AGCH
: Also known as: Access Grant Channel Access
Grant Channel (AGCH) is a downlink channel (base to mobile) used by
a BS (Base Station) to tell the MS (Mobile Station) which DCCH
(Dedicated Control Channel) to use, after the MS has previously
requested access to the network by sending a message over the RACH
(Random Access Channel). The AGCH is used to assign resources to
the user who has requested access to the network, and the BS
allocates a TCH (Traffic Channel) or SDCCH (Stand-Alone Dedicated
Control Channel) to the MS, allowing it access to the
network |
|
Algebraic Code Excited Linear
Prediction
: Also known as: ACELP Algebraic Code Excited
Linear Prediction, or ACELP, is a speech compression system, used
to provide a good standard of speech quality when the network is
operating at low data rates (i.e. narrow bandwidth). The analogue
voice signal is converted to a digital data signal, so that it can
be compressed for transmission over the network, and the process is
then reversed at the other end when the digital data is converted
back to an analogue voice signal. The quality of the reproduced
speech will appear to be much better at the receiving phone than
would have been the case if an ACELP system had not been used. The
technology associated with ACELP is defined by the ITU-T
(International Telecommunications Union-Telecommunication
Standardization Sector) and this has been used for a long time as a
standard on the Internet for voice applications, being integrated
into software such as Microsofts MediaPlayer?. |
|
Alphanumeric
: Alphanumeric is a term referring to
information that contains a combination of alphabetic letters or
words ("alphas") and numbers ("numerics"). Punctuation and other
symbols are also usually interpreted to be included in the term
alphanumeric. Alphanumeric displays are those that can show at
least all of the letters of the alphabet and the numbers 0 to 9.
Alphanumeric Directory Alphanumeric Directory refers to the part of
a phone that stores the user's list of names and phone numbers, so
that they may be easily retrieved. Alphanumeric DisplayAlphanumeric
Display is the display output device on a phone, typically an LCD
screen, which has the ability to display both text and numbers.
Alphanumeric Memory DialAlphanumeric Memory Dial is a special type
of dial-from-memory option on mobile phone handsets, which enables
the name of an individual and their phone number to both be
displayed for dialling purposes. This feature is now an accepted
standard on modern mobile phones. Alternatively, the name can also
be recalled by typing the letters on the phone keypad. By contrast,
the standard memory dial feature will recall just the numbers from
a number-only location. Alphanumeric MessagingAlphanumeric
Messaging is the capability of a phone to send and receive messages
(e.g. SMS messages) that contain both text and numbers |
|
American Standard Code for Information
Interchange
: Also known as: ASCII The American Standard
Code for Information Interchange (ASCII) is a standard coding
system developed by the USA Standards Institute. ASCII is
universally used to represent letters, numbers, punctuation marks,
symbols and control codes, which makes it possible to pass data
between computers and within communication systems (e.g. to mobile
phones). Digital equipment can only understand numbers, and ASCII
code gives every symbol or character a unique number in order to
identify it. The coding system is efficient, with each character
being represented by a single byte. There is a basic character set
of 128 codes numbered 0 to 127 (which uses 7 bits per character),
or an extended character set of 256 codes numbered 0 to 255 (which
uses 8 bits per character). ASCII files appear as unformatted plain
text, i.e. without any tabs, bold, italics, or other codes that
word processors introduce when formatting text. ASCII files are the
standard text format for SMS messages |
|
AMPS
: Also known as: Advanced Mobile Phone Service
Advanced Mobile Phone Service (AMPS) is a first generation analogue
cellular telephone system that originated in the USA in the 1980s.
