WIRELESS NETWORK SYSTEM SELECTION MECHANISM WITHIN A MOBILE STATION

• US 20030017842A1
• Filed: 05/24/1999
• Published: 01/23/2003
• Est. Priority Date: 05/24/1999
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: MOLES, BRYAN JEFFERY, LEUNG, NIM KEUNG, WU, SING-WAI
• Granted Patent: US 6,961,583 B2
• Time in Patent Office: Days
• US Class Current: 455/552.1
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A multi-mode mobile station independently determines the radio signal quality of a serving mobile system by evaluating the error rate associated with the received forward-link-channel messages. In response to a determination that the calculated error rate is greater than an acceptable threshold level, the mobile station then attempts to access an alternative service system capable of providing better and more reliable telecommunications service.

Claims

1. A method within a multi-mode mobile station for communicating over a particular radio system wherein said multi-mode mobile station is capable of selectively communicating over a first radio system and a second radio system and wherein said first radio system is preferred over said second radio system, said method comprising the steps of:

determining whether said preferred first radio system is available to provide mobile service;

accessing said preferred first radio system;

receiving a plurality of messages over a control channel associated with said preferred first radio system;

determining the error rate associated with said plurality of messages;

comparing said determined error rate with a predetermined threshold value; and

if said determined error rate exceeds said predetermined threshold value, then

accessing said less preferred second radio system.

2. The method of claim 1 wherein said step of determining whether said preferred first radio system is available further comprises the step of determining whether an acceptable number of said messages are received within a predetermined time period.

3. The method of claim 1 wherein said step of determining whether said preferred first radio system is available further comprises the step of determining whether a pilot signal from said preferred first radio system is detectable.

4. The method of claim 1 wherein said messages are page channel (PCH) messages.

5. The method of claim 1 wherein said step of determining said error rate comprises the step of determining a Frame Error Rate (FER) associated with said plurality of messages.

6. The method of claim 5 wherein said step of determining said FER is performed while said multi-mode mobile station is in Idle state.

7. The method of claim 5 wherein said step of accessing said less preferred second radio system is performed after said determined FER exceeds said predetermined threshold value over a plurality of consecutive time periods.

8. A method of selecting a radio system within a multi-mode mobile station wherein said multi-mode mobile station is capable of selectively communicating over a first radio system and a second radio system, said method comprising the steps of:

accessing said first radio system by said multi-mode mobile station;

periodically receiving a message signal over a forward channel associated with said first radio system;

determining the number of message signals received within a first predetermined time period;

determining the error rate associated with said message signals received within a second predetermined time period; and

accessing said second radio system in response to a determination that the number of message signals received within said first predetermined time period meets a first threshold value, but that said error rate associated with said message signals exceeds a second threshold value.

9. The method of claim 8 wherein said step of receiving said message signal comprises the step of receiving a page message over a page channel (PCH).

10. The method of claim 8 wherein said step of determining said error rate comprises the step of determining a Frame Error Rate (FER) associated with said received message signals.

11. The method of claim 8 wherein said first radio system is preferred over said second radio system within said multi-mode mobile station.

12. The method of claim 11 wherein said first system comprises a Code Division Multiple Access (CDMA) system.

13. The method of claim 11 wherein said second system comprises a Advanced Mobile Phone System (AMPS).

14. The method of claim 8 wherein said step of determining said FER is performed while said multi-mode mobile station is in Idle state.

15. The method of claim 8 wherein said step of accessing said second radio system is performed after said determined FER exceeds said predetermined threshold value over a plurality of time periods.

16. The method of claim 8 wherein said second threshold value is determined by calculating a signal-to-noise ratio (Ec/Io) associated with a pilot channel.

18. The multi-mode mobile station of claim 17 wherein said messages received over said forward channel comprise page messages over a page channel (PCH).

19. The multi-mode mobile station of claim 17 wherein said means for determining said error rate associated with said received messages comprises means for determining a Frame Error Rate (FER) associated with said messages.

20. The multi-mode mobile station of claim 17 wherein said threshold value is determined by calculating a signal-to-noise ratio (Ec/Io) associated with a pilot channel.

17. A multi-mode mobile station for selectively communicating over a first radio system and a second radio system wherein said first radio system is preferred over said second radio system, comprising:

means for determining whether said first radio system is available to provide service;

means for accessing said first radio system;

means for receiving messages over a forward channel associated with said first radio system;

means for determining an error rate associated with said received messages;

means for comparing said determined error rate against a particular threshold value; and

means for accessing said second radio system in response to a determination that said determined error rate exceeds said particular threshold value.