If a suitable chartplotter is not available, local area AIS transceiver signals may be viewed via a computer using one of several computer applications such as ShipPlotter and Gnuais. These demodulate the signal from a modified marine VHF radiotelephone tuned to the AIS frequencies and convert into a digital format that the computer can read and display on a monitor; this data may then be shared via a local or wide area network via TCP or UDP protocols but will still be limited to the collective range of the radio receivers used in the network.