Wireless Glossary – H

For a linearly polarized antenna, the plane containing the magnetic field vector and the direction of maximum radiation. The magnetic field or “H” plane lies at a right angle to the “E” plane. For a vertically-polarized antenna, the H-plane usually coincides with the horizontal/azimuth plane. For a horizontally-polarized antenna, the H-plane usually coincides with the vertical/elevation plane.

H.323 is a protocol standard for multimedia communications. H.323 was designed to support real-time transfer of audio and video data over packet networks like IP.

A one-direction communication transmission that produces lower throughput because it operates in a collision domain in which CSMA/CD must be enabled. Half duplex must be run when connected to a hub.

Handoff refers to the transfer of a communication link from one POP to another, while the subscriber is moving through the network. Handoffs are by their nature automatic, but not necessarily undetectable.

The process of putting data through an algorithm that produces a result (the hash) based on the actual data. Typically, the hash is then sent with the data to the receiving device. The receiving device can then rerun the algorithm, compare the results, and ensure that the data was not altered in transmission.

Half-Duplex Frequency Division Duplex is a type of Frequency Division Duplex where the uplink and downlink use different frequencies but not simultaneously, so as to avoid the need for a duplex filter in the receiver.

A WAN encapsulation without many features that can be utilized over leased lines and circuit-switched connections. It uses minimal network overhead when communicating.

A device that is attached to a microprocessor chip to keep it from overheating by absorbing its heat and dissipating it into the air. Most heatsinks are aluminum and have “fins” that extend from the base.

Cycles per second. A unit of measure for frequency.

A station on a wireless LAN that attempts to transmit data to another station but, due to its location relative to the others, cannot sense that there is a third station simultaneously communicating with the intended recipient. Lost message and multiple retries is the result.

Channel that supports low-latency traffic (such as Voice over IP) over low-latency traffic (such as standard web traffic and file downloads). To recognize the latency tolerance of traffic, this channel reads the IPv4 Type of Service Low Latency bit.

Hhome Location Register is a central database that contains details of each mobile phone subscriber that is authorized to use the GSM core network. There can be several logical, and physical, HLRs per public land mobile network (PLMN), though one international mobile subscriber identity (IMSI)/MSISDN pair can be associated with only one logical HLR (which can span several physical nodes) at a time.

A metric determined by the quantity of routers along the path to the destination.

That portion of the telecommunications cabling that provides connectivity between the horizontal cross-connect and the work-area telecommunications outlet. The horizontal cabling consists of transmission media, the work-area outlet, the terminations of the horizontal cables and horizontal cross-connect.

A global configuration command which names the router.

A hotspot is any location where Wi-Fi network access is made publicly available. Technically speaking, hotspots consist of one or several wireless access points installed inside buildngs and/or adjoining outdoor areas.

High-Speed Downlink Packet Access is a telephony protocol that improves and extends downlink packet data transmission.

High Speed Packet Access is an amalgamation of two mobile telephony protocols, High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA), that extends and improves the performance of existing 3rd generation mobile telecommunication networks utilizing the WCDMA protocols. A further improved 3GPP standard, Evolved HSPA (also known as HSPA+), was released late in 2008 with subsequent worldwide adoption beginning in 2010. The newer standard allows bit-rates to reach as high as 168 Mbit/s in the downlink and 22 Mbit/s in the uplink.

Home Subscriber Server or User Profile Server Function (UPSF), is a master user database that supports the IMS network entities that actually handle calls. It contains the subscription-related information (subscriber profiles), performs authentication and authorization of the user, and can provide information about the subscriber’s location and IP information.

A high-speed interface that provides up to 52Mbps transmission rates to the WAN from a Cisco router. If the corporate backbone requires high-speed Internet access and VPN connectivity, the higher speed capacity is of interest.

High-Speed Uplink Packet Access is a telephony protocol that improves and extends uplink packet data transmission.

High Throughput

Hyper Text Transfer Protocol is a client-server communication protocol developed for World Wide Web.

An Application layer protocol that facilitates web browsing by transmitting Hypertext Markup Language (HTML) documents on the Internet

An Application layer protocol that facilitates secure web browsing using SSL. A secure connection can be assumed when the URL begins with https:// or when there is a lock symbol in the lower-right corner of the web page.

A repeater with multiple ports. A smaller hub is comprised of four or five ports and can be called a workgroup hub. When data is received through one port, the hub then retransmits that data through all the other ports.

A low-cost packet-switched network design, all offices connect to a central office (the hub) through a single virtual circuit connection. If the hub router fails, all connectivity through the packet-switched network is lost.

A program that you can use to connect to other computers, Internet telnet sites, bulletin board systems (BBSs), online services, and host computers, using either your modem or your network card.