BLUETOOTH TECHNOLOGY:-
o Bluetooth is designed to be a personal area network, where participating entities are mobile and require sporadic communication with others.
o It’s omni directional.
o Bluetooth operates in the 2.4 GHz area of the spectrum, and provides a Range of 10 meters.
o It offers transfer speeds of around 720 Kbps.
o Bluetooth devices are connected to each other; they form a network called Piconet. Each piconet can have a master, and up to seven slaves.
o To accommodate interference from other signals, Bluetooth uses frequency hopping.
o To conserve power, devices can go into three modes when they aren’t actively involved in a piconet.
o In increasing order of power consumption, they can be in park mode, hold mode and sniff mode.
o All the slave devices in a piconet are assigned an active member address(AM_ADDR).when a slave enters the park mode; it will give up its AM_ADDR and get a park address, PM_ADDR.
o One of Bluetooth’s advantages is that it can handle both data (asynchronous) and voice (synchronous), which others such as infra-red can’t.
o Every Bluetooth devices has a 48-bit BDAddr (Bluetooth device address) burned into its ROM. This address can’t be easily changed by the user.
o A Bluetooth device can be set to periodically scan for other devices in its vicinity or users can perform manual scans.
WI-FI TECHNOLOGY:-
o Bluetooth is a convenient way of communication for a personal network, but it is not suitable as an LAN replacement, or for perennial data transfer.
o Wi-Fi and abbreviation for wireless fidelity, is a wireless standard that promises mobility while offering data rates comparable to those of a wired LAN.
o Wi-Fi is a collection of standards ratified by the IEEE. In 1997; IEEE approved the 802.11 standard, which laid down the specification for wireless LAN.
o Revisions were made to this standard and these resulted in three other standards, namely 802.11a, 802.11b and 802.11g.The entire family of 802.11 standards is collectively called Wi-Fi. The name Wi-Fi was first given to the 802.11b standard. Approved in 1999, 802.11b Offered extensions to the original 802.11 that improved the highest data rate from 2 Mbps to 11 Mbps. It operates in the 2.4 GHz frequency range, like as the original and has a range of about 300 feet. The latest is 802.11g that has the highest data rate of 100Mbps.
o 802.11a is a standard that operates at a frequency of 5 GHz, and hence it is incompatible with 802.11b.
o The range of 802.11a is lower than that 802.11b; hence, more access points are needed to cover a large area.
o 802.11a is less susceptible to interference when compared to other standards such as 802.11b.
o To solve the limitation of ‘b’ and at the same time provide the speed of ‘a’, the 802.11g was introduced.
o 802.11g offers speeds of 100 Mbps, while maintaining compatibility with 802.11b networks, while maintaining compatibility with 802.11b networks, so a laptop with an 802.11g card will be able to use an 802.11b access point.
o Wi-Fi has a basic level of security provided at the physical level, called WEP.
o All Wi-fi products come with a 40-bit encryption key. A 104-bit encryption key is also available, and it is recommended that the largest available key should be used.
Thursday, November 12, 2009
DATA RATE, THROUGHPUT AND RANGE
As Bluetooth and Wi-Fi were designed to serve differing usage scenarios, it is no surprise that the performance of the two systems differs as well. Bluetooth trades off speed for lower power consumption, whereas Wi-Fi attempts to match the performance of wired LANs. Bluetooth supports two types of links – packet and connection-oriented (known as SCO). Packet connection is used for data transmission and can operate symmetrically or asymmetrically. The maximum symmetric data transfer rate is 433.9 kbps in each direction; the maximum asymmetric data rate is 723.2 kbps upstream (57.6 kbps downstream). Dedicated connection-oriented links are used for audio applications. Bluetooth can support three 64 kbps voice channels simultaneously. These data rates are sufficient to accommodate the usage scenarios described in earlier sections. Wi-Fi supports four different data rates: 11 Mbps, 5.5 Mbps, 2 Mbps and 1 Mbps. A ratescaling algorithm is used to reduce the data rate when errors are detected in transmission. The result is that the data rate is reduced as a user moves farther away from an AP.
When a user wishes to connect to a LAN, Wi-Fi offers a simpler procedure, as it has been optimized for this function. Assuming a WLAN card is already in place, the user need merely turn on her computing device and enter the necessary authenticating user name and password. The user is then on the network. For Bluetooth, the process is lengthier, possibly requiring each of the following steps: 1) device discovery; 2) device connection; 3) the establishment of a LAN access connection; 4) the establishment of a PPP connection; 5) PIN entry; 6) network user name and password entry. Though most of these steps can be accomplished with a single click of the mouse or tap of the stylus, the entire process could take as long as 30 seconds. The fact that Bluetooth enables communication between disparate device types using many different types of applications means, inevitably, that some procedures will take longer with Bluetooth than with applicationspecific technologies such as Wi-Fi. In order to streamline this process, Pico has developed a proprietary application -- PicoConnect™ -- that allows onetouch network access.
