In many application contexts, communication systems characterized by a high energy efficiency – low power consumption, large coverage area – and high reliability are required. Emergency networks and homeland security applications are examples of these applications. Communication systems with these characteristics usually provide a voice service and low bit rate data over extremely reliable links over a wide area.
Similar requirements are exhibited by wireless sensor networks, where low data rate systems can serve a high number of sensors deployed over a wide area.In this case, the short messages that are periodically generated by heterogeneous sensors distributed on the territory may be conveyed to a data collection center for processing. By appropriately designing the network, it is possible in this way to address and control a large number of sensors.
Concerning emergency networks, the main objectives include the design of a regional DMR network consisting of several interconnected repeaters. Verification of the quality of voice service and data links will be carried out. This will include the execution of interoperability tests between portable and mobile terminals from different manufacturers and testing data from different sensors.
Such a receiver will be able to identify and demodulate the signals of digital standards for voice communication like DMR and D-STAR, as well as DRM, DAB and theS analog broadcasting modulations..