Motorola R-2002A Manual page 220

1.0 INTRODUCfiON
The R2008D/R20IOD is an expansion of the R2001D
which extends its testing capability to include the
unique requirements of cellular radio systems. Any
existing R2001 D communications system analyzer
can be modified to an R2008D/R20IOD. With the
modification, all of the capability of the R2001 D is
retained with the cellular test sequences being added
as an extension of the tone memory display.
Cellular test capability in the R2008D/R20IOD in-
cludes performance verification for both the digital
signaling and the RF transceive~ aspects of the cellu-
lar radio. In the cellular test mode; the analyzer simu-
lates the basic aspects of the central cell site. It pro-
vides all of the signaling required to allow both call
origination and call reception testing on the cellular
transceiver. In addition, once the voice path is estab-
lished, the R2008D/R20IOD can then be used to sim-
ulate cell site to cell site handoffs,
to
control the
transmitter power level, and to execute performance
tests normally associated with a transceiver.
A fully automatic test sequence is provided which se-
quences through an operator selectable number of
the 666 cellular channels and measures the transmit-
ter output power, frequency error, and modulation
limiting for each channel. Provision has been made
for attachment of a serial printer RS-232, (1200
baud) to provide hardcopy output of AUTOTEST
MODE results. The printer can also print the con-
tents of the CRT display in all modes except MODU-
LATION, SPECTRUM ANALYZER, IF, AND
SCOPE, by pressing both the left cursor key and the
"0" key together.
To complete the package, the R2008D/R2010D also
provides the interface to manually control the trans-
ceivers that are compatible with the Advanced
Mobile Phone Service Cellular Mobile Telephone
Equipment Specification, July 1983. This separate
interface bypasses the normal RF signaling interface
and allows direct control over transceiver functions
such as channel selection, transmitter key, transmit-
ter audio, and receiver audio. Also available through
this interface is access to the number assignment
module (NAM) and the nonvolatile memory (NVM).
A total of 43 commands are available for the purpose
of setting up, checking out, and troubleshooting the
cellular radio.
This manual is written as a supplement to the
R2001D Operator's Manual (68P81069A66); refer to
the R2001D Operator's Manual for the operating in-
structions in non-cellular testing.
U.K. Cellular Test Capability. The United King-
dom (U.K.) Cellular System Analyzer (R20IOD) is
the basic R2008D analyzer with modifications to per-
mit testing of U.K. "T ACS" System Cellular Mobile
Transceivers. A description of differences between
the U.S. cellular system and the "T ACS" system is
found in appendix "H".
2.0 THE CELLULAR CONCEPT
Conventional VHF mobile telephone systems us1
single transmitter site to cover a given service area.
cellular mobile telephone system, on the other ha1
divides the service area into smaller coverage ar1
called cells. A cellular system consists of a cc
~.
tinuous pattern of these hexagon-shaped cells,
e~
having a
5
to 10 mile radius. Within each cell is a c'
tralized based station which contains transceivers a
related control equipme·nt for the channels assigr
to that cell. All of the cells within a system are tt
connected either by dedicated land lines, microw:
links, or a combination of both to a central cont
site. The central control site, or controller, is respc
sible for the overall control of the system and the
terface to the land line network.
A cellular radio-telephone in the cell system is un1
the indirect control of the central controller. A ser
of control channels over which only digital signal:
is allowed and voice channels which allow both auc
and signaling are used for control and data trans
as well as for conversation once the call is est;
lished. The control channels are divided into th
groups: Forward control, paging, and access ch;
nels. The control channel generally provides so
basic information about the particular cellu
system such as the system identification number a
the range of channels to scan to find the paging a
access channels. Paging channels are the nor11
holding place for the idle cellular radio. When a c
is received at the central controller for a cellu
radio, the paging signaling will occur on a pagi
channel. In responding to a page or when originati
a call, the radio telephone will use an access chan
where two way data transfer occurs to determine
I
initial voice channel. In many systems all three
C(
trol channel functions will be served by the sa:
channel for a particular cell. The R2008D/R2011
operates in this single data. control channel mo1
Only in the very high density areas will multiple ch;
nels be required.
Voice channels are primarily used for conversati
with signaling being employed as necessary to eff
cell
to
cell handoffs, output power control on
1
cellular radio and special local control features. D:
from the cell site, forward data, and data from ·
mobile, reverse data, is sent at a 10 kilobit/secc
rate utilizing direct frequency modulation. The d.
is formatted into groups of words with a disti
binary preamble that allows the receiver to synch
nize to the incoming data.
In addition to the digital signaling there are two
11
signaling mechanisms employed in the cell sysu
The supervisory is one of three frequencies aroun
kilohertz. It is generated by the cell site, checked
frequency by the cellular radio, and then tra
ponded back to the cell site on the reverse cham
The cellular radio uses the SAT to verify that it tul
to the correct channel after a new voice channel cc
mand. When the central controller signals the mol