Edacs Trunking; Ltr Trunking - Uniden Trunk Tracker IV BCD996T User Manual

typically takes place in about a second...the person transmitting hears a beep from their radio when the channel is assigned and then
it is OK to start talking.
The systems in use are:
Motorola Type I – the radios send the radio ID, the fleet and subfleet talk group ID to the control channel each time they transmit. To
program a Type I system, you need to know the system's fleet map. The most common fleet maps are included in the Reference
section in this manual. You can also find fleet map resources on the web such as at http://www.radioreference.com.
Motorola Type II – the radios only send the radio ID and radio channel code to the control channel. The central computer keeps a
database of radio ID's and which talk group is assigned to which channel code for each radio, so with this system the user's radio
sends only about / the data as a Type I system with each transmission. Type II systems do not use Fleet-subfleet talk groups;
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instead they use a 5-digit ID for each talk group.
Type IIi Hybrid — these systems support a mix of both Type I and Type II users. Like Type I systems, you must know the system's
fleet map to ensure proper tracking.
Motorola ASTRO 25 (APCO 25) – these radios are similar to Type II systems, but send only the radio ID and radio channel code to
the control channel, transmitting voice in digital form.

EDACS Trunking

EDACS trunking works in much the same way as Motorola trunking with a couple of major differences. In an EDACS system, each
frequency used by the system is assigned a Logical Channel Number (LCN) so that less data needs to be transmitted by the control
channel. Talk groups are assigned in an Agency-Fleet-Subfleet (AFS) hierarchy.There is one variation of EDACS called SCAT that
your BCD996T can monitor.
Logical Channel Numbers – each frequency used by the system is assigned an LCN. This information is programmed into each
user radio. When a user presses PTT, their radio sends their AFS information to the control channel. The computer then assigns that
talk group to a channel and sends the LCN so that all other radios in that talk group will switch to the correct channel. To program an
EDACS system in your scanner, you will need to know both the frequencies used by the system and the LCN for each frequency.
Agency-Fleet-Subfleet – talk group ID's for EDACS systems are assigned in a way that makes it easy to see at a glance the
affiliation of the user. Each radio is assigned a 2-digit agency identifier from 00 – 15. For example, 01 might be used by the police, 02
by the ambulance service, 03 by the fire department, and so on. Each agency is then subdivided up to 16 times to provide fleet
identification, and then 8 more times to identify subfleets.
For example, the complete AFS for the Police Department West District's dispatch channel might be 01-062. 01 identifies the agency
as the police department, 06 identifies the fleet as the West district, and 2 identifies the subfleet as the dispatch channel. While these
assignments are somewhat arbitrary and vary from system to system, there are many resources on the web for finding the
assignments for most systems. Because of the logical hierarchy of the AFS system, your BCD996T lets you assign wildcard ID's that
let you, for example, use only one ID memory to identify all units in either an agency or a fleet.
EDACS SCAT – (Single Channel Autonomous Trunking) systems operate on a single channel and alternate control data with
analog voice traffic. While your BCD996T cannot track ID's in this system, it can eliminate the control data so that all you hear is the
voice transmissions when you monitor this type of system.

LTR Trunking

LTR (Logic Trunked Radio) systems are trunking systems used primarily by business or private communications service providers,
such as taxicabs, delivery trucks, and repair services. These systems encode all control information as digital sub audible data that
accompanies each transmission, so there is no separate control channel. Users on an LTR system are assigned to specific talk
groups, which are identified by the radio as six digit numbers.
These numbers are in the form AHHUUU, where:
A = Area code (0 or 1)
H = Home repeater (01 through 20)
U = User ID (000 through 254)
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