Efficient paging in a wireless communication system

• US 8,712,448 B2
• Filed: 03/31/2010
• Issued: 04/29/2014
• Est. Priority Date: 06/10/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Laroia, Rajiv, Li, Junyi, Rangan, Sundeep, Hande, Prashanth
• Primary Examiner(s): Doan, Kiet
• Assistant Examiner(s): Vu, Michael T
• Application Number:
  US12/751,961
• Publication Number:
  US 20100190514A1
• Time in Patent Office: 1,490 Days
• Field of Search: 455/458, 455/426.1, 455/343, 370/483, 370/342, 370/316
• US Class Current: 455/458
• CPC Class Codes: H04W 68/025 Indirect paging
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Methods and apparatus for efficient two-stage paging wireless communications systems are described. Wireless terminals are assigned to paging groups. A few first paging message information bits are modulated (using non-coherent modulation) into a first paging signal and communicated from a base station to wireless terminals. WTs wake-up, receive the first paging signal and quickly ascertain whether its paging group should expect a second paging signal, if so, the WT is operated to receive the second paging signal; otherwise, the WT goes back to sleep conserving power. The base station modulates (using coherent modulation) a number of second message information bits into a second paging signal and transmits the signal to WTs. From the information in first and second paging signals, a WT can determine that it is the paged WT and process the paging instructions. The intended paged WT can transmit an acknowledgement signal on a dedicated uplink resource.

Claims

1. A method of paging a wireless terminal in a communications system including multiple wireless terminals, the method comprising:

modulating, using a non-coherent type of modulation, a first number of bits of information to generate a first paging signal, said first paging signal conveying said first number of bits of information, said first paging signal including information indicating whether there is a paging message and indicating a wireless terminal group;

modulating, using a coherent type of modulation, a second number of bits of information to generate a second paging signal, said second paging signal including, when there is the paging message, at least a portion of said paging message where said first paging signal indicates that there is the paging message and indicates a particular wireless terminal within the wireless terminal group to which the page is directed;

transmitting said first paging signal; and

transmitting said second paging signal.

2. The method of claim 1 in which the wireless terminal group is one of a plurality of wireless terminal groups, some of the plurality of wireless terminal groups being multicast groups including a plurality of wireless terminals.

3. The method of claim 1 in which the first and second paging signals are transmitted at different points in time, the second paging signal being transmitted at a first fixed time offset from the time the first paging signal is transmitted.

4. The method of claim 1 in which:

the communications system supports a maximum number of wireless terminals which can be registered to receive pages in the communication system at a point in time; and

the first number of bits is less than a number of bits required to uniquely identify each of the maximum number of wireless terminals.

5. The method of claim 1, in which the first paging signal further indicates that there is no paging message for wireless terminals in a second wireless terminal group.

6. An apparatus for communicating with wireless terminals in a communications system, the system comprising:

means for modulating, using a non-coherent type of modulation, a first number of bits of information to generate a first paging signal, the first paging signal conveying the first number of bits of information, the first paging signal including information indicating whether there is a paging message and indicating a wireless terminal group;

means for modulating, using a coherent type of modulation, a second number of bits of information to generate a second paging signal, the second paging signal including, when there is the paging message, at least a portion of the paging message where the first paging signal indicates that there is the paging message and indicates a particular wireless terminal within the wireless terminal group to which the page is directed;

means for transmitting the first paging signal; and

means for transmitting the second paging signal.

7. The apparatus of claim 6 in which the wireless terminal group is one of a plurality of wireless terminal groups, some of the plurality of wireless terminal groups being multicast groups including a plurality of wireless terminals.

8. The aparatus of claim 6 in which the first and second paging signals are transmitted at different points in time, the second paging signal being transmitted at a first fixed time offset from the time the first paging signal is transmitted.

9. The apparatus of claim 6 in which:

the communications system supports a maximum number of wireless terminals which can be registered to receive pages in the communication system at a point in time; and

the first number of bits is less than a number of bits required to uniquely identify each of the maximum number of wireless terminals.

10. The apparatus of claim 6, in which the first paging signal further indicates that there is no paging message for wireless terminals in a second wireless terminal group.

11. A non-transitory

machine readable medium having program code recorded thereon, the program code comprising:

program code to modulate, using a non-coherent type of modulation, a first number of bits of information to generate a first paging signal, the first paging signal conveying the first number of bits of information, the first paging signal including information indicating whether there is a paging message and indicating a wireless terminal group;

program code to modulate, using a coherent type of modulation, a second number of bits of information to generate a second paging signal, the second paging signal including, when there is the paging message, at least a portion of the paging message where the first paging signal indicates that there is the paging message and indicates a particular wireless terminal within the wireless terminal group to which the page is directed;

program code to transmit the first paging signal; and

program code to transmit the second paging signal.

12. The non-transitory machine readable medium of claim 11 in which the wireless terminal group is one of a plurality of wireless terminal groups, some of the plurality of wireless terminal groups being multicast groups including a plurality of wireless terminals.

13. The non-transitory machine readable medium of claim 11 in which the first and second paging signals are transmitted at different points in time, the second paging signal being transmitted at a first fixed time offset from the time the first paging signal is transmitted.

14. The non-transitory machine readable medium of claim 11 in which:

the communications system supports a maximum number of wireless terminals which can be registered to receive pages in the communication system at a point in time; and

the first number of bits is less than a number of bits required to uniquely identify each of the maximum number of wireless terminals.

15. The non-transitory machine readable medium of claim 11, in which the first paging signal further indicates that there is no paging message for wireless terminals in a second wireless terminal group.

16. An apparatus configured for communicating with wireless terminals in a communications system, the apparatus comprising:

at least one processor; and

a memory coupled to the at least one processor, the at least one processor being configured;

to modulate, using a non-coherent type of modulation, a first number of bits of information to generate a first paging signal, the first paging signal conveying the first number of bits of information, the first paging signal including information indicating whether there is a paging message and indicating a wireless terminal group;

to modulate, using a coherent type of modulation, a second number of bits of information to generate a second paging signal, the second paging signal including, when there is the paging message, at least a portion of the paging message where the first paging signal indicates that there is the paging message and indicates a particular wireless terminal within the wireless terminal group to which the page is directed;

to transmit the first paging signal; and

to transmit the second paging signal.

17. The apparatus of claim 16 in which the wireless terminal group is one of a plurality of wireless terminal groups, some of the plurality of wireless terminal groups being multicast groups including a plurality of wireless terminals.

18. The apparatus of claim 16 in which the first and second paging signals are transmitted at different points in time, the second paging signal being transmitted at a first fixed time offset from the time the first paging signal is transmitted.

19. The apparatus of claim 16 in which:

the communications system supports a maximum number of wireless terminals which can be registered to receive pages in the communication system at a point in time; and

the first number of bits is less than a number of bits required to uniquely identify each of the maximum number of wireless terminals.

20. The apparatus of claim 16, wherein the first paging signal further indicates that there is no paging message for wireless terminals in a second wireless terminal group.