Degree Distribution of Wireless Networks for Mobile IoT Applications

In the vision of the Internet of Things (IoT), objects become smart by aggregating in a network and exchanging information. Thanks to this shared knowledge, the objects can interact for performing advanced tasks. The obtrusiveness of the services is guaranteed by the mobility of the smart objects. For example, mobile sensors are used to follow dynamic phenomena, whereas smartphones and wearable devices are always accessible to the user. The interaction among the smart devices can be described by means of a graph, where nodes, representing IoT objects, are linked if they can communicate. This paper studies the node degree (i.e., the number of links of the node) in a graph developed for describing heterogeneous wireless networks. With respect to previous work, the mobility of the network, which can change the degree of every node, is considered for the first time. Formulas for the degree distribution and the average degree are theoretically computed and then validated with simulations. In particular, as a case study the proposed formulas are applied considering IoT objects following the random waypoint model, one of the most common mobility models.