Modular digital telephone system with fully distributed local switching and control
First Claim
1. A method of switched communication between nodes, workstations and other resources of a modular digital telephone system and public network resources such as central office telephone lines, tie lines, private and hybrid wide area networks using shared time division multiplexed (TDM) highway signal paths comprising the steps of:
- mounting a plurality of circuit cards having selectable circuitry thereon in at least one card cage having a backplane;
interfacing the cards with the backplane of the card cage in which the cards are mounted;
forming a plurality of TDM highways, token passing communications media, Local Area Network (LAN) and Small Area Network (SAN), by interconnecting selected circuitry on said circuit cards on said backplane;
coupling resources to said cards permitting the intercommunication between said resources via said TDM highways;
dividing said signal paths on said TDM highways into time slots; and
performing all call processing between resources by exchanging requests directly on said token passing communications media, SAN and LAN, between the resources wishing to communicate whereby signaling between resources is directly exchanged without establishing a direct current connection or using a central processing unit.
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Accused Products
Abstract
A distributed digital telephone system is provided wherein a plurality of telephone consoles have instant access to a plurality of telephone lines wherein in all of the connections within such a system are non-blocking. The system architecture is that of a reverse ratio PBX in which the number of lines exceed the number of consoles and each handset has a reserved time slot on time division multiplex (TDM) highways for internal node or group connections. Accordingly, each handset is guaranteed access to idle lines within any given switching node. The distributed architecture is distinguished from central processing where all call processing is directed through a centralized point. In this decentralized system, all signal conditioning, protection, sensing and control are provided by the resource interface with the TDM highways. Resource data reporting is continually provided to all the resources connected to the system that require it. Redundancy of critical resources is provided in such a manner that only the portion of the system where a fault occurs is disabled while the remainder of the system continues to operate.
91 Citations
18 Claims
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1. A method of switched communication between nodes, workstations and other resources of a modular digital telephone system and public network resources such as central office telephone lines, tie lines, private and hybrid wide area networks using shared time division multiplexed (TDM) highway signal paths comprising the steps of:
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mounting a plurality of circuit cards having selectable circuitry thereon in at least one card cage having a backplane; interfacing the cards with the backplane of the card cage in which the cards are mounted; forming a plurality of TDM highways, token passing communications media, Local Area Network (LAN) and Small Area Network (SAN), by interconnecting selected circuitry on said circuit cards on said backplane; coupling resources to said cards permitting the intercommunication between said resources via said TDM highways; dividing said signal paths on said TDM highways into time slots; and performing all call processing between resources by exchanging requests directly on said token passing communications media, SAN and LAN, between the resources wishing to communicate whereby signaling between resources is directly exchanged without establishing a direct current connection or using a central processing unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A modular digital telephone system for providing switched communication between various communication resources such as telephone lines, workstations and other resources using shared time division multiplex TDM highway signal paths having time slots comprising:
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switching module means having card cage means, backplane means and digital card means mounted in said card cage and interfacing said digital card means with said backplane means; means for coupling telephone lines to said digital card means; means for coupling workstations having handset means connected thereto to said digital card means; first interconnecting means on said module backplane means for interconnecting said digital card means for forming a token passing communications media, a small area network (SAN), to provide a call control and signalling path for said telephone lines and workstations coupled thereto; second interconnecting means on said module backplane means for interconnecting said digital card means for forming TDM highways for carrying voice and data between said communication resources coupled to said digital card means; call processing means on said digital card means for directly exchanging calls between communication resources whereby communication can be established between resources in the modular digital telephone system without requiring a D.C. connection, a central processing unit or any type of a centralized point of control; link module means; means for interconnecting said switching module means with said link module means for providing an independent token passing communications media, a Local Area Network and TDM highways for interconnecting voice and data between said switching module means whereby said link module means provides a direct interconnection between the Local Arm Network and TDM highways of the switching module means. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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Specification