Tianlian is a Chinese data tracking and relay communications geostationary satellite series. The TL 2 (Tian Lian 2) satellites represent the second generation of this relay satellite network, and is based on the DFH-4 Bus, a three-axis-stabilized telecommunications satellite platform. TL 2 will be used to support real-time communications between orbiting satellites and ground control stations. This system will replace the current network of ground-based space tracking and telemetry stations and space tracking ships.