Multiple-access scheme for packet voice that uses voice activity detection
View Patent ↗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.
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.