New Technology

New chip 1,000 faster than Bluetooth :

Here is a new microchip that can transfer data the size of 80 MP3 song files (or 250 megabytes) 
wirelessly between mobile devices, in the flick of a second.

Or how about transferring a typical 2-hour, 8-gigabyte DVD movie in just half a minute compared to 8.5 hours on Bluetooth?

Such unprecedented speeds on the wireless platform are now a reality as scientists from the Nanyang Technological University (NTU) and A*STAR’s Institute for Infocomm Research (I²R) have developed a revolutionary microchip that can transmit large volumes of data at ultra-high speeds of 2 Gigabits per second  (or 1,000 times faster than Bluetooth^).

The chipset employs wireless millimetre-wave (mm-wave) technology to transmit large packets of information while consuming little power. This enables low-power applications, like smart phones and tablets, to transmit/receive data between platforms, like projectors and TVs, without the need for cables for the very first time.

“The demand for ultra high-speed wireless connectivity has fuelled the need for faster data transfer rates. Unfortunately, current technologies are unable to meet these stringent demands. The NTU-I2R team, being at the cutting edge of research and development, has successfully demonstrated an integrated 60GHz chipset for multi-gigabits per second wireless transmission,” said Professor Yeo Kiat Seng, the Principal Investigator of the project and Associate Chair of Research at NTU’s School of Electrical & Electronic Engineering.

How the VIRTUS chipset works

Named the VIRTUS chipset, it consists of three components: an antenna, a full radio-frequency transceiver (developed by NTU) and a baseband processor (developed by I²R). The antenna is connected to the transceiver, which filters and amplifies the signals. It then passes the signals to the baseband processor, which comprises non-linear analog signal processing and unique digital parallel processing and decoder architecture – key to lower power consumption.

The team of scientists from NTU and I²R is the first in the world to successfully put together an integrated low-power 60 Gigahertz (GHz) chipset solution consisting of the three components, making it one step closer to commercialisation. It is also the first team to demonstrate one of the technology’s applications – in the form of a high-definition wireless video stream.

The VIRTUS chipset has garnered 16 international patents. It has also been featured in 51 top-tier international journal and conference papers, on top of its other international accolades such as two best paper awards and two best chip design awards.

“This ground-breaking mm-wave integrated circuit (IC) technology will have significant commercial impact, enabling a wide range of new applications such as wireless display, mobile-distributed computing, live high-definition video streaming, real-time interactive multi-user gaming, and more,” added NTU’s Prof Yeo, who is also founding director of NTU’s VIRTUS IC Design Centre of Excellence.

The collaboration, which began in December 2009, was funded by A*STAR’s technology transfer arm, Exploit Technologies Pte Ltd. The team has been approached by leading players and global brand names in the electronics and semiconductor industry to develop the chipset commercially. It will also showcase the technology at a leading technical innovation event in June this year – Computex (Taiwan).

Optical coherence tomography

Optical coherence tomography (OCT)

Optical coherence tomography (OCT) is an optical signal acquisition and processing method. It captures micrometer-resolution, three-dimensional images from within optical scattering media (e.g., biological tissue). Optical coherence tomography is an interferometric technique, typically employing near-infrared light. The use of relatively long wavelength light allows it to penetrate into the scattering medium. Confocal microscopy, another similar technique, typically penetrates less deeply into the sample.

Depending on the properties of the light source (superluminescent diodes, ultrashort pulsed lasers and supercontinuum lasers have been employed), optical coherence tomography has achieved sub-micrometer resolution (with very wide-spectrum sources emitting over a ~100 nm wavelength range).

Optical coherence tomography is one of a class of optical tomographic techniques. A relatively recent implementation of optical coherence tomography, frequency-domain optical coherence tomography, provides advantages in signal-to-noise ratio, permitting faster signal acquisition. Commercially available optical coherence tomography systems are employed in diverse applications, including art conservation and diagnostic medicine, notably in ophthalmology where it can be used to obtain detailed images from within the retina. Recently it has also begun to be used in interventional cardiology to help diagnose coronary artery disease.

 

Introduction:

Starting from white-light interferometry for in vivo ocular eye measurements imaging of biological tissue, especially of the human eye, was investigated by multiple groups worldwide. A first two-dimensional in vivo depiction of a human eye fundus along a horizontal meridian based on white light interferometric depth scans was presented at the ICO-15 SAT conference in 1990. Further developed in 1990 by Naohiro Tanno, then a professor at Yamagata University, and in particular since 1991 by Huang et al., optical coherence tomography (OCT) with micrometer resolution and cross-sectional imaging capabilities has become a prominent biomedical tissue-imaging technique; it is particularly suited to ophthalmic applications and other tissue imaging requiring micrometer resolution and millimeter penetration depth. First in vivo OCT images – displaying retinal structures – were published in 1993. OCT has also been used for various art conservation projects, where it is used to analyze different layers in a painting. OCT has critical advantages over other medical imaging systems. Medical ultrasonography, magnetic resonance imaging (MRI) and confocal microscopy are not suited to morphological tissue imaging: the first two have poor resolution; the last lacks millimeter penetration depth.

