High capacity transportable radio communication systems are considered specially for transmitting high capacity information from tactical areas to operational commander levels. Whereas the communication services including single-channel communication equipment operated in tactical zones do not meet needs of brigades and divisions in operational areas, usually high capacity point-to-point transportable radio communication systems are benefited from higher level communication services. zTRC-421/E provides capability of establishing full duplex telephone communication, exchanging data/image with maximum capacity of 8Mbps in the UHF frequency range. In case that the capacity is used only for telephone communication, 128 subscribers can make high quality call. All of the exchanged information including voice, data, and image are encrypted by an advanced encryption unit, before being exchanged. Due to network interfaces, the two LAN networks available in both sides can be connected to each other via this transportable radio communication system. Frequency range of the TRC-421/E is a wide range of 225~400 MHz specified proportionate to distance of the two points, terrain, and exact operational frequency. In addition to operating the radio as a point-to-point radio, it can be used as a repeater for increasing communication distance.