Common use of System Model Clause in Contracts

System Model. We begin by describing a system model suitable for the deployment scenarios of WBANs. In this model, a System Administrator (SA) initializes the network. The network is composed of three types of nodes; a Hub Node (HN ), Intermediary Nodes (IN ) and Normal Nodes (N ). As the HN is usually a resourceful device with better hardware protection mechanisms in place, we assume it to be trusted and its secret Master Key to be protected. Normal nodes N are resource constrained and their transmission range is assumed to be limited; in particular, they are not always able to communicate directly with HN . Intermediary nodes IN are also located in and around the body but, at a particular time instance, are in direct communication with both N and HN , thus acting as intermediary nodes for the purpose of relaying traffic between HN and N when required.