on either optimization techniques or heuristics for instance a total time period could be assigned for the sum of the uplink and downlink times based on the qos requirement of real time applications the period could be divided in proportion to a running average of recent traffic load in each direction a similar method would use a time weighted running average of recent traffic load in each direction one or both directions could be assigned enough time to transmit an estimate of the backlog in that direction up to a maximum time unit alternatively one could employ a distributed approach it requires all stations to be synchronized and all client stations are required to release the channel at pre specified times u2014 we refer to this requirement as uplink channel release ucr then the synergy among the uplink transmissions in capturing the channel is eliminated if there is downlink traffic queued the ap would have the opportunity to contend for the channel at the time the channel is released with qos enhanced edcf because of its top priority treatment the ap will prevail over client stations competing to access the channel and will transmit successfully priority is afforded to the ap by allowing it to access the channel after an idle time shorter than for any client station u2014 i e at pifs downlink transmissions occur simultaneously on all beams if there is more traffic to be transmitted on one beam than on the others the ap must even out the time that the channel is occupied by downlink transmissions on all beams in order to prevent clients from accessing the channel while the ap is transmitting on another.