Abstract: Apparatus is provided that includes at least one entity for transmitting speech signals in a discontinuous transmission mode including transmitting speech frames interspersed with frames including comfort noise parameters during periods of speech pauses. The entit(ies) include a first entity for estimating a current noise value. In addition, the apparatus includes a second entity for selectively controlling a rate at which the frames including comfort noise parameters are transmitted during the periods of speech pauses based upon the estimated current noise value.

Abstract: An approach is provided for time-warping of speech. A condition that introduces delay in a communication system is determined to exist. Dynamic time-warping of a voice frame is performed in response to the determined condition for playout to a user.

Abstract: A method, apparatus and system for scheduling data packets in a wireless communications system. The invention includes determining a priority for at least one data packet, wherein determining the priority of the data packet is based at least on a plurality of quality of service factors, wherein each of the plurality of QoS factors has a corresponding weighting factor and the determined priority includes minimum-performance guarantees. The invention further includes scheduling transmission of the at least one data packet based at least on the determined priority.

Abstract: The present invention concerns methods for efficiently supporting Voice over Internet Protocol (VoIP) on the Forward Packet Data Channel (F-PDCH) in CDMA 2000 1xEV-DV systems. Active speech in VoIP is encoded using, for example enhanced variable rate codec (EVRC), which produces 171, 80 and 16 bits per 20 ms of speech for Rate 1, Rate 1/2 and Rate 1/8, respectively. However, about 60% of the time a user is inactive during a speech session, so an inordinate amount of system bandwidth is comprised of rate 1/8 VoIP packets. In one embodiment of the present invention the apparatus of the present invention identifies the Rate 1/8 voice frame packets and discards them. In another embodiment of the present invention, the apparatus of the present invention identifies the Rate 1/8 voice frame packets and selects some of them for further transmission. In both embodiments the efficiency of channel utilization is increased since the amount of channel band width used to communicate relatively little information, e.g.

Abstract: A codebook 58 includes a first subset of M codewords 82 and a second subset of N-M remaining codewords 84. Codewords in the first subset are used for signaling a beginning or end of an in-band stream of data. Designated frames 90 make up the stream and include both speech and data. Each codeword index defines L bits that are used to encode speech. Within the designated frames, D bits of the L bits carry data and the remaining L-D bits are used to search from a truncated number of codewords uniquely identifiable by the L-D bits. The designated frames may be a set number of consecutive frames, or the set number of frames dispersed to recur once every 1/K frames. The number of designated frames may be extended by re-transmitting a codeword from the first subset, or truncated by transmitting a stop codeword that is also within the first subset of codewords. All of the L bits are available to search the codebook in non-designated frames that do not carry data.

Abstract: The use of a cellular system's packet data channel for transport of speech communications is enhanced by dynamically controlling the transmission of data packets that were received in error and notified to the transmitter by the receiver in accordance with an algorithm that takes into account a self-generated determination of the perceptual quality importance of the frame and is generated once for each frame by the speech encoder. The calculation of the frame importance is codec-dependent, and depends on a number of attributes associated with each particular frame, including the frame rate (for variable-rate codecs), signal classification, transition characteristics, background noise, previous frame erasures, etc. The selective reduction in transmission and retransmission increases the capacity of the cellular system while maintaining or even improving the quality of the received voice signal.