COMPARING THE CAPABILITIESOF BLUETOOTH AND WI-FI:
POWER CONSUMPTION
Power consumption is a critical consideration as it directly affects device battery life. This consideration is obviously most crucial for devices that spend most or all their operating hours on battery power – devices such as PDAs and mobile phones. From its inception, Bluetooth was designed to be a small-form factor, low-cost, low-power technology. The Bluetooth specification incorporates a number of power saving features in order to keep power use to a minimum. These features include a standby mode as well as four connected modes – parked, hold, sniff and active. An adaptive transmission power feature further minimizes power use.
In order to achieve Ethernet-level data rates, Wi- Fi operates with higher radio power on fixed channels of greater bandwidth. Wi-Fi offers a power save mode in which STAs “sleep,” then reawaken periodically to check for messages. Bluetooth and Wi-Fi modules are available in many different form factors including PC cards 9PCMCIA), Compact Flash (CF) cards, Secure Digital (SD) cards, Springboard modules, PCI cards and mini-PCI cards. Table 1 below summarizes the power requirements of various Bluetooth and Wi-Fi devices classes under various operating modes.
As shown in the table above, current Bluetooth devices have a minimum current that is approximately one-tenth the amount of minimum Wi-Fi current requirements, and a transmit current as little as a tenth of Wi-Fi’s transmit current, depending upon the output power of the devices in question. The implication is that Bluetooth will drain the battery less quickly than will Wi-Fi, making Bluetooth a more attractive option for users with smaller devices. In fact, a typical PDA with a 500 mA-hr battery life could support Bluetooth running in idle mode for more than 250 hours, whereas Wi-Fi could only be supported for 20 – 50 hours in sleep mode. If both technologies were in full transmit or receive mode, a PDA using Wi-Fi could expect little more than an hour of operation while a PDA using Bluetooth could operate for five to ten hours.
Power consumption is a critical consideration as it directly affects device battery life. This consideration is obviously most crucial for devices that spend most or all their operating hours on battery power – devices such as PDAs and mobile phones. From its inception, Bluetooth was designed to be a small-form factor, low-cost, low-power technology. The Bluetooth specification incorporates a number of power saving features in order to keep power use to a minimum. These features include a standby mode as well as four connected modes – parked, hold, sniff and active. An adaptive transmission power feature further minimizes power use.
In order to achieve Ethernet-level data rates, Wi- Fi operates with higher radio power on fixed channels of greater bandwidth. Wi-Fi offers a power save mode in which STAs “sleep,” then reawaken periodically to check for messages. Bluetooth and Wi-Fi modules are available in many different form factors including PC cards 9PCMCIA), Compact Flash (CF) cards, Secure Digital (SD) cards, Springboard modules, PCI cards and mini-PCI cards. Table 1 below summarizes the power requirements of various Bluetooth and Wi-Fi devices classes under various operating modes.
PRACTICAL IMPLEMENTATION OF WI-FI TECHNOLOGY:
In this report we show you how we
created a Wi-Fi network using 2.4 GHz USB
Wireless Adapter DWL-122 and DI-
614+2.4GHz Wireless Router 5V DC Power
Adapter. Thus we can access the laptop from a
Wi-Fi PDA through the access point. The LAN
can also be accessed through it. We have also
created a peer-to-peer network to link up a Wi-Fi
enabled PDA and a laptop directly without the
access point. The following section explains how
to configure the network.
created a Wi-Fi network using 2.4 GHz USB
Wireless Adapter DWL-122 and DI-
614+2.4GHz Wireless Router 5V DC Power
Adapter. Thus we can access the laptop from a
Wi-Fi PDA through the access point. The LAN
can also be accessed through it. We have also
created a peer-to-peer network to link up a Wi-Fi
enabled PDA and a laptop directly without the
access point. The following section explains how
to configure the network.
HOW WI-FI WORKS:
SYSTEM SUPPORT:
For a system to connect to a Wi-Fi
network, it should have a Wi-Fi card, or an
access point connected to it. Wi-Fi network cards
are like normal network cards that plug into PCI
slots, but have a protruding antenna. It’s also
possible to plug an external Wi-Fi adapter into a
USB port. Once network card are installed and
configured, the system can connect to any Wi-Fi
network.
