Fire Departments have traditionally operated on the low
band in the 33 mhz range. At one time all departments
were on a single channel....33.70 mhz. As departments got
busier and communications more frequent, many departments
switched to their own "fire alarm" frequency.
The 33.70 mhz channel continued to be used as a common
"county" frequency for inter-department and
mutual aid communications. By the late 1970's all
departments were off the "county" frequency and
operating on their own channels. The county frequency
continued to be used, and is still in service today, for
mutual aid purposes.
"Skip" used to be a very common problem on the
33. mhz frequencies, particularly the summer. To overcome
this extremely irritating condition, all departments
added PL (private line) tones (CTCSS) to radios. The
common tone in the county is 114.8. This helped greatly
in reducing the foreign noise.
departments continued to grow in recent years, some added
additional VHF and UHF frequencies that could be used for
administrative purposes. Primary operations however,
continued on the 33. mhz channels.
Fire Departments utilize an 800 Mhz Trunked Radio
Police Departments originally operated in the high band.
The (4) channel 155. mhz police radio system was once
utilized by all Cape Police Departments. Ch.1 operated by
the Sheriff's Department was used for General Broadcasts
(GBCs), General Info broadcasts (GIs), Be On the Look
Outs (BOLOs) and other countywide communications. All
departments used FCC callsigns. Each department had
assigned car designations (Able, Baker, Charlie, David,
communications increased, some departments aquired their
own police channels, while others continued to use Ch.2,
3, and 4. Most of the departments continued to stay on
155. Mhz frequencies.
Mhz radios became available, some departments switched to
800 Mhz "conventional" frequencies with local
repeaters. Others remained on VHF high band.
800 Mhz Trunked Radio system came a couple years ago, all
the departments still on the VHF high channels joined the
800 Trunked system. Departments which already had
conventional 800 Mhz radio channels stayed on those.
Cape Police Departments are on 800 mhz, some trunked and
Fire Departments have provided EMS service on the Cape
for many years. In 1975 a 400 Mhz UHF EMS CMED radio
system was installed providing ambulance to hospital
communications for over 60 ambulances operating within
the region. The Cape & Islands Emergency Medical
Services System (CIEMSS) provided the system and the
Barnstable County Sheriff's Department staffs and
CMED is a system of radios, repeater sites, and telephone
circuits which connect ambulances to (4) area hospitals.
There are (6) repeater tower sites in the area, each
having multiple channels available for
"patches" to local hospitals. Channel 4 is the
primary calling channel for rescue units. Channels 2,5,7
and 8 are available for "patching" an ambulance
radio communication via phone line to the area hospital.
It is a duplex system allowing two way conversations.
Each channel has an input and output frequency. CMED is
an active system with over 35,000 incidents per year
years ago, the Massachusetts State Police radio system
upgrade to 800 mhz trunking began. Cape Fire and Police
Departments worked out arrangements to join with the
State Police Trunking System. The result has been a
considerable change in Cape Cod communications. While not
yet 100% completed, the system has been utilized quite
reliably now for over (2) years.
"Trunked Radio System" is someone complex to
understand and explain, but basically it is a Motorola
Type II system. It presently utilizes a bank of (15) 800
mhz frequencies. Within these frequencies is a
"data" channel which allows user radios to
track communications by user groups known as "Talk
Groups." The system utilizes several repeater sites
on the Cape. All radios must reach the repeater site to
transmit. A very sophisticated computer controls the
whole system. These frequencies are shared by all Cape
Cod Fire Departments, most Police Departments, the State
Police, Environmental Police, and perhaps more.
portable radios issued to fire departments have (3) banks
of 16 channels each.
"A" Bank, contains the home department's
channel, a mutual aid dispatch channel, 5 neighboring
departments, the local police channel, a Capewide
Administrative channel, a CIEMSS talkgroup, and (5)
common I-Call / T-Tac channels. Channel 1 in the
"A" bank is a low power, Direct channel. Radios
in the "A" Bank typically can scan the home
channel, neighboring departments, and the mutual aid
"B" Bank in each radio contains the remaining
fire department channels not included in the
"C" Bank has the home channel, (3) OPS channels
for major incidents, and other channels.
