Advanced priority statistical multiplexer

• US 6,570,891 B1
• Filed: 03/27/2000
• Issued: 05/27/2003
• Est. Priority Date: 04/19/1994
• Status: Expired due to Fees

• Current Assignee: Multi-Tech Systems Incorporated
• Original Assignee: Multi-Tech Systems Incorporated
• Inventors: Arimilli, Harinarayana
• Primary Examiner(s): Olms, Douglas
• Assistant Examiner(s): Phunkulh, Bob A.
• Application Number:
  US09/536,309
• Time in Patent Office: 1,156 Days
• Field of Search: 370/229, 370/230, 370/232, 370/235, 370/391, 370/412, 370/464, 370/465, 370/468, 370/477, 370/493, 370/435, 370/437, 370/538, 370/539, 370/540, 370/541, 370/542, 370/543
• US Class Current: 370/536
• CPC Class Codes: H04J 3/1688 the demands of the users being taken into account after redundancy removal, e.g. by predictive coding, by variable sampling reducing bandwidth of signals in general H04B1/66; in PCM-systems H04B14/046; removal of redundancy in telegraph communication H03M7/30
• CPC Class Codes: H04J 3/247 ATM or packet multiplexing
• CPC Class Codes: H04L 2012/6427 Subscriber Access Module; Concentrator; Group equipment
• CPC Class Codes: H04L 2012/6459 Multiplexing, e.g. TDMA, CDMA
• CPC Class Codes: H04L 2012/6462 Movable boundaries in packets or frames
• CPC Class Codes: H04L 2012/6464 Priority
• CPC Class Codes: H04L 2012/6486 Signalling Protocols
• CPC Class Codes: H04L 2012/6494 Silence suppression
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04M 1/253 Telephone sets using digital voice transmission
• CPC Class Codes: H04M 11/064 Data transmission during pauses in telephone conversation
• CPC Class Codes: H04N 1/00281 with a telecommunication apparatus, e.g. a switched network of teleprinters for the distribution of text-based information, a selective call terminal details of transmission H04N1/00095; establishing a communication with one of a facsimile machine or another apparatus sharing a single line H04N1/32704; interfacing cordless telephone terminals with an accessory to increase the functionality of user interface H04M1/72409
• CPC Class Codes: H04N 1/00302 with a telephonic apparatus, e.g. telephone answering machine or videotex terminal H04N1/00307 takes precedence; telephonic communication H04M
• CPC Class Codes: H04N 1/00312 with a digital transmission apparatus, e.g. a switched network of teleprinters for the distribution of text-based information, SMS or ISDN device transmitting or receiving via a computer, e.g. using e-mail, a computer network or the internet H04N1/00214; transmission of digital information H04L
• CPC Class Codes: Y10S 370/916 Multiplexer/demultiplexer

Abstract

A data multiplexing network is described which multiplexes a plurality of asynchronous data channels with an asynchronous data stream representing compressed voice signals and/or facsimile signals onto a single synchronous data packet stream. The single synchronous data packet stream is then transmitted by a high speed statistical multiplexer over a composite link to a second site using a modified high-level synchronous data link control protocol with an overlay of an advanced priority statistical multiplexing algorithm. The asynchronous data channels and the compressed voice channel and/or facsimile signals are demultiplexed and reconstructed for sending to other asynchronous computer terminals and to a standard telephone or facsimile analog port at the second site, respectively. PBX trunk interfaces are also provided to allow PBX'"'"'s to share the composite link between sites. Communication between the first site by voice or facsimile and the second site is transparent to the users. The multiplexer efficiently allocated the bandwidth of the composite link by detecting silence periods in the voice signals and suppressing the sending of the voice information to preserve bandwidth. An advanced priority statistical multiplexer is also described which dynamically allocates composite link bandwidth to both time sensitive and non-time-sensitive data to maximize data throughout efficiency and quality while simultaneously reducing multiplexer processing overhead.

Claims

1. A method for demultiplexing, comprising the steps of:

if high priority data is detected, receiving the high priority data;

if intermediate or low priority data is detected, only checking one byte after a number of intermediate or low priority data bytes to determine if following data is high priority data, the number equal to an interrupt boundary byte count; and

repeating the above steps until all data is demultiplexed.

2. The method of claim 1, further comprising the step of:

if the one byte after a number of intermediate or low priority data bytes matches a high priority data identifier, then receiving high priority data.

3. The method of claim 1, further comprising the step of:

if the one byte after a number of intermediate or low priority data bytes differs from a high priority data identifier, then receiving intermediate or low priority data, including the one byte.

4. The method of claim 1, wherein the interrupt boundary byte count is received from a remote source.

5. The method of claim 1, wherein the data is received in a frame.

6. The method of claim 1, wherein the data is received in a frame comprising a frame identifier.

7. The method of claim 1, wherein the data is received in a frame comprising an error correction code.

8. The method of claim 1, wherein the data is received in a frame and the high priority data is identified by a high priority identifier.

9. The method of claim 1, wherein the data is received in a frame and the high priority data includes a byte count.

10. The method of claim 1, further comprising the step of performing error correction for intermediate or low priority data.

11. The method of claim 1, wherein the data is received in a frame including a low priority byte count.

12. The method of claim 11, wherein the data is received in a frame and further including demultiplexing until the end of the frame is reached.