Transmitting Medical Imagery over 2-Meter Amateur Packet Radio Networks using TCP Reno and UDP

The United States Federal Communications Commission permits licensed amateur radio operators to transmit data using the 144.1 MHz - 148.0 MHz radio frequencies that comprise the amateur 2-meter band. Unfortunately, significant time is needed to transmit large files over 2-meter amateur packet radio networks because the required terminal node controllers (i.e. radio modems) transmit data at a standard rate of 1200 bps. In this paper, we evaluate the performance of the Reno variant of the transmission control protocol and the user datagram protocol when both are used to transmit medical imagery over ns-2 simulated 2-meter amateur packet radio networks. Specifically, we obtain file transmission times while varying protocol segment sizes and channel bit error rates, and find that smaller segment sizes are best for transmitting medical imagery when the bit error rate increases. We also discuss image quality measures as they relate to medical imagery transmitted using the user datagram protocol.