Environmental tele-monitoring: a flexible GSM-DECT based solution

This paper describes a low cost standard solution for environmental monitoring. The advent of modern wireless communication technologies have added flexibility to data collection from remotely distributed sensors. In particular, nowadays wireless Wide Area Network (WAN) like Global System for Mobile Communications (GSM) and satellite telephone services are ubiquitous: it becomes feasible to place and collect data from remote sensors at locations which were previously inaccessible due to distance or extremely restrictive conditions. The shortcoming of this approach can be found in the need of a subscription to the telephone service provider. Authors propose to overcome this limitation realizing a "local" cellular network exploiting a free and standard technology like DECT, typically used for cordless handsets. The link with existing infrastructures can be satisfied with a sort of access point implementing, for example, both the DECT and GSM controller. A working prototype has been realized and some experimental results have been reported. It has been possible to demonstrate the feasibility of a sampling station that is truly autonomous, since it is battery powered.