The subway line, which will be operated on a 9.22 kilometers long, double track route to serve between Tandoğan-Keçiören - among the most crowded areas of Ankara, has been tendered at the end of 2011 by the Ministry of Transportation, Maritime Affairs and Communication General Directorate of Infrastructure Investments.

The route starting with the Ataturk Culture Center (Atatürk Kültür Merkezi - AKM) Station continues with the ASKİ, Dışkapı, Meteoroloji, Belediye, Mecidiye, Kuyubaşı, Dutluk stations respectively, and ends at the Keçiören Şehitler Station.

Having previously completed the installation for M1, M2 and M3 subway routes in Ankara, Ateksis now finished the Public Address system installation also route M4, as an integrator.

Powered by Preasideo as a top-level public address system by Bosch, this solution offers local control at stations and management of all stations and routes via a command control center.

Each station is locally equipped with Preasideao and digital amplifiers of the system. Sensor microphones placed in platforms and ticket offices area allow to automatically measure ambient noise and adjust automatic volume control thanks to DSP (Digital Signal Processing) technology embedded in digital amplifiers.

The stations are additionally equipped with a desktop announcement microphones for operators to make announcements for passengers.

Bosch LC1 series modular speakers come into play for perfect audio quality. LC1 series ceiling-type speakers placed in suspended ceilings and LB1-UM06 series wall-type speakers are in compliance with EN 54-24 standards.

IP audio interface devices by Bosch with PRS-1AIP1 code have been put to use in an effort to transmit audio signals between the command control center and stations through a TCP/IP network. PRS-1AIP1 IP audio interface allows any operator at the command center to make a live or recorded announcement for one or more than one station or sub-zones of stations.

A graphical interface software (developed by Ateksis) runs at the command control center. Put into operation for the routes M1, M2 and M3, and developed in line with the needs of operators, the software displays the stations on a screen and allows operators to select any station they would like to make an announcement for. Any potential failure in the system is checked by the software, as well.