Bluetooth :
Technology standard for exchanging data over short distances (using short-wavelength radio transmissions in the ISM band from 2400–2480 MHz) from fixed and mobile devices, creating Personal Area Net works {PAN}, with high level security.
Created by telecoms vendor Ericson in 1994. it was originally conceived as a wireless alternative to RS-232 data cables.
It can connect several devices, overcoming problems of synchronization.
http://en.wikipedia.org/wiki/Bluetooth
Ultra-wideband
The high speed (AMP) feature of Bluetooth v3.0 was originally intended for UWB, but the WiMedia Alliance, the body responsible for the flavor of UWB intended for Bluetooth, announced in March 2009 that it was disbanding, and ultimately UWB was omitted from the Core v3.0 specification.
On March 16, 2009, the WiMedia Alliance announced it was entering into technology transfer agreements for the WiMedia Ultra-wideband (UWB) specifications. WiMedia has transferred all current and future specifications, including work on future high speed and power optimized implementations, to the Bluetooth Special Interest Group (SIG), Wireless USB Promoter Group and the USB Implementers Forum. After the successful completion of the technology transfer, marketing and related administrative items, the WiMedia Alliance will cease operations
In October 2009 the Bluetooth Special Interest Group suspended development of UWB as part of the alternative MAC/PHY, Bluetooth v3.0 + HS solution. A small, but significant, number of former WiMedia members had not and would not sign up to the necessary agreements for the IP transfer. The Bluetooth SIG is now in the process of evaluating other options for its longer term roadmap
Bluetooth v4.0
The Bluetooth SIG completed the Bluetooth Core Specification version 4.0, which includes Classic Bluetooth, Bluetooth high speed and Bluetooth low energy protocols. Bluetooth high speed is based on Wi-Fi, and Classic Bluetooth consists of legacy Bluetooth protocols. This version has been adopted as of June 30, 2010.
Bluetooth low energy (BLE), previously known as WiBreeis a subset to Bluetooth v4.0 with an entirely new protocol stack for rapid build-up of simple links. As an alternative to the Bluetooth standard protocols that were introduced in Bluetooth v1.0 to v3.0, it is aimed at very low power applications running off a coin cell. Chip designs allow for two types of implementation, dual-mode, single-mode and enhanced past versions.The provisional names Wibree and Bluetooth ULP (Ultra Low Power) were abandoned and the BLE name was used for a while. In late 2011, new logos “Bluetooth Smart Ready” for hosts and “Bluetooth Smart” for sensors were introduced as the general-public face of BLE.
L2CAP
The Logical Link Control and Adaptation Protocol (L2CAP) Used to multiplex multiple logical connections between two devices using different higher level protocols. Provides segmentation and reassembly of on-air packets.
In Basic mode, L2CAP provides packets with a payload configurable up to 64kB, with 672 bytes as the default MTU, and 48 bytes as the minimum mandatory supported MTU.
In Retransmission and Flow Control modes, L2CAP can be configured either for isochronous data or reliable data per channel by performing retransmissions and CRC checks.
Bluetooth Core Specification Addendum 1 adds two additional L2CAP modes to the core specification. These modes effectively deprecate original Retransmission and Flow Control modes:
Enhanced Retransmission Mode (ERTM): This mode is an improved version of the original retransmission mode. This mode provides a reliable L2CAP channel.
Streaming Mode (SM): This is a very simple mode, with no retransmission or flow control. This mode provides an unreliable L2CAP channel.
Reliability in any of these modes is optionally and/or additionally guaranteed by the lower layer Bluetooth BDR/EDR air interface by configuring the number of retransmissions and flush timeout (time after which the radio will flush packets). In-order sequencing is guaranteed by the lower layer.
Only L2CAP channels configured in ERTM or SM may be operated over AMP logical links.
SDP
The Service Discovery Protocol (SDP) allows a device to discover services offered by other devices, and their associated parameters. For example, when you use a mobile phone with a Bluetooth headset, the phone uses SDP to determine which Bluetooth profiles the headset can use (Headset Profile, Hands Free Profile, Advanced Audio Distribution Profile (A2DP) etc.) and the protocol multiplexer settings needed for the phone to connect to the headset using each of them. Each service is identified by a Universally Unique Identifier (UUID), with official services (Bluetooth profiles) assigned a short form UUID (16 bits rather than the full 128).
RFCOMM
Radio Frequency Communications (RFCOMM) is a cable replacement protocol used to create a virtual serial data stream. RFCOMM provides for binary data transport and emulates EIA-232 (formerly RS-232) control signals over the Bluetooth baseband layer, i.e. it is a serial port emulation.
