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Mian Muhammad Zulqarnain Aamir

                PROGRAM                      MBA
                ID                  012521-022

                       Mobile Computing

Q - What is Bluetooth?

Bluetooth is a low bandwidth wireless networking technology
designed primarily to replace cables for communication
between personal computing/communication devices. It is
intended to be used for both voice and data communications.
Bluetooth technology eliminates the need for numerous and
inconvenient      cable  attachments     for    connecting     fixed
computers, mobile phones, mobile computers, handheld
devices, digital cameras and even new breed of digital
appliances. It will enable users to connect a wide range of
computing and telecommunications devices easily and simply,
without the need to buy, carry, or connect cables - quite often
proprietary to a specific device. It delivers opportunities for
rapid ad hoc connections, and the possibility of automatic,
unconscious, connections between devices. It creates the
possibility of using mobile data in a variety of applications.

Bluetooth makes wireless communication and networking
between devices in a small localized area of a room or a small
office as easy as switching on the light. In Bluetooth all the
connections between devices are instantaneous and invisible
and the devices can talk even if they are not in line of sight
because Bluetooth utilizes a radio-based link. Your laptop could
send information to a printer in the next room, or your
microwave could send a message to your mobile phone telling
you that your meal is ready.

Bluetooth is a global de facto standard for wireless
connectivity. Based on a low-cost, short-range radio link,
Bluetooth cuts the cords that used to tie up digital devices.

When two Bluetooth equipped devices come within 10 meters
range of each other, they can establish a connection together.
And because Bluetooth utilizes a radio-based link, it doesn't
require a line-of-sight connection in order to communicate.
Your laptop could send information to a printer in the next
room, or your microwave could send a message to your mobile
phone telling you that your meal is ready.

In the future, Bluetooth is likely to be standard in tens of
millions of mobile phones, PCs, laptops and a whole range of
other electronic devices. As a result, the market is going to
demand new innovative applications, value-added services,
end-to-end solutions and much more. The possibilities opened
up really are limitless, and because the radio frequency used is
globally available, Bluetooth can offer fast and secure access to
wireless connectivity all over the world. With potential like that,
it's no wonder that Bluetooth is set to become the fastest
adopted              technology              in            history.

Bluetooth wireless technology is a system solution comprising
hardware, software and interoperability requirements. The
Bluetooth specifications specify the complete system.

The Bluetooth Specification defines a short (around 10 m) or
optionally a medium range (around 100 m) radio link capable
of voice or data transmission up to a maximum capacity of 720
Kb/s per channel.

Radio frequency operation is in the unlicensed industrial,
scientific and medical (ISM) band at 2.4 to 2.48 GHz, using a
spread spectrum, frequency hopping, full-duplex signal at up to
1600 hops/sec. The signal hops among 79 frequencies at 1
MHz intervals to give a high degree of interference immunity.
RF output is specified as 0 dBm (1 mW) in the 10m-range
version and -30 to +20 dBm (100 mW) in the longer range

When producing the radio specification, high emphasis was put
on making a design enabling single-chip implementation in
CMOS circuits, thereby reducing cost, power consumption and
the chip size required for implementation in mobile devices.
The Bluetooth Solution answers the need for short-range
wireless connectivity within three areas:

   Data and Voice access points
   Cable replacement
   Ad hoc networking

Data and Voice access points

Bluetooth wireless technology facilitates real-time voice and
data transmissions, which makes it possible to connect any
portable and stationary communication device as easily as
switching on the lights.

You can, for instance, surf the Internet and send e-mails on
your portable PC or notebook regardless of whether you are
wirelessly connected through a mobile phone or through a
wire-bound connection (PSTN, ISDN, LAN, xDSL).

Up to three simultaneous synchronous voice channels are used,
or a channel which simultaneously supports asynchronous data
and synchronous voice. Each voice channel supports a 64 kb/s
synchronous (voice) channel in each direction.

