CDMA2000

CDMA2000 is a unique radio and network access system that is part of the
IMT-2000 specification suite of access platforms that comprise what is
known collectively as third generation (3G). The International Mobile
Telecommunications 2000 (IMT-2000) specification from the International
Telecommunication Union (ITU) defines one of its platform standards that
comprises the 3G suite of access platforms and is called IMT-2000-MC, or
multi-carrier, called CDMA2000. CDMA2000 is unique in that, while supporting
3G services and bandwidth requirements, it enables a logical
migration from the existing 2G platforms to 3G without forklifting the
legacy system.
The IMT-2000 specification or vision for all the platforms supported has
a common set of goals that all the standards are meant to achieve. The general
specifications for the IMT-2000 are as follows:
■ Support high-speed data services
■ Global standard
■ Worldwide common frequency band
■ Flexibility for evolution
■ Improved spectrum efficiency
■ 2 Mbps for fixed environment
■ 384 Kbps for pedestrian use
■ 144 Kbps for vehicular uses
In reviewing this list, the underlying principal is that IMT-2000 is a
high-speed packet data network designed for mobility using IP as the
enabling protocol.
Some of the 3G applications that are envisioned to be enabled by
CDMA2000 are as follows:
■ Wireless Internet
■ Wireless e-mail
■ Wireless telecommuting
■ Telemetry
■ Wireless commerce
■ Location-based services
■ Longer standby battery life
CDMA2000 is standardized under the specification of IS-2000, which is
backward-compatible with IS-95A and B, as well as with J-STD-008 specifications that collectively are called cdmaOne. The IS-95 and J-STD-008
specifications make up the existing CDMA mobility systems deployed currently
in the world. CDMA2000, while being a 3G specification, is also backward-
compatible with cdmaOne systems, allowing operators to make
strategic deployment decisions in a graceful fashion.
Since CDMA2000 is backward-compatible with existing cdmaOne networks,
upgrades or, rather, changes to the network from a fixed network
aspect can be done in stages. More specifically, the upgrades or changes to
the network involve the Base Transceiver Stations (BTSs) with Multimode
Channel Element cards, the Base Station Controller (BSC) with IP-routing
capabilities, and the introduction of the Packet Data Server Network (PDSN).
The radio channel bandwidth is the same for CDMA2000-1X as it is for existing
cdmaOne channels, leading to a graceful upgrade. Of course, the subscriber
units and mobiles need to be capable of supporting the CDMA2000
specification, but this can be done in a more gradual fashion because the
existing cdmaOne subscriber units can utilize the new network.
As indicated earlier, CDMA2000 is IMT2000-MC, which stipulates the
use of more then one carrier. However, the initial introduction of the
CDMA2000 will primarily utilize a single carrier even though CDMA2000
supports multiple carrier operation. Several terms are used to describe
CDMA2000 for the different radio carrier platforms, some of which exist at
present while others are in the development phase. However, the sequence
of different CDMA2000 platforms or the migration path is as follows:
CDMA2000-1X (1xRTT)
1xEV-DO
1xEV-DV
CDMA2000-3X (3xRTT)
The 1xRTT utilizes a single carrier requiring 1.25 MHz of radio spectrum,
which is the same as the existing cdmaOne system’s channel bandwidth
requirement. However, the 1xRTT platforms can utilize a different
vocoder and more Walsh codes, 256/128 versus 64, allowing for higher data
rates and more voice conversions than are possible over existing cdmaOne
systems.
Under CDMA2000-1X, also called 1xRTT, three primary methods are
used: 1x, 1xEV-DO, and 1xEV-DV, which are not mutually exclusive of each
other.The term 1x is used to describe the first version of CDMA2000.1xEVDO
means one carrier, which is data-only, while 1xEV-DV means one carrier
that supports data and voice services.

However, when referring to CDMA2000-3X, the use of 3.75 MHz of the
spectrum, or 3
1.25 MHz, is defined with a change in the modulation
scheme as well as the vocoders to mention a few of the salient issues that
come about with the introduction of this platform. The migration from 1X
to 3X is talked about as being transparent but will likely involve the reallocation
of the existing spectrum. The details of this will be covered in the
design phase discussed later.
Another important aspect of CDMA2000 is that it supports not only IS-
41 system connectivity, as does IS-95, but it also supports Global System for
Mobile communications-Mobile Application Part (GSM-MAP) connectivity
requirements. This can lead to the eventual harmonization or dual-system
deployment in the same market by a wireless operator wanting to deploy
both WCDMA and CDMA2000 concurrently.
Several key specifications are used to help define the particulars associated
with a CDMA2000 system, as listed in Table 7-1.

TIA 3GPP2 Description

IS-2000-1 C.S.0001 Cdma2000 Introduction
IS-2000-2 C.S.0002 Cdma2000 Physical Layer
IS-2000-3 C.S.0003 CDMA2000 MAC Layer
IS-2000-4 C.S.0004 CDMA2000 Layer 2 LAC
IS-2000-5 C.S.0005 CDMA2000 Layer 3
IS-2000-6 C.S.0006 CDMA2000 Analog
TIA/EIA-97 C.S.0010 Base Station Minimum Standard
TIA/EIA-98 C.S.0011 Mobile Station Minimum Performance
IS-127 C.S.0014 Enhanced Variable Rate Codec (EVRC)
TIA/EIA-637 C.S.0015 Short Message Service
TIA/EIA-683 C.S.0016 Over the Air service provisioning
TIA/EIA-707 C.S.0017 Data Services for Spread Spectrum Systems
TIA/EIA-733 C.S.0020 High Rate (13 Kbps) Speech SO
IS-801 C.S.0022 Location Services (Position Determination Service)
IS-95A Mobile Station-Base Station Compatibility Standard for
Dual-Mode Wideband Spread Spectrum Cellular System
IS-95B Mobile Station-Base Station Compatibility Standard for
Dual-Mode Wideband Spread Spectrum Cellular System
A.S.0001 Access Network Interfaces Technical Specification