OCT bases itself upon low coherence interferometry. In conventional interferometry with long coherence length (laser interferometry), interference of light occurs over a distance of meters. In OCT, this interference is shortened to a distance of micrometers, thanks to the use of broadband light sources (sources that can emit light over a broad range of frequencies). Light with broad bandwidths can be generated by using superluminescent diodes(superbright LEDs) or lasers with extremely short pulses (femtosecond lasers). White light is also a broadband source with lower power.

Light in an OCT system is broken into two arms—a sample arm (containing the item of interest) and a reference arm (usually a mirror). The combination of reflected light from the sample arm and reference light from the reference arm gives rise to an interference pattern, but only if light from both arms have travelled the "same" optical distance ("same" meaning a difference of less than a coherence length). By scanning the mirror in the reference arm, a reflectivity profile of the sample can be obtained (this is time domain OCT). Areas of the sample that reflect back a lot of light will create greater interference than areas that don't. Any light that is outside the short coherence length will not interfere. This reflectivity profile, called an A-scan, contains information about the spatial dimensions and location of structures within the item of interest. A cross-sectional tomograph (B-scan) may be achieved by laterally combining a series of these axial depth scans (A-scan). En face imaging (C-scan) at an acquired depth is possible depending on the imaging engine used.

Laypersons explanation

Optical Coherence Tomography, or ‘OCT’, is a technique for obtaining sub-surface images of translucent or opaque materials at a resolution equivalent to a low-power microscope. It is effectively ‘optical ultrasound’, imaging reflections from within tissue to provide cross-sectional images.

OCT is attracting interest among the medical community, because it provides tissue morphology imagery at much higher resolution (better than 10 µm) than other imaging modalities such as MRI or ultrasound.

The key benefits of OCT are:

§  Live sub-surface images at near-microscopic resolution

§  Instant, direct imaging of tissue morphology

§  No preparation of the sample or subject

§  No ionizing radiation

OCT delivers high resolution because it is based on light, rather than sound or radio frequency. An optical beam is directed at the tissue, and a small portion of this light that reflects from sub-surface features is collected. Note that most light is not reflected but, rather, scatters off at large angles. In conventional imaging, this diffusely scattered light contributes background that obscures an image. However, in OCT, optical coherence is used to record the optical path length of received photons allowing rejection of most photons that scatter multiple times before detection. Thus OCT can build up clear 3D images of thick samples by rejecting background signal while collecting light directly reflected from surfaces of interest.

Within the range of noninvasive three-dimensional imaging techniques that have been introduced to the medical research community, OCT as an echo technique is similar to ultrasound imaging. Other medical imaging techniques such as computerized axial tomography, magnetic resonance imaging, or positron emission tomography do not utilize the echo-location principle.

The technique is limited to imaging 1 to 2 mm below the surface in biological tissue, because at greater depths the proportion of light that escapes without scattering is too small to be detected. No special preparation of a biological specimen is required, and images can be obtained ‘non-contact’ or through a transparent window or membrane. It is also important to note that the laser output from the instruments is low – eye-safe near-infra-red light is used – and no damage to the sample is therefore likely.

Theory

The principle OCT is white light or low coherence interferometry. The optical setup typically consists of an interferometer (Fig. 1, typically Michelson type) with a low coherence, broad bandwidth light source. Light is split into and recombined from reference and sample arm, respectively.

Time domain OCT

In time domain OCT the pathlength of the reference arm is translated longitudinally in time. A property of low coherence interferometry is that interference, i.e. the series of dark and bright fringes, is only achieved when the path difference lies within the coherence length of the light source. This interference is called auto correlation in a symmetric interferometer (both arms have the same reflectivity), or cross-correlation in the common case. The envelope of this modulation changes as pathlength difference is varied, where the peak of the envelope corresponds to pathlength matching.