The asynchronous data channel can support maximal 723.2
kb/s asymmetric (and still up to 57.6 kb/s in the return
direction), or 433.9 kb/s symmetric.

     a Master can share an asynchronous channel with up to 7
      simultaneously active Slaves in a Piconet.
     by swapping active and parked slaves out respectively in
      the piconet, 255 slaves can be virtually connected using
      the PM_ADDR (a device can participate again within 2
     to park even more slaves the BD_ADDR can be used.
      There is no limitation to the number of slaves that can be

Slaves can participate in different piconets and a master of one
piconet can be the slave in another, this is known as a
scatternet. Up to 10 piconets within range can form a
scatternet, with a minimum of collisions.

Cable replacement

Bluetooth wireless technology eliminates the need for
numerous, often proprietary, cable attachments for connection
of practically any kind of communication device.

Connections are instant and they are maintained even when
devices are not within line of sight. The range of each radio is
approximately 10 meters, but it can be extended to around 100
meters with an optional amplifier.

Ad hoc networking

A device equipped with a Bluetooth radio establishes instant
connection to another Bluetooth radio as soon as it comes into
Since each Bluetooth device supports both point-to-point and
point-to-multipoint connections, several piconets can be
established and linked together ad hoc. The Bluetooth topology
is best described as a multiple piconet structure.

Many companies have declared that Bluetooth wireless
technology will be incorporated into their products, especially
when components becomes cheaper. In a forecast made by
Cahners In-Stat Group (July 2000), the product availability
during the next couple of years was defined as three waves.

The first wave is believed to occur around the turn of the year
2000/2001 and will include products like:
     Adapters for mobile phones and adapters (dongles) and
      PC Cards for notebooks and PCs.
     High-end mobile phones and notebook PCs with integrated
      Bluetooth communication for the business users.
     Bluetooth headsets are expected to enter the market by
      the first half of 2001.
     Cordless phones, handheld PCs, and PDAs will also be
      included in this first wave. The first handheld PCs and
      PDAs are expected to enter the market during 2001.

The second wave will in many respects overlap the first. What
we will see here is:

     PCs with Bluetooth circuitry on the motherboard.
     Printers, fax machines, digital still cameras, and products
      for industrial/medical and vertical industries will also begin
      to move in the second wave.
     Some industrial solutions may become available as soon
      as the end of 2000 or 1Q2001.
     In the automotive sector the first Bluetooth options are
      expected to appear for the 2002 model year
      (hands-free mobile phone usage with your regular mobile

The third wave will include:

     Low-cost mobile phones and lower-cost portable devices
      and desktop PCs.

Competing Technologies

There is no single competitor covering the entire concept of the
Bluetooth wireless technology but in certain market segments
other                    technologies                     exist.

For cable replacement the infrared standard IrDA has been
around for some years and is quite well known and widespread.
IrDA is faster than the Bluetooth wireless technology but is
limited to point-to-point connections and above all it requires a
clear line-of-sight. In the past IrDA has had problems with
incompatible standard implementations, a lesson that the
Bluetooth SIG has learnt.

Two other short-range radio technologies using frequency
hopping technique reside in the 2.4 GHz band:

Wireless LANs based on the IEEE 802.11 standard. The
technology is used to replace a wired LAN throughout a
building. The transmission capacity is high and so is the
number of simultaneous users. On the other hand, compared
to Bluetooth wireless technology, it is more expensive and
power consuming, and the hardware requires more space. It is
therefore not suitable for small mobile devices.

The other 2.4 GHz radio is Home RF, which has many
similarities to the Bluetooth wireless technology. Home RF can
operate ad hoc networks (data only) or be under the control of
a connection point coordinating the system and providing a
gateway to the telephone network (data & voice). The hop
frequency is 8 Hz while a Bluetooth link hops at 1600 Hz.

