Analysis of communication alternatives over public networks for a supervision and control system of metropolitan scope

In this work different communication alternatives for a supervision and control system based on communications services provided over public networks are evaluated in order to determine which offers the best services and costs. Three communication alternatives for the interconnection of the remote station and the central station are analysed, all of which are situated in the metropolitan area of a large city: point-to-point connections over ISDN (integrated services digital network), (virtual private networks) VPN´s/IP over ISDN, and VPN over ADSL (asymmetric digital subscriber line). For the communication between the central station and the mobile remote clients, the connection via GPRS (general packet radio service) is evaluated. For the measurements and posterior analysis control information and images have been transmitted. The viability of these types of solutions in the proposed scenarios is shown and the costs involved in each solution are analysed.