RAPEL: Robust and Adaptive method for PIT Entry Lifetime in Wireless Content-Centric Networks

Content-Centric Networking (CCN) is an emerging Internet paradigm where the content is treated as the first-class citizen and content names are used for network layer communication instead of IP addresses. Use of CCN in wireless environment can cause various issues such as re-transmissions, collisions, delay and link failure. One of the key issues that affects the performance of CCN is the management of Pending Interest Table (PIT). PIT stores each broadcasted Interest packet forwarded upstream towards the content provider and is purged either when the requested content is returned or the PIT Entry Lifetime (PEL) expires. The conventional method in CCN for PEL does not considering the network impairments such as channel error, and congestion. As a result, timeout occurs, and Interest packets are re-transmitted for the chunks that have been dropped or delayed. Due to limited size of storage in wireless CCN, all new incoming Interest packets (including retransmissions) affect the performance of network by bloating PIT. In this paper, therefore, we propose a scheme that purges the PIT entries quickly by prefetching the un-obtained content in advance. Simulation results show that proposed protocol performs better as comparing with the conventional CCN and another recent proposed protocol.