PROS:
Given the current situation, Wi-Fi
should be adopted when there is a demand for
High speed on the move. Wi-Fi is suited for
corporate with several executives roaming
around the office with their laptops. Home
looking for a means to share a broad band
internet connection can also consider adopting
Wi-Fi.
CONS:
A wireless setup is rather expensive
when compared to a regular LAN. Also since
Wi-Fi drains batteries much quicker, PDA users
should avoid using it-especially if they have a
Bluetooth option available. It is difficult to
provide Wi-Fi network, as it is difficult to
control access to the network.
DEVICE USING WI-FI:
While Wi-Fi may be widely used for
communication between computers, there are
PDAs that support it. It’s also possible to add
Wi-Fi support to a PDA by inserting a Wi-Fi
card in to the SD (secure Digital) slot. PDA such
as the Toshiba e750 have inbuilt support for Wi-
Fi. Nokia announced plans to build mobile
phones that can seamlessly switch between
802.11b and public networks. The major
problem with Wi-Fi is the high power
consumption, which mobile devices just can’t
afford.
For a system to connect to a Wi-Fi
network, it should have a Wi-Fi card, or an
access point connected to it. Wi-Fi network cards
are like normal network cards that plug into PCI
slots, but have a protruding antenna. It’s also
possible to plug an external Wi-Fi adapter into a
USB port. Once network card are installed and
configured, the system can connect to any Wi-Fi
network.
PROS:
Given the current situation, Wi-Fi
should be adopted when there is a demand for
High speed on the move. Wi-Fi is suited for
corporate with several executives roaming
around the office with their laptops. Home
looking for a means to share a broad band
internet connection can also consider adopting
Wi-Fi.
CONS:
A wireless setup is rather expensive
when compared to a regular LAN. Also since
Wi-Fi drains batteries much quicker, PDA users
should avoid using it-especially if they have a
Bluetooth option available. It is difficult to
provide Wi-Fi network, as it is difficult to
control access to the network.
DEVICE USING WI-FI:
While Wi-Fi may be widely used for
communication between computers, there are
PDAs that support it. It’s also possible to add
Wi-Fi support to a PDA by inserting a Wi-Fi
card in to the SD (secure Digital) slot. PDA such
as the Toshiba e750 have inbuilt support for Wi-
Fi. Nokia announced plans to build mobile
phones that can seamlessly switch between
802.11b and public networks. The major
problem with Wi-Fi is the high power
consumption, which mobile devices just can’t
afford.
MAIN FEATURES: WI-FI TECHNOLOGY:-ADVANTAGES AND DISADVANTAGES:
MAIN FEATURES:
WI-FI TECHNOLOGY:-
o Wi-Fi networks operate in the unlicensed 2.4 and 5 GHz radio bands, with an 11 Mbps (802.11b) or 54 Mbps 9802.11a) or 100Mbps (802.11g) data rate or with products that contain both bands (dual band), so they can provide real-world performance similar to the basic 10BaseT wired Ethernet networks used in many offices.
o Modulation used in 802.11 has historically been phase-shift keying (PSK). The modulation method selected for 802.11b is known as complementary code keying or CCK, which makes possible high data speed and is less susceptible to multipath-propagation interference.
o It's powerful.
o Wi-Fi networks use radio technologies called IEEE 802.11b, IEEE 802.11b and IEEE 802.11g to provide reliable, fast wireless connectivity.
o A Wi-Fi network can be used to connect computers to each other, to the Internet, and to wired networks (which use IEEE 802.3 or Ethernet)
ADVANTAGES:
WI-FI TECHNOLOGY:-
Wi-Fi is cheap and fast. It's cheap, compared to 3G. It's already here and its nearterm rollout appears more widespread than 3G will be.
its standards based (IEEE 802.11b); therefore, consumers are not tied to proprietary technology. Since Wi-Fi is not based on proprietary technology, it ideally should allow many companies to enter the market and competitively hasten its evolution. Also, the standard has been improved. IEEE 802.11g, which operates at 100 Mbps.
vendors are backing Wi-Fi. Intel is one of the biggest proponents of Wi-Fi. It has recently unveiled a notebook chip called Banias that is to be the heart of a mobile brand called "Centrino." This chip is designed specifically for wireless computers to enable a longer battery life and to meet the heat/thermal requirements of the notebook and handheld markets. Other major players eager to step into the market include, a joint venture of AT&T, IBM, Intel (again), and others.
