Half-Duplex Transmission

Transmission in either direction but not both directions simultaneously.

Hiper LAN

A wireless LAN protocol developed by ETSI (European Telecommunications Standards Institute) akin to 802.11. There are two types of Hiper LAN, both operating in the 5GHz band. Hiper LAN/1 provides data-rates up to 20 Mbps and Hiper LAN/2 data rates up to 54 Mbps.


Any computer on a network that is a repository for services available to other computers. It is common to have one host machine provide several services, such as SMTP (eMail) and HTTP (Web).

Hosting/Hosted IP Telephony

This means that a reseller/supplier "host" all of the hardware infrastructure (I.e. Telephone PBX) in a secure central site and provide customers with access to this over a IP network. No hardware telephone system is required on the customer site.


HyperText Markup Language

Horizontal Cable

A cable connecting the floor distributor to the telecommunications outlet(s).

Horizontal Runs

The part of the premises distribution system installed on one floor that includes the cabling and distribution components connecting the riser backbone or equipment wiring to the information outlet.


High Speed Circuit Switch Data
 - Circuit-switched wireless data transmission for mobile users at data rates up to 38.4 Kbps, four times faster than the standard data rates of the Global System for Mobile (GSM) communication standard in 1999.


HyperText Transfer Protocol


The core of a star topology network or cabling system.

Hunt Groups

A means of finding a free extension to take a call. Calls are directed to a Hunt Group and will search for a free extension to take the call. Various hunting types are available, First Free or Terminal Hunting will search for the first free extension in the group, so this person gets most of the calls. Circular or UCD (Uniform Call Distribution) Hunting will share calls equally over the group.

Hybrid Cable

An assembly of two or more different types of cable units, cables or categories covered by an overall sheath. It may be covered by an overall shield.