Battery Meter
: Battery meter is a visual indicator of the
estimated amount of life remaining in the battery. Mobile phones
usually combine a meter with an audible warning signal, to help the
user to avoid dropping calls due to the battery running low before
they have the chance to recharge |
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Baud
: Also known as: Bd Baud (Bd) was the
traditional unit used to measure signalling speed or modulation
rate on a communications channel, and it was first used to measure
the speed of telegraph transmissions. The Baud was named after a
French engineer, Jean-Maurice-Emile Baudot, and one Baud is equal
to one signal change per second. Baud is often confused with the
bit rate or Bits per Second (bps), and the two terms are sometimes
used interchangeably. However, Bauds and bits are not always the
same thing, as more than one bit may be transferred in one Baud.
Nowadays Bits Per Second (bps) is used instead of Baud, because it
is a more accurate measurement of the actual data transfer rate,
and the Baud is best avoided |
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Baud Rate
: Baud Rate is a measure of the information
carrying capacity or signalling rate on a communications channel,
and is the maximum number of discrete signal events that can be
transmitted per second. Baud Rate has often been used as a measure
of the speed at which computers can transfer data through a modem.
However, it is a term that has caused a lot of confusion, and some
people have mistakenly used the term interchangeably with Bits per
Second (bps). Bauds and bits are not always the same thing, as more
than one bit may be transferred in one Baud. Nowadays Bits Per
Second (bps) is used instead of Baud, because it is a more accurate
measurement of the actual data transfer rate, and the Baud is best
avoided |
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BCCH
: Also known as: Broadcast Control Channel
Broadcast Control Channel (BCCH) is a downlink GSM Broadcast
Channel (BCH). The BCCH is transmitted by a Base Transceiver
Station (BTS) to provide the signalling information required by the
MS (Mobile Station) to access and identify the network. The BCCH
will include information such as the LAC (Location Area
Code). |
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BCH
: Also known as: Broadcast Channel Broadcast
Channels (BCH) are downlink channels in a GSM system and are
transmitted by the Base Transceiver Station (BTS). BCH provide
signalling information, so that the Mobile Stations (MS) in the
cell can locate, synchronise and access the network. Three types of
BCH are used: Broadcast Control Channel (BCCH), Synchronisation
Channel (SCH), and Frequency Correction Channel |
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BER
: Also known as: Bit Error Ratio, Bit Error Rate
Bit Error Rate or Bit Error Ratio (BER) is a measure of the
accuracy of transmission for digital information in a
telecommunications system. The BER is calculated as the number of
bits that were in error, as a proportion of the total number of
bits transmitted, or received, or processed over a given period of
time. This figure can be used to indicate the Quality of Service
for a service provider, and is typically of the order of one error
bit in a billion (or 1 in 10 to the power minus 9). |
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BERT
: Also known as: Bit Error Rate Test Bit Error
Rate Test (BERT) is a device or test used to determine the Bit
Error Rate for a particular transmission. The test is used to
discover how many received bits of data were in error, as a ratio
of the total number of bits received. The result is usually a very
small number, typically one in a billion (or 10 to the power minus
9). |
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Binary Digit
: Also known as: Bit Bit (binary digit) is the
smallest unit of data used in digital information systems, being
allocated only a single value of either 0 or 1, i.e. an "off" or an
"on" state. In the data communication field bits are counted using
the decimal number system, and so other units of bits are kilobit
(1,000 bits), Megabit (1,000,000 bits) and Gigabit (1,000,000,000
bits). The term "Bit" is derived from a combination of b(inary) and
(dig)it |
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Bits Per Second
: Also known as: bps Bits per Second (bps) is a
commonly used unit of measurement in telecommunications for the
rate or speed at which data is transferred. The bps indicates how
many binary digits (the number of 0's and 1's) are transmitted or
received in a serial form (one bit after another) each second. In
practice larger units are more convenient: one kilobit per second
(kbps) is equal to 1,000 bps, one Megabit per second (Mbps) is
equal to 1,000,000 bps or 1,000 kbps, one Gigabit per second (Gbps)
is equal to 1,000,000,000 bps or 1,000 Mbps. The bps is also an
indication of a signal's bandwidth, and usually the higher the bps
the greater is the signal bandwidth (a frequency measured in kHz or
MHz). The old measure of data speed was the Baud or "baud rate",
which is the number of times a digital signal changes state each
second. For a given digital signal Baud rate is almost always a
lower figure than bps, but Baud Rate and bps are often wrongly
interchanged |
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Busy Transfer
: Busy transfer is a phone feature similar to
call divert, except that the call is only re-directed if the
receiving phone is engaged |
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Byte
: Also known as: B Byte (B) is the name given to
a group of 8 bits of digital data that are read as a single unit or
word. Each byte can represent information that is used in a system,
such as a single character from the ASCII code. The number of bytes
is also commonly used as a measure to indicate information
capacity, and the storage of data in digital systems is normally
quoted in megabytes or gigabytes. In computer systems bytes are
always used to refer to the memory and disk space, as computers
deal easily with binary numbers (i.e. powers of 2). The size of
text and image files is also normally given in bytes (e.g. in
kilobytes or megabytes). In contrast, communication systems tend to
use bits when referring to data transmission speeds. Although there
are usually eight bits in a byte, longer sequences such as 16 and
32 bits are also possible |
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Z-Modem
: Also known as: Zmodem Z-Modem is an
error-correction protocol used in the transfer of serial data files
between modems. Z-Modem is a faster successor to Y-Modem and has
better error checking capability. Modems using the Z-Modem protocol
send data in 512-byte blocks or packets, and the error detection
method is cyclic redundancy check (CRC). Like Y-Modem, Z-Modem has
the capability of handling batch transmission (sending a number of
files with one command) and variable block sizes of data. Z-Modem
is also similar to Y-Modem-G, because it sends data in a continuous
