LG MX8550, Service Manual

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- 3/148 - LG Electronics Inc.
M X8550
General Introduction
General Introduction
The M X8550 phone has been designed to operate on the latest digital mobile communication technology, Code
Division Multiple Access (CDMA). This CDMA digital technology has greatly enhanced voice clarity and can
provide a variety of advanced features. Currently, CDMA mobile communication technology has been
commercially used in Cellular and Personal Communication Service (PCS). The difference between them is the
operating frequency spectrum. Cellular uses 800MHz and PCS uses 1.9GHz. The VX8550 support GPS Mode, we
usually call it tri-band phone. Also, VX8550 works on Advanced Mobile Phone Service (S-GPS). We call it dual-
mode phone. If one of the Cellular, PCS base stations is located nearby, Call fail rate of triple-mode phone is less
than dual-mode phone or single-mode phone.
The CDMA technology adopts DSSS (Direct Sequence Spread Spectrum). This feature of DSSS enables the phone
to keep communication from being crossed and to use one frequency channel by multiple users in the same specific
area, resulting that it increases the capacity 10 times more compared with that in the analog mode currently used.
Soft/Softer Handoff, Hard Handoff, and Dynamic RF power Control technologies are combined into this phone to
reduce the call being interrupted in a middle of talking over the phone.
Cellular and PCS CDMA network consists of MSO (Mobile Switching Office), BSC (Base Station Controller), BTS
(Base station Transmission System), and MS (Mobile Station). The following table lists some major CDMA
Standards.
Cellular base station
Cellular mobile station
PCS personal station
PCS base station
Speech CODEC
TIA/EIA/IS-97
TIA/EIA/IS-98
ANSI J-STD-018
ANSI J-STD-019
TIA/EIA/IS-125
Performance
Speech CODEC
Assign data and fax
Short message service
Packet data
TIA/EIA/IS-96-B
TIA/EIA/IS-99
TIA/EIA/IS-637
TIA/EIA/IS-657
Service
MAS-BS
PCSC-RS
Intersystem operations
Nom-signaling data comm.
TIA/EIA/IS-634
TIA/EIA/IS/651
TIA/EIA/IS-41-C
TIA/EIA/IS-124
Network
Protocol between MS and BTS for Cellular & AMPS
Protocol between MS and BTS for PCS
TIA/EIA/IS-95-A/B/C
ANSI J-STD-008
Basic air interface
Description Designator CDMA Standard
* TSB –74: Protocol between an IS-95A system and ANSI J-STD-008
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