CDMA 2000

CDMA 2000:

CDMA 2000


CDMA 2000 is a high data rate upgrade path for current users of 2G and 2.5G CDMA standards. It is a unique radio and network access system that is part of the International Mobile Telecommunications 2000 (IMT 2000). It is called as 3G standard.

It allows wireless carriers to introduce a family of new high data rate internet access and maintains backward compatibility with existing CdmaOne and IS-95 B.

The IMT 2000 specification from the International Telecommunication Union (ITU) defines one of its platform standards that make up the 3G suite of access platforms.

The general features for CDMA 2000 are:

  1. Supports high speed data services 
  2. It is a global standard
  3. It has flexibility for evolution
  4. It has improved spectrum efficiency
  5. It supports data rates of 384 kbps for pedestrian use, 144 kbps for vehicular use, and 2 Mbps for fixed environments.

The applications of CDMA 2000 are:

  1. Wireless internet
  2. Wireless email
  3. Wireless telecommunication
  4. Telemetry
  5. Wireless commerce
  6. Location-based services
  7. Standby battery life

The first 3G CDMA air interface CDMA 2000 1xRTT indicates that a sing 1.25 MHz radio channel is used RTT stands for Radio Transmission Technology language suggested by the IMT 2000 body.

CDMA 1x supports data rate up to 307 kbps for a single user in packet mode. It can provide throughput rates up to 144 kbps depending on the propagation conditions. the velocity of a user and the number of users.

CDMA 1x can support two twice as many users as the 2G standard. The subscriber unit has standby time twice for long-lasting battery life.

Must Read>> CDMA

CDMA2000 is being developed for both mobile radio (FDD) and cordless applications (TDD).

The improvements in CDMA2000 1x over 2G and 2.5G CDMA systems use adaptable baseband signaling rates and chipping rates for each user and multi-level keying within the same gross framework of the original CdmaOne standard. No additional RF equipment is needed to enhance performance. The changes are all made in software on the baseband hardware.

In order to upgrade from 2G CDMA to CDMA2000 1x, a wireless carrier needs to buy a new backbone software and new channel cards at the base station, without having to change out RF components at the base station.

Qualcomm developed CDMA2000 1xEV as an evolutionary advancement for CDMA, It is a high data rate (HDR) packet standard to be upgraded on the existing IS-95, IS-95B, and CDMA 2000 networks. 

Later the HDR standard was modified to be compatible with W-CDMA.

In August 2001, ITU recognized CDMA2000 1xEV as part of the IMT 2000 1xEV provides CDMA carriers with the option of installing radio channels with data only (CDMA 1xEV-DO) or data and voice (CDMA 2000 1xEV-DV).

With the help of CDMA 1xEV technology, individual 1.25 MHz channels can be installed in CDMA base stations to provide specific high speed packet data access within selected cells.

The CDMA 2000 1xEV-DO dedicates the radio channel strictly to data users and supports greater than 2.4 Mbps of instantaneous high-speed packet throughput per user on a particular CDMA channel, although the actual user data rates are typically much lower and highly dependent on the number of users, propagation conditions and vehicle speed. Typical users can obtain throughputs of the order of several hundred kilobits per second, which is sufficient to support web browsing, email access, and m-commerce applications.

CDMA2000 1xEV-DV supports both voice and data users. It can offer usable data rates up to 144 kilobits per second with about twice as many voice channels as IS-95B.

The CDMA2000 3xRTT standard uses three adjacent 1.25 MHz radio channels that are used together to provide instantaneous packet data. The actual throughput depends on cell loading, vehicle speed, and propagation conditions.

Three non-adjacent radio channels can be operated simultaneously and in parallel as individual 1.25 MHz channels, or adjacent channels can be combined into a single 3.75 MHz super-channel. With peak user data rates in excess of 2 Mbps, the CDMA2000 3x has a similar user data rate throughput.

CDMA 2000 allows the same spectrum, bandwidth, RF equipment, and air interface framework to be used at each station. Upgrades are introduced over time as compared to CdmaOne system.

To understand which radio and network components are needed for the successful implementation of a CDMA2000 system, whether it is 1xRTT, EV-DO we will study the architecture of a CDMA 2000 system.

The CDMA 2000 system architecture consists of various systems that interact between themselves and with the users through certain network interfaces.


Post a Comment

Previous Post Next Post