Method and apparatus for transmitting data in a packet data communication system

Abstract

A wireless communication system transmits data over a first link from a first mobile station (MS) to an infrastructure at a first speaker link power level, and over a second link from the infrastructure to a second MS at a first listener link power level, during a first time period. Each of the first power levels is designed to avoid the need for retransmissions of erroneously received data. Upon expiration of the first time period, data is transmitted over the first and second links at reduced power levels, which transmissions include retransmissions of erroneously received data. Error targets used in the transmission of data may also be adjusted after expiration of the first time period. In addition, the power levels and error rate targets may be individually adjusted on a link-by-link basis based on the RF loading of each link and/or based on error metrics determined for each link.

What is claimed is:  
     
         1 . A method for transmitting data comprising steps of: 
 transmitting, by a first communication device, a first set of data at a first power level during a first time period, wherein the first power level is such that the first set of data is received by a second communication device at an acceptable error rate without utilizing a retransmission of a portion of the first set of data;    transmitting, by the first communication device, a second set of data at a second power level upon expiration of the first time period, wherein the second power level is less than the first power level; and    when a portion of the second set of data is erroneously received by the second communication device, retransmitting the erroneously received portion.    
     
     
         2 . The method of  claim 1 , wherein the second communication device includes a jitter buffer and wherein the first time period is approximately the same size as the jitter buffer.  
     
     
         3 . The method of  claim 1 , wherein the first power level comprises a first speaker link power level, wherein the second power level comprises a second speaker link power level, wherein the second communication device comprises a wireless infrastructure, and wherein the method further comprises steps of: 
 transmitting, by the wireless infrastructure, the first set of data at a first listener link power level upon expiration of the first time period, wherein the first listener link power level is such that the first set of data is received by a third communication device at an acceptable error rate without utilizing a retransmission of a portion of the first set of data;    transmitting, by the by the wireless infrastructure, the second set of data at a second listener link power level upon expiration of the first time period, wherein the second listener link power level is less than the first listener link power level; and    when a portion of the second set of data is erroneously received by the third communication device, retransmitting, by the wireless infrastructure, the erroneously received portion.    
     
     
         4 . The method of  claim 3 , wherein the first time period comprises the time that expires between completing a set up of a traffic link between the first communication device and the infrastructure and the completing a set up of a traffic link between the infrastructure and the third communication device, and further comprising a step of playing out, by the third communication device, at least a portion of the first set of data upon receiving the at least a portion of the first set of data.  
     
     
         5 . The method of  claim 3 , wherein the third communication device includes a play-out buffer, wherein the first time period comprises a time period that is approximately equal to a buffer depth target for the play-out buffer, and further comprising a step of playing out, by the third communication device, at least a portion of the first set of data upon receiving the at least a portion of the first set of data.  
     
     
         6 . The method of  claim 5 , wherein a length of the first time period is preprogrammed into each of the first communication device, the infrastructure, and the third communication device.  
     
     
         7 . The method of  claim 5 , further comprising steps of: 
 determining, by the infrastructure, a length of the first time period; and    conveying, by the infrastructure, the determined length of the first time period to each of the first communication device and the third communication device.    
     
     
         8 . The method of  claim 3 , further comprising steps of: 
 determining, by the infrastructure, a length of the first time period; and    conveying, by the infrastructure, an expiration of the first time period to the third communication device through a data field in a radio link protocol (RLP) header.    
     
     
         9 . The method of  claim 1 , wherein the first power level comprises a first speaker link power level, wherein the second power level comprises a second speaker link power level, wherein the second communication device comprises a wireless infrastructure, and wherein the method further comprises steps of: 
 transmitting, by the wireless infrastructure, the first set of data at a first listener link power level upon expiration of the first time period, wherein the first listener link power level is such that the first set of data is received by a third communication device at an acceptable error rate without utilizing a retransmission of a portion of the first set of data;    transmitting, by the by the wireless infrastructure, the second set of data at a second listener link power level during the first time period, wherein the second listener link power level is less than the first listener link power level; and    when a portion of the second set of data is erroneously received by the third communication device, retransmitting, by the wireless infrastructure, the erroneously received portion.    
     
     
         10 . The method of  claim 9 , wherein the third communication device includes a play-out buffer, wherein the first time period comprises a time period that is approximately equal to a buffer depth target for the play-out buffer, and further comprising a step of playing out, by the third communication device, at least a portion of the first set of data upon expiration of the first time period.  
     
