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H.323

An International Telecommunication Union (ITU) standard that describes how multimedia communications occur over IP networks, specifically between terminals, network equipment and services. H.323 is part of a larger group of ITU recommendations for multimedia interoperability called H.3x. Today H.323 is considered to be the standard for interoperability in audio, video and data transmissions as well as voice-over-IP because it addresses call control and management for both point-to-point and multipoint conferences as well as gateway administration of media traffic, bandwidth, and user participation.

Hacker

A person with deep knowledge of and great interest in computer and network systems and who delves into the inner workings of a system to find out how it works. Originally, hacker was a term of respect among computer designers, programmers, and engineers for those among them who created truly original and ingenious programs, devices, or sometimes very clever practical jokes. However, the current popular meaning of the term is to describe those who break into systems, destroy data, steal copyrighted software, and perform other destructive or illegal acts with computers and networks.

Handheld Computer

These devices are normally a little larger than the palm-sized personal digital assistant (PDA). They typically use the Windows CE operating system, have a form factor that is more rugged than the typical PDA, need a larger battery than the typical PDA, are used with work-related applications like inventory management systems, are not pre-loaded with personal organization software, and offer specialized keys or touch-screens for easy input of regularized form-information. Compare with Personal Digital Assistant.

Hertz (Hz)

The international unit for measuring frequency is hertz (Hz), which is a measure of cycles per second.

HiperLAN

A set of wireless local area network (WLAN) communication standards that provide features and capabilities similar to those of the IEEE 802.11 wireless local area network (LAN) standards. The HiperLAN's two main standards, HiperLAN/1 and Hiper-LAN/2, are primarily used in European countries and both have been adopted by the European Telecommunications Standards Institute (ETSI).

HomeRF

Short for "Home Radio Frequency," this is a home networking standard developed by Proxim Inc. It combines the 802.11b and Digital Enhanced Cordless Telecommunication (DECT) portable phone standards into a single system. HomeRF uses a frequency hopping technique to deliver speeds of up to 1.6 Mbps over distances of up to 150 feet—too short a range for most business applications, but suitable for the home market that HomeRF was developed to serve.

HotSpot

In the Wi-Fi industry, this term refers to a specific geographic location in which an access point provides public wireless broadband network services to mobile visitors through a wireless LAN. HotSpots typically require that the end-user pay a fee before they can access the network and are usually situated in places that are heavily populated with mobile computer users, e.g. coffee houses, airports, restaurants, convention centers, hotels, etc.

HTTP

The acronym for HyperText Transfer Protocol.

See also Hypertext Transfer Protocol (HTTP).

Hub

In data communications, a hub is a hardware device that is used to network computers together. These devices serve as a common wiring point so that information can flow through one central location to any other computer on the network.

Hypertext Transfer Protocol (HTTP)

This application protocol defines how messages are formatted and transmitted over the World Wide Web, and what actions web servers and browsers should take in response to various commands.

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