stream, and does not require a positive acknowledgement (ACK) for
successfully transferred blocks of data. However, if an error is
detected in a received block, a negative acknowledgement (NAK) is
returned to the sender and the block resent. Z-Modem differs from
the earlier protocols in that it is able to recover after a
"crash", i.e. when a transmission is cancelled or for some other
reason interrupted, the transmission may be restarted without
resending the previously transferred blocks of data |
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Y-Modem
: Also known as: Ymodem Y-Modem is an
error-correction protocol used in the transfer of serial data files
between modems. Y-Modem is based on the earlier X-Modem protocol,
but has the additional feature of being able to cope with a batch
transmission mode, in which a number of files can be sent with one
command. For greater efficiency Y-Modem can also handle data with a
variable block size of up to a maximum 1024 bytes (1 kB). During
transmission, the size of text and binary files is included in the
Y-Modem header, so that the exact file length will be retained
after transfer. The error detection method in Y-Modem is cyclic
redundancy check (CRC). A later version of Y-Modem, Y-Modem-G,
transmits data in a continuous stream and does not acknowledge the
blocks successfully received; it is only the blocks with detected
errors that cause a negative acknowledgement (NAK), thus prompting
the resending of data |
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X-Modem
: Also known as: Ymodem Y-Modem is an
error-correction protocol used in the transfer of serial data files
between modems. Y-Modem is based on the earlier X-Modem protocol,
but has the additional feature of being able to cope with a batch
transmission mode, in which a number of files can be sent with one
command. For greater efficiency Y-Modem can also handle data with a
variable block size of up to a maximum 1024 bytes (1 kB). During
transmission, the size of text and binary files is included in the
Y-Modem header, so that the exact file length will be retained
after transfer. The error detection method in Y-Modem is cyclic
redundancy check (CRC). A later version of Y-Modem, Y-Modem-G,
transmits data in a continuous stream and does not acknowledge the
blocks successfully received; it is only the blocks with detected
errors that cause a negative acknowledgement (NAK), thus prompting
the resending of data |
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XHTML
: XHTML (a merger of XML and HTML) is an updated
HTML standard introduced to help tidy up all the developments and
additions to original HTML. Over the years, different browsers
added features and offered increased functionality, which all had
their own proprietary manifestation in HTML. This led to a mish
mash of tags and markup that often led to web authors putting in
duplicate attributes and code in order to make sure that a page
looked the same in different browsers browsers. XHTML is a unifying
standard from the W3C that brings the XML benefits of easy
validation and troubleshooting to HTML, which not only helps
developers but also makes the pages easier to read for programs
such as mobile browsers. There are three variations of XHTML, the
most common of which is Transitional. XHTML Transitional is a
stepping stone from the deprecated HTML standardsL, and as such is
fairly permissive, allowing many old and proprietary attributes,
although Transitional stipulates that all tags must have both
opening and a closing markup and be correctly nested. XHTML Strict
is a more rigourous standard that removes all the ’chaff’ gathered
by HTML not ruled out in Transitional, and is what web authors
should strive toward. Finally, XHTML Frameset is similar to XHTML
Transitional, but allows for the use of frames. |
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W
: Also known as: Watt Watt (W) is the standard
unit for measuring power, and it indicates the rate at which energy
- for example electrical or electromagnetic energy - is radiated,
absorbed, or dissipated. One Watt is equivalent to using one Joule
of energy per second. The RF and audio power available from a
mobile phone will determine its capacity to provide good signal
strength, which is necessary in order to maintain satisfactory
communications with users on the phone network. There has to be a
compromise however, as the higher the power used by the phone, then
the greater will be the drain on its battery. The power can be
determined by calculating the product of the voltage and the
current (i.e. Watts = Volts x Amps). |
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Wallpaper
: Wallpaper is a picture or graphical image that
fully covers the display screen of a computer, mobile phone or
other equipment with a visual monitor. This 'wallpaper' is used to
customise the background environment on the user's screen, and to
give the equipment a personalised or corporate appearance.
Wallpaper is available for free download from many websites,
although there are also specialist companies that sell designer
wallpaper |
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WAP Identity Module
: Also known as: WIM WIM (WAP identity module)
is a security module that provides a more secure environment when
using WAP related applications and services on a mobile device via
a WAP gateway. A WIM allows the user to store certificates and
digital signatures |
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Watt
: Watt (W) is the standard unit for measuring
power, and it indicates the rate at which energy - for example
electrical or electromagnetic energy - is radiated, absorbed, or
dissipated. One Watt is equivalent to using one Joule of energy per
second. The RF and audio power available from a mobile phone will
determine its capacity to provide good signal strength, which is
necessary in order to maintain satisfactory communications with
users on the phone network. There has to be a compromise however,
as the higher the power used by the phone, then the greater will be
the drain on its battery. The power can be determined by
calculating the product of the voltage and the current (i.e. Watts
= Volts x Amps). |
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Wavelength
: Wavelength is the physical distance spanned by
one complete cycle or wave of an alternating signal as it travels
through space. The term wavelength can be applied to many types of
wave, e.g. audio, radio, light, etc, but is generally only
applicable to a wave of a single frequency, such as the RF carrier
transmitted by a mobile phone. Wavelength (l), usually measured in
metres between the adjacent peaks or troughs of consecutive waves,
is related to frequency (f) and propagation velocity (v) by the
equation l = v / f. Note that the propagation velocity depends on
the type of wave and the material through which it passes: radio
waves travel at the speed of light, but audio waves at the speed of
sound |
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