JP2002218004A5 - - Google Patents

Claims (10)

A buffer for storing at least one data packet to be transmitted over the link;
Modulation that modulates / encodes a first segment of the data packet at a first modulation / coding level and modulates / encodes a second segment of the data packet at a more robust second modulation / coding level Encoder and encoder;
An apparatus for reducing a delay time in distributing data, comprising: a transmitter for transmitting the first and second segments. In a data communication system for transmitting variable length user data packets via a communication channel,
Means for dividing each data packet for transmission over a communication channel;
Means for using link adaptation to select different modulation and coding schemes for transmitting each data segment;
Means for selecting a modulation and coding scheme for each packet transmission based on both channel quality and packet delay performance, the data transmitting variable length user data packets over a communication channel. Communications system. 3. The system according to claim 2, wherein each packet size is known, and an MCS having a smaller delay amount with respect to the packet is selected. The MCS selects a packet having a small delay amount with respect to x% of the packet.
4. The system of claim 3, wherein x depends on a desired quality of service. The MCS is selected such that the value of μ + aσ is low,
4. The system of claim 3, wherein [mu] is a predicted delay for the packet, [sigma] is a standard deviation of the delay, and a is a positive value selected depending on a desired quality of service. . The system of claim 2, wherein the MCS is also dependent on a round trip delay of the channel. The system according to claim 2, wherein the MCS is determined based on an untransmitted amount of a user data buffer per packet and a low predicted delay in transmitting each packet. The system of claim 7, wherein the determination of x is determined such that the MCS selected to have the lowest expected delay has the highest throughput. In a method of performing data communication with data packets having different lengths through a communication channel,
Splitting each data packet for transmission over a communication channel;
Determining a certain modulation and coding scheme according to the link adaptation from the plurality of modulation and coding schemes for transmitting each data segment by a variable length data packet over the communication channel. A method of performing data communication. The method of claim 9, wherein the selection of a modulation and coding scheme for transmitting each packet segment is based on both channel quality and packet delay performance.