MaxStream has released stand-alone ZigBee-ready radios that allow for quick connections to both RS-232 and USB enabled devices. The stand-alone XBee-PRO radio is compatible with networks operating on XBee and XBee-PRO technology.
The 2.4 GHz XBee-PRO stand-alone radio features the 100 mW (EIRP) XBee-PRO RF module, which is capable of transmitting up to 0.9 miles (1.4 km) in line-of-sight conditions. Communicating at up to 250 Kbps, the XBee-PRO is ZigBee-ready and will be upgradeable to the latest ZigBee compliant networking protocol as it becomes available.
http://www.maxstream.net