The interference of two partially coherent light beams can be expressed in terms of the source intensity, , as

where  represents the interferometer beam splitting ratio, and  is called the complex degree of coherence, i.e. the interference envelope and carrier dependent on reference arm scan or time delay , and whose recovery of interest in OCT. Due to the coherence gating effect of OCT the complex degree of coherence is represented as a Gaussian function expressed as^[15]

where  represents the spectral width of the source in the optical frequency domain, and  is the centre optical frequency of the source. In equation (2), the Gaussian envelope is amplitude modulated by an optical carrier. The peak of this envelope represents the location of sample under test microstructure, with an amplitude dependent on the reflectivity of the surface. The optical carrier is due to the Doppler effect resulting from scanning one arm of the interferometer, and the frequency of this modulation is controlled by the speed of scanning. Therefore translating one arm of the interferometer has two functions; depth scanning and a Doppler-shifted optical carrier are accomplished by pathlength variation. In OCT, the Doppler-shifted optical carrier has a frequency expressed as

where  is the central optical frequency of the source,  is the scanning velocity of the pathlength variation, and  is the speed of light.

interference signals in TD vs. FD-OCT

The axial and lateral resolutions of OCT are decoupled from one another; the former being an equivalent to the coherence length of the light source and the latter being a function of the optics. The coherence length of a source and hence the axial resolution of OCT is defined as

Frequency domain OCT (FD-OCT)

In frequency domain OCT the broadband interference is acquired with spectrally separated detectors (either by encoding the optical frequency in time with a spectrally scanning source or with a dispersive detector, like a grating and a linear detector array). Due to the Fourier relation (Wiener-Khintchine theorem between the auto correlation and the spectral power density) the depth scan can be immediately calculated by a Fourier-transform from the acquired spectra, without movement of the reference arm. This feature improves imaging speed dramatically, while the reduced losses during a single scan improve the signal to noise proportional to the number of detection elements. The parallel detection at multiple wavelength ranges limits the scanning range, while the full spectral bandwidth sets the axial resolution.

Spatially encoded frequency domain OCT (spectral domain or Fourier domain OCT)

SEFD-OCT extracts spectral information by distributing different optical frequencies onto a detector stripe (line-array CCD or CMOS) via a dispersive element (see Fig. 4). Thereby the information of the full depth scan can be acquired within a single exposure. However, the large signal to noise advantage of FD-OCT is reduced due the lower dynamic range of stripe detectors in respect to single photosensitive diodes, resulting in an SNR (signal to noise ratio) advantage of ~10 dB at much higher speeds. This is not much of a problem when working at 1300 nm, however, since dynamic range is not a serious problem at this wavelength range.

The drawbacks of this technology are found in a strong fall-off of the SNR, which is proportional to the distance from the zero delay and a sinc-type reduction of the depth dependent sensitivity because of limited detection linewidth. (One pixel detects a quasi-rectangular portion of an optical frequency range instead of a single frequency, the Fourier-transform leads to the sinc(z) behavior). Additionally the dispersive elements in the spectroscopic detector usually do not distribute the light equally spaced in frequency on the detector, but mostly have an inverse dependence. Therefore the signal has to be resampled before processing, which can not take care of the difference in local (pixelwise) bandwidth, which results in further reduction of the signal quality. However, the fall-off is not a serious problem with the development of new generation CCD or photodiode array with a larger number of pixels.

Synthetic array heterodyne detection offers another approach to this problem without the need for high dispersion.

Time encoded frequency domain OCT (also swept source OCT)

TEFD-OCT tries to combine some of the advantages of standard TD and SEFD-OCT. Here the spectral components are not encoded by spatial separation, but they are encoded in time. The spectrum either filtered or generated in single successive frequency steps and reconstructed before Fourier-transformation. By accommodation of a frequency scanning light source (i.e. frequency scanning laser) the optical setup (see Fig. 5) becomes simpler than SEFD, but the problem of scanning is essentially translated from the TD-OCT reference-arm into the TEFD-OCT light source. Here the advantage lies in the proven high SNR detection technology, while swept laser sources achieve very small instantaneous bandwidths (=linewidth) at very high frequencies (20–200 kHz). Drawbacks are the nonlinearities in the wavelength, especially at high scanning frequencies. The broadening of the linewidth at high frequencies and a high sensitivity to movements of the scanning geometry or the sample (below the range of nanometers within successive frequency steps).

Scanning Schemes :

Focusing the light beam to a point on the surface of the sample under test, and recombining the reflected light with the reference will yield an interferogram with sample information corresponding to a single A-scan (Z axis only). Scanning of the sample can be accomplished by either scanning the light on the sample, or by moving the sample under test. A linear scan will yield a two-dimensional data set corresponding to a cross-sectional image (X-Z axes scan), whereas an area scan achieves a three-dimensional data set corresponding to a volumetric image (X-Y-Z axes scan), also called full-field OCT.

Single point (confocal) OCT

Systems based on single point, or flying-spot time domain OCT, must scan the sample in two lateral dimensions and reconstruct a three-dimensional image using depth information obtained by coherence-gating through an axially scanning reference arm (Fig. 2). Two-dimensional lateral scanning has been electromechanically implemented by moving the sample using a translation stage, and using a novel micro-electro-mechanical system scanner.

