| 2G |
2G, the second generation or GSM,
is the technology currently used in the operation of mobile phones. |
| 3G |
3G, or third generation, is the generic
term used for the next generation of mobile communications systems.
The new systems will enhance the services available today and offer
multimedia and internet access and the ability to view video footage.
The third generation technology used in the UK is called UMTS. These
services operate at 2100 MHz. (2.1GHz).
|
| Aerial/Antenna |
A device which transmits and receives radio
waves. There are different designs in operation. |
| Analogue |
First mobile phone technology which was phased
out in the UK in 2001 with the introduction of second generation technology. |
| Cabin |
 A
structure which protects transmitters and receivers from damage.
They can be in the form of large cabins or smaller cabinets. |
| Cell |
 A
geographic area of coverage that a radio base stations covers. |
| Dish Antenna |
 Dish
antenna transmit and receive highly focussed radio waves in one direction. |
| Electromagnetic Waves/Fields |
Electromagnetic waves are emitted by many
natural and man-made sources and play a very important part in our
lives. Electromagnetic waves are used to transmit and receive signals
from mobiles phones and their base stations. The type of electromagnetic
waves mobile phones use is called radio frequency (RF) waves/fields. |
| Feeder cable |
The co-axial cable which connects an antenna
to a base station transmitter or receiver. |
| Femto-cell base station |
A femto-cell base station allows mobile phone users to make calls inside their homes via their Internet broadband connection. The base station tends to be of the size and appearance of a typical WiFi router used in homes to connect a computer wirelessly to the Internet. It is a plug and play device that allows a mobile phone subscriber to use their mobile phone to make voice and data calls via their broadband connection to their mobile phone provider’s phone network. There are 2G and 3G variants available. As femto-cells provide small area coverage solutions they operate at low transmit powers meaning that the RF exposure levels at, or beyond, the casing of the unit will be below the ICNIRP guidelines. Further information on Femto-cells can be found on the Femtoforum website at www.femtoforum.org |
| Frequency |
Frequency is the number of times per second
at which an electromagnetic wave oscillates. It determines the wave's
properties and usage. Frequencies are measured in hertz (Hz). 1 Hz
is one oscillation per second, 1 kHz a thousand, 1 MHz is a million
and 1GHz is a thousand million. Frequencies between 30 kHz and 300
GHz are widely used for telecommunication, including broadcast radio
and television, and comprise the radio frequency band. Mobile telephony
systems currently operate at 900MHz, 1800MHz and 2100MHz. |
| GSM |
GSM - Global System for Mobile Communications
or Groupe Speciale Mobile is the international, pan-European operating
standard for the current generation of digital cellular mobile communications.
It enables mobile phones to be used across national boundaries. GSM
systems are operated by O2 and Vodafone at 900 and 1800 MHz, and by
T-Mobile and Orange at 1800MHz. |
| HPA |
The Health Protection Agency is an independent
body that protects the health and well-being of everyone in England
and Wales. The Agency plays a critical role in protecting people from
infectious diseases and in preventing harm when hazards involving
chemicals, poisons or radiation occur. It also prepares for new and
emerging threats, such as a bio-terrorist attack or virulent new strain
of disease. |
| ICNIRP |
The International Commission on Non-Ionizing
Radiation Protection (ICNIRP) is an independent scientific body which
has produced an international set of guidelines for public exposure
to radio frequency waves. These guidelines were recommended in the
Stewart Report and adopted by the Government, replacing the National
Radiological Protection Board (NRPB) guidelines. The mobile network
operators have accepted these guidelines and work within them. |
| Macrocell |
 A
macrocell provides the largest area of coverage within a mobile network.
The antennas for macrocells can be mounted on ground-based masts,
rooftops or other existing structures. They must be positioned at
a height that is not obstructed by terrain or buildings. Macrocells
provide radio coverage over varying distances depending on the frequency
used, the number of calls made and the physical terrain. Macrocell
base stations have a typical power output in tens of watts. |
| Mast |
 A
ground-based structure that supports antennas at a height where they
can satisfactorily send and receive radio waves. A typical mast is
15m high, and of steel lattice or tubular steel construction. New
slimmer versions of masts are now available which can be painted to
blend in with their surroundings, disguised as trees or used in conjunction
with street lighting and CCTV cameras. Masts themselves play no part
in the transmission of the radio waves. |
| Maximum Ground Level
Emission |
Maximum Ground Level Emission or the beam
of highest intensity usually occurs between 50m and 200m from an antenna.
The ground level emission within this area is the highest circling
a base station. It is usually many thousands of times lower than international
public exposure guidelines. Emission levels reduce rapidly as the
distance increases from the antenna. The highest emissions levels
are directly in front of the antenna, 15m or more off the ground. |
| Microcell |
 Microcells
provide additional coverage and capacity where there are high numbers
of users within urban and suburban macrocells. The antennas for microcells
are mounted at street level, typically on the external walls of existing
structures, lamp-posts and other street furniture. The antennas are
smaller than macro cell antennas and, when mounted on existing structures,
often blend in with building features to minimise visual impact.
Microcells provide radio coverage over distances, typically between
300m and 1000m and have lower output powers compared to macrocells,
usually a few watts. |
| NRPB |
The National Radiological Protection Board
(NRPB)', now part of the Health Protection Agency (HPA), has two main
functions: to advance knowledge about the protection of mankind from
radiation hazards and to provide information and advice to persons
in the UK with responsibilities relating to protection from radiation
hazards. |
| Picocell |
 A
picocell provides more localised coverage than a microcell. These
are normally found inside buildings where coverage is poor or where
there are a high number of users such as airport terminals, train
stations or shopping centres. |
| Radio Base
Station |
A radio base station is a macrocell, microcell
or picocell site and consists of transmitters and receivers in a cabin
or cabinet connected to antennas by feeder cable. |
Second Generation
|
See 2G |
| Sectored
Antenna |
 Antenna
which transmits or receives higher signal levels in a horizontal direction.
The antenna is split into several sectors (typically 3 or 6) to provide
360 degree coverage.
|
| Stub Mast
|
 A
roof-mounted mast structure which supports multiple antennas at a
height where it can satisfactorily send and receive radio waves. A
stub mast is typically 4m - 6m high and of steel lattice construction.
Stub masts themselves play no part in the transmission of radio waves. |
| Third Generation |
See 3G |
| Transmitter |
Electronic equipment that generates radio
frequency electromagnetic energy and is connected to an antenna via
a feeder cable. |
| UMTS |
Universal Mobile Telecommunication System
(UMTS) is part of the international vision of a global family of third
generation mobile communication systems. The UK refers to this as
3G. |
| Wavelength |
Wavelength is the distance in metres between
any two 'similar' points on a radio wave. This portion of the wave
is referred to as one complete cycle. The lower the frequency of a
wave the longer the wavelength. |
