rict delay requirements of VoIP traffic, necessitates the use of PDSCH multiuser sharing when high capacities are targeted. As each user is sched- uled by L1 control signaling, with multiuser channel sharing the control chan- nel overhead becomes the limiting factor for VoIP system performance and the dynamic packet scheduler is not able to fully exploit PDSCH air interface capacity. One attractive technique with the baseline scheduler to improve VoIP capacity within control channel limitations is to bundle multiple VoIP packets (of one user) together and transmit the bundled packets within the same TTI to a scheduled user. Packet bundling is CQI-based, meaning that it is used only for such users © 2009 by Taylor & Francis Group, LLC Radio Access Network VolP Optimization whose channel conditions are favorable enough to support bundling. With packet bundling, good users are scheduled less frequently, implying that transmission resources can be more efficiently used and L1/ L2 control overhead can be reduced. Hence packet bundling can be seen as an attractive method in DL to improve VoIP capacity for fully dynamic PS while keeping L1/L2 control overhead at a reasonable level. From the perspective of voice quality, it is important to keep the probability of losing consecutive packets as small as possible. This can be achieved by making the link adaptation for the TTIs carrying bundled packets in a more conservative manner, leading to a reduced packet error rate for the first transmission. In UL, packet bundling could be used as well, but it is not an attractive technique because of the limited UE transmission power and non-CQI-based scheduling. The impact of packet bundling on the PDSCH utilization rate in macro cell case 1 [27] with a AMR 12.2 kbps codec at 5 MHz bandwidth is presented in Figure 10.8, which contains a cumulative distribution function for scheduled PRBs per OFDM subframe. Here, it is assumed that the statistics are plotted with the load corresponding to a 5% outage point-this assumption is valid fo