Method of using link adaptation and power control for streaming services in wireless networks
View Patent ↗A method for improving the performance for a streaming service by link-adaptation and power-control in a wireless packet network such as an Enhanced General Packet Radio Services (EGPRS) cellular network is described. In particular, the effects of a combined link adaptation and power control scheme (referred to as an error-based scheme) for achieving a target error rate, which is non-zero but low enough so that limited retransmission and error concealment techniques are effective, is presented.
1. A method of providing streaming service in a wireless packet network comprising steps of:
utilizing a link adaptation technique to adapt a modulation and coding level to achieve a predetermined error rate for transmission of data packets, said link adaptation technique based on a relationship between said error rate and a signal-to-interference-plus-noise ratio, wherein said signal-to-interference-plus-noise ratio is predicted from a signal path gain, a maximum transmission power level, and a predicted interference power level;
utilizing a power control technique to adjust a transmission power to a level which provides desirable performance, said power control technique utilized in combination with said link adaptation technique and based on the adapted modulation and the coding level; and
transmitting said packets of data in accordance with said modulation and said coding level and with said transmission power.
2. The method of claim 1 wherein said service comprises a music delivery service.
3. The method of claim 1 wherein said streaming service is provided over a cellular network.
4. The method of claim 1 wherein said predetermined error rate comprises a non-zero error rate.
5. The method of claim 1 wherein said streaming service is provided over packet-switched bearers.
6. The method of claim 1 further comprising the step of applying error-concealment techniques to said data packets at a receiving end.
7. The method of claim 1 wherein said step of utilizing a link adaptation technique is performed at periodic intervals.
8. The method of claim 1 wherein said step of utilizing a power control technique is performed at periodic intervals.
9. The method of claim 2 wherein said music delivery service comprises a MPEG-4 Advanced Audio Coder music service.
10. The method of claim 3 wherein said cellular network comprises an Enhanced General Packet Radio Service cellular network.
11. The method of claim 1 wherein said signal-to-interference-plus-noise ratio is estimated by multiplying a value of said maximum transmission power level by a value of said signal path gain and dividing by a value of said predicted interference power level.
12. The method of claim 1 , wherein said transmission power level is determined from a value of said signal-to-interference-plus-noise ratio multiplied by a value of said predicted interference power level divided by a value of said signal path gain.