Central Maryland Area Regional Communications Committee (CMARC)

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Public Trunked Radio System

NameCentral Maryland Area Regional Communications Committee (CMARC)
OwnersAnne Arundel County, Carroll County, Harford County, Howard County, Baltimore City
Owner TypePublic
CountiesAnne Arundel, Baltimore, Carroll, Harford, Howard, Baltimore City
CountryUnited States

System Details
Band700/800 MHz
TypeProject 25 Phase I
NAC3D1 (Site 1.1) 3D2 (Site 1.2)

FCC Callsign(s)
WQNH702, WQNH714, WQNH763, WQNH768, WQNI382, WQPY875, WQPY892, WQTB744

System-specific links
DatabaseFCC Site Map
ForumRR Site Map

Other Resources

Wiki FAQMediaWiki
QuickRefPDF Card

Wiki HomeCollaboration Gateway → United States → MarylandAnne Arundel, Baltimore, Carroll, Harford, Howard, Baltimore City Counties → Central Maryland Area Regional Communications Committee (CMARC) TRS

Welcome to the Central Maryland Area Regional Communications Committee (CMARC) collaboration article, a Multi-County Public Trunked Radio System located in Anne Arundel, Baltimore, Carroll, Harford, Howard, Baltimore City Counties, Maryland, United States.
This is where you, the user, may index any articles you develop for scanning related topics for this Trunked Radio System.


The CMARC system is a three-part project that provides interoperability and wide area communication among the Central Maryland counties. The physical infrastructure and related FCC licenses are owned/held my the county in which the specific site/equipment exists. The equipment and systems, in general, is able to be utilized by any member-county agency.


The microwave backbone links all CMARC system RF sites, as well as each member county's PSAP. The backbone connects both radio systems, enabling wide-area calling (Project 25 system) and voted receiving and steered answering (NPSPAC system). The microwave backbone also allows for voice intercom exchanges between all member PSAPs. These intercom pathways can be used to patch county-specific communications systems across member counties as needed, and to the CMARC RF systems.

NPSPAC 800mhz

CMARC provides consolidated access and control for all of its member-counties to a structured NPSPAC 800mhz nation-wide frequency infrastructure. A network of base station/repeater sites around the served region allows for maximum utilization of the NPSPAC 800mhz "national" frequencies during times of inter-agency cooperations among ANY user who has radio access to the 800mhz 8TAC/8CALL frequencies in repeat/duplex mode.

The 8CALL frequency is available in non-repeated duplex mode at every system site. It is monitored by MEMA/MJOC, as well as by each participating PSAP. Upon request, MEMA/MJOC can switch the geographically appropriate 8TAC base station into repeater mode to allow for repeated communication during an incident. The 8TAC1 and 8TAC2 base stations, when enabled into repeater mode, create wide-area simulcast systems, while the 8TAC3 and 8TAC4 base stations, when activated, provide stand-alone single-site repeaters for their geographical areas.

Individual member PSAPs can patch their legacy communications systems into CMARC 8TAC channels for cross-system interoperability.

Project 25 700mhz

The second phase of the CMARC system is a wide-area 700mhz P25 trunked radio system that allows system users to communicate locally and throughout the served region on county-specific and regional talk groups. This allows a system user of any member agency to stay connected to their PSAP or their system users while roaming anywhere in the served region. This is especially useful when a pursuit crosses county boundaries, and leaves the coverage footprint of the originating county's radio system, or when an EMS unit transports to a hospital in another county, and would otherwise lose contact with their PSAP.

A series of event and coordination talk groups allow all system users to connect regardless of which county within the served area the event/incident is occurring.

Harford County

When the need was realized for Harford County to upgrade their 800mhz SmartZone radio system, the county chose to utilize the existing backbone and RF capacity of their county-owned CMARC 700mhz cell as a base for their upgraded system. Essentially, their "cell" became the county's primary radio system, the talk group template was upgraded to closely mirror their legacy system, and users were loaded onto the system one agency at a time. Once all users were loaded and stabilized, the 800mhz frequencies from the depreciated legacy system were "rolled over" into the RF capacity of their CMARC cell, making it a 700/800mhz system cell.

While most of the county-specific talk groups are only enabled on the Harford County cell, a handful are wide-area enabled, allowing them to be accessed by county users roaming anywhere in the CMARC-served region.

Related Wiki Pages

Harford County Wiki Pages

External Links

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