"C" Bank in each radio was designed for use at
multi-department incidents. Channel 1 is the Direct
channel. The direct channel is a conventional 800 (not
trunked). This is paired with the C2 channel which is the
home department's primary channel. C1 and C2 scan each
other. If for some reason, a portable in a building
cannot transmit out (it is unable to hit one of the
cape's repeater sites), the person in the building can
switch to the direct C1 position to reach command or
other units on the scene. The (3) OPS channels are
similarly paired....C3 is direct/C4 is OPS 1..........C5
is direct/C6 is OPS 2......etc.... Each pair scans itself
for this "backup" for emergency purposes. The
direct channel frequency is the same in all positions.
does not utilize a "regional" or centralized
dispatch center. Each of the Cape's Fire Departments have
their own dispatch centers, each department uses its own
channel (Talkgroup), and all of the departments using the
"Trunked" system simulcast radio communications
over their 33. mhz frequencies for tone activated pagers.
Most dispatch centers have (1) A fire alarm channel for
dispatch and day to day operations...simulcast over 33.
mhz, (2) a countywide "Mutual Aid Dispatch"
channel used for inter-department and mutual aid dispatch
purposes. This is strictly used for station to station
communications and is not used for mobile or portable
communications. Dispatch centers then use mobile radios
which can be selected as needed for access to OPS
channels during major incident.
for an incident is basically as follows. Each department
dispatches its incidents on their own "fire
alarm" talkgroup (A2 and C2 positions on their
radios.) These communications, including pager tones, are
simulcast on their 33. mhz frequency. When a working fire
or major incident is encountered, the fire alarm
dispatcher contacts the mutual aid center via phone or
the M/A Dispatch talkgroup, and is assigned an "OPS
channel" for fireground / incident communications.
All units responding to and operating at the incident are
instructed to switch to an OPS channel (OPS 1, 2, or 3).
Units on scene will stay on the OPS channel until the
incident is concluded. Units given coverage / moveup
assignments are dispatched by the mutual aid center on
the M/A Dispatch talkgroup. As apparatus responds, it
remains on its own fire alarm channel until reaching the
community to be covered. Upon reaching that community,
apparatus switches to the fire alarm talkgroup of the
department being covered and remains on that channel for
assignments. If additional moveups occur, units switch to
the talkgroup of the next community being covered. It is
complex and may be confusing to follow... but so far it
fire communications on the Cape by scanner has actually
improved greatly with the 800 trunked system. Obviously,
having a newer scanner with "Trunk Tracking"
capability helps to provide best control over what you
hear. Listening with older, non-trunking radios has also
improved, as the process of simulcasting communications
has made it possible to hear portable radios as well as
mobiles in most cases. Monitoring with a Trunk Tracker
scanner involves programming the (15) 800 mhz frequencies
and then the 5 digit talkgroups of the departments you
wish to hear.
trunked system is being improved on again at this time
with additional repeater sites being installed soon to
provide the desired 95%/95% coverage for in building use.
all Cape Fire Departments are capable of using the 800
mhz trunked system. Mobile and portable radios, as well
as dispatch center radios are in place. Due to some
concerns about "in building" coverage, Hyannis
and Yarmouth Fire Departments have not yet made the
switch to 100% use. The West Barnstable Department has
shared a low band frequency with the Barnstable Fire
Department. This creates a situation with simulcasting,
so WBFD has not switched to 800 mhz yet pending a new 33.
mhz channel to put pagers on. All other departments are
on and working well.
Aid Center for Barnstable County (Barnstable County
Control) is located at the barnstable Sheriff's
Department in Barnstable. This is the center piece of
Cape Fire Communications.