This thesis presents a design and construction of a terminal node controller for packet radio network with communication control software that can be used for microcomputer-to-microcomputer communication via UHF 422 MHz radio transmission system. By using AX.25 protocol, CSMA (carrier sense multiple access) channel control and the Bell system model 202 standard modem utilizing; frequency shift keying (FSK) modulation. This terminal node controller is designed to interface with a microcomputer or data terminal equipment (DTE) via the EIA-Standard: RS-232-C, with a push to talk (PTT)2-way radio transceiver via microphone and speaker. The communication control software consists of a user interfacing program on microcomputer and the AX.25 protocol program on the terminal node controller.