DISADVANTAGES:
WI-FI TECHNOLOGY:-
o Wi-Fi transmissions can be ruined by Bluetooth transmissions, since Bluetooth hops faster than Wi-Fi.
o It consumes lot of power so it cant be used efficiently for mobile devices.
o It’s expensive.
o It’s not very secure.
o Opponents of the technology argue correctly that Internet service can be affected by the user's proximity to the access point, the number of people using it, the speed of the server, interference from cordless phones and microwaves, and the user's surroundings (i.e., radio signals are not high powered and cannot travel through metal, water, or other dense materials). All of these factors can cloud Wi-Fi's wireless allure somewhat.
o You might be wondering where 3G fits into the Wi-Fi picture. Ultimately, the two may complement each other. Wi-Fi and 3G also may not even vie for the same pool of users.
o In theory, business travelers could use Wi-Fi to access the Internet when they are stationary, e.g., waiting for a flight in an airport, and 3G when they are in motion, e.g., commuting home from work on the train. However, this scenario must overcome some hurdles before it is realized. Currently, devices cannot alternate between Wi-Fi and 3G service, and it is uncertain when this issue will be addressed.
WI-FI TECHNOLOGY:-
o Wi-Fi networks operate in the unlicensed 2.4 and 5 GHz radio bands, with an 11 Mbps (802.11b) or 54 Mbps 9802.11a) or 100Mbps (802.11g) data rate or with products that contain both bands (dual band), so they can provide real-world performance similar to the basic 10BaseT wired Ethernet networks used in many offices.
o Modulation used in 802.11 has historically been phase-shift keying (PSK). The modulation method selected for 802.11b is known as complementary code keying or CCK, which makes possible high data speed and is less susceptible to multipath-propagation interference.
o It's powerful.
o Wi-Fi networks use radio technologies called IEEE 802.11b, IEEE 802.11b and IEEE 802.11g to provide reliable, fast wireless connectivity.
o A Wi-Fi network can be used to connect computers to each other, to the Internet, and to wired networks (which use IEEE 802.3 or Ethernet)
ADVANTAGES:
WI-FI TECHNOLOGY:-
Wi-Fi is cheap and fast. It's cheap, compared to 3G. It's already here and its nearterm rollout appears more widespread than 3G will be.
its standards based (IEEE 802.11b); therefore, consumers are not tied to proprietary technology. Since Wi-Fi is not based on proprietary technology, it ideally should allow many companies to enter the market and competitively hasten its evolution. Also, the standard has been improved. IEEE 802.11g, which operates at 100 Mbps.
vendors are backing Wi-Fi. Intel is one of the biggest proponents of Wi-Fi. It has recently unveiled a notebook chip called Banias that is to be the heart of a mobile brand called "Centrino." This chip is designed specifically for wireless computers to enable a longer battery life and to meet the heat/thermal requirements of the notebook and handheld markets. Other major players eager to step into the market include, a joint venture of AT&T, IBM, Intel (again), and others.
DISADVANTAGES:
WI-FI TECHNOLOGY:-
o Wi-Fi transmissions can be ruined by Bluetooth transmissions, since Bluetooth hops faster than Wi-Fi.
o It consumes lot of power so it cant be used efficiently for mobile devices.
o It’s expensive.
o It’s not very secure.
o Opponents of the technology argue correctly that Internet service can be affected by the user's proximity to the access point, the number of people using it, the speed of the server, interference from cordless phones and microwaves, and the user's surroundings (i.e., radio signals are not high powered and cannot travel through metal, water, or other dense materials). All of these factors can cloud Wi-Fi's wireless allure somewhat.
o You might be wondering where 3G fits into the Wi-Fi picture. Ultimately, the two may complement each other. Wi-Fi and 3G also may not even vie for the same pool of users.
o In theory, business travelers could use Wi-Fi to access the Internet when they are stationary, e.g., waiting for a flight in an airport, and 3G when they are in motion, e.g., commuting home from work on the train. However, this scenario must overcome some hurdles before it is realized. Currently, devices cannot alternate between Wi-Fi and 3G service, and it is uncertain when this issue will be addressed.
Wi-Fi
The 802 .11b standard was developed at the end of 1990’s and finally approved at the beginning of 1999. The first data transmission devices based on the standard were launched in 2000. Wi-Fi devices were designed for corporate clients to replace traditional cable networks. A wire network required a thorough design of the network topology and manual laying of hundreds of meters of cable, sometimes in the most unexpected places. Whereas all it takes to organize a wireless network is to install several base stations at one or several spots in the office (a central receiver and transmitter with an antenna connected to an outside network or a server) and insert a network card with an antenna. After that, both people and computers can be moved freely, and even changing offices wouldn’t damage the network. In the United States, a company had offered in December 2003 to make the whole of San Francisco Wi-Fi. In Spain, Telephonic launched the services ADSL Wi-Fi, which has led it to sign various agreements with public centers, like hotels or convention centers, to install access points. The operator has created almost 400 hotstops. Some educational institutes offering Wi-Fi are Pathways World School, Guraon while most IITs and IIMs, Anna University, Annamalai University, and International School of Business (ISB) in Hyderabad, Mount Zion College of Engineering and Technology have also become hotspots.
