Multiple-access scheme for packet voice that uses voice activity detection

• US 6,970,442 B1
• Filed: 07/19/2000
• Issued: 11/29/2005
• Est. Priority Date: 07/19/1999
• Status: Expired due to Fees

• Current Assignee: AT&T Intellectual Property II LP (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Nambirajan, Seshadri
• Primary Examiner(s): Vu, Huy D.
• Assistant Examiner(s): MATTIS, JASON E
• Application Number:
  US09/618,873
• Time in Patent Office: 1,959 Days
• Field of Search: 370328-330, 370336-337, 370/345, 370347-349, 370/437, 370/468, 370/477, 370/312, 370/326, 370/310
• US Class Current: 370/337
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/20 Negotiating bandwidth
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/51 based on terminal or device properties
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02

Abstract

A packet transmission arrangement maintains a certain minimum bandwidth for a call. When a silence period is detected, the bandwidth that is allocated to the call is reduced. When a speech period is detected, the reduced bandwidth remains in force, unless there is spare capacity, in which case a full measure of bandwidth is allocated to the call.

Claims

1. A method, executed in a control node, for controlling bandwidth of communication from a station to a destination module in time slots assigned by said control node that recur at a given rate where a preselected number of blocks of time slots form a frame, where said station sends packets that carry a voice signal in a channel specified by said control node, comprising the steps of:

a) first ascertaining whether said station is in a relative silence period;

b) when said step of first ascertaining concludes that said station is in said relative silence period, sending a control message to said station that reduces bandwidth of said channel, which control message specifies a slot in a subset of the blocks of a frame for transmission of packets belonging to said channel and the number of blocks in said subset is not less than a quarter of said number of blocks that form said frame;

c) second ascertaining whether said station is in an active period;

d) when said step of second ascertaining determines that said station is in an active period, determining whether there is excess capacity that can be assigned to said station; and

e) sending a control message to said station that increases said bandwidth of said channel when said step of determining concludes that there is excess capacity that can be assigned to said station.