Evaluation of H.264/AVC over IEEE 802.11p vehicular networks

Abstract

The capacity of vehicular networks to offer non-safety services, like infotainment applications or the exchange of multimedia information between vehicles, have attracted a great deal of attention to the field of Intelligent Transport Systems (ITS). In particular, in this article we focus our attention on IEEE 802.11p which defines enhancements to IEEE 802.11 required to support ITS applications. We present an FPGA-based testbed developed to evaluate H.264/AVC (Advanced Video Coding) video transmission over vehicular networks. The testbed covers some of the most common situations in vehicle-to-vehicle and roadside-to-vehicle communications and it is highly flexible, allowing the performance evaluation of different vehicular standard configurations. We also show several experimental results to illustrate the quality obtained when H.264/AVC encoded video is transmitted over IEEE 802.11p networks. The quality is measured considering two important parameters: the percentage of recovered group of pictures and the frame quality. In order to improve performance, we propose to substitute the convolutional channel encoder used in IEEE 802.11p for a low-density parity-check code encoder. In addition, we suggest a simple strategy to decide the optimum number of iterations needed to decode each packet received.

In-vehicle network latency analysis for a lane keeping assistance system

“…Therefore, in this study, we model the compression latency as linearly increasing with the data size. Specifically, we target the H.264 video compression for modeling compression latency since it is currently one of the most widely used video codecs, particularly in vehicular communications [34]. H.264 employs inter-frame compression, and the compression latency increases as the compression ratio rises according to the GOP size.…”

Mobility management for machine-to-machine (M2M) communications

“…The 802.11p standard defines enhancements to 802.11 with the objective of fulfilling the requirements of the ITS applications. This includes data exchange between high-speed vehicles and between the vehicles and the roadside infrastructure [17].…”

Estratégia adaptativa para disseminação de dados usando a força do sinal

“…Então, para comunicação na VANET, a extensão tecnológica promove a interação entre os diversos veículos de um ambiente e entre estes com o próprio ambiente, conforme necessário para aplicações que constituem ITS. Em outra perspectiva, acomoda a expectativa do usuário, que está relacionada com a possibilidade de usufruir dos recursos computacionais e da Internet de forma ubíqua (ROZAS-RAMALLAL et al, 2013). Entretanto, VANETs são propensas a instabilidades como ruídos, perdas, atrasos, colisões, desconexões frequentes e operam sobre a escassez ou inexistência de conectividade fim a fim.…”