DPEL: Dynamic PIT entry lifetime in Vehicular named data networks

Vehicular named data network (VNDN) has emerged as a promising network technology, where the focus of communication is moved from host-centric to information-centric. Since, the VNDN is at its early stage in development, there are several open issues to be explored and pending interest table (PIT) management is one of them. In VNDN, PIT stores each broadcasted interest until the required content is retrieved or its timer (PEL: PIT entry lifetime) expires. When the PIT storage is full, the vehicles discard new incoming interests, thus decreasing the network performance. Therefore, in this letter, we propose a dynamic PEL (DPEL) scheme that enables each relaying vehicle to dynamically compute PEL timer for each incoming interest using its interest satisfaction rate (ISR) and the hop count. The higher the ISR and the longer the hop count, the shorter the time the relaying vehicle keeps the PIT entry. Simulation results show DPEL reduces by more than 75% the PEL and the number of entries in VNDN.