Ultra-Wideband Radio (UWB) is a new radio technology still
under development. Short pulses are transmitted in a broad
frequency range. The capacity appears to be high while power
consumption is expected to be low.

Q 2- How is the technology is called Bluetooth?

Harald I Bluetooth (Danish Harald Blåtand) was the King of
Denmark between 940 and 985 AD. The name "Blåtand" was
probably taken from two old Danish words, 'blå' meaning dark
skinned and 'tan' meaning great man. He was born in 910 as
the son of King Grom The Old (King of Jutland, the main
peninsula of Denmark) and his wife Thyre Danebold (daughter
of King Ethelred of England). Like many Vikings, Harald
considered it honorable to fight for treasure in foreign lands.
When Harald's sister Gunhild was widowed after the death of
the violent Norwegian king Erik Blood Axe, she came to
Denmark to seek Harald's help in securing control of Norway.
Harald took the opportunity to seize control himself. By 960 he
was at the height of his powers, ruling over both Denmark and
Norway. He was baptized by a priest named Poppo, sent by the
German emperor. He then created a monument that read:
"King Harald raised this monument to the memory of Grom his
father and Thyre his mother. Harald conquered all of Denmark
and Norway and made the Danes Christian". These words were
also carved in stone called rune stones. Harald was killed in a
battle in 985. Harald completed the country's unification begun
by his father, converted the Danes to Christianity, and
conquered Norway. The expansion begun by Harald in Norway
was continued by his son Sweyn I, who conquered England in
1013. Under Sweyn's son Canute there grew up a great Anglo-
Scandinavian kingdom that included parts of Sweden.

Old Harald Bluetooth united Denmark and Norway, Bluetooth of
today will unite the worlds of computers and telecom (hopefully
longer than the few years Harald's Viking kingdom survived).
In 1994 Ericsson Mobile Communications initiated a study to
investigate the feasibility of a low-power low-cost radio
interface between mobile phones and their accessories. In Feb
1998, five companies Ericsson, Nokia, IBM, Toshiba and Intel
formed a Special Interest Group (SIG). The group contained
the necessary business sector members - two market leaders
in mobile telephony, two market leaders in laptop computing
and a market leader in digital signal processing technology. It
is estimated that before year 2002, Bluetooth will be a built-in
feature for more than 100 million mobile phones and several
million communication devices ranging from handsets and
portable PCs to desktop computers and notebooks.

Q - How is Bluetooth is used?

BluetoothTM wireless technology revolutionizes the personal
connectivity market by providing freedom from wired
connections - enabling links between mobile computers, mobile
phones, portable handheld devices, and connectivity to the
Internet. Interface, synchronize, exchange? All of the above,
and more. Bluetooth technology redefines the very way we
experience connectivity.

It works everywhere. Hardware that complies with the
Bluetooth wireless specification ensures communication
compatibility worldwide. As a low-cost, low-power solution with
industry-wide support, Bluetooth wireless technology allows
you to bring connectivity with you. You define the boundaries
of your productivity - in Europe, in Asia, in America, in
whatever place your business may take you.

Establishing a standard means integrating well-tested
technology with the power-efficiency and low-cost of a
compliant radio system (about the Specification. Establishing a
standard also means a group of industry leading promoter
companies who drive the specification forward. Bluetooth
technology works because it has been developed as a cross
industry solution that marries a vision of engineering
innovation with an understanding of business and consumer

Bluetooth wireless technology is supported by product and
application development in a wide range of market segments,
including software developers, silicon vendors, peripheral and
camera manufacturers, mobile PC manufacturers and handheld
device developers, consumer electronics manufacturers, car
manufacturers, and test and measurement equipment

Q - How secure is a Bluetooth network?


