CPO2 K.C. Dickens, Operations Chief of NRS Halifax provides this overview of the communications systems available to the Canadian Navy in 2009.


Maritime Semi-automatic Exchange (MSAX) Message Switching System (MSS)

MSAX is a messaging system which distributes message traffic to all broadcasts in the system for delivery to ships at sea, bases throughout Canada and the world via the Automatic Defense Data Network (ADDN).

There are 4 operator positions within MSAX. The Traffic Resource Manager (TRM) position is responsible for the overall operation of the MSAX system. The Service Position (SIP) is responsible for dealing with all service messages addressed to Naval Radio Section (NRS), which include misrouted, rerun requests, ships setting and ceasing watch and operational messages. That person is also responsible for dealing with messages which arrive at NRS with errors in them and drafting administrative messages. The RSS and AGA terminals are used to transfer messages received at their terminals into the MSAX system for onward delivery.


Listed below are the call signs used for the three broadcast types.

Broadcast traffic is transmitted on high frequency and low frequency. 
Broadcasts are also transmitted via satellite communications. Ships equipped with Demand Assigned Multiple Access (DAMA) or Super High Frequency  can copy broadcasts that are transmitted on applicable satellites.


RATT = radioteletype

Ships at sea utilize RSS to transmit administrative and operational traffic ashore. NRS Halifax transmits on working frequencies in 5, 10 and 15 MHz bands. To operators it is known as the ZKR list. Ships at sea in turn will transmit their traffic on frequencies in the 2, 3, 4, 6, 8, 16 and 22 MHz bands.

Operators at NRS utilize the RSS System to receive traffic from terminals at seas running at 300 or 600 baud. To accommodate certain NATO countries, the RSS system is also configured to receive at 75 baud. There are four consoles associated with the RSS system and each one is configured to operate on any of the working frequencies. Satellite Ship/Shore communications is also received through the RSS System via  DAMA and SHF.


Demand Assigned Multiple Access (DAMA)

NRS Halifax utilizes DAMA for transmitting secure broadcasts to ships at sea and as a means of receiving message traffic from ships anywhere in the world.

Super High Frequency (SHF)

SHF is fitted on HMC Destroyers (command platforms). With SHF,  Command has access to local phone service with MARLANTHQ Halifax, multiple broadcasts, high data rate of transmitting ship/shore traffic and MCOIN messaging services. NRS Halifax provides these ships with the link for operation of all circuits used on

Air Ground Air (AGA)

AGA provides HF long-range communications between aircraft and shore-based operational authorities. The MARLANTHQ (ATLANTIC) Network is part of the NATO Maritime Air Telecommunications Organization (MATELO). A bilateral agreement with the United States allows USN aircraft to make separate use of the Maritime Command AGA Network.

In addition to providing an operational network for Maritime tasked aircraft, AGA Halifax provides telephone patches to and from aircraft, terminal weather for selected bases and a back-up communications system for ships/subs in the event that all transmitters of a Canadian Area Broadcast become unserviceable. Communications are also provided between Search and Rescue (SAR) aircraft and RCC Halifax. NRS Halifax AGA will also provide backup services for MACS Trenton and vice versa.

AGA Specific Responsibilities:
- To provide HF comms between the Joint Maritime Operations Center and the Rescue Coordination Center
- Provide HF comms (voice/data) for training flights from Gander, Greenwood and Shearwater.
- Transmit updated hourly weather updates and long range forecasts to military flights and upon request relay by voice to commercial flights.
- AGA Halifax has provided service to flights throughout the Western Atlantic seaboard to Iceland, south to the Azores and Northern Patrols as far north as Nunavut.
- Operators working at AGA have the responsibility of providing HF comms to Search and Rescue missions throughout the Western Atlantic.

Other Services And Capabilities At NRS Halifax

- Remote Control and Monitoring System (RCMS)  - is a software  program designed to give operators the capability of remotely controlling receivers at the receiver site in Mill Cove and the transmitters in Newport Corners.

- Should NRS Esquimalt have a MSAX failure, NRS Halifax has the capabilities to service the West Coast broadcasts to a maximum of 5 HF and 3 LF streams and vice versa.

- BBE Line is used for receiving administrative traffic. It is also a back-up for the MSAX system, used for transferring operational traffic from deployed units for onward delivery.

- One Maritime Command Operational Information Network (MCOIN) Terminal and 2 MCOIN Messaging terminals used for receiving administrative and operational traffic from ships VIA secure e-mail.

- Unclassified and secure FAX.

- Three MCAN Terminals used for administrative purposes by operators at NRS.

- One land line direct to Cutler, Maine, used for sending broadcast data to be up linked to satellites or transmitted via HF or LF to ships and submarines.

- Two land lines direct to Norfolk, Virginia, used for sending broadcast data to be up linked to satellites or passed to Key West Florida for extended HF broadcast availability.

-  PC to PC communications is used by ships to send traffic ashore using a STE/OMNI equipped telephone.


Chuck Dickens <Chuck.Dickens(at)>

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June 19/09