Cellular mobile telephone network and method of operating the same

• US 20010046864A1
• Filed: 03/13/2001
• Published: 11/29/2001
• Est. Priority Date: 03/14/2000
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Bhatoolaul, David Lahiri, Charriere, Patrick Georges Venceslas, Cao, Qiang, Lim, Seau Sian
• Granted Patent: US 6,788,940 B2
• Time in Patent Office: Days
• US Class Current: 455/442
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 52/04 TPC
• CPC Class Codes: H04W 74/0866 using a dedicated channel for access

Abstract

A cellular mobile telephone network is disclosed in which a mobile station requests service in data modulated on a common random access channel (RACH) in a format associated with first a cell in which the mobile station is located. Base stations in cells neighbouring the first cell, are configured to demodulate the RACH message burst having the format associated with the first cell, and to pass the demodulated data to a radio network controller (RNC). This enables the average power required for a successful RACH transmission to be reduced.

Claims

1. A cellular mobile telephone network, wherein a mobile station requests service in data modulated on a common random access channel (RACH) in a format associated with first a cell in which the mobile station is located, and wherein base stations in cells neighbouring the first cell, are configured to demodulate the RACH message burst having the format associated with the first cell, and to pass the demodulated data to a radio network controller (RNC).

2. A cellular mobile telephone network as claimed in

claim 1

, wherein said data is sent in separate preamble and message bursts;

and wherein a radio network controller (RNC) is responsive to receipt of the preamble burst, to instruct base stations in the neighbouring cells to demodulate the RACH message burst having the format associated with the first cell, and to pass the demodulated data to a radio network controller (RNC).

3. A network as claimed in

claim 2

, in which the RNC is operative to determine from the propagation delay of a data burst from a mobile station located in the first cell, whether the mobile station is in a handover region and, if it is in a handover region, to instruct base stations in neighbouring cells to which the mobile station may move from the handover region, to demodulate the RACH message burst having the format associated with the first cell, and to pass the demodulated data to a radio network controller (RNC) as said.

4. A network as claimed in

claim 1

or

2

, wherein the mobile station is operative to compare the signal strengths of transmissions received from different base stations to determine whether or not it is in a handover region, and to send RACH data with one of a reserved set of physical channel attributes if the base station is in the handover region.

5. A network as claimed in

claim 4

, wherein the RNC is operative to instruct a base station in the first cell to assign first hardware to search for RACH data having the physical channel attributes belonging to mobile stations located in a handover region, and to assign second hardware to search for RACH data having the physical channel attributes belonging to mobile stations located in a non-handover region.

6. A network as claimed in

claim 5

, wherein the RNC is operative to instruct a base station in a neighbouring cell to assign hardware to search for RACH data having a format associated with the first cell and physical channel attributes belonging to mobile stations located in a handover region.

7. A method of operating a cellular mobile telephone network, comprising;

sending a request for service from a mobile station by means of data modulated on a common random access channel (RACH) in a format associated with first a cell in which the mobile station is located, and at base stations in cells neighbouring the first cell, demodulating the RACH message burst having the format associated with the first cell, and passing the demodulated data to a radio network controller (RNC).

8. A method as claimed in

claim 7

, wherein said data is sent in separate preamble and message bursts;

and including responding to receipt by the RNC of the preamble burst, to instruct base stations in the neighbouring cells to demodulate the RACH message burst having the format associated with the first cell, and to pass the demodulated data to a radio network controller (RNC).

9. A method as claimed in

claim 8

, including determining from the propagation delay of a data burst from a mobile station located in the first cell, whether the mobile station is in a handover region and, if it is in a handover region, instructing base stations in neighbouring cells to which the mobile station may move from the handover region, to demodulate the RACH message burst having the format associated with the first cell, and to pass the demodulated data to a radio network controller (RNC) as said.

10. A method as claimed in

claim 8

or

9

, including comparing the signal strengths of transmissions received from different base stations to determine whether or not it is in a handover region, and to sending RACH data with one of a reserved set of physical channel attributes if the base station is in the handover region.

11. A network as claimed in

claim 10

, including instructing a base station in the first cell to assign first hardware to search for RACH data having the physical channel attributes belonging to mobile stations located in a handover region, and to assign second hardware to search for RACH data having the physical channel attributes belonging to mobile stations located in a non-handover region.

12. A network as claimed in

claim 11

, including instructing a base station in a neighbouring cell to assign hardware to search for RACH data having a format associated with the first cell and physical channel attributes belonging to mobile stations located in a handover region.

13. A computer program for carrying out the method of any of

claims 7

to

9

.