HOW BLUETOOTH WORKS:- SYSTEM SUPPORT:-
The easiest way to enable Bluetooth
support in a system is to attach Bluetooth USB
sticks. Some motherboards, such as MSI KT3
Ultra2-BR, come with inbuilt Bluetooth support.
Once plugged into the system, you’ll have to
install the drivers for the device to start using it.
The system will then periodically scan the
surroundings for Bluetooth devices.
PROS:-
Currently Bluetooth offers the best
solution for hassle-free communication between
portable devices. With low power consumption
and user friendliness, Bluetooth has all the
requirements of a personal area network. Those
who need to transfer data on a regular basis and
prefer portable device should definably opt for
Bluetooth.
CONS:-
In spite of promises that Bluetooth
support will be cheap, consumers avoid this due
to the cost. A Bluetooth USB sticks costs about
Rs 2,000, which may be on the higher side of
main stream customers. The cost is expected to
come down to Rs 250. Don’t think this
technology as a LAN replacement, though.
DEVICE USING BLUETOOTH:-
Bluetooth is slowly beginning to reach
the hands of consumers. Most premium-range
mobiles and PDAs support Bluetooth; it has
started appering in the main stream range as
well. Users buying mobiles phones, or PDAs
should look for Bluetooth enable devices .Using
Bluetooth, you can transfer contacts, ring tones,
images etc., between devices easily.
support in a system is to attach Bluetooth USB
sticks. Some motherboards, such as MSI KT3
Ultra2-BR, come with inbuilt Bluetooth support.
Once plugged into the system, you’ll have to
install the drivers for the device to start using it.
The system will then periodically scan the
surroundings for Bluetooth devices.
PROS:-
Currently Bluetooth offers the best
solution for hassle-free communication between
portable devices. With low power consumption
and user friendliness, Bluetooth has all the
requirements of a personal area network. Those
who need to transfer data on a regular basis and
prefer portable device should definably opt for
Bluetooth.
CONS:-
In spite of promises that Bluetooth
support will be cheap, consumers avoid this due
to the cost. A Bluetooth USB sticks costs about
Rs 2,000, which may be on the higher side of
main stream customers. The cost is expected to
come down to Rs 250. Don’t think this
technology as a LAN replacement, though.
DEVICE USING BLUETOOTH:-
Bluetooth is slowly beginning to reach
the hands of consumers. Most premium-range
mobiles and PDAs support Bluetooth; it has
started appering in the main stream range as
well. Users buying mobiles phones, or PDAs
should look for Bluetooth enable devices .Using
Bluetooth, you can transfer contacts, ring tones,
images etc., between devices easily.
BLUETOOTH SETTINGS AND CONFIGURATION:
To customize the configuration settings of Bluetooth software for Windows operating system, follow the instructions described below:
1. Right click on the Bluetooth icon on the righthand side of the task bar of your screen. The “Bluetooth Configuration” window appears to allow you to customize the configuration settings of “Explore”, “Setup”, or “Services”. In the “Setup” menu, there are two extended items, “Security” and “Configuration”.
2. Click on “Configuration”.
a) The “General” tab of “Configuration” allows you to customize the device’s user name, type, and security type.
b) The “Accessibility” tab allows you to specify which individual devices are allowed to access the user’s computer.
c) The “Discovery” tab allows you to specify which individual devices, type of, or class of device the user’s computer is allowed access to.
d) The “Information Exchange” tab allows you to specify the location of different types of files.
e) The “Local Services” tab indicates the services this computer makes available to the other computers.
f) The “Client Applications” tab indicates the properties of each application.
g) The “Hardware” tab indicates device information of the user’s hardware.
h) The “Version Info” tab indicates the module version of the user’s software component.
i) The “Notifications” tab lets you associate a sound (Windows *.wav file) with specific Bluetooth events.
1. Right click on the Bluetooth icon on the righthand side of the task bar of your screen. The “Bluetooth Configuration” window appears to allow you to customize the configuration settings of “Explore”, “Setup”, or “Services”. In the “Setup” menu, there are two extended items, “Security” and “Configuration”.
