Three representative scenarios have been defined to determine the usage of the available communication capacity by the realisation of STIS, the Dutch implementation of RIS (River Information Services). Each of these three scenarios imposes some specific requirements with respect to communication. For example, the type of broadcasted messages may vary, but also the priority of these messages. The three defined scenarios are a port environment, the environment of a lock, and an incident situation. In the port scenario, the geographical area under consideration is limited. Ships are communicating with shore from a fixed location and transmitting large amounts of data. The lock scenario considers a quite large geographical area, through which the ships are moving. The information exchange consists mainly of operational reports between ships and the lock. The incident scenario is probably the most complex scenario with respect to the communication. In this scenario, it must be able to send and receive certain messages instantaneously, within seconds. These messages should receive a high priority and based on this priority, they should be handled first. The type of messages used in this scenario is quite extensive. For each of these scenarios, the broadcasted messages have been defined and the size of these messages has been determined. Next, the frequency with which the messages are broadcasted has been estimated. The frequency and size of the messages are used to compute the network load. Finally, the communication network types that could be used for each scenario have been identified. It was found that the current communication systems do not form a restriction for the realization of (parts of) STIS. (Author/publisher)
Abstract