Cell reselection and handover with multimedia broadcast/multicast service

• US 8,712,414 B2
• Filed: 04/25/2008
• Issued: 04/29/2014
• Est. Priority Date: 04/30/2007
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Somasundaram, Shankar, Sammour, Mohammed, Mukherjee, Rajat P., Olvera-Hernandez, Ulises, Wang, Jin, Miller, James M.
• Primary Examiner(s): Eng, George
• Assistant Examiner(s): DEAN, JR, JOSEPH E
• Application Number:
  US12/109,492
• Publication Number:
  US 20080287129A1
• Time in Patent Office: 2,195 Days
• Field of Search: 455/436
• US Class Current: 455/436
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04W 36/0007 for multicast or broadcast services, e.g. MBMS multicast or broadcast application services H04W4/06; resource management for broadcast services H04W72/30; connection management for selective distribution or broadcast H04W76/40
• CPC Class Codes: H04W 36/0055 Transmission or use of information for re-establishing the radio link
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states

Abstract

A method and apparatus for providing wireless communication services, (e.g., multimedia broadcast multicast services (MBMS)), are disclosed. A wireless transmit/receive unit (WTRU) detects a plurality of target cell evolved Node-Bs (eNodeBs) that neighbor a serving cell eNodeB. The WTRU evaluates cell reselection criteria and determines a neighboring target cell eNodeB to reselect. The WTRU receives and reads master information block (MIB) and system information messages of the neighboring target cell eNodeB, and confirms that the determined neighboring target cell eNodeB is not part of a multimedia broadcast single frequency network (MBSFN). The WTRU identifies the neighboring target cell eNodeB to the serving cell eNodeB. The WTRU then receives and reads MIB messages of the neighboring target cell eNodeB again to determine whether the system information has changed and, if so, the WTRU reads the system information and reselects to the neighboring target cell eNodeB, which provides the wireless communication services.

Claims

1. A method of providing wireless communication services, the method comprising:

receiving, from a serving cell of an evolved Node-B (eNodeB), cell information associated with target cells of eNodeBs that neighbor the serving cell;

evaluating, at a wireless transmit and/or receive unit (WTRU), cell reselection criteria including preference given to multimedia broadcast multicast services (MBMS) frequencies the WTRU is currently and/or interested in receiving via a MBMS single frequency network (MBSFN);

determining, at the WTRU, a neighboring target cell to reselect to based, at least in part, on the preference given to MBMS frequencies the WTRU is currently and/or interested in receiving;

receiving and reading master information block (MIB) and system information messages of the neighboring target cell;

transmitting, to the neighboring target cell, a random access channel (RACH) preamble or RACH message;

receiving a RACH response from the neighboring target cell; and

receiving, from the neighboring target cell, MBMS including the MBMS previously being received from the serving cell.

2. The method of claim 1, further comprising:

determining that the neighboring target cell is not ready to provide the MBMS;

transmitting, to the serving cell, a random access channel (RACH) preamble or RACH message indicating the neighboring target cell prior to reselection;

transmitting, to the neighboring target cell, a cell update message including capability information and service requirements; and

receiving, from the neighboring target cell, a cell update confirmation message indicating that the neighboring target cell is ready to provide the MBMS.

3. The method of claim 1, further comprising:

reselecting to the neighboring target cell.

4. The method of claim 1, further comprising:

reselecting to the neighboring target cell; and

receiving a signal from the neighboring target cell indicating that the neighboring target cell is ready to provide the MBMS.

5. The method of claim 1, wherein determining a neighboring target cell to reselect to comprises:

determining the neighboring target cell to reselect to based, at least in part, on the preference given to frequencies of the MBMS frequencies the WTRU is currently and/or interested in receiving.

6. A wireless transmit/receive unit (WTRU) comprising a receiver, processor and a transmitter, wherein:

the receiver is configured to receive, from a serving cell of an evolved Node-B (eNodeB), cell information associated with target cells of eNodeBs that neighbor the serving cell;

the processor is configured to;

evaluate cell reselection criteria including preference given to multimedia broadcast multicast services (MBMS) frequencies the WTRU is currently and/or interested in receiving via a MBMS single frequency network (MBSFN); and

determine a neighboring target cell to reselect to based, at least in part, on the preference given to MBMS frequencies the WTRU is currently and/or interested in receiving;

the receiver is configured to receive and read master information block (MIB) and system information messages of the neighboring target cell;

the transmitter is the transmitter is configured to transmit, to the neighboring target cell eNodeB, a random access channel (RACH) preamble or RACH message; and

the receiver is configured to;

receive a RACH response from the neighboring target cell; and

receive, from the neighboring target cell, MBMS including the MBMS previously being received from the serving cell.

7. The WTRU of claim 6, wherein:

the processor is configured to determine that the neighboring target cell is not ready to provide the MBMS;

the transmitter is further configured to;

transmit, to the serving cell, a random access channel (RACH) preamble or RACH message indicating the neighboring target cell prior to reselection, and

transmit, to the neighboring target cell, a cell update message including capability information and service requirements, and

the receiver is configured to receive, from the neighboring target cell, a cell update confirmation message indicating that the neighboring target cell is ready to provide the MBMS.