2. Click on “Configuration”.
a) The “General” tab of “Configuration” allows you to customize the device’s user name, type, and security type.
b) The “Accessibility” tab allows you to specify which individual devices are allowed to access the user’s computer.
c) The “Discovery” tab allows you to specify which individual devices, type of, or class of device the user’s computer is allowed access to.
d) The “Information Exchange” tab allows you to specify the location of different types of files.
e) The “Local Services” tab indicates the services this computer makes available to the other computers.
f) The “Client Applications” tab indicates the properties of each application.
g) The “Hardware” tab indicates device information of the user’s hardware.
h) The “Version Info” tab indicates the module version of the user’s software component.
i) The “Notifications” tab lets you associate a sound (Windows *.wav file) with specific Bluetooth events.
PRACTICAL IMPLEMENTATION OF BLUETOOTH TECHNOLOGY:
The following hardware components were used:
Two laptops of the following specification were
taken:
LAPTOP 1: System Model: Dell Precision M50 Workstation, Mobile Intel® Pentium® 4- MCPU-1.8Ghz 789 MHz, 512 MB – RAM, OS:Microsoft Windows XP Professional Version2002 Service Pack 1
LAPTOP 2: System Model: 1200XL - Compaq Presario, Celeron - 633 MHz, 4.5 GB HDD, 128 MB – RAM, OS: Windows 98
Two Belkin’s Bluetooth USB Adapters were attached to the above laptops:
ADAPTER 1: BD_Addr: 0003C92D5225
ADAPTER2: BD_Addr: 0003C92D5226
Two laptops of the following specification were
taken:
LAPTOP 1: System Model: Dell Precision M50 Workstation, Mobile Intel® Pentium® 4- MCPU-1.8Ghz 789 MHz, 512 MB – RAM, OS:Microsoft Windows XP Professional Version2002 Service Pack 1
LAPTOP 2: System Model: 1200XL - Compaq Presario, Celeron - 633 MHz, 4.5 GB HDD, 128 MB – RAM, OS: Windows 98
Two Belkin’s Bluetooth USB Adapters were attached to the above laptops:
ADAPTER 1: BD_Addr: 0003C92D5225
ADAPTER2: BD_Addr: 0003C92D5226
INTERNET CONNECTION THROUGH MOBILE PHONE :
The Bluetooth Clock,
Every Bluetooth unit has an internal system clock, which determines the timing and hopping of the transceiver. The Bluetooth clock is derived from a free running native
clock, which is never adjusted and is never turned off. For synchronization with other
units, only offsets are used. These offsets, when added to the native clock, provide
temporary Bluetooth clocks, which are mutually synchronized. The Bluetooth clock has
no relation to the time of day and can therefore be initialized to any value. The Bluetooth clock provides the heart beat of the Bluetooth transceiver. Its resolution is at least half the TX or RX slot length, or 312.5 µs. The Bluetooth clock has a cycle of about a day. If the clock is implemented with a counter, a 28-bit counter is required that wraps around at 2 28 -1. The LSB ticks in units of 312.5 µs, giving a clock rate of 3.2 KHz
clock, which is never adjusted and is never turned off. For synchronization with other
units, only offsets are used. These offsets, when added to the native clock, provide
temporary Bluetooth clocks, which are mutually synchronized. The Bluetooth clock has
no relation to the time of day and can therefore be initialized to any value. The Bluetooth clock provides the heart beat of the Bluetooth transceiver. Its resolution is at least half the TX or RX slot length, or 312.5 µs. The Bluetooth clock has a cycle of about a day. If the clock is implemented with a counter, a 28-bit counter is required that wraps around at 2 28 -1. The LSB ticks in units of 312.5 µs, giving a clock rate of 3.2 KHz
Bluetooth, on the other hand, supports a much wider variety of usage scenarios, including:
Bluetooth, on the other hand, supports a much wider variety of usage scenarios, including:
• Device interoperability (also known as cable replacement);
• Peer-to-peer collaboration between multiple PDAs and/or notebooks;
• Notebook and PDA internet access via mobile phone;
• PDA, notebook and PC LAN and Internet access via Bluetooth access points.
DEVICE INTEROPERABILITY :
The first scenario provides the fundamental basis for the development of the Bluetooth specification. It is, quite simply, the seamless interconnection of multiple Bluetooth-enabled devices that eliminates the need for cables to connect the devices. The most obvious example is a PC connected wirelessly to all of its peripheral devices. Not only are cables eliminated but the user also can place the peripheral wherever he wishes without regard for cable length. Since Bluetooth supports both voice and data, a single Bluetooth headset can be used in conjunction with multiple consumer and communication devices such as a desk phone, a mobile phone, and a portable music player. The need for separate cables and device-specific headsets is eliminated.
