Telecommunications interface

• US 4,748,618 A
• Filed: 05/21/1986
• Issued: 05/31/1988
• Est. Priority Date: 05/21/1986
• Status: Expired due to Term

• Current Assignee: Telcordia Technologies Incorporated (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Bell Communications Research, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Brown, Earl F., Kline, Robert V.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Marcelo, Melvin
• Application Number:
  US06/865,871
• Time in Patent Office: 741 Days
• Field of Search: 379/53, 379/54, 379/202, 358/85, 370/60, 370/62, 370/94, 370/84, 370/99
• US Class Current: 370/419
• CPC Class Codes: H04L 12/56 Packet switching systems
• CPC Class Codes: H04N 7/15 Conference systems
• CPC Class Codes: H04N 7/152 Multipoint control units therefor
• CPC Class Codes: Y10S 379/908 Multimedia

Abstract

A telecommunications interface is disclosed. The inventive telecommunications interface is capable of collecting multiple asynchronous video, audio, graphic and data signals from a variety of different kinds of sources and retransmitting such signals in a suitable form for display or detection with one or more types of receiver equipment at one or more locations. The interface operates at rates ranging from several hundred bits per second to several gigabits per second.

The telecommunications interface includes a dual port RAM whose input and output operate asynchronously. Signals from the user sources are stripped of timing and source identification information and are written into the dual port RAM, while output processors read previously stored user signals out from the dual port RAM. The output processor appropriately format the retrieved signals, which are then transmitted to the receiver equipment.

Claims

1. A telecommunications interface for receiving asynchronous input data packets at preselected input bit rates and employing preselected input protocols from one or more user sources and for retransmitting the input data at preselected output bit rates and employing preselected output protocols compatible with the requirements of one or more reeiving devices,

said telecommunications interface comprising:

a memory for storing data contained in said input data packets,

input means for sequentially receiving said asynchronous input data packets, stripping said packets of protocol information, and sequentially writing said data contained in said input packets into said memory,

an address generator for generating the address in said memory where each of said input data packets is stored,

address storage means for storing in an organized fashion addresses generated by said address generator, and

means for retrieving particular addresses from said address storage means, means for retrieving the data stored in said memory means at said retrieved addresses, and output processors for receiving said retrieved data and for retransmitting said retrieved data at said preselected bit rates and employing said preselected protocols to said receiving devices.

2. The telecommunications interface of claim 1 further including means for returning said retrieved addresses to said address generator so that said retrieved addresses can be reused to store subsequently received input data packets.

3. The telecommunications interface of claim 1 wherein said memory is a dual port random access memory having an input and output capable of operating asynchronously with respect to one another, so that data from an input data packet can be written into said memory at one address, while data from another data packet, previously written into said memory at another address can be read out of said memory.

4. The telecommunications interface of claim 1 wherein said input means includes means for removing timing and source identification information from each incoming data packet.

5. The telecommunications interface of claim 1 wherein

said address storage means comprises a plurality of storage portions,

each of said input data packets includes address routing information, and

said interface further includes routing means for routing memory addresses generated by said address generator for each input data packet to a particular portion of said address storage means depending on the address routing information in the packet.

6. The telecommunications interface of claim 1 wherein

said address storage means comprises a plurality of first-in-first-out (FIFO) memories, and

said telecommunications interface further comprises a central control processor, said processor providing a mapping between said output processors and said FIFOs so that when an address is retrieved from a particular FIFO, and the data stored at the retrieved address is accessed from said memory, said accessed data is routed to a particular output processor.

7. The telecommunications interface of claim 1 wherein said address storage means comprises a plurality of first-in-first-out (FIFO) memories.

8. The telecommunications interface of claim 7 wherein each of said incoming data packets includes address routing information and wherein said interface further includes routing means for routing the memory address generated by said address generator for each incoming data packet to a particular one of said FIFO memories depending on the address routing information contained in the packet.

9. The telecommunications interface of claim 7 wherein each of said incoming data packets includes information identifying its source and wherein said interface includes routing means for routing memory addresses generated by said address generator for each incoming data packet to a particular one of said FIFO memories based on the surface identifying information in the packet.

10. The telecommunications interface of claim 1 wherein

said address storage means comprises a plurality of storage portions, and wherein

at least some of said output processors are associated with particular ones of said storage portions, so that when an address is retrieved from a particular storage portion and the data stored at the retrieved address is accessed from said memory, the accessed data is routed to a particular output processor.

11. A telecommunications interface for receiving input data packets from one or more user sources and for retransmitting the input data in a format compatible with and for use by one or more receiving devices,

said telecommunications interface comprising:

a memory for storing said input data packets,

input means for sequentially receiving said input data packets and sequentially writing said input packets into said memory, wherein each incoming data packet includes clock frequency data and user data and wherein said input means comprises

clock recovery means for recovering the clock frequency data of each incoming data packet,

clock means for maintaining the recovered clock frequency for the duration of each incoming packet,

shift register means including at least first and second shift registers for receiving the user data in each incoming packet after the clock frequency data has been removed therefrom, said user data being clocked into said shift register means at a rate determined by said recovered clock frequency data, and

means for writing said user data into said memory when said first or second shift register is full,

an address generator for generating the address in said memory where each of said input data packets is stored,

address storage means for storing in an organized fashion addresses generated by said address generator, and

output means for retrieving particular addresses from said address storage means, for accessing the data stored in the said memory at said retrieved addresses, and for retransmitting said accessed data to a particular receiving device.

12. The telecommunications interface of claim 11 wherein said input data packets are comprised of video signals and wherein said input means further comprises a sync separator circuit for inhibiting the transfer of data from said input means to said memory during the horizontal and vertical blanking intervals of said video signals.

13. A telecommunications interface for receiving input signals from one or more user sources and for retransmitting the input signals in a format compatible with and for use by one or more receiving devices, said telecommunications interface comprising

a dual port random access memory,

input means for receiving said input signals from said user sources and for writing said input signals into said dual port random access memory,

an address generator for generating the addresses in said random access memory where said input signals are stored,

a plurality of first-in-first-out (FIFO) memories for storing the addresses generated by said address generator,

routing means for routing the addresses of input signals from particular ones of said user sources to particular ones of said FIFO memories,

a plurality of output processors, at least some of said output processors being associated with one or more of said FIFO memories,

means for retrieving addresses from at least some of said FIFO memories,

means for accessing the signals stored at said retrieved addresses in said dual port random access memory,

means for routing the accessed signals to an output processor associated with the FIFO memory from which the address of said accessed signal was retrieved, said output processors being capable of retransmitting the accessed signals to particular ones of said receiving devices, and feedback means so that signals routed from said memory to one of said output processors can be rewritten in said dual port random access memory.