AMPS is still the most widely deployed cellular system in the
United States, and has been used in other countries of North and
South America, as well as the Asia/Pacific region, although it is
not compatible with European mobile phone standards. AMPS can be
found in countries such as Canada, Australia, Hong Kong, New
Zealand, South Korea, Singapore, Taiwan, Thailand and Israel. AMPS
operates in the 800 and 900 MHz frequency bands. Frequency Division
Multiple Access (FDMA) is used to divide each band of operating
frequencies into 30 kHz channels. Adjacent cells will then employ
different channels for their transmitted and received signals, so
that one cell does not interfere with another, and as a user moves
between cells the channels change without any noticeable
transition. AMPS was updated with digital cellular service, i.e.
digital AMPS (DAMPS), by adding Time Division Multiple Access
(TDMA) to each channel |
|
Animated Screensaver
: Animated screensaver is a changing pattern or
animation, which replaces the original screen image when a mobile
phone has been idle for a predetermined period of time. The use of
a screensaver is designed to prevent damage that might result when
fixed bright images remain on the screen for long periods. Only the
more recent mobile phone models currently include animated
screensavers |
|
Animation
: Animation is a moving image produced by
sequentially displayed image frames, which creates the illusion of
movement. Mobile phone animations usually consist of short,
animated greetings and messages in a variety of sizes, colours, and
levels of complexity |
|
Answering Machine
: Answering machine is a device that
automatically answers a telephone call when the recipient is for
some reason unable to answer it personally. Typically, a user
stores an outgoing message to tell callers that the phone cannot be
answered personally, and the caller is then requested to leave a
recorded message stating the purpose of their call, which the user
can playback at a convenient time. Conventional landline answering
machines often use magnetic tape or a microchip memory to record
messages. Some mobile handsets are capable of storing messages in
their internal memory, and most mobile operators provide an
answering service whereby subscribers can dial a special number and
listen to their stored messages |
|
Audible Keypad Tone
: Audible Keypad Tone is a facility that can be
set on some handsets, which causes them to play a tone when the
keys are pressed, so confirming that they have operated correctly.
This was introduced to reduce airtime charges to incorrect numbers,
although it also provides a better interface and positive feedback
for the user. The sound played is usually the DTMF tone relevant to
that particular number, and for consistency, another non-DTMF tone
can be played when control keys are pressed |
|
Automatic Answer
: Automatic answer is a phone feature that
allows a recipient to answer a call without the need to press any
keys. Once the phone has started to ring the conversation can be
started immediately, because the sound of the recipient's voice
speaking into the phone's microphone will trigger the answering of
the call |
|
Automatic Backlight
: Automatic backlighting means that touching any
key will illuminate the display and keypad for ease of viewing. The
backlight will turn itself off automatically after a preset period,
so avoiding excessive drain on the battery. This feature will only
be available on mobile phones that have a backlight |
|
Automatic Redial
: Automatic redial is a feature designed to make
it easier to dial numbers that are engaged. After the dialled
number is found to be engaged, the phone will either repeatedly
redial the number automatically, or it can be set to redial by
pressing the appropriate key. This feature saves the user from
dialling the number many times until a ringing tone can be
obtained. Automatic redial will usually operate for a set number of
redials before giving up, to avoid the negative consequences of
battery drain, blocking the phone, and causing unnecessary network
traffic |
|
Broadband
: Sometimes referred to as a high-speed
internet, broadband is an ‘always on’ fast connection to the
internet. Today there are a wide variety of broadband technologies
available in most areas; two of the more commonly found and used
technologies are cable and DSL broadband. |
|
Churn
: Churn is a term referring to customer
turnover. The word churn is used to describe those customers
abandoning a service or product, and it is particularly applied to
Internet and cell-phone subscribers, who tend to often switch
providers as a result of intense competition. Churn rate is
calculated as the number of customers lost over a time period,
divided by the average total number of customers during that
period.
For commercial reasons providers will be anxious to understand why
the churn rate is high, and whether it is due to customer
dissatisfaction with the price or type of services offered. Some
providers even offer special deals of free equipment or an initial
charge-free period to attract new customers. Also, to discourage
churn, the customer may be asked to sign a service agreement
containing penalty clauses, to ensure that they stay with the
provider for a minimum period |
|
Band
: content Band Go back to BackboneSkip content
Also known as: Frequency Band Band (Frequency Band) is a term used
in telecommunications to refer to a range of frequencies authorised
for specific purposes. Each band will be a continuous spectrum of
frequencies, with upper and lower limits, and international use of
these bands is regulated by the International Telecommunication
Union (ITU) to prevent interference. For example, the medium wave
band is approved for several purposes, the most well-known being
its use for public service AM (Amplitude Modulation) radio
broadcasts |
|
Bandwidth
: Bandwidth is a measure of the information
carrying capacity of a communications channel, whether it be of the
wired or wireless type. In analogue systems bandwidth is measured
as a frequency in Hertz (Hz), and it is calculated as the
difference between the highest and lowest frequencies of a band.