     
         11 . A method for transmitting data in a wireless communication system, wherein the communication system comprises a first wireless communication device, a wireless infrastructure in communication with the first communication device via a reverse link, and a second wireless communication device in communication with the infrastructure via a forward link, the method comprising steps of: 
 determining a first radio frequency (RF) load metric corresponding to an RF load of the reverse link;    determining a second RF load metric corresponding to an RF load of the forward link;    determining an acceptable error rate for the forward link based on the first and second RF load metrics; and    determining an acceptable error rate for the reverse link based on the first and second RF load metrics.    
     
     
         12 . The method of  claim 11 , wherein the wireless infrastructure is in communication with the first communication device via a first reverse link and a first forward link, wherein the wireless infrastructure is in communication with the second communication device via a second reverse link and a second forward link, wherein the step of determining a first radio frequency (RF load) metric comprises a step of determining a first RF load metric corresponding to the first reverse link, wherein the step of determining a second RF load metric comprises a step of determining a second RF load metric corresponding to the second forward link, and further comprising steps of: 
 determining a third RF load metric corresponding to a RF load of the first forward link;    determining a fourth RF load metric corresponding to a RF load of the second reverse link; and    wherein acceptable error rates are determined for each of the first forward link, the first reverse link, the second forward link, and the second reverse link based on the first, second, third, and fourth RF load metrics.    
     
     
         13 . A method for transmitting data in a wireless communication system, wherein the communication system comprises a first wireless communication device, a wireless infrastructure in communication with the first communication device via a first reverse link and a first forward link, and a second wireless communication device in communication with the infrastructure via a second reverse link and a second forward link, the method comprising steps of: 
 determining a first error metric corresponding the first reverse link;    determining a second error metric corresponding the first forward link; and    determining an acceptable frame error rate of one or more of the first reverse link, and the second forward link based on the first error metric and the second error metric.    
     
     
         14 . The method of  claim 13 , further comprising steps of: 
 determining a third error metric corresponding the second reverse link;    determining a fourth error metric corresponding the second forward link; and    determining an acceptable frame error rate of one or more of the first reverse link and the second forward link based on the first second, third, and fourth error metrics.    
     
     
         15 . The method of  claim 13 , further comprising steps of: 
 determining a third error metric corresponding the second reverse link;    determining a fourth error metric corresponding the second forward link; and    determining a probability of aborting a transmission of data from the first communication unit to the second communication unit based on the first, second, third, and fourth error metrics to produce an abort probability;    comparing the abort probability to an abort probability threshold to produce a comparison; and    adjusting an acceptable error rate of one or more of the first reverse link, the first forward link, the second reverse link, and the second forward link based on the comparison.    
     
     
         16 . The method of  claim 13 , further comprising steps of: 
 determining a first radio frequency (RF) load metric corresponding to a RF load of the first reverse link;    determining a second RF load metric corresponding to a RF load of the first forward link;    determining a third RF load metric corresponding to a RF load of the second reverse link;    determining a fourth RF load metric corresponding to a RF load of the second forward link; and    determining which link, from among the first reverse link, the first forward link, the second reverse link, and the second forward link, has a greatest RF load based on the first, second, third, and fourth RF load metrics; and    wherein the step of adjusting an acceptable error rate comprises a step of decreasing an acceptable error rate of the link that has the greatest RF load when the abort probability is greater than the abort probability threshold.    
     
     
         17 . The method of  claim 16 , wherein the error rate is adjusted by reducing a number of attempted retransmissions of erroneously received data on the link that has the greatest radio frequency (RF) load when the abort probability is greater than the abort probability threshold.  
     
     
         18 . The method of  claim 16 , wherein the number of attempted retransmissions is reduced by reducing the use of acknowledgments on the link that has the greatest radio frequency (RF) load.  
     
     
         19 . The method of  claim 13 , further comprising steps of: 
 determining a first radio frequency (RF) load metric corresponding to a RF load of the first reverse link;    determining a second RF load metric corresponding to a RF load of the first forward link;    determining a third RF load metric corresponding to a RF load of the second reverse link;    determining a fourth RF load metric corresponding to a RF load of the second forward link; and    determining which link, from among the first reverse link, the first forward link, the second reverse link, and the second forward link, has a lowest utilization rate based on the first, second, third, and fourth RF load metrics; and    wherein the step of adjusting an acceptable error rate comprises a step of increasing an acceptable error rate of the link that has the lowest RF load when the abort probability is less than the abort probability threshold.    
     
     
         20 . The method of  claim 19 , wherein the error rate is adjusted by increasing a number of attempted retransmissions of erroneously received data on the link that has the lowest RF load when the abort probability is less than the abort probability threshold.  
     
     
         21 . The method of  claim 19 , wherein the number of attempted retransmissions of erroneously received data is reduced by reducing the use of acknowledgments on the link that has the lowest RF load.