8. The WTRU of claim 6, wherein the processor is configured to reselect to the neighboring target cell.

9. The WTRU of claim 6, wherein:

the processor is configured to reselect the neighboring target cell; and

the receiver is further configured to receive an indication indicating that the neighboring target cell is ready to provide the MBMS.

10. The WTRU of claim 9, wherein the processor is configured to determine the neighboring target cell to reselect to based, at least in part, on the preference given to frequencies of the MBMS frequencies the WTRU is currently and/or interested in receiving.

11. A method of providing wireless communication services, the method comprising:

receiving neighbor cell information and capability information for a multimedia broadcast multicast services (MBMS) single frequency network (MBSFN);

transmitting, to a wireless transmit/receive unit (WTRU), cell information associated with target cells evolved Node-Bs (eNodeBs) that neighbor a serving cell of an eNodeB, the cell information including multimedia broadcast multicast services (MBMS) frequencies associated with the target cells so as to allow the WTRU to determine a neighboring target cell to reselect to;

receiving, at a given target cell, a random access channel (RACH) preamble or RACH message;

transmitting, to the WTRU, a RACH response from the given target cell; and

transmitting, from the given target cell, MBMS including the MBMS previously being received from the serving cell.

12. A system for providing wireless communication services, wherein:

the system comprises a serving cell of an evolved Node-B (eNodeB) and one or more target cells of eNodeBs;

the serving cell eNodeB comprises;

a receiver configured to receive cell information associated with the target cells for a multimedia broadcast multicast services (MBMS) single frequency network (MBSFN); and

a transmitter configured to transmit, to a wireless transmit/receive unit (WTRU), the received cell information, the cell information including multimedia broadcast multicast services (MBMS) frequencies associated with the target cells so as to allow the WTRU to determine a neighboring target cell to reselect to;

each of the neighboring target cell eNodeBs comprises;

a receiver configured to receive, from the WTRU, a random access channel (RACH) preamble or RACH message; and

a transmitter configured to (i) transmit, to the WTRU, a RACH response, and (ii) transmit MBMS including the MBMS previously being received from the serving cell.

13. A method of providing wireless communication services, the method comprising:

detecting a plurality of target cells of evolved Node-Bs (eNodeBs) that neighbor a serving cell of an eNodeB;

evaluating, at a wireless transmit and/or receive unit (WTRU), cell reselection criteria including preference given to multimedia broadcast multicast services (MBMS) frequencies the WTRU is currently and/or interested in receiving via a MBMS single frequency network (MBSFN);

determining a neighboring target cell to reselect to based, at least in part, on the preference given to MBMS frequencies the WTRU is currently and/or interested in receiving;

receiving and reading master information block (MIB) and system information messages of the neighboring target cell;

transmitting to the neighboring target cell, a random access channel (RACH) preamble or RACH message;

receiving a RACH response from the neighboring target cell; and

receiving, from the neighboring target cell, MBMS including the MBMS previously being received from the serving cell eNodeB.

14. The method of claim 13 further comprising:

determining that the neighboring target cell is not ready to provide the MBMS;

transmitting, to the serving cell, a random access channel (RACH) preamble or RACH message indicating the neighboring target cell prior to reselection;

receiving and reading MIB messages of the neighboring target cell again to determine whether the system information has changed;

if it is determined that the system information has changed, reading the system information and reselecting to the neighboring target cell;

if reselection to the neighboring target cell occurs, transmitting, to the neighboring target cell, a cell update message including capability information and service requirements; and

receiving, from the neighboring target cell, a cell update confirmation message indicating that the neighboring target cell is ready to provide the MBMS.

15. The method of claim 13, further comprising:

reselecting to the neighboring target cell.

16. The method of claim 13, further comprising:

if reselection to the neighboring target cell occurs, receiving, from the neighboring target cell, a signal indicating that the neighboring target cell is ready to provide the MBMS.

17. The method of claim 13, wherein determining a neighboring target cell reselect to comprises:

determining the neighboring target cell to reselect to based, at least in part, on the preference given to frequencies of the MBMS frequencies the WTRU is currently and/or interested in receiving.

18. A wireless transmit/receive unit (WTRU) comprising:

a receiver configured to detect a plurality of target cells of evolved Node-Bs (eNodeBs) that neighbor a serving cell of an eNodeB;

a processor configured to;

evaluate cell reselection criteria including preference given to multimedia broadcast multicast services (MBMS) frequencies the WTRU is currently and/or interested in receiving via a MBMS single frequency network (MBSFN), and

determine a neighboring target cell to reselect to based, at least in part, on the preference given to MBMS frequencies the WTRU is currently and/or interested in receiving;

the receiver further configured to receive master information block (MIB) and system information messages of the neighboring target cell;

the processor being further configured to read MIB messages of the neighboring target cell;

the transmitter further configured to transmit, to the neighboring target cell, a random access channel (RACH) preamble or RACH message; and

the receiver further configured to;

receive a RACH response from the neighboring target cell; and

receive, from the neighboring target cell, MBMS including the MBMS previously being received from the serving cell.

