CAI

Common Air Interface; a standard developed for the UK's public CT2 networks which enabled the same handset to be used on different networks

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CAMEL

Customized Application for Mobile network Enhanced Logic; an IN feature in GSM networks that enables users to carry personal services with them when roaming into other networks that support CAMEL.

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Capacity

A measure of a cellular network's ability to support simultaneous calls.

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CAPEX

Capital expenditure

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CB

Cell Broadcase.

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CC

Call Control; manages call connections.

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CCB

Customer Care and Billing.

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CCCH

Common Control Channels; a group of uplink and downlink channels between the MS and the BTS (see PCH, AGCH and RACH).

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CCH

Broadcast control Channel; the logical channel used in cellular networks to broadcase signaling and control information to all mobile phones within the network.

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CCS7

Common Channel Signaling No. 7.

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CDMA

Code Division Multiple Access; also known as spread spectrum, CDMA cellular systems utilize a single frequency band for all traffic, differentiating the individual transmissions by assigning them unique codes before transmission. There are a number of variants of CDMA (see W-CDMA, B-CDMA, TD-SCDMA et al).

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CDMA 1X

The first generation of cdma2000; the standardization process indicated that there would be CDMA 2X and CDMA 3X but this no longer appears likely.

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CDMA 1X EV-DO

A variant of CDMA 1X which delivers data only.

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CDMA2000

A member of the IMT-2000 3G family; backward compatible with cdmaOne.

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CDMAone

First commercial CDMA cellular system, also known as IS-95 (deployed in North America and Korea).

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CDPD

Cellular Digital Packet Data; a packet switched data service largely deployed in the USA. The service uses idle analog channels to carry the packetized information.

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CDPSK

Coherent differential Phase Shift Keying.

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CDR

Call Detail Records; the record made within the cellular network of all details of both incoming and outgoing calls made by subscribers. The CDR is passed to the billing system for action.

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Cell

he geographic area encompassing the signal range from one base station (a site containing radio transmitter/receiver and network communication equipment). Wireless transmission networks are comprised of many hexagonal, overlapping cell sites to efficiently use radio spectrum for wireless transmissions. Also, the basis for the term "cellular phone.

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Cell site

The facility housing the transmitters/receivers, the antennas and associated equipment.

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Cell splitting

The process of converting a single cell to multiple cells by sectorizingg the antennas in the cell site or constructing additional cells within a cell site.

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Cellular

In wireless communications, cellular refers most basically to the structure of the wireless transmission networks which are comprised of cells or transmission sites. Cellular is also the name of the wireless telephone system originally developed by Bell Laboratories that used low-powered analog radio equipment to transmit within cells. The terms "cellular phone" or "cell phone" are used interchangeably to refer to wireless phones. Within the wireless industry, cellular is also used to refer to non-PCS products and services.

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Cellular handoff

In cellular communications, a telephone call is switched by computers from one transmitter to the next, without disconnecting the signal, as a vehicle moves from cell to cell. The mobile remains on a specific channel until signal strength diminishes, then, is automatically told to go to another channel and pick up the transferred transmissions there.

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CF

Call Forwarding.

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CGF

Charging Gateway Function. GSN Lite product contains a Charging Agent that collects Charging Data Records (CDRs) from GMM, SNDCP and GDT and delivers them to CGF through the GTP protocol.

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Channel

A general term used to describe a communications path between two systems. They may be either physical or logical depending on the application. An RF channel is a physical channel, whereas control and traffic channels within the RF channel would be considered logical channels.

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Channel coding

The application of forward error correction codes to an RF channel to improve performance and throughput.

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CI

Carrier to Interference ratio.

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CID

Caller Identification.

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Circuit switching

A method used in telecommunications where a temporary dedicated circuit of constant bandwidth is established between two distant endpoints in a network. Mainly used for voice traffic, it is the opposite of packet switching. A switched circuit is only maintained while the sender and recipient are communicating, as opposed to a dedicated circuit which is held open regardless of whether data is being sent or not.

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Co-channel interference

Unwanted interference within a radio channel from another transmitter using the same channel at a different location. Co-channel interference is very common in a frequency reuse system and must be carefully controlled to prevent problems.

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Codec

A word formed by combining codec and decoder, the codec is a device that encodes and decodes signals. The voice codec in a cellular network converts voice signals into and back from bit strings. In GSM networks, in addition to the standard voice codec, it is possible to implement Half Rate (HR) codecs and Enhanced Full Rate (EFR) codecs.

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Concurrent users

Users using the same resources or application at the same time. The term implies that multiple processes are taking place simultaneously.

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Control signal

A signal sent to a cellular phone from a base station or vice versa which carries information essential to the call but not including the audio portion of a conversation.

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Core network

Core Network refers to the discrete Ethernet segments up to the end station port of an Ethernet hub, the routing equipment attached to these ethernet segments and the wide area network (WAN) connections between the routing equipment.

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CPE

Customer Premises Equipment; all the equipment on the end user's side of the newtork interface.

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CPU

Central Processing Unit.

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CRC

Cyclic Redundancy Check.

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CRM

Customer Relationship Management.

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CSE

CAMEL Service Environment.

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CSS

Customer Support System.

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CT

cordless Telephony.

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CTM

Cordless Terminal Mobility.

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CTR

Common Technical Regulation; part of the ETSI standardization process.

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