CELL ACCESS RESTRICTION AND WTRU ACCESS CLASS OPTIMIZATION IN LTE SYSTEM INFORMATION

• US 20080200146A1
• Filed: 01/30/2008
• Published: 08/21/2008
• Est. Priority Date: 01/30/2007
• Status: Abandoned Application

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Wang, Peter S., Wang, Jin, Olvera-Hernandez, Ulises
• Application Number:
  US12/022,528
• Publication Number:
  US 20080200146A1
• Time in Patent Office: Days
• US Class Current: 455/410
• CPC Class Codes: H04J 11/0069 Cell search, i.e. determining cell identity [cell-ID] design of multiplexing codes H04J13/00; processing access restriction or access information H04W48/16; discovery of network devices for network data management H04W8/005; sounding signals for channel estimation H04L25/0226; structure of reference signals in multicarrier modulation systems H04L27/2613; frame, time or carrier synchronisation in multicarrier modulation systems H04L27/2655
• CPC Class Codes: H04W 48/02 Access restriction performed under specific conditions
• CPC Class Codes: H04W 48/12 using downlink control channel

Abstract

A method and apparatus for cell access restriction, wherein a new access class (AC) definition including a WTRU barred-bit assignment is assigned during cell subscription. A cell access restriction information element (IE) is then broadcast when an operator is restricting access to a cell. The WTRU then can determine whether a cell is restricted based on a comparison of the cell access restriction IE to the barred-bit definition. A base station (BS) is able to transmit the new cell access restriction IE in a fast-read master information block (MIB).

Claims

1. A method for cell access restriction of a wireless transmit/receive unit (WTRU), the method comprising:

transmitting a cell access restriction information element (IE) in a fast-read master information block (MIB).

2. The method of claim 1, wherein the cell access restriction IE comprises at least one cell restriction status variable selected from Barred to All, Barred for PLMN Maintenance, and Barred Reselection Possible;

and

restricting cell access based on a value of the at least one cell restriction status variable.

3. The method of claim 2, wherein the value of the at least one cell restriction status variable includes at least one of the following indications:

the cell is accessible;

the cell is barred to the WTRU;

the cell access is restricted to allow access only to a WTRU used for maintenance; and

the cell is barred for a limited amount of time.

4. The method of claim 3, wherein if the cell is barred to the WTRU for a limited amount of time, the at least one cell restriction status variable value includes a time interval indicating a period of time for which the cell is barred.

5. The method of claim 2, further comprising:

transmitting an indication that a WTRU is allowed to select a new cell.

6. The method of claim 1, wherein the MIB further comprises a load factor for the cell.

7. A method for cell access restriction, the method comprising:

receiving at least one access class (AC) definition including a WTRU barred-bit assignment;

receiving a broadcast including at least one cell access restriction information element (IE); and

determining whether a cell is restricted based on a comparison of the at least one cell access restriction IE to the WTRU barred-bit assignment.

8. The method of claim 7, wherein the cell access restriction IE is contained in a system information block (SIB).

9. The method of claim 7, wherein the cell access restriction IE is contained in a master information block (MIB).

10. The method of claim 7, wherein the cell access restriction IE is contained in a long term evolution signaling unit (SU).

11. A method for cell access restriction of a wireless transmit/receive unit (WTRU) for emergency call handling, the method comprising:

determining a priority order based on an assigned access class (AC) definition, where the assigned AC definition includes at least one of the following;

ordinary user;

public utilities;

security services;

emergency services;

Public Land Mobile Network (PLMN) use; and

PLMN staff;

transmitting a barred bit based on the assigned AC definition; and

transmitting a cell access restriction information element (IE) having a cell access restriction status and a cell access emergency call barred status.

