Modulation mode: GFSK/FSK Working frequency: 420.00í½450.30/860~875/910~925MHz Output power: 17dBm(50mW) Receiving sensitivity: -115 í½ -118dBm Channels: 8/16/32 Transmitting current: í_100mA Receiving current: í_30mA Sleeping current: í_20mA Interface rate: 1,200/2,400/4,800/9,600/19,200bps Interface mode: UART TTL, RS-232 and RS-485 Power supply: DC +3.3 to 5V Working temperature: -25íµ to 80íµ Working humidity: 10% to 90% Dimension: 47 x 26 x 10mm Reliable transmit distance (AT-4 antenna): 1,200m Communication mode: half-duplex Network topology: point to point and point to multi-point.