RFCOMM provides a simple reliable data stream to the user, similar to TCP. It is used directly by many telephony related profiles as a carrier for AT commands, as well as being a transport layer for OBEX over Bluetooth.
Many Bluetooth applications use RFCOMM because of its widespread support and publicly available API on most operating systems. Additionally, applications that used a serial port to communicate can be quickly ported to use RFCOMM.
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Setting up connections
Any Bluetooth device in discoverable mode will transmit the following information on demand:
Device name
Device class
List of services
Technical information (for example: device features, manufacturer, Bluetooth specification used, clock offset)
Any device may perform an inquiry to find other devices to connect to, and any device can be configured to respond to such inquiries. However, if the device trying to connect knows the address of the device, it always responds to direct connection requests and transmits the information shown in the list above if requested. Use of a device’s services may require pairing or acceptance by its owner, but the connection itself can be initiated by any device and held until it goes out of range. Some devices can be connected to only one device at a time, and connecting to them prevents them from connecting to other devices and appearing in inquiries until they disconnect from the other device.
Every device has a unique 48-bit address. However, these addresses are generally not shown in inquiries. Instead, friendly Bluetooth names are used, which can be set by the user. This name appears when another user scans for devices and in lists of paired devices.
Most phones have the Bluetooth name set to the manufacturer and model of the phone by default. Most phones and laptops show only the Bluetooth names and special programs are required to get additional information about remote devices. This can be confusing as, for example, there could be several phones in range named T610
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Pairing/Bonding
Motivation
Many of the services offered over Bluetooth can expose private data or allow the connecting party to control the Bluetooth device. For security reasons it is necessary to be able to recognize specific devices and thus enable control over which devices are allowed to connect to a given Bluetooth device. At the same time, it is useful for Bluetooth devices to be able to establish a connection without user intervention (for example, as soon as they are in range).
To resolve this conflict, Bluetooth uses a process called bonding, and a bond is created through a process called pairing. The pairing process is triggered either by a specific request from a user to create a bond (for example, the user explicitly requests to “Add a Bluetooth device”), or it is triggered automatically when connecting to a service where (for the first time) the identity of a device is required for security purposes. These two cases are referred to as dedicated bonding and general bonding respectively.
Pairing often involves some level of user interaction; this user interaction is the basis for confirming the identity of the devices. Once pairing successfully completes, a bond will have been formed between the two devices, enabling those two devices to connect to each other in the future without requiring the pairing process in order to confirm the identity of the devices. When desired, the bonding relationship can later be removed by the user.
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Health concerns
Bluetooth uses the microwave radio frequency spectrum in the 2.402 GHz to 2.480 GHz range
Maximum power output from a Bluetooth radio is 100 mW, 2.5 mW, and 1 mW for Class 1, Class 2, and Class 3 devices respectively, which puts Class 1 at a lower level than mobile phones, and the other two classes much lower
UMTS & W-CDMA outputs 250 mW, GSM1800/1900 outputs 1000 mW, and GSM850/900 outputs 2000 mW.
The radiated output power of Bluetooth devices varies between 1 and 100 mW, and can operate continuously or sporadically (on demand), so total exposure to EMF radiation is quite variable. Bluetooth devices have not been linked with any health issues.http://en.wikipedia.org/wiki/Wireless_electronic_devices_and_health
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Bluetooth EMF Safety
Health Effects, Risks & Dangers of Bluetooth Radiation
Are Bluetooth Headsets Dangerous?
All Bluetooth Headsets and Technologies emit wireless microwave radiation.
Microwave frequencies have a short wavelength and a rapid rate of oscillation. This is what enables them to travel long distances carrying information without needing to be contained in a wire.
The short wavelength and rapid oscillation of microwave frequencies also make them adept at being able to penetrate living tissue down to a cellular level.
This characteristic is what led Soviet Russia in the 1950’s to utilize microwave frequencies for weapons. By beaming microwave radiation at the US Embassy in Russia, the Soviets were able to induce leukemia in several US ambassadors.
Microwave Radiation Exposure Dangers from Bluetooth
Using any type of wireless technology is putting yourself in a field of microwave radiation. The effects of long term microwave radiation exposure upon the body have been documented in countless studies for decades.
Long-term exposure to microwave radiation has been linked to:
cancer
leukemia
brain tumors
alzheimers
autism
ADD
miscarriages
birth defects
autoimmune illnesses
multiple sclerosis
hair loss
suicide
Microwave radiation has been shown to affect biological changes within the body. These biological changes happen on a cellular level and their effects can be passed on to offspring via genetic damage (DNA, RNA).