Parallel (or full field) OCT

Parallel OCT using a charge-coupled device (CCD) camera has been used in which the sample is full-field illuminated and en face imaged with the CCD, hence eliminating the electromechanical lateral scan. By stepping the reference mirror and recording successive en face images a three-dimensional representation can be reconstructed. Three-dimensional OCT using a CCD camera was demonstrated in a phase-stepped technique, using geometric phase-shifting with a Linnik interferometer, utilising a pair of CCDs and heterodyne detection, and in a Linnik interferometer with an oscillating reference mirror and axial translation stage. Central to the CCD approach is the necessity for either very fast CCDs or carrier generation separate to the stepping reference mirror to track the high frequency OCT carrier.

Smart detector array for parallel TD-OCT

A two-dimensional smart detector array, fabricated using a 2 µm complementary metal-oxide-semiconductor (CMOS) process, was used to demonstrate full-field OCT. Featuring an uncomplicated optical setup (Fig. 3), each pixel of the 58x58 pixel smart detector array acted as an individual photodiode and included its own hardware demodulation circuitry.

Optical coherence tomography is an established medical imaging technique. It is widely used, for example, to obtain high-resolution images of the retinaand the anterior segment of the eye, which can, for example, provide a straightforward method of assessing axonal integrity in multiple sclerosis.Researchers also seek to develop a method that uses frequency domain OCT to image coronary arteries in order to detect vulnerable lipid-rich plaques. Furthermore, studies by Dr. Thomas Milner and Dr. Grady Rylander at the University of Texas in Austin suggest its use as a valuable tool in early-stage detection of glaucoma.

Optical coherence tomography is also applicable and increasingly used in industrial applications, such as Non Destructive Testing(NDT), material thickness measurements, and in particular thin silicon wafers and compound semiconductor wafers thickness measurements surface roughness characterization, surface and cross-section imaging and volume loss measurements. OCT systems with feedback can be used to control manufacturing processes. With high speed data acquisition, and sub-micron resolution, OCT is adaptable to perform both inline and off-line. Fiber-based OCT systems are particularly adaptable to industrial environments.These can access and scan interiors of hard-to-reach spaces, and are able to operate in hostile environments - whether radioactive, cryogenic or very hot.Optical coherence tomography is an established medical imaging technique. It is widely used, for example, to obtain high-resolution images of the retinaand the anterior segment of the eye, which can, for example, provide a straightforward method of assessing axonal integrity in multiple sclerosis.Researchers also seek to develop a method that uses frequency domain OCT to image coronary arteries in order to detect vulnerable lipid-rich plaques. Furthermore, studies by Dr. Thomas Milner and Dr. Grady Rylander at the University of Texas in Austin suggest its use as a valuable tool in early-stage detection of glaucoma.
Optical coherence tomography is also applicable and increasingly used in industrial applications, such as Non Destructive Testing(NDT), material thickness measurements, and in particular thin silicon wafers and compound semiconductor wafers thickness measurements surface roughness characterization, surface and cross-section imaging and volume loss measurements. OCT systems with feedback can be used to control manufacturing processes. With high speed data acquisition, and sub-micron resolution, OCT is adaptable to perform both inline and off-line. Fiber-based OCT systems are particularly adaptable to industrial environments.These can access and scan interiors of hard-to-reach spaces, and are able to operate in hostile environments - whether radioactive, cryogenic or very hot.

Top Countries For Mechanical Engg.

Top Countries For MECHANICAL ENGINEERING Jobs & Career Growth :

This topic would certainly help you to decide in which country you want to work. Certainly Engineering professionals would prefer the destination where they are going to work. This is because many countries are very conducive for Engineering companies due to government policies,infrastructure,skill set available and so on. But we will take a closer at countries which favors Mechanical Engineering career development and job opportunities.

According to news reports, Germany stands out first in exporting Engineering equipments and machines, rate has increased by 11% in the financial year 2007. German export of mechanical engineering products increased four years in a row through 2007.

Top countries provide Mechanical Engineering career growth:

• Germany
• USA
• UAE & Middle East
• Japan
• Italy
• China

This has made Germany to rank first position for Mechanical Engineering career opportunities. Everyone also know about German products are the best for innovative and complex engineering.

Next comes, USA with well known for its nano technology and most engineering companies presence.According to ASME report, the U.S. Department of Labor expects that America will need as many as 87,000 new mechanical engineers by the time today's high school seniors graduate.On average, a mechanical engineer who is just starting out in the profession can expect to earn about $51,000 a year.  Within several years, that annual salary can jump to an average of over $70,000.

