Adaptive application of forward error correction mechanism for reliable vehicle-to-vehicle communication
AuthorsMuhammad, Shehu Jabaka
SubjectsVehicular Ad Hoc Networks
Adaptive Forward Error Correction
Hybrid Automatic Repeat reQuest
MetadataShow full item record
AbstractRecently, the intelligent transportation system (ITS), which provides vehicles with the capabilities to cooperatively and wirelessly exchange messages to circumvent, for instance, hazardous motorway traffic circumstances, have attracted an enormous amount of attention in academia and the automotive industry. Moreover, vehicular adhoc networks (VANETs) are considered to be at the centre of ITS, owing to the recent demands to minimise the number of injuries leading to fatalities, loss of lives and finances, consequent to the increased number of accidents on the highways. However, VANETs have many challenges, among which is the need for timely, reliable and scalable message transmission. Solving these challenges will require a shared media access control (MAC) layer that will guarantee timely, reliable as well as scalable communication of safety messages. This research investigates the application of error correction coding for reliable transmission in VANETs. An adaptive application of Forward Error Code (Adaptive FEC scheme) for reliable safety message transmission in VANETs is proposed. The solution combined Automatic repeat request (ARQ) with FEC at the MAC layer. The Adaptive FEC scheme used the existing channel condition, an estimate of the maximum number of transmissions and message type as an index into the code lookup ensemble (CLE) to get the optimum code (optCode) for current transmission. Furthermore, the proposed Adaptive FEC scheme also sets the transmission timeout delay RTT, encodes the message with the optCode and transmits. However, if the transmission timeout delay elapses before receiving an ACK/NAK, the scheme will go back to the initial stage for possible retransmission of the message. In this solution each transmission is self-decodable. Although the proposed Adaptive FEC scheme has shown remarkable performance, it needs improvement to minimise the incurred overhead due to the collision effect of the retransmission requests. To overcome the weaknesses of the proposed Adaptive FEC scheme, an Adaptive FEC-based Timely and Efficient Multihop Broadcast (Adaptive FEC-based TEMB) scheme is proposed for Reliable Inter-Vehicular Communication. The Adaptive application of error control and the utilisation of dynamic transmission range reduces the hops count between faulty vehicle and other nearby vehicles in a region on the motorway. Furthermore, in order to mitigate the hidden and exposed node problems, which will minimise the rate of collision in the network, a novel request to transmit (RTT) and clear to transmit (CTT) mechanisms is designed for the Adaptive FEC-based TEMB. In addition, a pre-emptive queuing mechanism is developed and applied to give the highest priority to the safety critical messages. This enables faster safety message transmission between the source vehicle and the destination vehicles. On the other hand, in VANETs, designing an efficient media access protocol poses a major challenge, as the number of vehicles is not known before transmission and could not be bounded. Thus, the scalability of the MAC approach has a significant effect on the operation of vehicular communication. Therefore, an investigation was conducted into the scalability issue of 802.11p and compared with Self-Organised Time Division Multiple Access (STDMA), using time-triggered and event-triggered safety messages. The proposed solutions’ performance is clearly demonstrated through detailed theoretical analysis which was further validated by results of the simulation experiments. The results of the theoretical analysis and simulation experiments show that our proposed schemes mentioned above outperformed the existing related solutions.
CitationMuhammad, S.J. (2018) 'Adaptive Application of Forward Error Correction Mechanism for Reliable Vehicle-to-vehicle Communication'. PhD thesis. University of Bedfordshire.
PublisherUniversity of Bedfordshire
TypeThesis or dissertation
Description"A thesis submitted to the University of Bedfordshire, in partial fulfilment of the requirements for the degree of Doctor of Philosophy".
The following license files are associated with this item:
- Creative Commons
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-NoDerivatives 4.0 International