Bluetooth employs frequency hopping (1600 hops/sec); which
adds some protection against eavesdropping, and there is also
built-in security at the physical layer. The built-in security
features allow one-way, two-way, or no authentication.
The key management and security setup will be done by the
software layers; which will allow the user set the security
requirements as needed. This way, it will be possible to define
different trust relationships between Bluetooth nodes and
networks; i.e. you will be able to allow a co-worker's PDA
access your business card scanner; but prevent him from
synchronizing             with             your             PC.
When Bluetooth is used for networking, it is always possible to
use stronger forms of encryption like SSH over the transport

Q - What is the frequency hoping spread spectrum?

Frequency hopping is one of two basic modulation techniques
used in spread spectrum signal transmission. It is the repeated
switching of frequencies during radio transmission, often to
minimize the effectiveness of "electronic warfare" - that is, the
unauthorized interception or jamming of telecommunications.
It also is known as frequency- hopping code division multiple
access (FH-CDMA).

Spread spectrum modulation techniques have become more
common in recent years. Spread spectrum enables a signal to
be transmitted across a frequency band that is much wider
than the minimum bandwidth required by the information
signal. The transmitter "spreads" the energy, originally
concentrated in narrowband, across a number of frequency
band channels on a wider electromagnetic spectrum. Benefits
include improved privacy, decreased narrowband interference,
and increased signal capacity.

In an FH-CDMA system, a transmitter "hops" between available
frequencies according to a specified algorithm, which can be
either random or preplanned. The transmitter operates in
synchronization with a receiver, which remains tuned to the
same center frequency as the transmitter. A short burst of data
is transmitted on a narrowband. Then, the transmitter tunes to
another frequency and transmits again. The receiver thus is
capable of hopping its frequency over a given bandwidth
several times a second, transmitting on one frequency for a
certain period of time, then hopping to another frequency and
transmitting again. Frequency hopping requires a much wider
bandwidth than is needed to transmit the same information
using only one carrier frequency.

The spread spectrum approach that is an alternative to FH-
CDMA is direct sequence code division multiple access (DS-
CDMA), which chops the data into small pieces and spreads
them across the frequency domain. FH-CDMA devices use less
power and are generally cheaper, but the performance of DS-
CDMA systems is usually better and more reliable. The biggest
advantage of frequency hopping lies in the coexistence of
several access points in the same area, something not possible
with direct sequence.

Certain rules govern how frequency-hopping devices are used.
In North America, the Industrial, Scientific, and Medial (ISM)
waveband is divided into 75 hopping channels, with power
transmission not to exceed 1 watt on each channel. These
restrictions ensure that a single device does not consume too
much bandwidth or linger too long on a single frequency.

The Federal Communications Commission (Fcc) has amended
rules to allow frequency hopping spread spectrum systems in
the unregulated 2.4 GHz band. The rule change is designed to
allow wider bandwidths, thus enabling Internet devices to
operate at higher speeds and fostering development of wireless
LANs and wireless cable modems.

Movie star Hedy Lamarr is generally credited as co-originator of
the idea of spread spectrum transmission. She and her pianist
were issued a patent for the technique during World War II.
They discovered the technique using a player piano to control
the frequency hops, and envisioned it as a way to provide
secure communications during wartime. The pair never made
any money off the invention and their patent eventually
expired. Sylvania introduced a similar concept in the 1950s and
coined the term "spread spectrum."

Q - Will other RF (radio frequency) devices interfere with
Bluetooth devices?
Bluetooth is a technology to connect devices without wires. The
intended use is to provide short-range connections between
mobile devices and to the Internet via bridging devices to
different networks (wired and wireless) that provide Internet
capability. HomeRF SWAP is a wireless technology optimized
for the home environment. Its primary use is to provide data
networking and dial tones between devices such as PC's,
cordless phones, Web Tablets, and a broadband cable or DSL
modem. Both technologies share the same frequency spectrum
but do not interfere when operating in the same space.

