Patent ID: 7349330

Claim:
A packet receiver connected to a network for receiving communication packets sent from a packet transmitter and containing coded speech data via said network, decoding said communication packets, and outputting decoded speech data, said packet receiver comprising: a packet memory circuit for temporarily storing received packets including the communication packets in a first-in first-out fashion to thereby form a queue; a read start threshold setting circuit for setting, with respect to a length of the queue, a read start threshold at which the received packets should begin to be read out for decoding the received packets and outputting decoded speech data; a read comparing circuit for determining whether or not the length of the queue has reached said read start threshold, and outputting a read command signal in accordance with a result of a decision; a read control circuit for causing, in response to said read command signal, the received packets to be read out of said packet memory circuit, wherein by using a standard deviation of said coded speech data that reflects a jitter distribution of the network and causes a receipt time of the communication packet to vary, said read start point setting circuit sets the read start threshold at a length of the queue that is three times to four times as great as said standard deviation; and a diminishment control circuit for setting, with respect to the length of the queue, a discard start threshold and a discard end threshold at which the received packets should begin to be discarded and should stop being discarded, respectively, designating, when the length of said queue exceeds said discard start threshold, a received packet to be read out as a candidate to be discarded, and discarding said packet designated as a candidate, wherein said discard end threshold is set to a value between said discard start threshold and said read start threshold, and different than either of said discard start threshold and said read start threshold, if said discard start threshold is greater than said read start threshold.