Patent EP0356012A2 successfully refreshed from Google Patents.
EP0356012A2
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EP
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TDM Demultiplexer
Assignee: NEC Corp
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Filing: 1989-07-25
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Granted: —
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Expires: 2009-07-25
Abstract
Abstract In a channel bank at one of TDM hierarchical levels, a TDM demultiplexer includes a plurality of high-speed interfaces connected respectively to high-speed digital transmission lines. Each interface receives detects a line fault and appends an alarm signal of a time-slot duration to time slots of digital signals. The outputs of the high-speed interfaces are multiplexed into a TDM frame sequency and the time slots of data signals in that TDM frame sequence are interchanged according to a prescribed rule. The slot-interchange frame sequence is demultiplexed into plurality of TDM signals greater in number than the number of high-speed interfaces. Low-speed interfaces respectively receive the demultiplexed TDM signals to detect the time slot in which the alarm signal is contained and transmits a line fault signal to a respective one of low-speed transmission lines.
Inventors
- 👤 Akifumi C/O Nec Corporation Yonehara
- 👤 Yoshio C/O Nec Telecom Systems Ltd. Yokose
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 23:50
CPC Classifications
H; H04; H04Q; H04Q11/00; H04Q11/04; H04Q11/08; H04J; H04J3/00; H04J3/02; H04J3/14
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
152 words
A TDM demultiplexer for a channel bank at one of TDM hierarchical levels, comprising: a plurality of high-speed interfaces connected respectively to high-speed digital transmission lines, each of said interfaces receiving TDM digital signals from the transmission line, detecting a line fault in said transmission line and generating an alarm signal indicating the line fault; a plurality of low-speed interfaces greater in number than the number of said high-speed interfaces, outputs of said low-speed interfaces being respectively coupled to low-speed transmission lines; and means for establishing data channels between the outputs of said high-speed interfaces and the inputs of said low-speed interfaces for passing said data signals from said high-speed transmission lines to said low-speed transmission lines and establishing maintenance channels between the outputs of said said high-speed interfaces and the inputs of said low-speed interfaces for passing the alarm signals from said high-speed transmission lines to said low speed transmission lines.
Claim 2
Dependent Claim
152 words
A TDM demultiplexer for a channel bank at one of TDM hierarchical levels, comprising: a plurality of high-speed interfaces connected respectively to high-speed digital transmission lines, each of said interfaces receiving TDM digital signals from the transmission line, detecting a line fault in said transmission line and generating an alarm signal indicating the line fault; a plurality of low-speed interfaces greater in number than the number of said high-speed interfaces, outputs of said low-speed interfaces being respectively coupled to low-speed transmission lines; and means for establishing data channels between the outputs of said high-speed interfaces and the inputs of said low-speed interfaces for passing said data signals from said high-speed transmission lines to said low-speed transmission lines and establishing maintenance channels between the outputs of said said high-speed interfaces and the inputs of said low-speed interfaces for passing the alarm signals from said high-speed transmission lines to said low speed transmission lines.
Claim 3
Dependent Claim
205 words
A TDM demultiplexer for a channel bank at one of TDM hierarchical levels, comprising: a plurality of high-speed interfaces connected respectively to high-speed digital transmission lines, each of said interfaces receiving TDM digital signals from the transmission line, detecting a line fault in said transmission line and appending an alarm signal of a time-slot duration indicating the line fault to time slots of said digital signals; time division multiplexer means for multiplexing the outputs of said high-speed interfaces into a first TDM frame sequence; time slot interchanging means for interchanging the time slots of data signals in said first TDM frame sequence according to prescribed relationships between the time slots of said high-speed transmission lines and those of low-speed transmission lines and generating therefrom a second TDM frame sequence; time division demultiplexer means for demultiplexing said second TDM frame sequence into plurality of TDM signals greater in number than the number of said high-speed interfaces; and a plurality of low-speed interfaces for respectively receiving the demultiplexed TDM signals from said time division demultiplexer means, each of said low-speed interfaces detecting the time slot in which said alarm signal is contained and transmitting a line fault signal to a respective one of said low-speed transmission lines.
Claim 4
Dependent Claim
205 words
A TDM demultiplexer for a channel bank at one of TDM hierarchical levels, comprising: a plurality of high-speed interfaces connected respectively to high-speed digital transmission lines, each of said interfaces receiving TDM digital signals from the transmission line, detecting a line fault in said transmission line and appending an alarm signal of a time-slot duration indicating the line fault to time slots of said digital signals; time division multiplexer means for multiplexing the outputs of said high-speed interfaces into a first TDM frame sequence; time slot interchanging means for interchanging the time slots of data signals in said first TDM frame sequence according to prescribed relationships between the time slots of said high-speed transmission lines and those of low-speed transmission lines and generating therefrom a second TDM frame sequence; time division demultiplexer means for demultiplexing said second TDM frame sequence into plurality of TDM signals greater in number than the number of said high-speed interfaces; and a plurality of low-speed interfaces for respectively receiving the demultiplexed TDM signals from said time division demultiplexer means, each of said low-speed interfaces detecting the time slot in which said alarm signal is contained and transmitting a line fault signal to a respective one of said low-speed transmission lines.
References Cited (Backward Citations)
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