4 switch, 5 call processor and system and subscriber manager, 6 locality – Viking 242-2009-632 User Manual
Page 26: 7 home repeater channel, 8 status repeater channel, 9 monitor repeater channel, 10 home channel aliasing
 
INTRODUCTION AND OPERATION
1-10
March 1999
Part No. 001-2009-600
1.14.4 SWITCH
The Switch can connect several different forms of
communication together to form a communication net-
work that requires the Call Processor. It has up to six 
shelves with 12 or 16 device slots each (72 or 96 slots 
available) and up to three racks (for 216 or 288 slots). 
Many different modules are available to complete the 
network. Some modules have specific device slot 
requirements.
1.14.5 CALL PROCESSOR AND SYSTEM AND
SUBSCRIBER MANAGER
The Call Processor, along with the System and
Subscriber Manager, controls the LTR-Net System. 
The Call Processor (CP) is an IBM
PC or compatible
computer that is running the EFJohnson management 
program. The System and Subscriber Manager soft-
ware is used by the System Administrator to program, 
control and continuously monitor Switch operation, 
and provides logging of information for billing pur-
poses. 
The System and Subscriber Manager (SSM) is a
program that executes on an IBM PC or compatible 
computer. The function of the SSM is to manage the 
database information that the Call Processor uses in its 
operation. The SSM has the capability to generate 
reports from the logged information of the CP. The 
SSM also has the ability to setup and initiate such 
activities as Dynamic Reprogramming of certain 
mobile parameters (Group 11), disabling (Kill) of lost 
or stolen mobiles and many other functions.
1.14.6 LOCALITY
A Locality is the location where one or more
repeaters are housed. Trunked system repeaters are 
connected to the same high-speed data bus and are 
required to be located close together. LTR-Net can 
have a maximum of 20 repeaters at a Locality. One 
CIM (Channel Interface Module) is required for each 
LTR-Net repeater. A CCM (Conventional Channel 
Module) is required for a conventional channel.
1.14.7 HOME REPEATER CHANNEL
All LTR-Net mobiles have one of the Locality
repeaters assigned as their "Home Repeater". This 
repeater handles the data and audio unless a failure 
causes the Status Repeater to take over. The Group ID 
calls use the Home Repeater number in identifying the 
mobiles (see Section 1.15.3).
1.14.8 STATUS REPEATER CHANNEL
The Status Repeater Channel is one repeater at a
Locality designated to transmit update information for 
all calls occurring at that Locality. The Status repeater 
is a "Home Repeater" backup usually not assigned 
voice traffic.
1.14.9 MONITOR REPEATER CHANNEL
This is the repeater channel that a mobile is cur-
rently monitoring for update messages. This repeater 
may be either the mobile’s Home Repeater or the 
Locality Status Repeater. A special algorithm is used 
by the mobile to determine which is to be monitored. 
Generally, it is the last repeater that a valid data mes-
sage was detected on.
1.14.10 HOME CHANNEL ALIASING
The LTR-Net Home Channel Aliasing feature
increases the number of addresses available on a 
Locality for Group calls. It does this by allowing calls 
to be programmed on non-exisent Home repeaters.
Each Home repeater can be programmed with 1-
239 Group ID codes. Assume a Locality has four 
active repeaters and one of these is the Status repeater 
(that is normally not assigned as a Home repeater). 
The number of calls that can be programmed are then 
as follows:
Without Aliasing - 3 x 239 or 717 calls
With Aliasing - 20 x 239 or 4780 calls
When a call is placed on a non-existent Home
repeater, the subscriber unit automatically uses the 
next lower numbered active repeater. 
NOTE: Since this feature does not increase system 
capacity, adding too many users may result in unsatis-
factory operation due to frequency busy conditions.