METHOD AND APPARATUS OF MEASUREMENT MECHANISM AND EFFICIENT PAGING AND BROADCASTING SCHEME IMPLEMENTATION IN MBMS DEDICATED CELL OF LTE SYSTEMS

• US 20080268878A1
• Filed: 04/25/2008
• Published: 10/30/2008
• Est. Priority Date: 04/26/2007
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Wang, Peter S., Wang, Jin, Olvera-Hernandez, Ulises
• Granted Patent: US 8,135,419 B2
• Time in Patent Office: Days
• US Class Current: 455/458
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 68/00 User notification, e.g. alerting and paging, for incoming communication, change of service or the like
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems

Abstract

A WTRU configured to receive a multicast, a unicast or mixed signal. A multimedia signal may be a Multimedia Broadcast Multicast Signal (MBMS). The WTRU switches between an MBMS and a mixed signal and determines optimal time to switch between the MBMS and mixed signal. The WTRU switches between receiving the MBMS and mixed signal in an adaptive or semi-static pattern. A flat broadcast channel (BCH) structure in an MBMS dedicated cell is provided, eliminating need for a dedicated broadcast channel (D-BCH). An MBMS-dedicated cell uses a single paging channel for both paging-indicators and paging-record-blocks. A system information broadcast indicates flexible resource usage and paging-record-block limits. Tracking area (TA)/cell association is provided for an MBMS-dedicated cell and geographically co-located non-MBMS-dedicated cells. MBMS-dedicated cell system information is broadcast to regulate WTRU operation while receiving MBMS within said cell. Generic Access Profile (GAP) definitions is part of system information.

Claims

1. A method for paging employed by a long-term evolution (LTE) node, the method comprising:

sending paging indicators (PIs) in a specific sub-frame of each long-term evolution (LTE) frame to indicate to wireless transmitter receiver units (WTRUs) a presence of an incoming call for a WTRU identified in the paging indicator; and

sending a paging record in an LTE frame following the frame containing the PI for the WTRU to provide instructions to the identified WTRU.

2. The method of claim 1, wherein the PI includes a group identification (ID) identifying WTRUs which are members of said group.

3. The method of claim 1, wherein paging is performed in an multimedia broadcast multicast services (MBMS) dedicated cell.

4. The method of claim 3, wherein the MBMS-dedicated cell employs a single paging channel for both PIs and paging record blocks.

5. A method for use by a multimedia broadcast multicast services (MBMS) dedicated cell, comprising:

sending paging indicators (PIs) and paging record blocks to WTRUs over a single paging channel (PCH) and employing a different channel for paging unicast MBMS service, the paging channel being configured to convey system change information to the WTRUs.

6. The method of claim 5, wherein the paging channel provides specific parameters including physical layer parameters.

7. The method of claim 6, wherein the physical layer parameters include power off-set, channel coding, transmit diversity information and antenna information.

8. The method of claim 5, wherein the paging indicator includes at least one of a sub-frame off-set within a frame and a paging indicator length as represented by n-sub-frames.

9. The method of claim 8, wherein paging indicator information further includes at least one of paging indicator internal-allocation-bit-composition, and paging indicator radio network temporary identity (PI-RNTI) information for each paging occasion.

10. A method for use by a multimedia, broadcast, multicast service (MBMS) cell comprising:

sending a uniform discontinuous reception (DRX) cycle length assignment provided as part of system information to avoid use of a current DRX cycle assigned to the WTRU at a radio resource control (RRC) connection time to even a paging load distribution.

11. A method for use in an arrangement wherein at least one MBMS-dedicated-cell is provided in a Multimedia Broadcast Multicast Service synchronized network (MBMSFN) and having at least one non-MBMS-dedicated cell geographically co-located to said at least one MBMS-dedicated cell in said MBMSFN, comprising:

assigning a given TA-ID to the MBMS-dedicated cell geographically co-located with the at least one non-MBMS-dedicated cell and assigning another TA-ID different from said given TA-ID to the geographically co-located non-MBMS-dedicated cells to reduce unnecessary paging overhead.

12. The method of claim 11, comprising:

assigning a regular TA-ID to a WTRU identified as being located only in said at least one geographically co-located non-MBMS-dedicated cell.

13. A method employed for reducing paging overhead to WTRUs in a multimedia broadcast multicast service synchronized transmission network (MBMSFN) having a plurality of MBMS-dedicated cells, and a plurality of non-MBMS-dedicated cells geographically co-located with at least one of said MBMS-dedicated cells, comprising:

assigning a TA-ID to the at least one MBMS-dedicated cell co-located with said non-MBMS-dedicated cells and another TA-ID to the non-MBMS-dedicated cells.

14. A method employed by a WTRU supported by dedicated MBMS-service from an MBMS-dedicated cell, comprising:

performing incoming paging monitoring only in a cell currently supporting the WTRU and under the MBMS-service target area (TA);

performing MBMS measurements to cells in the MBMS-service TA;

performing regular measurements to cells in a regular TA; and

performing non-MBMS operations with only one non-MBMS-dedicated cell under the regular TA which is geographically co-located with MBMS-dedicated cell.

