Glossary

Antenna

A passive device designed to radiate and receive electromagnetic energy.

dBW

dBW.

A dBW is a convenient unit to express a power in relation to a reference level of 1 Watt.

dBW= 10*log (Power in Watts)

To convert a power expressed in dBW into a power in Watts:

Watts = 10^(dBW/10)


Examples:

20dBW = 10^(20/10) Watts
= 10^(2) Watts
= 100 Watts


15dBW = 10^(15/10) Watts
= 10^(1.5) Watts
= 31.6 Watts

EiRP

Equivalent isotropic radiated power is the maximum power out of the antenna in a given direction (usually a few degrees down to the horizontal). The antenna acts to focus the radio beam, like a lamp reflector, therefore the maximum power will appear in a particular direction. The power in other directions, such as vertically downwards is sometimes significantly less.

Frequency

The number of complete cycles of an electromagnetic wave in a second measured in units of Hertz (Hz)

Frequency band of operation.

In the UK the following frequency bands are used for public cellular telephony:

GHz (Gigahertz)

Thousand million Hz (cycles per second).

Example: 2.2 GHz = 2,200,000,000 or 2.2 x 10⁹

GSM

Global system for Mobile Communications or Groupe Speciale Mobile.

The international, operating standard for the current generation of digital cellular mobile communications. Enables mobile phones to be used across national boundaries.

The Ofcom publishes details of the technical requirements for GSM technology operating in the UK in the form of UK Interface Requirement [IR2014]

Height of Antenna above ground.

In terms of metres above ground level.

Maximum licensed power.

In EiRP dBW per channel. The maximum licenced power is the maximum power any one antenna is allowed to transmit per channel. In practice, most transmitters would operate substantially below this limit.

MHz (Megahertz)

A Million Hz (cycles per second).

Example: 900 MHz = 900,000,000 or 900 x 10⁶

Macrocell

A macrocell is normally a mast or other structure supporting a large antenna designed to give coverage over a large area.

Microcell

A micro cell is a low power station, often using unobtrusive antennas, designed to give coverage over a small localised area.

Transmitter Power.

This is the design power for the particular channel, during quiet periods the power may be less then the stated EiRP.

Types of transmission

This is specified in terms of the technology used. Two types of cellular technologies operate in the UK; GSM and UMTS.

UMTS

Universal Mobile Telecommunication System

The next evolution of mobile phone technology and expected to result in widespread use of video phones and access to multimedia information.

The Ofcom publishes details of the technical requirements for UMTS technology operating in the UK in the form of UK Interface Requirement [IR2019].