19. The WTRU of claim 18, wherein:

the processor is configured to determine that the neighboring target cell is not ready to provide the MBMS;

the transmitter is configured to transmit, to the serving cell, a random access channel (RACH) preamble or RACH message indicating the neighboring target cell prior to reselection;

the receiver is configured to receive MIB messages of the neighboring target cell again to determine whether the system information has changed;

the processor is configured to read MIB messages of the neighboring target cell again to determine whether the system information has changed; and

if reselection to the neighboring target cell occurs;

the transmitter is configured to transmit, to the neighboring target cell, a cell update message including capability information and service requirements; and

the receiver is further configured to receive, from the neighboring target cell, a cell update confirmation message indicating that the neighboring target cell is ready to provide the MBMS.

20. The WTRU of claim 19, wherein the processor is configured to reselect to the neighboring target cell.

21. A target cell of an evolved Node-B (eNodeB) for providing wireless communication services, the target-cell eNodeB comprising:

a receiver configured to receive, from a serving cell of an eNodeB, a signal including the identity of a wireless transmit/receive unit (WTRU) and required services information;

a processor configured to determine whether the target cell has the required services; and

a transmitter configured to transmit master information block (MIB) and system information messages, and if when the target cell does not have the required services, the transmitter is further configured to transmit, prior to selection or reselection of the target cell by the WTRU, a first message requesting that the target cell be joined to a multicast distribution tree for providing the required services.

22. The target-cell eNodeB of claim 21 wherein the receiver is further configured to receive, from the WTRU, a cell update message including capability information and service requirements, and the transmitter is further configured to transmit, to the WTRU, a cell update confirmation message indicating that the target cell is ready to provide a wireless communication service.

23. The target-cell eNodeB of claim 22 wherein the wireless communication service is multimedia broadcast multicast services (MBMS).

24. The target-cell eNodeB of claim 22 wherein the receiver is further configured to receive a second message acknowledging the first message requesting that the target cell be joined to a multicast distribution tree for providing the required services.

25. A method of providing service continuity for a wireless transmit and/or receive unit (WTRU), the method comprising:

transmitting, to a serving cell of an evolved Node-B (eNodeB), measurement reports associated with target cells of eNodeBs that neighbor the serving cell;

transmitting, to the serving cell, a radio resource control (RRC) message including an indication of multimedia broadcast multicast services (MBMS) frequencies the WTRU is currently and/or interested in receiving via a MBMS single frequency network (MBSFN);

receiving, from the serving cell, a handover command to handover to a neighboring target cell, the neighboring target cell being selected based, at least in part, on the indication of MBMS the WTRU is currently and/or interested in receiving;

transmitting, to the given target cell, a random access channel (RACH) preamble or RACH message;

receiving a RACH response from the given target cell; and

receiving, from the given target cell, MBMS including the MBMS previously being received from the serving cell.

26. The method of claim 25, wherein the handover command is received by way of an RRC connection reconfiguration message.

27. The method of claim 25, wherein the radio resource control (RRC) message is transmitted responsive to a change in the MBMS the WTRU is interested in receiving.

28. The method of claim 27, wherein the change in the MBMS the WTRU is interested in receiving includes a change to the WTRU being no longer interested in the MBMS frequencies the WTRU is currently receiving.

29. The method of claim 25, wherein the radio resource control (RRC) message is transmitted as part of RRC connection establishment.

30. The method of claim 25, wherein the radio resource control (RRC) message includes an indication of preference given to MBMS over unicast.

31. A wireless transmit and/or receive unit (WTRU) adapted for service continuity, the WTRU comprising a transmitter and receiver, wherein:

the transmitter is configured to;

transmit, to a serving cell of an evolved Node-B (eNodeB), measurement reports associated with target cells of eNodeBs that neighbor the serving cell; and

transmit, to the serving cell, a radio resource control (RRC) message including an indication of multimedia broadcast multicast services (MBMS) frequencies the WTRU is currently and/or interested in receiving via a MBMS single frequency network (MBSFN);

the receiver is configured to receive, from the serving cell, a handover command to handover to a neighboring target cell, the neighboring target cell being selected based, at least in part, on the indication of MBMS the WTRU is currently and/or interested in receiving;

the transmitter is configured to transmit, to the given target cell, a random access channel (RACH) preamble or RACH message;

the receiver is configured to;

receive a RACH response from the given target cell; and

receive, from the given target cell, MBMS including the MBMS previously being received from the serving cell.

32. The WTRU of claim 31, wherein the receiver is configured to receive the handover command by way of an RRC connection reconfiguration message.

33. The WTRU of claim 31, wherein the radio resource control (RRC) message is transmitted responsive to a change in the MBMS the WTRU is interested in receiving.

34. The WTRU of claim 33, wherein the change in the MBMS the WTRU is interested in receiving includes a change to the WTRU being no longer interested in the MBMS frequencies the WTRU is currently receiving.

35. The WTRU of claim 31, wherein the radio resource control (RRC) message is transmitted as part of RRC connection establishment.

36. The WTRU of claim 31, wherein the radio resource control (RRC) message includes an indication of preference given to MBMS over unicast