LEPaNTU: Long Polling Based Energy Efficient Passive NAT Traversal through UDP In IoT scenario, a device can be deployed in a particular environment to serve a particular purpose. It can be any smart device acting as an integral part of any smart system deployed in any environment, which requires remote supervision. To facilitate ondemand remote control of such smart systems, from any public server, that sever must be able to propagate the required signal to the appropriate devices. But, these devices are not publicly addressable as they reside behind various Network Address Translators (NAT). These devices even have energy constraints as they are battery powered. Therefore, for such devices, maintaining a TCP connection or performing repeated polling to the public server is not an energy efficient solution. This paper proposes a scheme that facilitates the server to maintain a UDP connection to the client residing behind a NAT, by dynamic determination of that NATu0027s translation entry lifetime and by maintaining the translation entry on that NAT through periodic keepalives from the Server. Thus leading to an energy efficient solution towards ondemand acquiring of sensing resources for IoT based cloud services.

LoBaPS: Load Balancing Parent Selection for RPL Using WakeUp Radios WakeUp Radios is an emerging technology, aiming at pushing forward the frontiers of energy efficiency without trading it off for latency nor reliability. Extending the lifetime of the nodes as much as possible is one of the main goals in Multihop Wireless Sensor Networks. The Routing Protocol for Low Power and Lossy Networks (RPL) is commonly used in these applications. However, there is still an open problem in its design when it comes to achieving both stability and efficient routing at the same time. In this article, we present Load Balancing Parent Selection (LoBaPS), an algorithm to select opportunistically the next hop, based on RPL. It capitalizes on the WakeUp Radio and its alwayson feature, as well as its UltraLow Power consumption. We compare the performance of LoBaPS with that of WMAC, a reference protocol that uses WakeUp Radio and supports RPL in its traditional way. The results are obtained through simulations in COOJA for a network of nodes running ContikiOS, and show that the lifetime can be improved up to 55%, while the Packet Delivery Ratio (PDR) can raise a maximum of 20%, keeping a reasonable level of latency. In addition, the network is more robust to node shutdowns and requires less control overhead.