Improving performance of H.264/AVC transmissions over vehicular networks

This paper evaluates the performance of H.264/AVC transmissions over IEEE 802.11p -a standard explicitly designed to perform vehicular communications- and proposes two different strategies for improving performance. The first one consists in substituting the convolutional codes used in IEEE 802.11p with Low-Density Parity-Check (LDPC) codes. The second strategy consists in adapting the transmission power by taking into account the picture type (I/P/B picture). Experimental simulation results show that the utilization of these two methods allows us to reduce GOP (Group Of Pictures) losses and improves video quality without increasing computational requirements. The evaluation has been carried out using a testbed that integrates the H.264/AVC JM encoder, an IEEE 802.11p transceiver and an FPGA-based channel emulator that implements vehicular channel models based on a measurement campaign performed in 2006 in Atlanta, Georgia.