Using a Bluetooth Headset exposes the brain, the ears and the eyes to a strong field of microwave radiation.
Studies have linked Bluetooth Headset use to:
blindness
deafness
brain tumors
neck pain
skin rashes
headaches
Bluetooth Wireless Radiation vs Cell Phone Radiation
Bluetooth Technology uses the same microwave radiation to transmit data as cell phones do to receive calls. The only difference is the range. A cell phone antenna picks up signals from cell phone towers and satellites, while a Bluetooth headset/technologies is receiving radiations from a few feet away.
Bluetooth Radiation Hazards and Safety Testing
Bluetooth radiation has been even less tested than cell phone radiation. The lack of any formal studies have enabled the ‘experts’ to claim that Bluetooth radiation is safe. This claim is based not on research proving Bluetooth radiation safe, but rather on the lack of any research proving it to be unsafe. This type of hollow safety claim is a technique used to by companies to buy time for new technology because time equals money.
What the FDA Says About Bluetooth Technology
The FDA has approved Bluetooth Technology for use by consumers without any regulations or premarket testing, which is exactly how cell phones were approved. However, it seems that as of 2006 the FDA felt a need to revisit its approval on cell phones in lieu of a recent study conducted by the Swedish National Institute for Working LIfe that showed cell phone users have a 240% greater risk of developing brain tumors on the same side of the head where they use their phone. Bluetooth headsets function in the same radiowave frequency as cell phones.
Bluetooth Technologies (wireless keyboards, printers, etc.) emit the same microwave radiation as the headsets and pose similar health problems.
Cell phones have been wildly popular for only a matter of years, and it can take at least a decade for cancers to show up. Studies contradict each other, and scientists bicker: Some will tell you with great conviction that there’s nothing to worry about. Others will tell you with equal conviction that an epidemic of brain tumors may be just around the corner.
The cell phone industry itself says “the overwhelming majority of studies that have been published in scientific journals around the globe show that wireless phones do not pose a health risk.” You can this week.So what are we all to do until they figure it out? After enough interviews with physicists, engineers and doctors to make me want to stick my head in a microwave oven, one common line of reasoning emerged.
Cell phones do emit radiation. No one knows definitively whether it’s enough to worry about.
Mobile phones meet federal safety limits, but if you’re still worried, there are some simple steps you can take to lower your exposure to radiation.
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Bluetooth technology, of course, has revolutionized the way we communicate with the people. There is no botheration about using wires or hands. You have to just put the device in your ear, and be ready to communicate with the world around you. The convenience and comfort is par excellence. There is a divided opinion whether the Bluetooth device held near your ears causes health hazards or not. Some are of the opinion that the electromagnetic waves being emitted from the Bluetooth phones may develop brain tumors or bring a sort of change in body cells. Experiments conducted by scientists in several countries has proved this to be true to certain extent. It is better to make the minimum use of these devices in the interest of our health. Precaution is always better than cure. In the modern world, the people usually compromise health with comfort and convenience.
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http://www.ehow.com/about_6780868_bluetooth-health-risks.html
Bluetooth technology is generally considered safer than using a wireless phone. Both mobile phones and Bluetooth devices emit non-ionizing radiation typically at frequencies from 1 to 2.5 gigahertz. While a phone needs to transmit with enough power to reach a base station antenna a couple of miles away, a Bluetooth generally transmits at a range of no more than 30 feet. Since radio energy dissipates at a rate proportional to the square of the distance, the transmission power of a Bluetooth is lower than that of a mobile phone. One study cited by Wildstrom in another Bloomsberg Businessweek article found that a typical Bluetooth generated a SAR of just 0.001 watts per kilogram.
Read more: Bluetooth Health Risks | eHow.com http://www.ehow.com/about_6780868_bluetooth-health-risks.html#ixzz23Y00X6KQ
http://en.wikipedia.org/wiki/Mobile_phone_radiation_and_health
Many scientific studies have investigated possible health symptoms of mobile phone radiation. These studies are occasionally reviewed by some scientific committees to assess overall risks. A recent assessment was published in 2007 by the European Commission Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR).[4] It concludes that the three lines of evidence, viz. animal, in vitro, and epidemiological studies, indicate that “exposure to RF fields is unlikely to lead to an increase in cancer in humans”.
