IMAP4

Internet Messaging Access Protocol. A remote mailbox access protocol. It enables efficient operation such as downloading only essential data by first acquisitioning the e-mail header prior to actual e-mail download. This feature makes the protocol well suited to remote environments.

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IMEI

International Mobile Station Equipment Identity. An identification number assigned to GSM mobile stations that uniquely identifies each one. It is a 15-digit serial number that contains a type approval code, final assembly code and serial number.

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I-MODE

Internet Mode. A wireless service launched in Japan in spring 1999 by NTT DoCoMo. I-Mode was licensed to operators in Germany, France, Spain, Italy, the Netherlands, and Taiwan, where it operates over GPRS using WAP. I-mode delivers a huge range of services to subscribers and has proved enormously popular with some 30 million regular users. The revenue sharing model used for I-mode is being adopted by other operators as the basis for the new services enabled by GPRS and 3G.

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IMSI

International Mobile Station Identity. A unique 15 digit number assigned to a mobile station at the time of service subscription. It contains a mobile country code, a mobile network code, mobile subscriber identification number, and a national mobile subscriber identity.

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IMT-2000

The family of third generation technologies approved by the ITU. There are five members of the family: IMT-DS, a direct sequence WCDMA FDD solution; IMT-TC, a WCDMA FDD solution; IMT-MC, a multi-carrier solution developed from cdma2000; IMT-SC, a single carrier solution developed from IS-136/UWC-136; IMT-FT, a TDMA/TDD solution derived from DECT.

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IN

Intelligent Network.

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INAP

Intelligent Network Application Part.

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Instant messaging

Exchanging messages in real-time between two or more people logged on to an instant messaging service. Popular IM services include AOL's Instant Messenger (AIM), AOL's ICQ, Microsoft's MSN Messenger and Yahoo!

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Interface

The common boundary between two associated systems.

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Internet

A loose confederation of autonomous databases and networks. Originally developed for academic use, the Internet is now a glob al structure of millions of sites accessible by anyone.

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Intranet

A private network that utilizes the same techniques as the Internet but is accessible only by authorized users.

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IP

Internet Protocol a set of instructions defining how information is handled as it travels between systems across the Internet. Also Intellectual Property.

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IPR

Intellectual Property Rights. Also known as patents, these are the rights of an inventor or assignee to develop and commercialize an invention and license it, usually for a fee, to other manufacturers.

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Iridium

A low earth orbit satellite communications system developed initially by Motorola.

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IS-136

Cellular standard known also as TDMA or D-AMPS.

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IS-95

Cellular standard also known as CDMAone.

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ISDN

Integrated Services Digital Network.

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ISP

Internet Service Provider.

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ITU

International telecommunications Union.

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ITU-R

ITU Telecommunications Radio Sector.

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ITU-T

ITU Telecommunications Standardization Sector.

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Iub

The interface between the Node B and the RNC in a UMTS network.

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Iucs

The connection between the RNC and the circuit switched network in a GSM/GPRS, UMTS network.

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Iups

The connection between the RNC and the packet switched network in a GSM/GPRS/UMTS network.

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Iur

The interface between RNCs in a UMTS network.

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