Trunked Radio Systems in Hawaii
A trunked radio system is a complex
type of radio system that is used to maximize available capacity
in a two-way radio system. Groups of users are given a logical
talkgroup to share for their communications, rather than a dedicated
radio frequency. Trunking is used by many government entities
to provide two-way communication for fire departments, police,
and other municipal services, who all share spectrum allocated
to a city, county, or other entity.
Trunking systems in use in Hawaii
Trunked radio systems from the three
major companies (Motorola, M/A Com, and EF Johnson) are in use
in Hawaii. The most common system in use on all islands are the
Motorola Type II standard. When Motorola systems were first put
into place, the older Type I and Type IIi Hybrid (Type I talkgroups
[less common] mixed with Type II talkgroups) existed alongside
the regular Type II systems.
Because Type I systems are based on fleet and subfleets (very
similar to EDACS radio systems), Type I systems are not scalable
because they limit the amount of IDs any fleet or subfleet can
support. All Type I or IIi systems were upgraded to a Type II
Honolulu County uses Ericsson EDACS standard with a mix of analog
and ProVoice digital transmissions, while Maui County uses the
LTR Multi-Net standard. Maui County is planning to upgrade its
800 MHz radio system to Project 25 standards.
In 1997, radio scanners compatible with trunked
systems appeared on the market. One of the first companies to
bring these devices to market, Uniden, trademarked the term trunk
tracking on 5 December 1997.
The first scanner with Ericsson EDACS trunking
capability, the Uniden BC245XLT, was released for sale in July
The first scanner with LTR trunking capability, the Radio Shack
Pro-92, was released in November 1999.
800 MHz Rebanding and the Future of Scanning
Expect to see a number of changes to the 800 MHz public safety
trunked radio systems in Hawaii during 2008. An R&O (Report
and Order) from the Federal Communications Commission regarding
rebanding (reconfiguration) of the 800 MHz radio spectrum
is expected to take place beginning this year.
Scanners monitoring Ericsson EDACS and LTR Standard systems will
work fine after rebanding. Users will have to reprogram frequencies
into their correct LCN order. However, current analog-capable
scanners monitoring Motorola systems in the 866-869 MHz range
will not work properly because of the changes Motorola
will make to the trunking channel plan that is hard coded into
Radio Shack and Uniden scanners. After rebanding, radios will
not scan to the correct channel when the system assigns a call
that was previously on a frequency between 866-869 MHz and was
retuned to a new rebanded frequency 15 MHz lower between 851-854
Frequencies in the 866-869 MHz range are spaced 12.5 kHz apart,
where as pre-rebanding channels in the 851-854 MHz range are 25
kHz apart. The trunking channel plan allows certain scanners to
track trunking systems using only the control channel.
The Pro-96/Pro-2096 scanners will be able to monitor Motorola
rebanded public safety radio systems switching over to the 851-853
MHz band. These scanners out of the box is not programmed with
the correct channel spacing data on the rebanded systems. The
only way to correct this issue is to use scanner programming software
for the Pro-96.
Systems for which information is confirmed and available