Video applications over wireless networks exhibit great potential due to the tremendous progress of wireless network development and video compression techniques. However, the variant wireless channel conditions significantly increase the challenge of providing effective packetization and unequal error protection. Basically, the packetization work is a tradeoff between the header overhead and the packet error rate for determining an efficient packet size. On the other hand, the property that video packets with different types in the encoding process have different significance should be considered to provide an effective unequal error protection.

    This thesis proposes an optimal transmission strategy for delivering video data over WLAN environment in the case of multi-users. The proposed framework includes two major parts: an optimal packet size determination method and a shared ARQ mechanism. The optimal packet size is obtained based on the current error situation of WLAN, header overhead, scheduling delay, transmission delay, and the number of users, for achieving the maximum bandwidth utilization. A mathematic closed form of the optimal packet size is derived. The shared ARQ mechanism introduces a share concept for the retransmission opportunities of different video frames and dynamically allocates these retransmission opportunities based on their importance. Simulation results show that using the proposed mechanisms can achieve the maximum bandwidth utilization in various WLAN environments with different IP implementations, including IPv4/IPv6, over IEEE 802.11b/a/g/e networks. Moreover, integrating with the optimal transmission strategy, the proposed shared ARQ mechanism can improve the received PSNR up to 2.5dB.