Automatic train control (ATC) is a general class of train protection systems for railways that involves a speed control mechanism in response to external inputs. For example, a system could effect an emergency brake application if the driver does not react to a signal at danger. ATC systems tend to integrate various cab signalling technologies and they use more granular deceleration patterns in lieu of the rigid stops encountered with the older automatic train stop (ATS) technology. ATC can also be used with automatic train operation (ATO) and is usually considered to be the safety-critical part of a railway system. There have been numerous different safety systems referred to as "automatic train control" over time. The first experimental apparatus was installed on the Henley branch line in January 1906 by the Great Western Railway, although it would now be referred to as an automatic warning system (AWS) because the driver retained full command of braking. The term is especially common in Japan, where ATC is used on all Shinkansen (bullet train) lines, and on some conventional rail lines, as a replacement for ATS. Africa Egypt The accident report for the 2006 Qalyoub accident mentions an ATC system. South Africa In 2017, Huawei was contracted to install GSM-R partly to provide communication services to automatic train protection systems. Asia Japan In Japan, the Automatic Train Control (ATC) system was developed for high-speed trains like the Shinkansen, which travel so fast that the driver has almost no time to acknowledge trackside signals. Although the ATC system sends AF signals carrying information about the speed limit for the specific track section along the track circuit. When these signals are received on board, the train's current speed is compared with the speed limit and the brakes are applied automatically if the train is travelling too fast. The brakes are released as soon as the train slows below the speed limit. This system offers a higher degree of safety, preventing collisions that might be caused by driver error, so it has also been installed in heavily used lines, such as Tokyo's Yamanote Line and some subway lines. Although the ATC applies the brakes automatically when the train speed exceeds the speed limit, it cannot control the motor power or train stop position when pulling into stations. However, the automatic train operation (ATO) system can automatically control departure from stations, the speed between stations, and the