:

a packet data node controlling a number of packet paging areas each containing a number of cells, said packet data node comprising mobile station information handling means keeping information about mobile stations registered with it and cell information handling means keeping information about packet data communication channels used for packet data communication in the cells in the packet paging areas, and

calculating means for calculating which packet data communication channel resource that is to be used by the mobile station when a cell has been updated,

wherein when a cell is updated, paging of the mobile station is performed by sending a number of first paging messages from the packet data node on the calculated packet data communication channel resource in all cells within the packet paging area in which the mobile station is registered, and if the mobile station is not found, a second paging message is sent out to all cells which have been updated using all packet data communication channel resources of such cells or using all packet data communication channel resources of such cells except the cell in which the mobile station is registered.

19. An arrangement according to claim 18, wherein a packet data communication channel using one frequency comprises one, two or three functional channels, each functional channel corresponding to one time slot on said frequency.

20. An arrangement according to claim 18, wherein in the calculating means a calculation is performed to calculate which packet data communication channel is to be used by the mobile station after the cell update, and said calculating means also calculates which functional channel(s) on said packet data communication channel is/are to be used for paging messages.

21. An arrangement according to claim 20, wherein the first paging message(s) is/are sent on the calculated functional channel(s) in all cells within the packet paging area.

22. An arrangement according to claim 21, wherein the second paging message is sent on all functional channels of all packet data communication channels in all updated cells within the packet paging area including the cell in which the mobile station is registered if it is updated.

23. An arrangement according to claim 21, wherein the second paging message is sent on all functional channels in all cells within the packet paging area except in the cell in which the mobile station is registered, in which, in case it is updated, the second paging message only is sent on the calculated functional channel and on the functional channel on which it is registered.

24. An arrangement according to claim 23, wherein if the mobile station is not successfully paged by the second paging message, a third paging message is sent out in the cell in which the mobile station is registered, at least on the functional channels on which the second paging message was not sent.

25. An arrangement according to claim 22, wherein the mobile station information handling means keeps information about data communication traffic or registration events of the mobile station, mobile station stamping means are provided for stamping the time at which such events occur, the cell information handling means keep information about which packet data communication channel resources are used in each cell within the packet paging area, including information about which functional channels of the corresponding packet data communication channels are used, and cell time stamping means are provided for stamping the time when a cell is updated.

26. A system according to any one of claim 18, wherein the packet data node includes a paging timer for which a time interval is given, upon the expiration of which a second paging message is sent out, said timer being initiated upon sending out of the (a) first paging message.

27. An arrangement according to claim 26, wherein the second paging message is sent out to all cells having a time stamp which is later than the time stamp of the mobile station.

28. Method of paging a mobile station in a cellular communication system supporting packet data communication, said mobile station being in a stand-by state and registered in a packet paging area controlled by a packet data node, the method comprising the steps of:

sending a first paging message to all cells within the packet paging area in which the mobile station is registered using up-to-date packet data communication channel resources in each cell,

waiting for a given period of time for confirmation that the mobile station has received the first paging message, and,

if no confirmation is received within the predetermined time period, examining for each cell whether the cell has been updated since a last packet data communication event between the packet data node and the mobile station,

sending a second paging message to all cells having been updated since the last contact between the packet data node and the mobile station, said second paging message being sent on all packet data communication channel resources, at least in all cells in which the mobile station is not registered.

29. A method according to claim 28, further comprising the steps of:

calculating which packet data communication channel resource that the mobile station should use in the cell when the cell has been updated, including calculation of which functional channel, among a number of functional channels which the packet data communication channel comprises, the mobile station should use.

30. A method according to claim 29, further comprising the steps of:

sending the first paging message on the calculated functional channel (s) in all cells within the packet paging area, and

sending the second paging message on all functional channels of all packet data communication channels in all updated cells within the packet paging area.

31. A method according to claim 30, further comprising the steps of:

stamping the time for packet data communication events relating to the mobile station in the packet data node,

stamping the time for each cell when it is updated,

examining which cells have been updated since the last time stamped data communication event relating to the mobile station, and

sending the second paging message to the cells having being updated after the last time stamp relating to the mobile station.

32. A method according to claim 28, further comprising the steps of:

sending a second paging message on the calculated functional channel and on the registered functional channel in the cell in which the mobile station is registered, and

if that cell is updated, sending the second paging message on all functional channels in all other cells having been updated,

if no confirmation is received from the mobile station that it has received the second paging message, sending a third paging message in the cell in which the mobile station is registered using at least all functional channels which were not used when sending the second paging message.

33. A method according to claim 28, further comprising the step of performing voice paging of the mobile station by a voice paging message on the functional channel.