Radiation absorption
Part of the radio waves emitted by a mobile telephone handset are absorbed by the human head. The radio waves emitted by a GSM handset can have a peak power of 2 watts, and a US analogue phone had a maximum transmit power of 3.6 watts. Other digital mobile technologies, such as CDMA2000 and D-AMPS, use lower output power, typically below 1 watt. The maximum power output from a mobile phone is regulated by the mobile phone standard and by the regulatory agencies in each country.[citation needed] In most systems the cellphone and the base station check reception quality and signal strength and the power level is increased or decreased automatically, within a certain span, to accommodate different situations, such as inside or outside of buildings and vehicles. The rate at which radiation is absorbed by the human body is measured by the Specific Absorption Rate (SAR), and its maximum levels for modern handsets have been set by governmental regulating agencies in many countries.
In the USA, the Federal Communications Commission (FCC) has set a SAR limit of 1.6 W/kg, averaged over a volume of 1 gram of tissue, for the head. In Europe, the limit is 2 W/kg, averaged over a volume of 10 grams of tissue. SAR values are heavily dependent on the size of the averaging volume. Without information about the averaging volume used, comparisons between different measurements cannot be made. Thus, the European 10-gram ratings should be compared among themselves, and the American 1-gram ratings should only be compared among themselves. SAR data for specific mobile phones, along with other useful information, can be found directly on manufacturers’ websites, as well as on third party web sites.
It is worth noting that thermal radiation is not comparable to ionizing radiation in that it only increases the temperature in normal matter, it does not break molecular bonds or release electrons from their atoms.
Thermal effects
One well-understood effect of microwave radiation is dielectric heating, in which any dielectric material (such as living tissue) is heated by rotations of polar molecules induced by the electromagnetic field. In the case of a person using a cell phone, most of the heating effect will occur at the surface of the head, causing its temperature to increase by a fraction of a degree. In this case, the level of temperature increase is an order of magnitude less than that obtained during the exposure of the head to direct sunlight. The brain’s blood circulation is capable of disposing of excess heat by increasing local blood flow. However, the cornea of the eye does not have this temperature regulation mechanism and exposure of 2–3 hours duration has been reported to produce cataracts in rabbits’ eyes at SAR values from 100-140W/kg, which produced lenticular temperatures of 41°C. There were no cataracts detected in the eyes of monkeys exposed under similar conditions. Premature cataracts have not been linked with cell phone use, possibly because of the lower power output of mobile phones.
Non-thermal effects
The communications protocols used by mobile phones often result in low-frequency pulsing of the carrier signal. Whether these modulations have biological significance has been subject to debate.
Some researchers have argued that so-called “non-thermal effects” could be reinterpreted as a normal cellular response to an increase in temperature. The German biophysicist Roland Glaser, for example, has argued that there are several thermoreceptor molecules in cells, and that they activate a cascade of second and third messenger systems, gene expression mechanisms and production of heat shock proteins in order to defend the cell against metabolic cell stress caused by heat. The increases in temperature that cause these changes are too small to be detected by studies such as REFLEX, which base their whole argument on the apparent stability of thermal equilibrium in their cell cultures.
Blood–brain barrier effects
Swedish researchers from Lund University (Salford, Brun, Persson, Eberhardt, and Malmgren) have studied the effects of microwave radiation on the rat brain. They found a leakage of albumin into the brain via a permeated blood–brain barrier.This confirms earlier work on the blood–brain barrier by Allan Frey, Oscar and Hawkins, and Albert and Kerns.Other groups have not confirmed these findings in in vitro cell studies or whole animal studies.
Cognitive effects
A 2009 study examined the effects of exposure to radiofrequency radiation (RFR) emitted by standard GSM cell phones on the cognitive functions of humans. The study confirmed longer (slower) response times to a spatial working memory task when exposed to RFR from a standard GSM cellular phone placed next to the head of male subjects, and showed that longer duration of exposure to RFR may increase the effects on performance. Right-handed subjects exposed to RFR on the left side of their head on average had significantly longer response times when compared to exposure to the right side and sham-exposure
Electromagnetic hypersensitivity
Genotoxic effects
Sleep and EEG effects
Behavioral effects
A study on mice suggested that cell phone use during pregnancy may cause behavioral problems for their offspring that resemble the effects of ADHD
Use hands-free to decrease the radiation to the head.
Keep the mobile phone away from the body.
Do not use telephone in a car without an external antenna.
The use of “hands-free” was not recommended by the British Consumers’ Association in a statement in November 2000 as they believed that exposure was increased.
However, measurements for the (then) UK Department of Trade and Industry and others for the French l’Agence française de sécurité sanitaire environnementale showed substantial reductions. In 2005 Professor Lawrie Challis and others said clipping a ferrite bead onto hands-free kits stops the radio waves travelling up the wire and into the head
[Health hazards of base stations:Another related issue on debate]
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