Performance evaluation of energy efficient vehicular networks with physical channel impairments

The need for reducing the carbon footprint in the information and communication technology (lCT) sector encourages researchers to explore various paradigms of energy efficiency especially in vehicular communication networks. In a vehicular communication network, vehicles are equipped with on board sensing, computational and communication devices in order to communicate with neighbouring vehicles aud/or mobile and fixed resources to provide safety, security and entertainment to travellers and pedestrians. The diversity of wireless technologies available, varying vehicular densities, high mobility and random topology changes in these networks pose several challenges from system design perspectives. Furthermore, providing real time communication with the required Quality of Service (QoS), while saving Significant amount of energy, is quite challenging in these networks. This thesis investigates the performance of motorway vehicular communication systems from both QoS and energy perspectives. To start with a detailed statistical analysis of real vehicular traffic profiles recorded by inductive loops on the M4 motorway in the UK is carried out, which is subsequently utilised to develop a motorway vehicular mobility simulator. Next, the impact of physical channel impairments (attenuation, fading and shadowing) on a modified version of packet reservation multiple access (M-PRMA) protocol is studied in this environment. The performance of the M-PRMA protocol in terms of both QoS and energy effiCiency is evaluated and compared with that of the IEEE 802.11p based medium access control (MAC) protocol. The model of the M-PRMA protocol is further extended by incorporating wireless channel outage as a slot/server on vacation, which is solved using a matrix geometric method (MGM). In addition, to access external resources such as the Internet, an access point (AP) architecture is studied, where an AP sleeps (takes vacations) to save energy while maintaining the required QoS. Moreover, a novel double cluster-head (DCH) routing scheme with buffer optimisation and average packet delay minimisation is proposed to save energy, where other QoS parameters are significantly improved. Finally, two traffic shaping techniques at the AP are introduced to reduce energy overhead and t heir approximate analytical models (G/G/1 queues with sleep cycles) are developed.EThOS - Electronic Theses Online ServiceGBUnited Kingdo