We've compiled a list of key words that we figure people might have questions
on. This is just a preliminary list of terms. If you run across cell phone
terminology that you think would benefit others, please
contact us.
H
|
Half-Rate |
A variant of GSM, Half-Rate doubles system capacity by more efficient speech coding. |
Handheld Device Markup Language (HDML) |
A specialized version of HTML designed to enable wireless pagers, cell phones and other handheld devices to obtain information from Web pages. HDML was developed by Phone.com (formerly Unwired Planet) before the WAP specification was standardized. It is a subset of WAP with some features, not included in WAP. AT&T Wireless launched the first HDML-based service in 1996. |
Handoff |
The process by which the Mobile Telephone Switching Office passes a cellular phone conversation from one radio frequency in one cell to another radio frequency in another. The handoff is performed so quickly that users usually never notice. |
Hands-Free |
An important safety feature that's included with most of today's mobile phones. It permits drivers to use their cellular phone without lifting or holding the hand-set to their ear. |
Handset Subsidy |
Frequently, a wireless company will sell a phone (handset) below cost, with the hope of making up the loss later on customer usage fees. The amount of loss per handset is called the handset subsidy. |
Hertz (Hz) |
A unit of measurement of one cycle per second when one radio wave passes one point in one second of time. Named in honor of Heinrich Hertz, the physicist who developed the theory of radio waves. |
High-Speed Circuit Switched Data (HSCSD) |
The final evolution of circuit switched data within the GSM environment. HSCSD enables the transmission of data over a GSM link at speeds of up to 57.6kbit/s. This is achieved by concatenating consecutive GSM timeslots, each of, which is capable of supporting 14.4kbit/s. Up to four GSM timeslots are needed for the transmission of HSCSD. |
Home Location Register (HLR) |
A database residing in a local wireless network that contains service profiles and checks the identity of a local subscriber. |
I
|
I-Mode |
NTT DoCoMo's mobile Internet access, launched in February 1999. I-mode is an alternative to WAP, though it is only implemented in Japan. It offers Internet access and email service. While WAP uses HDML, I-mode relies on Compact HTML (C-HTML). Both languages are a simple version of HTML, for use on mobile phones. Today more than 7000 sites are I-mode compatible and offer a wide range of services over mobile phones: mobile banking, ticket reservation, cartoons downloading, etc. |
Incumbent Local Exchange Carrier (ILEC) |
The historic local phone service provider in a market, often a former Bell company. Distinct from competitive local exchange carriers (CLECs), new market entrants. |
Independent Telephone Network (ITN) |
Companies not affiliated with the local telephone companies. |
Industrial Telecommunications Association (ITA) |
A Washington, D.C. trade group serving private wireless licensees such as airlines and oil companies. |
Infrared Data Association (IrDA) |
A membership organization founded in 1993 and dedicated to developing standards for wireless, infrared transmission systems between computers. With IrDA ports, a laptop or PDA can exchange data with a desktop computer or use a printer without a cable connection. Like a TV remote control, IrDA requires line-of-sight transmission. IrDA products began to appear in 1995. |
Integrated Circuit Card ID (ICCID) |
19 or 20-digit serial number of the SIM card. |
Integrated Digital Enhanced Network (iDEN) |
A wireless communications technology from Motorola that provides support for voice, data, short messages (SMS) and dispatch radio (two-way radio) in one phone. Operating in the 800MHz and 1.5GHz bands and based on TDMA, iDEN uses Motorola's VSELP (Vector Sum Excited Linear Predictors) vocoder for voice compression and QAM modulation to deliver 64 Kbps over a 25KHz channel. Each 25KHz channel can be divided six times to transmit any mix of voice, data, dispatch or text message. Used by various carriers around the globe, Nextel Communications provides nationwide coverage in the U.S. |
Intelligent Roaming Database (IRDB) |
A list of acceptable and unacceptable networks for a phone to roam with stored either on a SIM card or in the phone. |
Interactive Messaging |
Short Message Service that allows users to send alphanumeric messages from their wireless handset to other wireless handsets or to email addresses. Interactive Messaging also allows the user to receive emails and web messages from the internet. |
Interconnection |
The connecting of one network with another, e.g. a cellular carrier's wireless network with the local exchange. |
Interim Standard (IS) |
A designation of the Telecommunications Industry Association --usually followed by a number--that refers to an accepted industry protocol; e.g., IS-95, IS-136, IS-54. |
International Mobile Equipment Identifier (IMEI) |
A unique 15-digit number that serves as the serial number of the GSM handset. The IMEI appears on the label located on the back of the phone. The IMEI is automatically transmitted by the phone when the network asks for it. A network operator might request the IMEI to determine if a device is in disrepair, stolen or to gather statistics on fraud or faults. |
International Mobile Subscriber Identifier (IMSI) |
A unique 15-digit number which designates the subscriber. This number is used for provisioning in network elements. |
International Mobile Telecommunications Association (IMTA) |
A trade group serving specialized mobile radio and public access mobile radio carriers around the world. |
International Telecommunication Union (ITU) |
An agency of the United Nations, headquartered in Geneva that furthers the development of telecommunications services worldwide and oversees global allocation of spectrum for future uses. |
Interoperability |
The ability of a network to operate with other networks, such as two systems based on different protocols or technologies. |
Ionizing Radiation |
Very high energy electromagnetic radiation that strips electrons away from their normal locations in atoms and molecules. |
Iridium |
First LEO-based global communications system backed by Motorola. Built primarily for voice transmissions, it was launched in 1998 and went into Chapter 11 in 1999. |
IS-136 |
The latest generation of the digital standard TDMA technology. |
IS-41 |
The network standard that allows all switches to exchange information about subscribers. |
IS-54 |
The first generation of the digital standard TDMA technology. |
IS-661 |
North American standard for 1.9 GHz wireless spread spectrum radio-frequency access technology based on a composite of CDMA and TDMA technologies To reduce infrastructure costs and allow higher data speeds than mainstream GSM or TDMA platforms. |
IS-95 |
The standard for CDMA. |
J
|
Japanese Total Access Communication (JTAC) |
Like the European TACS, JTAC is the Japanese analog cellular system. |
