Modular switching network for telecommunication system

• US 4,597,075 A
• Filed: 06/12/1985
• Issued: 06/24/1986
• Est. Priority Date: 08/21/1981
• Status: Expired due to Fees

• Current Assignee: Italtel Societa Italiana Telecomunicazioni SPA (Abaco Innovazione SPA)
• Original Assignee: Italtel Societa Italiana Telecomunicazioni SPA (Abaco Innovazione SPA)
• Inventors: Israel, John W.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Rokoff, Kenneth I.
• Application Number:
  US06/744,129
• Time in Patent Office: 377 Days
• Field of Search: 370/58, 370/59, 370/63, 370/64, 370/67, 370/85, 370/94
• US Class Current: 370/366
• CPC Class Codes: H04Q 11/04 for time-division multiplexing H04Q11/0001 takes precedence

Abstract

A plurality of routing modules in a switching network of a telecommunication system each includes several interfaces connected to a first channel concentrator via respective data stores receiving and temporarily memorizing incoming data words coding the voltage levels of message samples from associated peripheral units served by the respective interface. In response to commands from a control unit, included in the module, this first concentrator selectively transmits memorized data words in respective phases of a PCM frame to all the modules in the network. Outgoing data words issuing from any routing module are registered in other data stores and selectively extracted therefrom by a second channel concentrator under instructions from the control unit, the extracted data words being distributed by a channel expander commanded by the control unit to registers assigned to respective peripheral units. The contents of these latter registers are read in a predetermined sequence to the interfaces for transmission to the peripheral units in response to instructions generated by the control unit. A PCM frame has 32 time slots of 8 phases each, the maximum number of peripheral units served by each interface being equal to the number of phases per PCM frame, i.e. 256. A conference bridge may be provided in each module for the implementation of multiparty calls between telephone subscribers.

Claims

1. A modular switching unit network adapted to facilitate selective message transmission among a multiplicity of peripheral units of a telecommunication system, comprising:

a plurality of signal-routing modules each having a set of input/output terminals divided into a plurality of subsets and connected to respective peripheral units of a group of such units divided into a plurality of subgroups, said peripheral units being individually associated with each module;

a control unit in each module;

a plurality of interfaces in each module each connected to a plurality of peripheral units in a respective subgroup of the associated group via corresponding subsets of said set of terminals;

first register means in each of said interfaces for temporarily storing incoming m-bit data words representing message samples of PCM channels received from the associated subgroup of peripheral units in respective time slots of an operating cycle coinciding with a recurrent PCM frame divided into a multiplicity of phases, each of said time slots accommodating a PCM frame and encompassing m phases;

first channel-concentrating means in each module with first input connections to said first register means of all said interfaces and with a number of first output less than the number of said first input connections carrying in each phase the bits of an incoming data word extracted from said first register means in response to instructions from each control unit;

second register means in each module with inputs connected to said first outputs of all said modules for temporarily storing the data words carried thereon in each phase;

second channel-concentrating means in each module with input connections to said second register means and with a number of second outputs less than the number of said second input connections carrying in each phase the bits of an outgoing data word extracted from said second register means in response to instructions from said control unit;

third register means in each of said interfaces for temporarily storing outgoing data words destined for peripheral units in the associated subgroup; and

distributing means in each module inserted between said second channel-concentrating means and said interfaces for selectively feeding outgoing data words from said second outputs to said third register means in response to instructions from said control unit, said third register means being responsive to instructions from said control unit for directing message samples corresponding to the stored outgoing data words in successive time slots to designated peripheral units of the associated subgroup, said distributing means including channel-expanding means and a plurality of data stores with output connections to said third register means in respective interfaces, said channel-expanding means entering outgoing data words destined for any of said interfaces in the corresponding data stores.

2. A network as defined in claim 1 wherein each of said interfaces further includes transcoding means inserted between said input/output terminals and said first register means for converting analog message samples into digital data words and vice versa.

3. A network as defined in claim 1 or 2 wherein said first register means includes conversion means for supplementing each incoming m-bit data word with additional bits constituting a corrective code and for reading out the resulting bit combination in parallel to said first channel-concentrating means.

4. A network as defined in claim 1 or 2 wherein each of said register means comprises a multiplicity of register pairs, the registers of each pair being alternately enabled by said control unit for the reception of data words to be stored and for the emission of the data words so stored.

5. A network as defined in claim 1 or 2 wherein the number of said input/output terminals in each subset is at most equal to the number of phases in each PCM frame.

6. A network as defined in claim 1 or 2 wherein each module further includes a conference bridge addressable by said second outputs under instructions from said control unit for emitting the algebraic sum of data words from several channels, extracted from said second register means during a given operating cycle, to said distributing means.

7. A network as defined in claim 1 or 2, wherein said data stores include conversion means for reading out each m-bit data word in series, corrected according to the associated additional bit.