US 4,377,859 A · Time slot interchanger and control processor apparatus for use in a telephone switching network

Abstract

A telephone switching network is disclosed, which network is adapted to provide connections between a plurality of input subscriber lines. The network includes a time slot interchanger which comprises a transmit switch memory and a receive switch memory. The transmit and receive memories are capable of storing data at addressable storage locations, which data is indicative of digital data to be transmitted from a line circuit and digital data to be received by a line circuit during a connection between the two line circuits. A connect memory is also employed for storing data indicative of connections to be made between line circuits. The connect memory as well as the switch memories are controlled in operation by a processor, which processor includes an access control means. The processor and the access control means are operative to cause the connect memory to couple corresponding storage locations of the transmit and receive memories indicative of one subscriber line to corresponding storage locations indicative of another subscriber line. In this manner, any line associated with the system can communicate with any other line. A trunk interface is provided to enable each subscriber associated with a first switching network as above described to communicate with other subscribers associated with an identical switching network via a communications link or trunk. Also disclosed is a unique data format to enable the use of an asynchronous trunk for communication between two or more switching systems of the above described configuration. The data format enables easy detection and recognition of null characters, control characters and data characters by utilizing a unique eight digit format for each of the above described characters.

Claims24

Dependent claims

A telephone switching network of the type adapted to provide connections between a plurality of input subscriber line terminals, comprising:

a time slot interchanger means, including a first transmit switch memory (41) having a first plurality of storage locations each associated with a specific address indicative of a given subscriber terminal for storing at said location data to be transmitted by said line, a second receive switch memory (42) having a second plurality of storage locations each associated with a specific address indicative of a given subscriber terminal for storing at said location data to be received by said line,
a connect memory (43) having a plurality of storage locations therein for storing data indicative of connections to be made between subscriber terminals, with each of said locations capable of being accessed by a given address for said location,
subscriber terminal interface means (40) having input terminals coupled to said plurality of subscribers and output terminals coupled to said first and second memories (41 and 42) with certain of said output terminals as coupled to said first memory providing transmitted data, and other terminals coupled to said second memory for receiving data,
processing means coupled to said subscriber terminal interface means, said first and second memories and said connect memory and adapted to direct all transmitted data emanating from said certain output terminals of said interface means to said first memory locations, and all received data emanating from said second storage locations to said other terminals, said processing means including access control means for controlling said connect memory to couple any of said first and second storage locations associated with any one subscriber terminal to any other of said first and second storage locations associated with another subscriber terminal via said interface means and according to an address stored in said connect memory, whereby any two subscriber terminals are capable of communicating with each other.

1 more element

A telephone switching network system of the type adapted to provide connections between a plurality of local and remote subscriber terminals, comprising:

a first time slot interchanger means, including a transmit switch memory having a plurality of storage locations each associated with a specific address indicative of a given local subscriber terminal for storing at said locations data to be transmitted by said subscriber line, a second receive switch memory having a plurality of storage locations each associated with a specific address indicative of a given subscriber terminal for storing at said locations, data to be received by said lines,
a first connect memory having a plurality of storage locations therein for storing data indicative of connections to be made between subscriber terminals, with each of said locations capable of being accessed by a given address for said location,
first subscriber terminal interface means having input terminals coupled to said plurality of local subscriber terminals and output terminals coupled to said transmit and receive memories, with certain of said output terminals as coupled to said transmit memory providing transmitted data and other terminals coupled to said receive memory for receiving data.
first processing means coupled to said first subscriber terminal interface means, said transmit and receive memories and said connect memory and adapted to direct all transmitted data emanating from said certain output terminals of said interface means to said transmit storage locations, and all receive data emanating from said receive storage locations to said other terminals, said processing means including access control means for controlling said connect memory to access any of desired ones of said transmit and receive storage locations,
first accessible trunk interface means coupled to said transmit and receive memories and to said first processing means for receiving stored transmit data from said transmit means and for sending received data to said receive memory,
a communications link having one end coupled to said first interface means and having a data transmit path for sending data and data receive path for receiving data,
a remote accessible trunk interface means coupled to said communications link at said other end with a receive data path connected to said data transmit path of said first trunk interface and a transmit path connected to said data receive path of said first trunk interface means whereby communications via said communications link can occur between said trunk interface means, and
a remote switching network coupled to said remote accessible trunk interface means for connecting a second plurality of remote subscriber terminals associated with said remote system to said remote trunk interface means to enable communications between any one of said remote subscribers with one of said local subscribers.

5 more elements

Dependencies are inferred from the claim text.

Time slot interchanger and control processor apparatus for use in a telephone switching network

Life of this patent

Time slot interchanger and control processor apparatus for use in a telephone switching network

Life of this patent

Abstract

Claims24