Antenna Interface Standards Group (AISG)
The Antenna Interface Standards Group (AISG) is both an organization and a protocol that defines communication standards between the RET (Remote Electrical Tilt) antenna system and the base station.
The AISG organization is made up of various antenna manufacturers. Its main goal is to standardize the interfaces of RET antennas using common protocols, allowing Antenna Line Devices (ALDs) from different vendors to be monitored and managed in a consistent way. AISG is responsible for creating and maintaining the control and monitoring standards that define how ALDs interact with base stations. These standards are known as AISG protocols. The most widely used versions today are AISG v1.1, AISG v2.0, and AISG v3.0.
AISG Protocol Overview
The AISG communication protocol works with one main device (the control center) and multiple secondary devices. All communication is started by the main device, which sends control commands to the secondary devices.
AISG also defines data interfaces for ALDs and provides a simplified three-layer communication model based on the OSI seven-layer model. This lightweight protocol stack ensures reliable communication between the controller and antenna devices while keeping system resources optimized.
Scope of the AISG Protocol
The AISG protocol defines how ALDs are remotely controlled by the base station through standardized data interfaces.
Using the OSI seven-layer model as a reference, the AISG protocol simplifies it to a compact three-layer structure — layer 1, layer 2, and layer 7. Each version of the AISG protocol defines ALDs differently. In AISG v1.1 and v2.0, ALDs are defined by logical functions. The main ALDs include:
- Remote Electrical Tilt (RET)
- Tower Mounted Amplifier (TMA)
- Antenna Location and Orientation Sensor (ALS)
AISG v3.0 expands this by introducing two hardware-based ALD types:
- Single-Primary Antenna Line Device (SALD)
- Multi-Primary Antenna Line Device (MALD)
Evolution of AISG
In June 2004, AISG v1.1 was released. It provided basic compatibility and interoperability between RET antennas and control systems but did not fully comply with 3GPP standards.
In June 2006, AISG v2.0 was released. This version was fully aligned with 3GPP specifications and ensured compatibility with other 3GPP-compliant products. It mainly introduced settings for electrical downtilt, TMA gain control, and TMA status monitoring.
In May 2015, AISG v3.0 was launched as the latest version. It defines how a primary device (such as a base station) communicates with ALDs and allows multiple base stations to control one or more ALDs. To achieve this, AISG v3.0 defines two ALD types — SALD and MALD.
Advantages of AISG v3.0
Compared to version 2.0, AISG v3.0 offers several improvements. It supports MALDs, enabling multiple network elements to manage the same device simultaneously. In multi-band antennas, configurations can be adjusted locally from the base station using the antenna, without affecting others.
AISG v3.0 also supports Site Mapping and Ping functions, allowing automatic drawing of the feeder connection topology between antennas and RF modules. This helps detect incorrect cable connections remotely.
Additionally, a single serial number is now used for each physical device, reducing scanning time. Configuration, maintenance, and testing are also improved through new features like logging, diagnostics, and alarm reporting.