Fault detection in a frequency duplexed system
First Claim
1. In a frequency duplexed communication system operating with a downlink frequency band and an uplink frequency band, comprising a communication station having a duplexing means, said system further comprising a downlink path to said duplexing means and an uplink path from said duplexing means, a fault diagnostic system comprising:
- a) a test generating means for producing a test signal and feeding said test signal into said downlink path, said test signal having frequencies between said downlink frequency band and said uplink frequency band; and
b) a detecting means for detecting at a point on said uplink path said test signal fed through said downlink path which leaks through said duplexing means of said communication station and into said uplink path, wherein the detected portion of said test signal indicating operability status of said frequency duplexed communication system.
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0 Petitions
Accused Products
Abstract
A frequency band, or test band, located between the uplink and downlink frequency bands of a distributed, frequency duplexed network is used in a novel way to isolate block-level faults within the network. A test signal having frequencies within the test signal band is generated and fed into a downlink path of a branch of the communication network. When the test signal encounters a remote station having duplexing means, the test signal leaks through the duplexing means into an uplink path of the remote station. This occurs because the real filters of the duplexing means do not work perfectly, frequencies outside of the uplink and downlink bands, especially those in the test signal band, will leak through its components. The amount of attenuation of the test signal in leaking through the communication station indicates the operability status of the components therein. By monitoring the power level of the test signal in the uplink and downlink paths of the branch, faults can be quickly isolated.
151 Citations
32 Claims
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1. In a frequency duplexed communication system operating with a downlink frequency band and an uplink frequency band, comprising a communication station having a duplexing means, said system further comprising a downlink path to said duplexing means and an uplink path from said duplexing means, a fault diagnostic system comprising:
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a) a test generating means for producing a test signal and feeding said test signal into said downlink path, said test signal having frequencies between said downlink frequency band and said uplink frequency band; and b) a detecting means for detecting at a point on said uplink path said test signal fed through said downlink path which leaks through said duplexing means of said communication station and into said uplink path, wherein the detected portion of said test signal indicating operability status of said frequency duplexed communication system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of fault diagnostics for a frequency duplexed communication network operating on a downlink frequency band and an uplink frequency band, said communication network comprising a downlink path and an uplink path, said uplink path and said downlink path having a coupling means allowing signals of frequencies between said uplink frequency band and said downlink frquency band to travel from said downlink path to said uplink path, said method comprising the following steps:
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a) feeding a test signal into said downlink path, said test signal having frequencies between said downlink frequency band and said uplink frequency band; and b) detecting on said uplink path said test signal fed through said downlink path which leaks through said coupling means and into said uplink path, wherein the detected test signal indicating operability status of said frequency duplexed communication network. - View Dependent Claims (15, 16, 17)
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18. In a frequency duplexed communication network, operating with a downlink frequency band and an uplink frequency band, a fault diagnostic system for a branch of said communication network, said branch comprising a principal communication station having a principal downlink connection and a principal uplink connection to said network, said branch further comprising a secondary downlink connection and a secondary uplink connection from said principal communication station, said fault diagnostic system comprising:
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a) a test signal generating means for producing a test signal and feeding said test signal into said branch through said principal downlink connection of said branch whereupon said test signal travels into said principal communication station and into said secondary downlink connection, said test signal having frequencies between said downlink frequency band and said uplink frequency band; b) a coupling means between said secondary downlink connection and said secondary uplink connection whereby signals having frequencies between said downlink frequency band and said uplink frequency band may leak through to said secondary uplink connection; and c) a detecting means for detecting said test signal which leaks through said coupling means to said secondary uplink connection. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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Specification