AISG protocol is based on half duplex communication and HDLC protocol. The AISG bus is a single master multi slave bus. Communication media can be either RS-485 based using a dedicated cable specified in the AISG standard or OOK carrier injected into the RF antenna feeder cable of a base station site. The master controlling the communication is called a primary and the slave devices on the bus are called secondaries and ALDs (Antenna Line Devices). Primary functionality can be integrated into a base station. Primary can also be a stand alone controller installed on the BTS site or a handheld / portable controller typically used during the installation of a base station site. Secondary device types include a RET (actuator tilting antenna beam electronically), a TMA (Tower Mounted Amplifier), a GLS (Geographic Location Sensor) or an ASD (Alignment Sensor Device). Data Basic baud rate used by the AISG bus is 9.6 kbit/s. When using a separate cable for AISG communication, the data is transmitted using RS-485 protocol. When the RF antenna feeder cable is used for AISG communication, OOK carrier with frequency is 2.176MHz is injected into the feeder cable using Bias-Ts. Connector An 8 pin circular connector is used to connect (or daisy chain) AISG devices. AISG consortium has released C485 standard for this RS-485 connector. This standard specifies the mechanical dimensions of the connector more tightly than the previously used standard (IEC 60130-9 - Ed. 3.0 standard with screw-ring locking ring). The C485 standard also specifies the IP rating of this connector to be IP68. This new standard was created to avoid connection problems between connectors from different manufacturers. Power In AISG v2.0 the 8-pin connector has dedicated DC power pins for +12V, 10–30V and −48V DC. Typically the 10–30V DC pin is used to power the secondary devices. In AISG v3.0 the 8-pin connector has only one pin dedicated for DC power, the 10–30V pin. AISG v2.0 Features AISG v2.0 standard features include setting the antenna beam tilt, setting the gain of the tower mounted amplifier and monitoring the health of the tower mounted amplifier electronics. References External links Standards Working groups Antennas (radio)