Method and apparatus for selecting a control channel based on service availability

• US 5,778,316 A
• Filed: 06/07/1995
• Issued: 07/07/1998
• Est. Priority Date: 11/01/1993
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Persson, Bengt, Turcotte, Joseph Eric
• Primary Examiner(s): Patel, Ajit
• Application Number:
  US08/478,735
• Time in Patent Office: 1,126 Days
• Field of Search: 370/95.1, 370/95.3, 370/84, 370/99, 370/94.1, 370/80, 370/50, 370/62, 370/337, 370/348, 370/332, 370/331, 379/59-62, 379/202, 340/825.44, 340/825.49, 455/33.1, 455/33.2, 455/33.3, 455/33.4, 455/34.1, 455/34.2, 455/35.1, 455/54.1, 455/54.2, 455/56.1, 455/62, 455/434, 455/450, 455/455, 455/515
• US Class Current: 455/434
• CPC Class Codes: H04B 7/2643 using time-division multiple access [TDMA] H04B7/2615, H04B7/2618 take precedence
• CPC Class Codes: H04B 7/2656 for structure of frame, burst
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0046 Code rate detection or code type detection H04L1/0038 takes precedence; detection of the data rate H04L25/0262; for packet format H04L1/0091
• CPC Class Codes: H04L 1/0056 Systems characterized by the type of code used H04L1/08 takes precedence
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/0072 Error control for data other than payload data, e.g. control data
• CPC Class Codes: H04L 1/0083 Formatting with frames or packets; Protocol or part of protocol for error control
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/1614 using bitmaps
• CPC Class Codes: H04L 1/1685 the supervisory signal being transmitted in response to a specific request, e.g. to a polling signal
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 1/1803 Stop-and-wait protocols
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• CPC Class Codes: H04L 1/1848 Time-out mechanisms
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 2001/0093 : Point-to-multipoint
• CPC Class Codes: H04L 9/40 : Network security protocols
• CPC Class Codes: H04W 36/30 : by measured or perceived connection quality data
• CPC Class Codes: H04W 48/10 : using broadcasted information
• CPC Class Codes: H04W 48/16 : Discovering, processing access restriction or access information
• CPC Class Codes: H04W 48/20 : Selecting an access point
• CPC Class Codes: H04W 52/0212 : managed by the network, e.g. network or access point is master and terminal is slave
• CPC Class Codes: H04W 52/0245 : according to signal strength
• 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 68/025 : Indirect paging
• CPC Class Codes: H04W 88/02 : Terminal devices
• CPC Class Codes: Y02D 30/70 : in wireless communication networks

Abstract

A communications system in which information is transmitted in a plurality of time slots grouped into a plurality of superframes which are, in turn, grouped into a plurality of paging frames. A remote station receives paging messages once in each paging frame.

Claims

1. A method for selecting a control channel in a radio communication network comprising the steps of:

receiving, at a remote station, an offset on a control channel;

evaluating, in said remote station, a plurality of control channels using a cell selection function to generate a cell selection value associated with each of said plurality of control channels, wherein said cell selection function subtracts said offset for control channels associated with cells that do not offer a desired service; and

selecting a control channel based on said cell selection value.

2. The method of claim 1, where in said remote station is a mobile station.

3. A method for selecting one control channel from a plurality of control channels by a mobile station comprising the steps of:

broadcasting a predetermined offset;

evaluating each of said plurality of control channels based upon a signal strength at which each control channel is received and an availability of a service using each control channel wherein a selection value associated with each control channel is lowered by a predetermined offset if a cell associated with said control channel does not offer said service; and

selecting said one control channel based on results of said evaluating step.

4. A remote station comprising:

means for evaluating a plurality of control channels using a cell selection function to generate a cell selection value associated with each of said plurality of control channels, wherein said cell selection function includes a parameter associated with a desired service and further including means for subtracting an offset received on a broadcast control channel in said cell selection function for control channels associated with cells that do not offer said desired service; and

means for selecting a control channel based on said cell selection value.

5. A remote station comprising:

means for evaluating each of a plurality of control channels based upon a signal strength at which each control channel is received and an availability of a service using each control channel wherein a selection value associated with each control channel is lowered by a predetermined offset received on a broadcast control channel if a cell associated with said control channel does not offer said service; and

means for selecting said one control channel based on results generated by said means for evaluating.