Intermittent node resolution for voice and data communication system

• US 6,459,692 B1
• Filed: 06/08/1999
• Issued: 10/01/2002
• Est. Priority Date: 01/12/1999
• Status: Expired due to Fees

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Tsaliovich, Anatoly A., Ben-Michael, Rafael, Miller, Robert Raymond II, Bennett, Robert, Jamer, Theodore P.
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): PHAM, BRENDA H
• Application Number:
  US09/327,792
• Time in Patent Office: 1,211 Days
• Field of Search: 370/294, 370/314, 370/321, 370/326, 370/329, 370/332, 370/335, 370/336, 370/338, 370/341, 370/346, 370/358, 370/442, 370/431, 370/437, 370/458
• US Class Current: 370/341
• CPC Class Codes: H04B 2203/5408 using protocols
• CPC Class Codes: H04B 2203/5425 improving S/N by matching impedance, noise reduction, gain control
• CPC Class Codes: H04B 2203/5445 Local network
• CPC Class Codes: H04B 2203/545 Audio/video application, e.g. interphone
• CPC Class Codes: H04B 3/542 the information being in digital form

Abstract

A method of identifying and communicating the existence of Intermittent nodes in a communication network with a mixed TDMA/CSMA-CD MAC frame format, and of preventing these nodes from unnecessarily debasing existing voice channel connections. Information pertaining to intermittent nodes is included in a database for an extended operational duration and used as primary information in control of the creation of any newly requested voice channels. Intermittent nodes are treated for the purpose of assigning voice channels as existing permanent nodes, whether currently visible or not. Newly revealed intermittent nodes are added to the database through intermediate nodes. This invention increases reliability and quality of voice communications during noise/impedance level changes of the network that may render one or more nodes not visible.

Claims

1. In a communication system including a plurality of nodes/modems connected by communication links and in which link quality renders at least one node/modem intermittent in connection with other nodes/modems in the communication system, comprising:

the links connecting the nodes/modems propagating frames of both voice and data signal with voice time division multiplexed and data includes as part of an overall frame;

a database listing all permanent and intermittent nodes/modems of a particular region of the communication system;

each node/modem operative for permitting a connection of voice signals through a particular choice channel to the network only if the voice channel is not pre-empted by an active assignment of a voice channel specified in the data base.

2. A communication system as claimed in claim 1, wherein:

the database is formatted in a tabular format.

3. A communication system as claimed in claim 2, wherein:

the database includes a list of assigned and unassigned visible nodes/modems, and new voice channels are assigned to unassigned visible nodes/modems.

4. A communication system as claimed in claim 3, wherein:

at least one instance of the database is included in a node/modem.

5. A method of time division assignment of voice channels within frames containing both voice channels and data, within a system of networked node/modems experiencing intermittent masking of some of the node/modems, comprising the steps of:

maintaining a database list of node/modems visible to each modem by working network connections; and

maintaining those node/modems in the database list that have lost visibility to said each node/modem for a specified time duration;

said database list classifying the list of visible node/modems in accord with one of actively supporting voice channels and with availability for accepting voice channels

assigning voice channels to voice channel requesting node/modems to available time division assignments.

6. The method of claim 5 further including a step of:

including the database list of node/modems visible to each node/modem in at least one of the node/modems.

7. The method of claim 5 further including a step of:

generating the database list of node/modems formatted in a tabular format.

8. The method of claim 7 further including a step of:

assigning newly requested voice channels by a node/modem to a voice channel reserved for nodes/modems visible to the requesting node/modem.