15. A method employed by a network having MBMS-dedicated cells and non-MBMS-dedicated cells for providing Generic Access Profile (GAP) scheduling information as part of MBMS-services to at least one WTRU receiving MBMS-services, comprising:

providing the GAP to the WTRU to perform non-MBMS operations in any non-MBMS cell, the GAP scheduling information including a beginning frame number, a length in units of frames and a repetition period length in terms of frames.

16. A method employed by a WTRU serviced by an MBMS-dedicated cells for performing measurement activities, comprising:

measuring MBMS reception quality on the MBMS-dedicated cell by way of one of a retrieved state reply (RSRP) and block error rate (BLER).

17. The method of claim 16 further comprising attaching the MBMS measurement to a tracking area (TA) update message and reporting the measurement directly when the measured values are outside of given thresholds to indicate MBMS transmission problems.

18. The method of claim 16 further comprising measuring non-MBMS-dedicated cells in an associated regular-TA for retrieved state reply (RSRP).

19. The method of claim 18 further comprising measuring the non-MBMS-dedicated cells in the associated regular-TA by measuring the retrieved state request (RSRQ).

20. The method of claim 16, wherein WTRU starts a scan for a new non-MBMS cell when measurement is below a given threshold.

21. A wireless transmit/receive unit (WTRU) configured to receive a multimedia signal from a Long-Term-Evolution system, said signal periodically including an instruction message.

22. The WTRU of claim 21 wherein the WTRU is configured to receive the multimedia signal which is a Multicast Broadcast Multimedia Signal (MBMS).

23. The WTRU of claim 22 wherein the WTRU is further configured to switch between receiving the MBMS and a mixed signal responsive to the instruction message.

24. The WTRU of claim 23 wherein the WTRU is further configured to determine an optimal time to switch between receiving the MBMS signal and one of a unicast signal and the mixed signal.

25. The WTRU of claim 24 wherein the WTRU is further configured to switch between receiving the MBMS signal and one of the mixed signal and the unicast signal during a scheduling gap for performing non-MBMS activities.

26. The WTRU of claim 23 wherein the WTRU is further configured to perform non-MBMS activities during a scheduled gap interval.

27. The WTRU of claim 25 being further configured to perform non-MBMS activities comprising performing neighbor cell measurements and tracking area (TA) updates.

28. The WTRU of claim 21 being further configured to perform uplink (UL) reporting responsive to at least one of WTRU mobility, WTRU trajectory and WTRU location in a cell servicing the WTRU.

29. The WTRU of claim 28 wherein the WTRU is further configured to determine WTRU mobility during a gap interval.

30. The WTRU of claim 27 being configured to obtain WTRU mobility;

and

bypass a need for performing one measurements and updates responsive to mobility below a given level.

31. The WTRU of claim 22 being further configured to receive an instruction message comprising a number of gaps the WTRU may use to perform at least one of switch between the MBMS and the mixed signal and perform measurements and updates.

32. The WTRU of claim 23 being further configured to determine gap intervals responsive to location of the WTRU in a cell supporting the WTRU.

33. The WTRU of claim 23 being further configured to switch between the MBMS signal and the mixed signal at a low rate based on a location of the WTRU near a center of a cell supporting the WTRU.

34. The WTRU of claim 23 being further configured to switch between the MBMS signal and the mixed signal at a high rate based on a location of the WTRU near an edge of a cell supporting the WTRU.

35. The WTRU of claim 21 being further configured to receive broadcast information comprising measurements for the WTRU to perform when switching.

36. The WTRU of claim 21 being further configured to transmit related neighbor and response cell information only within a particular tracking area (TA) responsive to the instruction message.

37. The WTRU of claim 21 being further configured to accept a first tracking area TA and a second TA.

38. The WTRU of claim 37 wherein the first TA is associated with an MBMS dedicated cell and the second TA is associated with a mixed cell geographically co-located with the MBMS dedicated cell.

39. The WTRU of claim 38 being further configured to switch between the MBMS dedicated cell and the mixed cell and avoiding a need for performing a tracking area update (TAU) responsive to receipt of a message assigning a common TA to both the MBMS dedicated cell and the mixed cell.

40. The WTRU of claim 21 wherein a network Mobility Management Entity (MME) is configured to assign an MBMS-TA to only one cell;

and

assigning the WTRU an MBMS-TA identifier (ID).

41. The WTRU of claim 40 wherein the network MME is further configured to transmit a paging message to multiple TAs.

42. A Long-Term-Evolution (LTE) network for providing tracking area (TA) information to a WTRU, comprising:

(a) determining at least one of mobility, trajectory and cell location of the WTRU; and

(b) sending TA paging information based on determinations obtained at step (a).

43. The network of claim 42 being further configured to determine a number of TAs to be sent as part of the information based on one of movement of the WTRU towards an edge of a TA and a speed of the WTRU greater than a given speed.

44. A WTRU operating in Long-Term-Evolution (LTE) being configured to:

provide at least one of mobility, trajectory and cell location of the WTRU to the network;

receive tracking area (TA) information from the network; and

measure cells in the TA responsive the TA information.