Enhanced Specialized Mobile Radio
ESMR (Enhanced Specialized Mobile Radio) is a wireless communication system in which numerous mobile/portable transceivers are linked in a network of repeaters. Each repeater has a range of approximately 5 to 10 miles. Operating frequencies are in the UHF (ultra-high-frequency) range, that is, between approximately 300 MHz and 3 GHz. Usually, the working band is near 900 MHz. ESMR can function like its fundamentally simpler cousin, SMR, but it can also offer features similar to those of a cellular telephone network. The PTT (push-to-talk), half-duplex mode can be used; in this case the operation resembles communications between old style two-way radios. full-duplex mode can also be used, so either party can listen and talk at the same time. Interconnection with the telephone networks is commonly done. In addition to voice communication, an ESMR system can offer paging, wireless fax, and data transmission
ESMR stands for Enhanced Specialized Mobile Radio. A Motorola-developed mobile communications implementation that integrates radio services with TDM mobile telephony to provide digital mobile communications service using primarily the 800 MHz frequency band, facilitating applications such as paging, data