CDMA: CDMA2000 1X, backforward compatible IS-95A CDMA800: Transmit 824-829 MHz, Receive 869-894 MHz CDMA1900: Transmit 1850-1910 MHz receive1930-1990 MHz GSM: GSM900: Transmit 880- 915 MHz, Receive 925- 960 MHz GSM1800: Transmit 1710- 1785 MHz, Receive 1805- 1880 MHz Power supports 220V AC and 48V DC One 16 pin port is used for connecting 2/3/4 pieces of S1804 to 8/12/16 ports One RS232 connects NMS to charge billing or configure parameter Four individual SMA-KY antenna interfaces have high signal sensitivity, little interference The indicator of signal intensity LED: PWR1 and PWR2,each of them has three lights which denote state ,run ,billing Four standard RJ11 ports is used for connecting with DTMF phones Console port is used for connecting with fixed wireless billing system of S1804(billing meter) Multi-charging modes: Console Port,S1804 billing meter, reverse polarity billing Flexible tariff modes Can saves 20000 particular calls list when power of S1804 cuts off Meter billing can monitor 8 phones at the same time Meter billing supports billing statistic about latest 8 days and 4 months, and one person multi-calling. The mode of configuration and maintenance: Console NMS, remote SMS Supports lock of terminal and card, locks-in the subdistrict. Supports PIN code protection Automatically adds IP numbers, and supports 8 digits length Automatically adds area numbers, and supports 8 digits length Supports DTMF phone Caller ID Supports 512 area numbers Supports 100 barred numbers Accurate charging by signal or bidirectional voice detection Provides reverse charge signal to connect meter