A5 is the encryption algorithm commonly used by GSM networks in Europe. It has a 64-bit key, although in practice at least ten of these bits are unused. A weaker version of A5 called A5/2 is exported to some countries, including Australia. It was originally a secret algorithm but was eventually leaked, which helped the case for using the open Kasumi algorithm as a replacement for A5. Comp128 is the more common GSM alternative to A5
Keyword(s):
AAC
:
advanced analogue coding
Keyword(s):
Abandoned Call
:
Abandoned call is one in which a connection is made with the recipient, but the caller then decides to terminate the call before any proper communication is established.
Organisations usually wish to keep abandoned calls to a minimum, as they may indicate a slow response to incoming calls
Keyword(s):
AC Wall Charger
:
AC Wall Charger is an essential accessory for use with mobile�phones and other electronic devices. The charger enables the mobile device to be powered, and for its battery to be recharged, by connecting it to a mains electricity supply socket.
AC wall chargers are often the only means of recharging the battery, and are usually supplied with a phone as they are designed to work with a particular product or type of battery. Wall chargers should not be interchanged without first taking advice, or expensive damage could result. Also note that it is normal for chargers to get warm while in use
Keyword(s):
Access Grant Channel
:
Also known as: AGCH
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
Keyword(s):
ACELP
:
Also known as: Algebraic Code Excited Linear Prediction
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?.
Keyword(s):
Action Script
:
ActionScript is an ECMAScript-based programming language
used for scripting Adobe Flash movies and applications.
ActionScript
:
an ActionScript is the the language
used in the Macromedia Flash program.
Look in the help menu in Macromedia Flash for more detailed
information.
Keyword(s):
Active Matrix
:
Also known as: Thin Film Transistor, TFT
TFT (Thin Film Transistor or Active Matrix) LCD is a mass produced display technology that offers improved refresh rates and good contrast over passive matrix displays. It achieves this by adding an individual switch at every single pixel, which means that voltage can be actively supplied to individual pixels instead of one row and one column receiving current at a time.
A thin film transistor at each pixel allows much greater contrast and vastly improved refresh rates compared with older displays. This makes full motion video feasible with an active matrix.
The two disadvantages to TFT displays are that they have higher power consumption as each individual pixel drains current, and they are more expensive; it is not cheap to manufacture perfect large sheets of transistors, as current processes are low-yield
Keyword(s):
Adaptive Differential Pulse Code
Modulation
:
Also known as: ADPCM
Adaptive Differential Pulse Code Modulation (ADPCM) is a compression/decompression technique, used for converting analogue sound or data into a string of digital binary code. Frequent samples are taken of the analogue signal, and the difference between the actual value of each sample and its predicted value (derived from the previous samples) is quantized and converted to a digital signal.
This technique is called 'adaptive', because the encoding predictions are adjusted in accordance with the changing characteristics of the input signal, and the coding scale is modified to accommodate any large or small differences. The ADPCM method of encoding takes up less storage space, and produces a lower bit rate, than standard PCM (Pulse Code Modulation). This greater efficiency is achieved because only the differences between samples are recorded. At the decoder the quantized difference signal is added to the predicted signal to produce the reconstructed speech signal.
ADPCM can typically give a compression ratio of 4:1, and one version of ADPCM is used to encode audio and compress more data onto Sony's Mini Discs
Keyword(s):
ADC
:
analogue to digital converter
Keyword(s):
ADSL
:
Also known as: Asymmetric Digital Subscriber Line
Asymmetric Digital Subscriber Line (ADSL) is a technology allowing high rates of digital data to be sent over conventional twisted-pair copper telephone lines. It is referred to as asymmetric because it provides a significantly greater bandwidth in one direction than the other, with faster data transfer from the network to the subscriber than it is in the opposite direction. Consequently, ADSL suits the Internet user who downloads large amounts of data from the Net, but tends to send comparatively little data back in return.
Theoretically, data speeds of up to 9 Mbps (megabits per second) are possible downstream to the customer, and up to 800 kbps (kilobits per second) upstream. This high-speed, high bandwidth digital communication makes live MPEG2 video signals possible, as well as a range of other multimedia broadband services. However, in practice capacity is lower than the theoretical maximum, because line length reduces data speed and limits the exchange to subscriber distance at about 2 miles.
ADSL requires the installation of a special modem, but ADSL then provides an 'always on' connection to subscribers. Simultaneous voice and data transmission is also possible over the same line, because the data transfer uses a section of the phone line bandwidth not utilised by voice. Therefore, subscribers can leave their computers logged onto the Net without interrupting their normal phone connections.
A form of ADSL, called Universal ADSL (G.lite), has been approved as a standard by the ITU-TS for services to homes and businesses. Universal ADSL can provide speeds of up to 1.5 Mbps over conventional phone lines. However, although a provider might typically offer a downstream rate of 512 kbps, this is still about 10 times faster than the fastest analogue-to-digital modems, and several times faster than an ISDN (Integrated Services Digital Network) connection. Upstream speeds can reach 128 kbps
Keyword(s):
Advanced Mobile Phone Service
:
Also known as: AMPS
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
Keyword(s):
Adventure Game,
:
A form of fictional simulation. These are often set in fantasy worlds and involve decision making and exploration.
advertisement
:
n. item of publicity for a product or service, in magazine, on TV etc
advertising agency
:
n. company specializing in producing and placing advertisements for clients
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
AI
:
artificial intelligence
Keyword(s):
AIDA
:
abbr. Attention, Interest, Desire, Action the
objective of all advertisements
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
AMS
:
automated manufacturing system
Keyword(s):
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
ANN
:
artificial neural network
Keyword(s):
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
Ariel
:
Also known as: antenna
The antenna (or aerial) is the physical part of a mobile phone that is designed to receive or transmit the radio frequency signals, which the�handset uses to communicate with the telephone network. A mobile may contain an internal antenna that is concealed within its case, or there may be a short or stubby external antenna that protrudes about 3 cm or more outside the case.
Some mobile phones include an FM radio, and in this case the headset lead usually acts as the radio's antenna. The headset must then be connected to the phone to ensure good reception
Array
:
An Array is just a computer term for a: List or
Vector. is one of the simplest date
sturctures,
and are useful in Flash, and there are numerous uses for Arrays in other
programs.
ASCII
:
American standard code for information interchange
Keyword(s):
ATM
:
automatic teller machine
Keyword(s):
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
Authoring Software
:
A category of software [which] lets you make a web page without
having any knowledge of HTML.
Keyword(s):
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
