System Feature Overview 21
• In an IP Site Connect system, a customer can configure a logical channel as either a
local channel or a wide area channel. A call over a local channel is repeated only over
the local site, whereas a call over a wide area channel is repeated over all the sites
where at least a channel is idle. Instead of local and wide area channels of IP Site
Connect, LCP supports both local and wide area talkgroups. A repeater handles a local
talkgroup call in the same method as in a Capacity Plus configuration. However, a wide
area talkgroup call is repeated over all the associated sites where at least one logical
channel is idle.
• In an IP Site Connect system, a call starts at all sites. This is often called “All sites light-
up”. An advantage of this is the simplicity in implementation because repeaters are not
required to know the list of radios present at its site. A disadvantage is that a multi-site
configuration does not increase the capacity of a system. Only the coverage of the
system increases. LCP makes the following enhancements:
- LCP allows defining a talkgroup as a wide area talkgroup. A wide area talkgroup call
lights up only the sites which are statically associated with the talkgroup. The call is
rejected when a radio tries to initiate a wide area Group Call from a site not associated
with the talkgroup.
- The talkgroups not defined as wide-area are local talkgroups. A local call ‘lights-up’
only one site where the initiating radio is located.
- The LCP Private Call initially “lights-up” all the sites but after approximately 400
milliseconds, the call continues only at the sites (at most two) where the source radio
or destination radio are present.
• In LCP, a wide area non-Emergency talkgroup call starts only if all the associated sites
have idle channels. This is defined as “All Start.” Additionally, LCP allows a customer to
reserve a number of logical channels for wide area talkgroup calls only. This improves
the success of “All Start” for the wide area talkgroup calls.
• Just like a Capacity Plus system, an LCP system has no controller. Repeaters of a site
trunk the logical channels available at the site. The trunking process in LCP is similar to
that of Capacity Plus. Repeaters of a site do not participate in trunking the RF resources
of another site. Each site trunks their channels independently.
2.2.2 MOTOTRBO Supports Analog and Digital Operation
The MOTOTRBO system can be configured to operate in analog mode, digital mode, or in
Dynamic Mixed Mode. The system can consist of multiple repeaters. A single MOTOTRBO
repeater configured to operate in Dynamic Mixed Mode can dynamically switch between analog
and digital modes depending on the type of call it receives. A repeater in Dynamic Mixed Mode
system cannot be part of multiple repeater system in which the repeaters are connected over the
network for IP Site Connect, Capacity Plus, or Linked Capacity Plus operation.
MOTOTRBO portable and mobile radios can communicate in analog and digital. The mobile or
portable radio user selects the mode of operation (analog or digital), and physical and logical
channel using his channel selector knob (each channel selection position is configured for a
particular call type on either a digital channel that specifies both frequency and time slot, or an
analog channel that specifies both frequency and 25 kHz or 12.5 kHz bandwidth). Radio channels
are either analog or digital. This is configured by the CPS. The radio can scan between analog and
digital channels.
Greater detail on channel planning and configuration is provided in “System Design
Considerations” on page 249.
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