In third position,UAE and Middle East countries welcomes Mechanical Engineering Industry and offers much more career growth for mechanical engineers.

Not to forget Japan is far behind, holding fourth position brings bright future Mechanical Engineering professionals.

Italy and China take fifth and sixth position respectively. These countries provide good career growth and high salaries with challenging jobs for Mechanical Engineering professionals.

The above table represents Top 20 countries in Engineering provides career growth for mechanical professionals,taken as of the latest bimonthly update of essential science indicators attracted the highest total; citations to their papers published in Thomson Reuters journals of Engineering published over an 11 year period starting from 1998 December till 2008.

Radio-frequency identification

Radio-frequency identification (RFID) is the use of a wireless non-contact system that uses radio-frequency electromagnetic fields to transfer data from a tag attached to an object, for the purposes of automatic identification and tracking. Some tags require no battery and are powered by the electromagnetic fields used to read them. Others use a local power source and emit radio waves (electromagnetic radiation at radio frequencies). The tag contains electronically stored information which can be read from up to several metres (yards) away. Unlike a bar code, the tag does not need to be within line of sight of the reader and may be embedded in the tracked object.

RFID tags are used in many industries. An RFID tag attached to an automobile during production can be used to track its progress through the assembly line. Pharmaceuticals can be tracked through warehouses. Livestock and pets may have tags injected, allowing positive identification of the animal. RFID identity cards can give employees access to locked areas of a building, and RF transponders mounted in automobiles can be used to bill motorists for access to toll roads or parking.

Since RFID tags can be attached to clothing, possessions, or even implanted within people, the possibility of reading personally-linked information without consent has raised privacy concerns.

Applications

The RFID tag can be affixed to an object and used to track and manage inventory, assets, people, etc. For example, it can be affixed to cars, computer equipment, books, mobile phones, etc.

In social media, RFID is being used to tie the physical world with the virtual world. RFID in Social Media first came to light in 2010 with Facebook's annual conference.

RFID offers advantages over manual systems or use of bar codes. The tag can be read if passed near a reader, even if it is covered by the object or not visible. The tag can be read inside a case, carton, box or other container, and unlike barcodes RFID tags can be read hundreds at a time. Bar codes can only be read one at a time.

In 2011, the cost of passive tags started at US$0.05 each; special tags, meant to be mounted on metal or withstand gamma sterilization, can go up to US$5. Active tags for tracking containers, medical assets, or monitoring environmental conditions in data centers start at US$50 and can go up over US$100 each. Battery Assisted Passive (BAP) tags are in the US$3–10 range and also have sensor capability like temperature and humidity.

RFID can be used in a variety of applications, such as:

• Access management
• Tracking of goods
• Tracking of persons and animals
• Toll collection and contactless payment
• Machine readable travel documents
• Smartdust (for massively distributed sensor networks)
• Tracking sports memorabilia to verify authenticity
• Airport baggage tracking logistics 

Applications:

A radio-frequency identification system uses tags, or labels attached to the objects to be identified. Two-way radio transmitter-receivers called interrogators or readers send a signal to the tag and read its response. The readers generally transmit their observations to a computer system running RFID software or RFID middle ware.

The tag's information is stored electronically in a non-volatile memory. The RFID tag includes a small RF transmitter and receiver. An RFID reader transmits an encoded radio signal to interrogate the tag. The tag receives the message and responds with its identification information. This may be only a unique tag serial number, or may be product-related information such as a stock number, lot or batch number, production date, or other specific information.

RFID tags can be either passive, active or battery assisted passive. An active tag has an on-board battery that periodically transmits its ID signal. A battery assisted passive (BAP) has a small battery on board that is activated when in the presence of a RFID reader. A passive tag is cheaper and smaller because it has no battery. Instead, the tag uses the radio energy transmitted by the reader as its energy source. The interrogator must be close for RF field to be strong enough to transfer sufficient power to the tag. Since tags have individual serial numbers, the RFID system design can discriminate several tags that might be within the range of the RFID reader and read them simultaneously.

Tags may either be read-only, having a factory-assigned serial number that is used as a key into a database, or may be read/write, where object-specific data can be written into the tag by the system user. Field programmable tags may be write-once, read-multiple; "blank" tags may be written with an electronic product code by the user.

RFID tags contain at least two parts: an integrated circuit for storing and processing information, modulating and demodulating a radio-frequency (RF) signal, collecting DC power from the incident reader signal, and other specialized functions; and an antenna for receiving and transmitting the signal.

Fixed readers are set up to create a specific interrogation zone which can be tightly controlled. This allows a highly defined reading area for when tags go in and out of the interrogation zone. Mobile readers may be hand-held or mounted on carts or vehicles.