Q - What is the data throughput speed of a Bluetooth

Bluetooth supports both voice and data. The voice channels
support 64Kb/s. An asymmetric data rate (one way) of
721Kb/s (while permitting 57.6Kb/s in the return direction);
and symmetric rate of 432.6Kb/s is possible according to
Bluetooth                                                  spec.
There are preparations for newer versions of the Bluetooth
specifications, and these versions will most likely allow higher
data rates.

Q    -    What     is   the        range      of     Bluetooth

Bluetooth is designed for very low power use, and the
transmission range will only be 10m, about 30ft. High-powered
Bluetooth devices will enable ranges up to 100m (300ft).
Considering the design philosophy behind Bluetooth, even the
10m range is adequate for the purposes Bluetooth is intended
Later versions of the Bluetooth spec may allow longer ranges.

Q - What kind of encryption will be used for Bluetooth
The Bluetooth specification 1.0 describes the link encryption
algorithm as a stream cipher using 4 LFSR(linear feedback shift
registers). The sum of the width of the LFSRs is 128, and the
spec says the effective key length is selectable between 8 and
128 bits.This arrangement allows Bluetooth to be used in
countries with regulations limiting encryption strength, and
"facilitate a future upgrade path for the security without the
need for a costly redesign of the algorithms and encryption
hardware" according to the Bluetooth specification. Key
generation and authentication seems to be using the 8-round
SAFER+                      encryption               algorithm.
The information available suggests that Bluetooth security will
be adequate for most purposes; but users with higher security
requirements will need to employ stronger algorithms to ensure
the security of their data.

Q - Is Bluetooth practical for use with mobile devices?

Bluetooth will be used for personal area networks: very small
range networks between cell phones, PDAs, MP3 players, etc.
and computers. The built-in voice channels will allow cordless
telephony     and    headset    applications.   PDA-computer
synchronization, wireless home networking, connection of
keyboards, modems, cameras etc. are all possible.

Q - What is a personal area network (PAN)

A personal area network is a technology that could enable
wearable computer devices to communicate with other nearby
computers and exchange digital information using the electrical
conductivity of the human body as a data network. For
example, two people each wearing business card-size
transmitters and receivers conceivably could exchange
information by shaking hands. The transference of data
through intra-body contact, such as handshakes, is known as
linkup. The human body's natural salinity makes it a good
conductor of electricity. An electric field passes tiny currents,
known as Pico amps, through the body when the two people
shake hands. The handshake completes an electric circuit and
each person's data, such as e-mail addresses and phone
numbers, are transferred to the other person's laptop computer
or a similar device. A person's clothing also could act as a
mechanism for transferring this data.

The concept of a PAN first was developed by Thomas
Zimmerman and other researchers at M.I.T.'s Media Lab and
later supported by IBM's Almaden research lab. In a research
paper, Zimmerman explains why the concept might be useful:

As electronic devices become smaller, lower in power
requirements, and less expensive, we have begun to adorn our
bodies with personal information and communication
appliances. Such devices include cellular phones, personal
digital assistants (PDAs), pocket video games, and pagers.
Currently there is no method for these devices to share data.
Networking these devices can reduce functional I/O
redundancies and allow new conveniences and services.

Q - What is Home RF?

In simple terms, HomeRF is wireless home networking - a way
to connect PCs, peripherals, cordless phones, and many other
consumer electronic devices so they can "talk" with each other,
sharing resources and access to the Internet. Wireless home
networking makes this possible without the expense and
complexity associated with running wires.

In more technical terms, HomeRF is an open industry
specification that defines how these devices share and
communicate voice, data and streaming media in and around
the home. HomeRF-compliant products operate in the license-
free 2.4 GHz frequency band and utilize frequency-hopping
spread spectrum RF technology for secure and robust wireless

HomeRF blends technologies from several worldwide standards
since none of them alone could meet the market requirements.
Data networking technologies based on CSMA/CA protocols
(essentially wireless Ethernet) were derived from the OpenAir
and IEEE 802.11 standards, and cordless phone technologies
based on TDMA are adapted from DECT.

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