12. The method of claim 11, wherein the security services and the emergency services ACs have the same priority order.

13. The method of claim 11, wherein PLMN use and PLMN staff have the same priority order.

14. The method of claim 13, wherein the ordinary user'"'"'s AC definition includes at least one of the following:

home PLMN (HPLMN) users; and

visiting PLMN (VPLMN) users;

wherein the HPLMN users have higher priority than VPLMN users.

15. The method of claim 11, wherein the cell access restriction IE is transmitted in a first system information block (SIB), whereby a WTRU reads the first SIB for cell selection and PLMN selection.

16. The method of claim 11, further comprising:

barring cell access on an AC having a higher priority order AC in order to indicate that all the lower priority order ACs are barred from emergency calls.

17. The method of claim 16, further comprising:

including a cell load factor in the long term evolution (LTE) first-to-read SIB if the cell is not barred for access.

18. A base station (BS), the BS comprising:

a processor configured to determine an access class assignment; and

a transmitter configured to transmit a cell access restriction information element (IE) in a fast-read master information block (MIB).

19. The BS of claim 18, wherein the cell access restriction IE comprises at least one cell restriction status variable selected from Barred to All, Barred for PLMN Maintenance, and Barred Reselection Possible;

and

the processor is further configured to restrict cell access based on a value of the at least one cell restriction status variable.

20. The BS of claim 19, wherein the value of the at least one cell restriction status variable includes at least one of the following indications:

the cell is accessible;

the cell is barred to the WTRU;

the cell access is restricted to allow access only to a WTRU used for maintenance; and

the cell is barred for a limited amount of time.

21. The BS of claim 20, wherein if the cell is barred to the WTRU for a limited amount of time, the cell restriction status variable value includes a time interval indicating the period of time for which the cell is barred.

22. The BS of claim 19, wherein the transmitter is further transmit to receive an indication that the WTRU is allowed to select a new cell.

23. The BS of claim 18, wherein the MIB further comprises a load factor for the cell.

24. A wireless transmit/receive unit (WTRU), the WTRU comprising:

a receiver configured to receive at least one access class (AC) definition including a WTRU barred-bit assignment and to receive a broadcast including at least one cell access restriction information element (IE); and

a processor configured to determine whether a cell is restricted based on a comparison of the at least one cell access restriction IE to the WTRU barred-bit assignment.

25. The WTRU of claim 24, wherein the cell access restriction IE is contained in a system information block (SIB).

26. The WTRU of claim 24, wherein the cell access restriction IE is contained in a master information block (MIB).

27. The WTRU of claim 24, wherein the cell access restriction IE is contained in a long term evolution (LTE) signaling unit (SU).

28. A base station (BS), the BS comprising:

a processor configured to determine a priority order based on an assigned access class (AC) definition, where the assigned AC definition includes at least one of the following;

ordinary user;

public utilities;

security services;

emergency services;

Public Land Mobile Network (PLMN) use; and

PLMN staff;

a transmitter configured to transmit a barred bit based on the assigned AC definition and to transmit a cell access restriction information element (IE) having a cell access restriction status and a cell access emergency call barred status.

29. The BS of claim 28, wherein the security services and the emergency services ACs have the same priority order.

30. The BS of claim 28, wherein PLMN use and PLMN staff have the same priority order.

31. The BS of claim 30, wherein the ordinary user'"'"'s AC definition includes at least one of the following:

home PLMN (HPLMN) users; and

visiting PLMN (VPLMN) users;

wherein the HPLMN users have higher priority than VPLMN users.

32. The BS of claim 28, wherein the transmitter is further configured to transmit the cell access restriction IE in a first system information block (SIB), whereby a WTRU reads the first SIB for cell selection and PLMN selection.

33. The BS of claim 28, further comprising:

a processor configured to bar cell access on an AC having a higher priority order AC in order to indicate that all the lower priority order ACs are barred from emergency calls.

34. The BS of claim 33, wherein the transmitter is further configured to transmit a cell load factor in the long term evolution (LTE) first-to-read SIB only if the cell is not barred for access.