Design and implementation of internet of things in nanosats

Abstract

A constellation of low earth orbit nanosatellites is often deployed to achieve what is difficult to do with a single much larger higher orbit satellite. This study looks at this common purpose constellation as a self-organising peer-to-peer network of equipotent, decentralised and distributed nodes. These nodes being much smaller in size and memory, are unable to individually store all the resources shared on the network. The Chord peer-to-peer algorithm is presented as a way for each node to keep only its allotted share of resources and thus reducing the memory load of each nanosat. Through consistent hashing of port and IP vs resource name, each resource can be looked up. Resource lookup simulations were done using internet connected MSP-430 wireless sensor nodes from the IoT-Lab platform. Other simulations were done using a developed (platform independent) Java application. The study found that the network can easily scale, without putting strain on the memory of each node, as each node only has to keep log2 n reference to other nodes. It was found that 66 such satellites in a mesh topology could be enough to cover the globe. UDP was considered as a transport layer protocol of choice. A lightweight encryption mechanism was found to provide security, by exchanging various key parameters instead of the encryption key itself. The study found that nanosats can be connected as Internet of Things devices without needing a different internet protocol (IP).