Analysis and performance evaluation of RPL under mobility

Wireless Sensor Networks (WSN) have become popular in the last years. Paths between sensors are computed by routing protocols, which are specifically designed to cope with the characteristics of WSN. Lately, the IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL) has been accepted as the Internet Engineering Task Force (IETF) standard for routing packets in WSN. However, this protocol does not pay particular attention to mobile nodes. Furthermore, mobility has been contemplated as a way to improve sensing coverage and connectivity in unattended WSN. In addition, WSN will account for an increasingly huge number of connections, from 1.9 billion devices today to 9 billion by 2018 among which most of them would be mobile (e.g. wearable devices). Using RPL to support the mobility of nodes is the main problem investigated in this article. We propose a new version of the trickle algorithm which allows mobile nodes to move seamlessly into a routing topology build by RPL together with limiting the signalling overhead. Our proposal is compared to two other schemes available in the literature. Results highlight that our proposal significantly reduces disconnection times and increases the packet delivery ratio while mitigating the extra control traffic.