ISDN private local switching system
AssigneeNEC Corporation
InventorMasahito Fujioka
Life of this patent
Estimating the term…
Abstract
In a private branch exchange connected to an Integrated Services Digital Network, an ISDN user interface unit separates a signal from each user terminal into a B-channel packet and a D-channel packet and further separates the latter into a signaling message and a D-channel packet mode signal. The separated D-channel packet mode signal is multiplexed with D-channel packet mode signals from other user terminals into a D-channel packet mode multiplex signal and applied through a channel to an ISDN network interface unit, while the signaling message is applied to a controller for processing. In the ISDN network interface unit, the D-channel packet mode multiplex signal is multiplexed with the signaling message processed by the controller into an outgoing D-channel signal and transmitted with the B-channel packet to the ISDN.
Claims7
A private local switching system connected to an Integrated Services Digital Network (ISDN) which supports B-channel and D-channel packet transmission rates, comprising:
- an ISDN user interface circuit connected to user terminals, each of said user terminals transmitting a signal comprising a B-channel packet and a D-channel packet, said D-channel packet comprising a signaling message and a D-channel packet mode signal, said ISDN user interface circuit comprising:
- a plurality of first separator means corresponding respectively with said user terminals, each of said first separator means separating the B-channel packet and the D-channel packet of a signal transmitted from said corresponding user terminal;
- second separator means, connected to receive D-channel packets from said plurality of said first separator means for separating the signaling message and the D-channel packet mode signal of each of said D-channel packets;
- first multiplexer means connected to receive the D-channel packet mode signal of each of said user terminals from said second separator means for multiplexing said D-channel packet mode signals from all of said user terminals into a D-channel packet mode multiplex signal;
- a controller connected to receive the signaling messages of each of said user terminals from said second separator means for processing said signaling messages and producing a control signal;
- switching means connected to receive B-channel packets from said plurality of first separator means for switching said B-channel packets and for switching individual components of said D-channel packet mode multiplex signal according to said control signal;
- and
- an ISDN network interface circuit comprising:
- second multiplexer means connected to receive said control signal for multiplexing said signaling messages from each of said first separator means processed by said controller with a corresponding one of said individual components of said D-channel packet mode multiplex signal received from said switching means into an outgoing D-channel signal;
- and
- means connected to receive said B-channel packets from said switching means for receiving a particular B-channel packet and said outgoing D-channel signal from said second multiplexer means corresponding to said particular B-channel packet and transmitting said particular B-channel packet with said received outgoing D-channel signal to said Network.
Dependencies are inferred from the claim text.