CDMA2000 Mobile Wireless Network Architecture

CDMA2000 is a hybrid 2.5G / 3G technology of mobile telecommunications that use CDMA (code division multiple access) to send digital radio, voice, data, and signaling data between mobile phones and cell sites. CDMA2000 is standardized by the 3rd Generation Partnership Project 2 (3GPP2).

The cdma2000 network comprises three major parts: the core network (CN), the radio access network (RAN) and the mobile station (MS). The core network is further decomposed in two parts, one interfacing to external networks such as the Public Switched Telephone Network (PSTN) and the other interfacing to the IP based network such as Internet. The mobile station terminates the radio path on the user side of the network and enables subscribers to access network services over the Um interface.

In a CDMA2000 access network, two radio access network technologies are supported: 1xRTT and EV-DO. CDMA2000 is considered a 2.5G (or 2.75G) technology when the 1xRTT access network is used and a 3G technology when the EV-DO access network is used.

CDMA2000 1xRTT, the core CDMA2000 wireless air interface standard, is also known as 1x, 1xRTT, and IS-2000. The designation "1x", meaning "1 times Radio Transmission Technology", indicates the same RF bandwidth as IS-95 (CDMA-One): a duplex pair of 1.25 MHz radio channels. 1xRTT almost doubles the capacity of IS-95 by adding 64 more traffic channels to the forward link, orthogonal to the original set of 64. Although capable of higher data rates, most deployments are limited to a peak of 144 kbit/s. IS-2000 also made changes to the data link layer for the greater use of data services, including medium and link access control protocols and QoS.

CDMA2000 EV-DO (Evolution-Data Optimized or Evolution-Data only), a broadband access radio technology standardized by 3rd Generation Partnership Project 2 (3GPP2), provides access to mobile devices with air interface speeds of up to 2.4 Mbit/s with Rev. 0 and up to 3.1 Mbit/s with Rev. A. The industry is working newer generations of EV-DO such as Rev. B and Rev. C, etc.

The CDMA2000 access network may perform mobility management functions for registering, authorizing, authenticating and paging IP based terminals, independent of circuit based terminals. The access network may perform handoffs within an access network and between access networks of the same technology and may support handoffs between access networks of differing technologies.

The key components of the cdma2000 access network are:
Base Transceiver System (BTS): an entity that provides transmission capabilities across the Um reference point. The BTS consists of radio devices, antenna and equipment.

Base Station Controller (BSC): an entity that provides control and management for one or more BTSs.

Packet Control Function (PCF): an entity that provides interface function between the access network and the packet switched network.