PEER-TO-PEER COLLABORATION :
Bluetooth enables devices that are in close proximity to form ad hoc networks, also known as piconets.
The Piconet
Bluetooth devices can interact with one or more other Bluetooth devices in several different ways. The simplest scheme is when only two devices are involved. This is referred to as point-to-point. One of the devices acts as the master and the other as a
slave. This adhoc network is referred to as a Piconet.
As a matter of fact, a Piconet is any such Bluetooth network with one master 2 and one or more slaves. A diagram of a Piconet is provided in the adjoining figure. In the case of multiple slaves, the communication topology is referred to as point-to-multipoint. In this case, the channel (and bandwidth) is shared among all the devices in the Piconet. There can be up to seven active slaves in a Piconet. Each of the active slaves has an assigned 3-bit Active Member address. There can be additional slaves, which remain synchronized to the master, but do not have an Active Member address. These slaves are not active and are referred to as parked. For the case of both active and parked units, all channel access is regulated by the master. A parked device has an 8-bit Parked Member Address, thus limiting the number of parked members to 256. A parked device remains synchronized to the master clock and can quickly become active and begin communicating in the Piconet.
• Device interoperability (also known as cable replacement);
• Peer-to-peer collaboration between multiple PDAs and/or notebooks;
• Notebook and PDA internet access via mobile phone;
• PDA, notebook and PC LAN and Internet access via Bluetooth access points.
DEVICE INTEROPERABILITY :
The first scenario provides the fundamental basis for the development of the Bluetooth specification. It is, quite simply, the seamless interconnection of multiple Bluetooth-enabled devices that eliminates the need for cables to connect the devices. The most obvious example is a PC connected wirelessly to all of its peripheral devices. Not only are cables eliminated but the user also can place the peripheral wherever he wishes without regard for cable length. Since Bluetooth supports both voice and data, a single Bluetooth headset can be used in conjunction with multiple consumer and communication devices such as a desk phone, a mobile phone, and a portable music player. The need for separate cables and device-specific headsets is eliminated.
PEER-TO-PEER COLLABORATION :
Bluetooth enables devices that are in close proximity to form ad hoc networks, also known as piconets.
The Piconet
Bluetooth devices can interact with one or more other Bluetooth devices in several different ways. The simplest scheme is when only two devices are involved. This is referred to as point-to-point. One of the devices acts as the master and the other as a
slave. This adhoc network is referred to as a Piconet.
As a matter of fact, a Piconet is any such Bluetooth network with one master 2 and one or more slaves. A diagram of a Piconet is provided in the adjoining figure. In the case of multiple slaves, the communication topology is referred to as point-to-multipoint. In this case, the channel (and bandwidth) is shared among all the devices in the Piconet. There can be up to seven active slaves in a Piconet. Each of the active slaves has an assigned 3-bit Active Member address. There can be additional slaves, which remain synchronized to the master, but do not have an Active Member address. These slaves are not active and are referred to as parked. For the case of both active and parked units, all channel access is regulated by the master. A parked device has an 8-bit Parked Member Address, thus limiting the number of parked members to 256. A parked device remains synchronized to the master clock and can quickly become active and begin communicating in the Piconet.
ADVANTAGES AND DISADVANTAGES
ADVANTAGES: BLUETOOTH TECHNOLOGY:-
It attempts to provide advantages over IrDA (Infrared Data Association) and Home RF (Radio Frequency). IrDA is popular in PC peripherals but is severely limited by short connection distance of 1m and by line of sight requirement for communication. It eliminates the feasibility of using IrDA for hidden computing. Due to its RF nature Bluetooth is not subject to such limitations. In addition to wireless device connections up to 10m (and up to 100m if transmitter power is increased), devices need not be within line of sight and may connect through walls or other non-metal objects. Bluetooth could also be used in homenetworking applications. There is a need for networks that are simple to install and maintain. Wireless connections circumvent the hassle of adding wiring to existing residences. Other technologies cost more than $100 per node Bluetooth is designed to be low cost – eventually under $10 per unit. It is now $5 per unit.
DISADVANTAGES:
BLUETOOTH TECHNOLOGY:-
o Bluetooth devices are expected to be omnipresent and at some places assess to this devices by public users many have to be restricted.
o Personal privacy is at risk.
o The range cant be increased without compromising on power
It attempts to provide advantages over IrDA (Infrared Data Association) and Home RF (Radio Frequency). IrDA is popular in PC peripherals but is severely limited by short connection distance of 1m and by line of sight requirement for communication. It eliminates the feasibility of using IrDA for hidden computing. Due to its RF nature Bluetooth is not subject to such limitations. In addition to wireless device connections up to 10m (and up to 100m if transmitter power is increased), devices need not be within line of sight and may connect through walls or other non-metal objects. Bluetooth could also be used in homenetworking applications. There is a need for networks that are simple to install and maintain. Wireless connections circumvent the hassle of adding wiring to existing residences. Other technologies cost more than $100 per node Bluetooth is designed to be low cost – eventually under $10 per unit. It is now $5 per unit.
