Remote Control Air Ground (RCAG) System

RCAG System Understanding:
RCAG:- Remote Control Air-Ground
RCAG is a facility for a/g communications of VHF and UHF controlled remotely by ACC. This allows direct communications between a control facility and aircraft in a remote area. RCAG system mainly deals with:

1. Remote Control and Monitoring System (RCMS)
2. Multi-Access Remote Control System (MARC)

Multi-Access Remote Control System (MARC):
MARC is a Remote Control and Monitoring system (RCMS) software package designed to monitor, and provide engineering control of an Air Traffic Control (ATC) radio system. A typical system comprises a number of remote radio sites that are operated from an Air Traffic Control centre. The remote sites may be part of a single airport complex or can be located over a wide geographical area. Note that MARC is an engineering facility that does not affect air traffic controllers normal usages of the radio system.
MARC contains two software packages namely: Navigator and Configurator.
Navigator is the software that runs when MARC is in use. It presents a series of graphical screens that show the user's radio system, or some part of it.Status indications provide a visual guide to system, site and equipment serviceability. Additionally, Navigator provides control functions, allows some automatic events to be programmed and generates historical system data.
The Configurator is the software used to define the user's radio system and compile the screens that are used by Navigator.
 MARC can operate with radio systems containing up to 30 Control Central Equipment (CCEs), 999 remote radio sites and 7992 radios. The radio system is monitored, and  control functions initiated from, a Personal Computer (PC) normally located at the air traffic center. A series of graphical screens provide monitoring and control functions.
MARC Functions:
Following monitoring and control functions are available through MARC;

1. Monitoring functions: 
1. Monitors the complete system and indicates any site where a fault is detected on the main screen. 
2. Monitors the site and indicates any faulty radio, remote site equipment or MARC data link. Also monitors any alrams that have been configured and indicates which are active on site screen.
3. Monitors each radio and indicates the nature of any fault on equipment screen.
2. Main and Standby Switching:
1. Automatic Switching: The standby equipment becomes operational should a fault be detected on the main equipment.
2. Manual Switching: The main or standby equipment can be manually selected as operational.
3. Automatic Events: Some, or all, radios configuraed as main/standby pairs can be pre-programmed to switch from the main to standby (or vice-versa) once at any predetermined time, or at regular periods.
3. Control Functions:
1. Frequency Change: The operating frequency of any radio can be changed or any stored frequency channel can be recalled.
2. Radio Parameters: Many radio parameters can be changed.
3. User Configurable outputs: A number of user outputs can be configured at the remote sites. These outputs can be used to switch building services on and off; for e.g. lighting circuits. The configurable outputs are activated/deactivated from the MARC-PC.
4. BIT Tests:
1. BIT test: A BIT test can be initiated on any radio.
2. Automatic Events: Some, or all radios can be pre-programmed to perform a BIT test once at any predetermined time or at regular periods.

In addition to the monitoring and control functions, MARC makes a number of reports available for display or printing. The reports include current and historic data pertaining to the radio system.