RFID frequency bands 

Band	Regulations	Range	Data speed	Remarks	Approximate tag cost in volume (2006) US $
120–150 kHz (LF)	Unregulated	10 cm	Low	Animal identification, factory data collection	$1 US
13.56 MHz (HF)	ISM band worldwide	1 m	Low to moderate	Smart cards	$0.50
433 MHz (UHF)	Short Range Devices	1–100 m	Moderate	Defence applications, with active tags	$5
868-870 MHz (Europe) 902-928 MHz (North America) UHF	ISM band	1–2 m	Moderate to high	EAN, various standards	$0.15 (passive tags)
2450-5800 MHz (microwave)	ISM band	1–2 m	High	802.11 WLAN, Bluetooth standards	$25 (active tags)
3.1–10 GHz (microwave)	Ultra wide band	to 200 M	High	requires semi-active or active tags	$5 projected

Signaling between the reader and the tag is done in several different incompatible ways, depending on the frequency band used by the tag. Tags operating on LF and HF frequencies are, in terms of radio wavelength, very close to the reader antenna, less than one wavelength away. In this near field region, the tag is closely coupled electrically with the transmitter in the reader. The tag can modulate the field produced by the reader by changing the electrical loading the tag represents. By switching between lower and higher relative loads, the tag produces a change that the reader can detect. At UHF and higher frequencies, the tag is more than one radio wavelength from the reader. The tag can backscatter a signal. Active tags may contain functionally separated transmitters and receivers, and the tag need not respond on a frequency related to the reader's interrogation signal.^[7]

An Electronic Product Code (EPC) is one common type of data stored in a tag. When written into the tag by an RFID printer, the tag contains a 96-bit string of data. The first eight bits are a header which identifies the version of the protocol. The next 28 bits identify the organization that manages the data for this tag; the organization number is assigned by the EPCGlobal consortium. The next 24 bits are an object class, identifying the kind of product; the last 36 bits are a unique serial number for a particular tag. These last two fields are set by the organization that issued the tag. Rather like a URL, the total electronic product code number can be used as a key into a global database to uniquely identify a particular product.

Often more than one tag will respond to a tag reader, for example, many individual products with tags may be shipped in a common box or on a common pallet. Collision detection is important to allow reading of data. Two different types of protocols are used to "singulate" a particular tag, allowing its data to be read in the midst of many similar tags. In a slotted Aloha system, the reader broadcasts an initialization command and a parameter that the tags individually use to pseudo-randomly delay their responses. When using an "adaptive binary tree" protocol, the reader sends an intialization symbol and then transmits one bit of ID data at a time; only tags with matching bits respond, and eventually only one tag matches the complete ID string

History and technology background

An RFID tag used for electronic toll collection.

In 1945 Léon Theremin invented an espionage tool for the Soviet Union which retransmitted incident radio waves with audio information. Sound waves vibrated a diaphragm which slightly altered the shape of the resonator, which modulated the reflected radio frequency. Even though this device was acovert listening device, not an identification tag, it is considered to be a predecessor of RFID technology, because it was likewise passive, being energized and activated by waves from an outside source.

Similar technology, such as the IFF transponder developed in the United Kingdom, was routinely used by the allies in World War II to identify aircraft as friend or foe. Transponders are still used by most powered aircraft to this day. Another early work exploring RFID is the landmark 1948 paper by Harry Stockman, titled "Communication by Means of Reflected Power" (Proceedings of the IRE, pp 1196–1204, October 1948). Stockman predicted that "... considerable research and development work has to be done before the remaining basic problems in reflected-power communication are solved, and before the field of useful applications is explored."

Mario Cardullo's device, patented on January 23, 1973, was the first true ancestor of modern RFID, as it was a passive radio transponder with memory.The initial device was passive, powered by the interrogating signal, and was demonstrated in 1971 to the New York Port Authority and other potential users and consisted of a transponder with 16 bit memory for use as a toll device. The basic Cardullo patent covers the use of RF, sound and light as transmission media. The original business plan presented to investors in 1969 showed uses in transportation (automotive vehicle identification, automatic toll system, electronic license plate, electronic manifest, vehicle routing, vehicle performance monitoring), banking (electronic check book, electronic credit card), security (personnel identification, automatic gates, surveillance) and medical (identification, patient history).

An early demonstration of reflected power (modulated backscatter) RFID tags, both passive and semi-passive, was performed by Steven Depp, Alfred Koelle, and Robert Freyman at the Los Alamos National Laboratory in 1973.^[13] The portable system operated at 915 MHz and used 12-bit tags. This technique is used by the majority of today's UHFID and microwave RFID tags.