The term bandwidth can apply to various types of equipment, e.g.
audio, radio, video, etc., and in each case the bandwidth is
calculated by subtracting the lower frequency limit of the band
from its upper frequency limit. The range of frequencies that a
particular signal will occupy can also be referred to as its
bandwidth (as all signals inherently occupy a certain amount of
bandwidth), or alternatively it may mean the range of frequencies
that a piece of equipment will respond to. Furthermore, because the
rate at which digital data flows through a system will depend on
the bandwidth, this data rate can also be shown to be a measure of
the system's bandwidth. In digital systems the bandwidth is usually
described as the maximum transmission speed that a channel will
support, and is measured as a data rate in bits per second (bps).
If the bandwidth of a system is too narrow for a particular signal
to pass through it, then there will be some distortion to that
signal, or loss of its information content. Because bandwidth is
closely related to the signal frequencies being transmitted, it
gives an indication of the capacity of the system to cope with
different signals. This means that a wide bandwidth will allow
higher data rates, and conversely a narrow bandwidth will restrict
the data rate. A voice signal requires only about a 3 kHz
bandwidth, whereas a TV video signal needs about 6 MHz of
bandwidth, because it contains much more information. Signals
outside the band of interest are usually suppressed, in order to
prevent interference to or from other equipment. Bandwidth has a
general meaning of how much information can be carried in a given
time period (usually a second). For example, a broadband link (i.e.
one with a wide bandwidth) may be able to carry enough information
to present moving video images. If one link or piece of equipment
in a communication network has a much smaller bandwidth than the
rest, then this will determine the data rate for the whole
system |
|
Base Station
: Also known as: BS Base Station (BS) is a fixed
radio station in the cellular network, which communicates with
mobile telephones using radio waves. The Base Station will include
transmitters, receivers, tower and antenna, and control equipment
to interconnect with other base stations and the public switched
network via landline or microwave links. A mobile telephone service
consists of a network of many Base Stations, each of which covers
one cell or geographical area within a total cellular service area.
The Base Station communicates with the mobile phones within its
given cell, and then transfers calls to other base stations and the
fixed telephone network |
|
Base Station Colour Code
: Also known as: BCC Base Station Colour Code
(BCC) is the code transmitted in the SB (Synchronisation Burst) of
GSM systems. The BCC is used by the MS (Mobile Station) to
distinguish between cells using the same frequencies, when the MS
is deciding on which cell to select and to lock-on to. The BCC is
also important during the receiving of the BCCH (Broadcast Control
Channel), to identify the TSC (Training Sequence Code) to be
used |
|
Base Station Identity Code
: Also known as: BSIC Base Station Identity Code
(BSIC) is a 6 bit 'colour code' broadcast on the SCH
(Synchronisation Channel) in GSM systems, which uniquely identifies
the beacon frequency. The BSIC is broadcasted in order to identify
the NCC (Network Colour Code) and the BCC (Base Station Colour
Code) to the Mobile Stations in the area. Adjacent cells in the
cellular system will have different 'colours' or BSICs |
|
Base Station Subsystem
: Also known as: BSS Base Station Subsystem /
System (BSS) refers to a segment of a GSM system, comprising a Base
Station Controller (BSC) and the one or more Base Transceiver
Stations (BTS) that are associated with it. The Base Station
Controller manages the Base Transceiver Stations, and at a higher
level a Mobile Switching Centre (MSC) controls one or more of these
Base Station Subsystems. The BSS is the interface between the
Mobile Station (MS) and the Mobile Switching Centre (MSC). |
|