Multi-channel(MCR) / line of sight relay systems are used for high-rate, digital data (telephony, video, multimedia) transmission over radio links. The system provides high- capacity data wireless communications. ’s Multi-Channel Radio product line include the GRC-408E (offering 8 Mb/s, ECCM capable radio system), and the GRC-2000, Band IV (4,400-5,000 MHz fast frequency-hopping, radio system). The most recent model, the GRC-408E, evolved from the GRC-408A and the GRC-408HC+, providing 8 Mb/s data capabilities and spectral efficiency over the extended frequency Band III (1350-2690 MHz), while maintaining full backward compatibility with earlier models. The GRC-2000, a frequency hopping line-of-sight multi-channel radio system, emerged as the fourth generation radio relay out of Communications’ line of sight multi-channel radio legacy. It provides ultimate ECCM capabilities for the 21st century’s digitized battlespace.