DISADVANTAGES:
BLUETOOTH TECHNOLOGY:-
o Bluetooth devices are expected to be omnipresent and at some places assess to this devices by public users many have to be restricted.
o Personal privacy is at risk.
o The range cant be increased without compromising on power
MAIN FEATURES OF BLUETOOTH TECHNOLOGY:-
o It is wireless
o It is inexpensive.
o You don’t have to think about it i.e., does not require you to do anything special to make it work.
o Operates in the 2.56 GHz ISM band, which is globally available.
o Uses FHSS (Frequency Hopping Spread Spectrum)
o Can support up to 8 devices in the Pico net.
o Omni-directional, non line of sight transmissions through walls.
o 10m to 100m range.
o 1mW power.
o Extended range with external power amplifier (100m).
o Its main strength is its ability to simultaneously handle both data and voice transmissions.
o It is capable of supporting one asynchronous data channel and up to three synchronous voice channels, or one channel supporting both voice and data.
o It is inexpensive.
o You don’t have to think about it i.e., does not require you to do anything special to make it work.
o Operates in the 2.56 GHz ISM band, which is globally available.
o Uses FHSS (Frequency Hopping Spread Spectrum)
o Can support up to 8 devices in the Pico net.
o Omni-directional, non line of sight transmissions through walls.
o 10m to 100m range.
o 1mW power.
o Extended range with external power amplifier (100m).
o Its main strength is its ability to simultaneously handle both data and voice transmissions.
o It is capable of supporting one asynchronous data channel and up to three synchronous voice channels, or one channel supporting both voice and data.
THE BLUETOOTH TECHNOLOGY
ABSTRACT
The seemingly endless entanglement of data wires connecting today’s electronic devices has become slightly less jumbled with the introduction of Bluetooth technology and the creation of a wireless data link. This article delves into the implementation and architecture of Bluetooth. It also describes the functional overview and applications of Bluetooth. It gives significant advantages of Bluetooth over other data transfer technologies such as IrDA and Home RF. It illustrates how a connection is made in Bluetooth between two environments. It mainly emphasizes the architecture of Bluetooth. It gives over all Bluetooth packet structure and different communication and data information protocols such as WAP, UDP, IP, TCP, RFCOMM, and L2CAP etc. It also explains Link Security by Data Encryption. Finally it narrates how Bluetooth will bring a new level of connectivity and convenience when operating electronic devices. These details in the article establish the growing need for Bluetooth technology.
ORIGIN:
The idea that resulted in Bluetooth technology arose in 1994. Ericsson Mobile Communication initiated a study to investigate the feasibility of a low-power, low cost radio interface between mobile phones and their accessories. The aim of the study was to eliminate cables between mobile phones and PC cards, handsets and desktop devices, etc. In February 1998, Ericsson, Nokia, IBM, Toshiba and Intel formed a Special Interest Group (SIG). The group contained two market leaders in mobile telephony, two in laptop computing and one in digital signal processor technology.
The seemingly endless entanglement of data wires connecting today’s electronic devices has become slightly less jumbled with the introduction of Bluetooth technology and the creation of a wireless data link. This article delves into the implementation and architecture of Bluetooth. It also describes the functional overview and applications of Bluetooth. It gives significant advantages of Bluetooth over other data transfer technologies such as IrDA and Home RF. It illustrates how a connection is made in Bluetooth between two environments. It mainly emphasizes the architecture of Bluetooth. It gives over all Bluetooth packet structure and different communication and data information protocols such as WAP, UDP, IP, TCP, RFCOMM, and L2CAP etc. It also explains Link Security by Data Encryption. Finally it narrates how Bluetooth will bring a new level of connectivity and convenience when operating electronic devices. These details in the article establish the growing need for Bluetooth technology.
The idea that resulted in Bluetooth technology arose in 1994. Ericsson Mobile Communication initiated a study to investigate the feasibility of a low-power, low cost radio interface between mobile phones and their accessories. The aim of the study was to eliminate cables between mobile phones and PC cards, handsets and desktop devices, etc. In February 1998, Ericsson, Nokia, IBM, Toshiba and Intel formed a Special Interest Group (SIG). The group contained two market leaders in mobile telephony, two in laptop computing and one in digital signal processor technology.
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