The first patent to be associated with the abbreviation RFID was granted to Charles Walton in 1983.

[edit]Miniaturization

RFIDs are easy to conceal or incorporate in other items. For example, in 2009 researchers at Bristol University successfully glued RFID micro-transponders to live ants in order to study their behavior. This trend towards increasingly miniaturized RFIDs is likely to continue as technology advances.

Hitachi holds the record for the smallest RFID chip, at 0.05mm × 0.05mm. This is 1/64th the size of the previous record holder, the mu-chip. Manufacture is enabled by using the silicon-on-insulator (SOI) process. These dust-sized chips can store 38-digit numbers using 128-bit Read Only Memory (ROM).A major challenge is the attachment of the antennas, thus limiting read range to only millimeters.

[edit]Current uses

In 2010 three key factors drove a significant increase in RFID usage: decreased cost of equipment and tags, increased performance to a reliability of 99.9% and a stable international standard around UHF passive RFID. The adoption of these standards were driven by EPCglobal, a joint venture between GS1 and GS1 US, which were responsible for driving global adoption of the barcode in the 1970s and 1980s. The EPCglobal Network was developed by the Auto-ID Center, an academic research project headquartered at the Massachusetts Institute of Technology (MIT) with labs at five leading research universities around the globe: Cambridge, Adelaide, Keio, Shanghai, Fudan, St. Gallen. At RFID Journal Live 2010 in Orlando, Airbus detailed 16 active projects, IBMand—most recently added to the team—CSC. The two other areas of significant use are financial services for IT asset tracking and healthcare. RFID is becoming increasingly prevalent as the price of the technology decreases.

[edit]Commerce

[edit]Payment by mobile phones

Since summer 2009, two credit card companies have been working with Dallas, Texas-based DeviceFidelity to develop specialized microSD cards. When inserted into a mobile phone, the microSD card can be both a passive tag and an RFID reader. After inserting the microSD, a user's phone can be linked to bank accounts and used in mobile payment.

Dairy Queen in conjunction with Vivotech has also begun using RFIDs on mobile phones as part of their new loyalty and rewards program.Patrons can ask to receive an RFID tag to place on their phone. After activation, the phone can receive promotions and coupons, which can be read by ViVOtech's specialized NFC devices.

Similarly, 7-Eleven has been working alongside MasterCard to promote a new touch-free payment system. Those joining the trial are given a complimentary Nokia 3220 cell phone – after activation, it can be used as an RFID-capable MasterCard credit card at any of 7-Eleven's worldwide chains.

Nokia's 2008 device, the 6212, has RFID capabilities also. Credit card information can be stored, and bank accounts can be directly accessed using the enabled handset. The phone, if used as a vector for mobile payment, has added security in that users would be required to enter a passcode or PIN before payment is authorized.

[edit]Asset management

RFID combined with mobile computing and Web technologies provide a way for organizations to identify and manage their assets. Mobile computers, with integrated RFID readers, can now deliver a complete set of tools that eliminate paperwork, give proof of identification and attendance. This approach eliminates manual data entry.

Web based management tools allow organizations to monitor their assets and make management decisions from anywhere in the world. Web based applications now mean that third parties, such as manufacturers and contractors can be granted access to update asset data, including for example, inspection history and transfer documentation online ensuring that the end user always has accurate, real-time data. Organizations are already using RFID tags combined with a mobile asset management solution to record and monitor the location of their assets, their current status, and whether they have been maintained.

RFID is being adopted for item-level retail uses. Aside from efficiency and product availability gains, the system offers a superior form of electronic article surveillance (EAS), and a superior self checkout process for consumers. The first commercial, public item-level RFID retail system installation is believed to be in May 2005 by Freedom Shopping, Inc. in North Carolina, USA.

2009 witnessed the beginning of wide-scale asset tracking with passive RFID. Wells Fargo and Bank of America made announcements that they would track every item in their data centers using passive RFID. Most of the leading banks have since followed suit. The Financial Services Technology Consortium(FSTC) set a technical standard for tagging IT assets and other industries have used that standard as a guideline. For instance the US State Department is now tagging IT assets with passive RFID using the ISO/IEC 18000-6 standard.

[edit]Inventory systems

An advanced automatic identification technology based on RFID technology has significant value for inventory systems. The system can provide accurate knowledge of the current inventory. In an academic study performed at Wal-Mart, RFID reduced Out-of-Stocks by 30 percent for products selling between 0.1 and 15 units a day. Other benefits of using RFID include the reduction of labor costs, the simplification of business processes, and the reduction of inventory inaccuracies.

