Abstract: A data terminal apparatus comprising a wireless radio and a communications bridge is provided. The data terminal apparatus provides a link between data from a user equipment and a GSM network, connecting user equipment designed for circuit switched call link communications to a destination equipment via short message service or general packet radio service communications. According to an aspect of the invention, the data terminal apparatus simulates a circuit switched call link to the user equipment, thereby bridging legacy serial data communications systems with convenient wireless network technology. The result is a highly portable and easily integrated data terminal appartus for a wide variety of user equipment. In one embodiment, the invention is particularly advantageous in utility service monitoring applications.

Abstract: A communications bridge for simulating circuit switched call links to user equipment is provided. According to one embodiment, the communications bridge receives data from the user equipment over a serial data interface. The communications bridge simulates circuit switched call link responses back to the user equipment so that the user equipment believes that a circuit switched call link has been made. Once the simulated circuit switched call link is established, data from the user equipment is packetized into short message service or general packet radio service packets for transmission over a non-circuit switched call link.