Exploiting Network Coding for Data Forwarding in Delay Tolerant Networks

Network coding may be used to improve resource efficiency and transmission reliability in the network. In this paper, we explore linear network coding for data forwarding in delay tolerant networks, which enable data transmission with intermittent connectivity. Specifically, we focus on vehicular ad hoc networks with scheduled routes such as bus systems. Traditional forwarding schemes may be inefficient in such networks because data losses at intermediate nodes may cause long delay in data delivery and thus low delivery ratio in data forwarding. Therefore, improving transmission reliability in delay tolerant networks is an important issue. In this paper, we propose a new coding-based forwarding protocol called vCF for vehicular ad hoc networks under the scenario of bus systems. In vCF, each message is fragmented into a set of blocks and encoded via linear network coding. Each node then schedules coded blocks to transmit when a contact opportunity occurs, and drops blocks when the buffer overflows. The simulation results show that vCF has a higher delivery rate and lower delivery delay as compared with existing schemes.