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 system, comprising:
a wireless router configured to cause data to be transmitted via an antenna, wherein the wireless router is configured to:
select a modulation and coding level for transmission of data packets, wherein selecting the modulation and coding level is based at least on a relationship between a predetermined error rate and a signal-to-interference-plus-noise ratio, wherein the signal-to-interference-plus-noise ratio is determined at least based on a signal path gain between a transmitter and a receiver, a maximum transmission power level, and a predicted interference power level for the transmission of the data packets; and
select a transmission power level for the transmission of the data packets based at least on the selected modulation and coding level;
wherein the wireless router is configured to cause transmission of the data packets in accordance with the selected modulation and coding level and with the selected transmission power level.
2. The system of claim 1 , wherein the wireless router includes a Generalized Packet Radio Service (GPRS) Support Node.
3. The system of claim 1 , wherein the wireless router further includes a filter configured to predict an interference power level.
4. The system of claim 3 , wherein the filter includes a Kalman filter.
5. The system of claim 1 , wherein the transmission of data packets is for a music delivery service.
6. The system of claim 1 , wherein said predetermined error rate comprises a non-zero error rate.
7. The system of claim 1 , wherein the wireless router is further configured to apply error-concealment techniques affecting reception of the data packets at a receiving end.
8. The system of claim 1 , wherein the wireless router is further configured to modify the modulation and coding level at periodic intervals.
9. The system of claim 1 , wherein the wireless router is further configured to adjust the transmission power at periodic intervals.
10. The system of claim 1 , wherein the wireless router is configured to determine the signal-to-interference-plus-noise ratio by multiplying a value of the maximum transmission power level by a value of the signal path gain and dividing by a value of the predicted interference power level.
11. A method, comprising:
selecting a modulation and coding level for transmission of data packets from a network node, wherein selecting the modulation and coding level is based at least on a relationship between a predetermined error rate and a signal-to-interference-plus-noise ratio, wherein the signal-to-interference-plus-noise ratio is determined at least based on a signal path gain between a transmitter and a receiver, a maximum transmission power level, and a predicted interference power level for the transmission of the data packets; and
selecting a transmission power level for the transmission of the data packets based at least on the selected modulation and coding level, wherein the network node is configured to cause transmission of the data packets in accordance with the selected modulation and coding level and with the selected transmission power level.
12. The method of claim 11 , wherein the predetermined error rate is based on a streaming music service.
13. The method of claim 12 , wherein the streaming music service includes transmission of music according to Advanced Audio Coding (AAC).
14. The method of claim 11 , wherein the network node includes a Generalized Packet Radio Service (GPRS) Support Node.
15. The method of claim 11 , further comprising transmitting the data packets to a receiver.
16. The method of claim 15 , further comprising transmitting additional data packets to the receiver according to a modified transmission power level.
17. The method of claim 15 , wherein the receiver is a mobile phone device.
18. The method of claim 11 , wherein the predetermined error rate is less than an error rate allowing maximum throughput of data packets.
19. The method of claim 11 , wherein the selected transmission power level for the transmission of the data packets is less than the maximum transmission power level.
20. The method of claim 18 , wherein an error rate corresponding to the maximum transmission power is greater than an error rate corresponding to the selected transmission power level.