In 2004, Boeing integrated the use of RFID technology to help reduce maintenance and inventory costs on the Boeing 787 Dreamliner. With the high costs of aircraft parts, RFID technology allowed Boeing to keep track of inventory despite the unique sizes, shapes and environmental concerns. During the first six months after integration, the company was able to save $29,000 in labor.

In 2007, Recall Corporation integrated the use of RFID to help organizations track and audit their records, to support compliance with regulations such as the Sarbanes-Oxley Act and HIPAA.

[edit]Product tracking

RFID use in product tracking applications begins with plant-based production processes, and then extends into post-sales configuration management policies for large buyers.

In 2005, the Wynn Casino, Las Vegas, began placing individual RFID tags on high value chips. These tags allowed casinos the ability to detect counterfeit chips, track betting habits of individual players, speed up chip tallies, and determine counting mistakes of dealers. In 2010, the Bellagio casino was robbed of $1.5 million in chips. The RFID tags of these chips were immediately invalidated, thus making the cash value of these chips $0.

RFID can also be used for supply chain management in the fashion industry. The RFID label is attached at the garment at production, can be read/traced througout the entire supply chain and is removed at the point of sale (POS).

[edit]Access control

High-frequency tags are widely used in identification badges, replacing earlier magnetic stripe cards. These badges need only be held within a certain distance of the reader to authenticate the holder. The American Express Blue credit card now includes a HighFID tag. In Feb 2008, Emirates Airline started a trial of RFID baggage tracing at London and Dubai airports.

[edit]Promotion tracking

To prevent retailers diverting products, manufacturers are exploring the use of RFID tags on promoted merchandise so that they can track exactly which product has sold through the supply chain at fully discounted prices.

[edit]Advertising

When customers enter a dressing room, the mirror reflects their image and also images of the apparel item being worn by celebrities on an interactive display. A webcam also projects an image of the consumer wearing the item on the website for everyone to see. This creates an interaction between the consumers inside the store and their social network outside the store. The technology in this system is an RFID interrogator antenna in the dressing room and Electronic Product Code RFID tags on the apparel item.

[edit]Transportation and logistics

Logistics and transportation are major areas of implementation for RFID technology. Yard management, shipping and freight and distribution centers use RFID tracking technology. In the railroadindusry, RFID tags mounted on locomotives and rolling stock identify the owner, identification number and type of equipment and its characteristics. This can be used with a database to identify the lading, origin, destination, etc. of the commodities being carried.

In commercial aviation, RFID technology is being incorporated to support maintenance on commercial aircraft. RFID tags are used to identify baggage and cargo at several airports and airlines.

Some countries are using RFID technology for vehicle registration and enforcement.RFID can help detect and retrieve stolen cars.

[edit]Passports

The first RFID passports ("E-passport") were issued by Malaysia in 1998. In addition to information also contained on the visual data page of the passport, Malaysian e-passports record the travel history (time, date, and place) of entries and exits from the country.

Other countries that insert RFID in passports include Norway (2005), Japan (March 1, 2006), most EU countries (around 2006) including Spain, Ireland and the UK, Australia, Hong Kong and the United States (2007), Serbia (July 2008), Republic of Korea (August 2008), Taiwan (December 2008), Albania (January 2009), The Philippines (August 2009), Republic of Macedonia (2010).

Standards for RFID passports are determined by the International Civil Aviation Organization (ICAO), and are contained in ICAO Document 9303, Part 1, Volumes 1 and 2 (6th edition, 2006). ICAO refers to the ISO/IEC 14443 RFID chips in e-passports as "contactless integrated circuits". ICAO standards provide for e-passports to be identifiable by a standard e-passport logo on the front cover.

Since 2006, RFID tags included in new US passports will store the same information that is printed within the passport and also include a digital picture of the owner. The US State Departmentinitially stated the chips could only be read from a distance of 10 cm (4 in), but after widespread criticism and a clear demonstration that special equipment can read the test passports from 10 meters (33 ft) away, the passports were designed to incorporate a thin metal lining to make it more difficult for unauthorized readers to "skim" information when the passport is closed. The department will also implement Basic Access Control (BAC), which functions as a Personal Identification Number (PIN) in the form of characters printed on the passport data page. Before a passport's tag can be read, this PIN must be entered into an RFID reader. The BAC also enables the encryption of any communication between the chip and interrogator.

[edit]Transportation payments

In many countries, RFID tags can be used to pay for mass transit fares on bus, trains, or subways, or to collect tolls on highways.

Some bike lockers are operated with RFID cards assigned to individual users. A prepaid card is required to open or enter a facility or locker and is used to track and charge based on how long the bike is parked.

The Zipcar car-sharing service uses RFID cards for locking and unlocking cars and for member identification.

In Singapore, RFID replaces paper Season Parking Ticket (SPT).