Method and system for forward error correction with different frame sizes

Abstract

A mechanism for recovering data associated with lost packets, suitable for use in a VoIP network. The telecommunications network is preferably a packet switched network having IP telephony gateways serving as interfaces between a telephone device and the IP network. The IP telephony gateway receives a conversation signal from the telephone device, and implements an improved forward error correction method. The method includes generating payload information defined by at least two packet sequences from the same audio information, and transmitting those two packet sequences on the IP network for receipt by a remote network device. The packet sequences are transmitted using RTP with two independent data streams or, alternatively, using a single data stream. The first and second data streams are data packet streams each defining a sequence of data packets. The first data stream is preferably formed using a G.711 vocoder, and the second data stream is preferably formed using a G.723.1 vocoder. The receiver inserts the G.711 packets into a receive buffer, and, in the event that G.711 data is missing or corrupted, the receiver will decode the relevant G.723.1 packets and place it in the buffer in the appropriate location. The buffered data is then used to reproduce the audio information at the receiver.

Dependencies are inferred from the claim text.