User's Manual
Table Of Contents
and Type II systems place radios (or radio users) into groups, called talkgroups,
and these
talkgroups are also assigned unique IDs. Some radios have access to only one
talkgroup,
while others have access to many talkgroups. The talkgroup(s) each radio can
access is
called the radio’s affiliation(s).
In a Type II system, when someone uses their radio, only the radio ID is
transmitted when
PTT is pressed, whereas in a Type I system the radio ID and its current
affiliation are both
transmitted when PTT is pressed.
Why the difference? Type II systems are slightly more advanced because the
central
computer maintains a database which is used to determine each radio’s
affiliation(s).
Changes to a Type II system are easier than Type I because the system manager
only
needs to update the database instead of reprogramming individual radios.
Another difference between the systems is that Type I systems are arranged in
a Fleet-
Subfleet hierarchy. For example, its possible for a city using a Type I system to
designate 4
Fleets, each with 8 Subfleets. Their fleets might be the Police Department, the
Fire
Department, Utilities, and Administration. The Police may decide to further
divide their fleet
into subfleets such as Dispatch, Tactical Operations, Detectives, North, South,
East and
West Side Patrols, and Supervisors. All the available police radios would then
be assigned
to one of the police subfleets. Determining the exact Fleet-Subfleet hierarchy for
a particular
area is referred to as Fleet Map Programming, which is discussed further in this
manual.
The disadvantage of a Type I system is that when PTT is pressed, the brief
burst of data
must contain the radio’s ID and its Fleet and Subfleet. This is three times the
amount of data
a Type II system radio sends, and as a result Type I systems usually
accommodate fewer
users than Type II systems.