Transmission line switch-over control system

• US 6,141,532 A
• Filed: 12/02/1998
• Issued: 10/31/2000
• Est. Priority Date: 12/03/1997
• Status: Expired due to Fees

• Current Assignee: KDDI Corporation
• Original Assignee: KDD Corporation (KDDI Corporation)
• Inventors: Mizuike, Takeshi, Konishi, Satoshi, Kishi, Yoji
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): Jackson, Blane J.
• Application Number:
  US09/204,637
• Time in Patent Office: 699 Days
• Field of Search: 455/8, 455/445, 455/3.1, 455/63, 455/501, 455/226.1, 455/226.3, 379/93.31, 379/165, 379/166, 379/163, 379/164, 379/15, 379/16, 340/825.03, 340/825.01, 340/825.16, 370/216, 370/225, 370/227, 370/228
• US Class Current: 455/8
• CPC Class Codes: H04B 1/74 for increasing reliability, e.g. using redundant or spare channels or apparatus replacing by standby devices for amplifiers H03F1/52, H03F1/542

Abstract

There is provided a transmission line switch-over control system capable of significantly improving the nonoperational situation such as circuit disconnection during call or call quality deterioration without conducting unnecessary switch-over of a circuit or a transmission line.

A line quality input data handler 5 acquires at least one transmission line quality data out of a received level, a received C/N, and a bit error rate of a normal transmission line 3 and sends it to a forecaster 6. The forecaster 6 produces estimated data of situation of transmission line based on the input quality data of the transmission line. A switch-over controller 7 presumes possibility that the line quality will deteriorate within a predetermined time such as, for example, the mean call holding time. If the presumed possibility of deterioration is larger than a predetermined decision threshold, the switch-over controller effects control so as to switch over the normal transmission line 3 to a back-up transmission line 4. On the other hand, if the possibility of deterioration of the normal transmission line 3 becomes smaller than the above described decision threshold when the back-up transmission line 4 is in use, the switch-over controller effects control so as to switch back to the normal transmission line 3.

Claims

1. A transmission line switch-over control system having a normal transmission line and a back-up transmission line, said transmission line switch-over control system effecting control so as to switch over from said normal transmission line or a circuit accommodated in said normal transmission line to said back-up transmission line according to line quality of said normal transmission line, said transmission line switch-over control system comprising:

forecaster means for producing estimated data of line quality of transmission line of said normal transmission line; and

switch-over control means for presuming possibility that the line quality will deteriorate within a predetermined time from a decision time point based upon estimated data produced by said forecaster means and for effecting the switch-over control based upon said presumed possibility,

wherein said transmission line switch-over control system switches over said normal transmission line or the circuit accommodated in said normal transmission line to said back-up transmission line or communicates necessity of said switch-over, prior to occurrence of quality deterioration or circuit disconnection by using a switch-over control signal from said switch-over control means.

2. A transmission line switch-over control system according to claim 1 wherein said switch-over control means evaluates probability that estimated data of the normal transmission line quality deteriorates below a predetermined permissible value within a predetermined time, and decides to switch back said normal transmission line to the back-up transmission line when said possibility is larger than a decision threshold.

3. A transmission line switch-over control system according to claim 1, wherein said estimated data comprises an estimated value and a confidence interval of the line quality.

4. A transmission line switch-over control system according to claim 1, wherein said estimated data is an estimated value of the line quality.

5. A transmission line switch-over control system according to claim 1, wherein said estimated data is produced by using at least one transmission line quality data out of a received level, a received C/N, and a bit error rate of the normal transmission line.

6. A transmission line switch-over control system according to claim 5, wherein said transmission line quality data is acquired at time intervals depending upon a quality requirement of the circuit accommodated in said normal transmission line.

7. A transmission line switch-over control system having a normal transmission line and a back-up transmission line, said transmission line switch-over control system effecting control so as to switch over from said normal transmission line or a circuit accommodated in said normal transmission line to said back-up transmission line according to line quality of said normal transmission line, said transmission line switch-over control system comprising:

forecaster means for producing estimated data of line quality of transmission line of said normal transmission line in such a state that switch-over to the back-up transmission line has been conducted; and

switch-over control means for judging the possibility that the line quality will deteriorate within a predetermined time to have disappeared and effecting switch-over control based thereupon,

wherein said transmission line switch-over control system switches back the circuit previously switched over to the back-up transmission line to the normal transmission line again or urges operators to switch over by using a switch-over control signal from said switch-over control means.

8. A transmission line switch-over control system according to claim 7, wherein in such a state that switch-over to the back-up transmission line has been conducted, said switch-over control means evaluates probability that estimated data of the normal transmission line quality deteriorates below a predetermined permissible value within a predetermined time, and decides to switch back to the normal transmission line again when said deterioration possibility has become smaller than a decision threshold.

9. A transmission line switch-over control system according to claim 7, wherein said estimated data comprises an estimated value and a confidence interval of the line quality.

10. A transmission line switch-over control system according to claim 7, wherein said estimated data is an estimated value of the line quality.

11. A transmission line switch-over control system according to claim 7, wherein said estimated data is produced by using at least one transmission line quality data out of a received level, a received C/N, and a bit error rate of the normal transmission line.

12. A transmission line switch-over control system according to claim 11, wherein said transmission line quality data is acquired at time intervals depending upon a quality requirement of the circuit accommodated in said normal transmission line.