Motorola V186 - Cell Phone - GSM System Planner Manual page 130

Communications
Digital Trunked Radio Systems
In digital trunked radio systems such as ASTRO IV&D and TETRA (Dimetra), the
ACE3600 uses the packet data capability of the system. The digital trunked radio system
behaves as an IP network. The ACE3600 interfaces to the digital radio using an RS232
port configured to PPP protocol. For more information refer to the MDLC over ASTRO
IV&D chapter in the ACE3600 STS Advanced Features Manual.
Conventional Radio Interoperability
Introduction
Since the first MOSCAD RTU was introduced to the market, various models of Motorola
conventional radios had been used with Motorola RTUs. In cases where new RTUs are
added to existing systems with newer radio models, or when legacy radios are replaced
with newer models, it is important to make sure the radios can interoperate in the same
system.
The purpose of this technical note is to provide important information on Motorola radio
interoperability in control systems that use MOSCAD, MOSCAD-L, MOSCAD-M,
ACE3600, and Front End Processors (FEPs) such as MCP-M and IP Gateway. The radios
discussed in this document are Motorola conventional radios.
Channel Monitor Resolution Parameter (MDLC Slot Time)
The MDLC protocol uses a slotted time channel access algorithm for radio
communications. The Channel Monitor Resolution parameter sets the time slot period (in
milliseconds) in the RTU/FEP. The types of radios used in the system determine the
value of this parameter (typically 100 to 300 ms).
Please note that the Channel Monitor Resolution parameter should be the same in
all the RTUs/FEPs in the system. When different radios are used in the system, the
parameter is determined by the radio that requires the longest slot time.
For example, in a system which uses both 200 ms and 300 ms radios, the Channel
Monitor Resolution parameter should be set to 300 ms in all the RTUs/FEPs in the
system. To determine how to set up the Channel Monitor Resolution parameter in RTUs
in your system, see the table on the following page.
First Warm-up Delay Parameter
When the radio's PTT is activated, the radio starts transmitting a carrier wave. The other
radios on the same frequency channel that receive the carrier wave activate the Channel
Monitor and signal the RTU that the channel is busy. For each type of radio, there is a
specific delay between the activation of the PTT in the transmitting radio and the
activation of the channel monitor signal in the receiving radios. The types of radios that
are used in the system determine the value of this parameter (typically 200 to 350 ms in
Motorola conventional radios).
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