NFC Technology Could Rock Your World

Smartphones are no longer just fancy mobile devices that let you e-mail and surf the Web. A contemporary smartphone has more computing power than all of the computers that were at NASA's disposal back in 1969 when the United States first landed on the moon [source: PC Mag]. Although you probably won't use your phone to control your own lunar lander anytime soon, it will likely do all sorts of other nifty stuff, like replace your wallet, thanks to NFC (near-field communication) technology.

The beauty and utility of NFC -- a short-range, wireless communication standard -- can be summed up in three primary purposes: sharing, pairing and transactions. NFC can turn your phone into a digital wallet, become a master key for everything from your house to your car, or serve as a government or corporate identification badge. And that's just for starters. Check out a whole swath of other nifty uses at NFC Rumor's sprawling infographic.

The possibilities for NFC tech are limited only by the imaginations of clever engineers and programmers. And because of its vast range of uses, the revolution is starting with your phone.

Armed with these tiny chips, smartphones are about to graduate from smart to downright brainiac status. Right now, only about 34 million phones have NFC, but some experts think that number will blow past 100 million in 2012 [source: USA Today]. Keep reading and you'll see how NFC phones and other gadgets could transform your tech-driven life.

NFC Pays Your Way

Chuck your cash in the trash and snip every last credit card into itty bitty pieces. With NFC, your smartphone becomes an ATM machine and credit device all in one. Instead of counting cash or swiping a card, you'll just wave your phone at a payment kiosk to complete a transaction and receive an email receipt instead of paper one.

Of all of the capabilities that NFC may bring to fruition, payment options are perhaps the likeliest to emerge soon. Executives at Google actually expect NFC smartphones to account for about 50 percent of the phone marketplace by 2014 [source: Popular Science], which would likely benefit its Google Wallet application. Google Wallet is a smartphone app that lets you wave your phone at a properly-equipped point-of-sale register to pay for all kinds of goods and services.

Other credit card companies and wireless service providers are working on similar systems to compete with Google. And it's that competition and lack of standardization, along with a lack of NFC-capable checkout systems at your local stores, that may delay the deployment of widespread NFC payment options.

Still, some pundits, including those at Juniper Research, expect that NFC transactions will hit around $50 billion by 2014 [source: Retail Merchandiser]. So be ready – your days of lugging around multiple plastic cards and a wad of paper money might just be numbered.

4: Data Grabbing Goodness

The chips and tags that an NFC-capable phone can read are so tiny that they could eventually be ubiquitous, embedded in everything from posters in movie theaters and schools to real estate signs, and much more. These so-called infotags orsmart tags will offer up all sorts of information to anyone who waves a smartphone at them.

At a movie theater, patrons could touch their phones to a poster for an intriguing film and be instantly directly to an online trailer. Or at school, students could use their phones to grab updated information on schedules and announcements.

Strolling by a home that's for sale? Wiggle your phone at the real estate company's sign and your phone immediately brings up all pertinent sales information on that house, including a video tour of the interior.

The chips work even in places more of more permanent residence. A system called Personal Rosetta Stone that lets cemetery visitors pull information from chip-laden headstones to read the life stories and obituaries of the deceased [source: Rosetta Stone].

There are thousands of other applications for this technology, and smartphones will help drive the proliferation of NFC. But suffice it to say, your smartphone will only find more and more ways to gather information from your tech-saturated environment, no matter where on Earth you might be.

3: Chips are Good for Your Health

Don't let anyone tell you that chips are bad for you. When it comes to your health care, NFC tags and the smart devices that can read them may help make health care data more accurate, more efficient and safer for patients and their caregivers.

Forget the clunky, inefficient ER rooms of the past. Now, patients could check into medical facilities using their phones, tap their prescription bottles for all instructions and side effects for a specific medication and make payments for services and products.

Medical professionals can use their NFC phones to access secure areas, scan patient tags to ensure that each person is receiving appropriate medicine and care, and automatically receive updates on when to check that patient again.

And thanks to the quick spread of smartphones throughout the developing world, health workers can better identify patients and track specific ailments, both of which help improve patient referral, emergency response, and disease data collection. In an age where health authorities fear pandemics, NFC could put health workers ahead of their bacterial and viral foes.

You may get much better personal care, too. The more data your doctor collects on your environmental exposure and your body's idiosyncrasies, the more likely you'll receive accurate diagnoses. A company named Gentag makes diagnostic skin tags that are affixed directly to the patient. These tags can monitor temperature, glucose levels or ultraviolet light exposure and then send pertinent health information directly to a smartphone.

So really, chips really are good for you. NFC devices could save many lives, including yours, and improve the quality of life for people all over the globe.

2: A Legendary Digital Locksmith

You already know that your smartphone can replace your wayward billboard. It can also help you do away with your keys and security cards.

You don't really need a key to get into your car. Nor do you need that jagged bit of metal and plastic for engine ignition. All you really need is permission. And your NFC smartphone might soon be able to give you that permission. Just wave your phone to unlock your car; then tap the dash to fire up the engine.

When you arrive at work, you don't need to show your ID badge to a security guard. You don't even need your badge anymore, because your phone tells the NFC access point exactly who you are and unlocks the door for you.

Then, when arrive at home from a long day at the office you won't need to dig through your purse for your keys. Your phone will unlock your apartment or house door so that you can waltz in without even the need to twist a key.

As with all such technologies, there are indeed security concerns galore with NFC. It won't hurt you to dosome reading before you recycle your keys (and credit cards) for good.

So although many of the first uses of NFC will likely apply to intangible digital payments, these examples show how NFC can grant access to all sorts of real physical places. You'll have few items to carry with you, too -- just don't lose your smartphone in the couch cushions.

1: Your Friendly Network Facilitator

You already know that NFC is good for sharing and transactions. It's also a handy way to quickly pair two devices so that they can exchange information via higher-speed networks, and in this sense, NFC could be heaven-sent, doing away with convoluted encryption schemes and long-winded, clunky passwords.

For example, if you and your co-worker are stranded at an airport and want to play a team racing game on your smartphones, you won't have to deal with a tedious configuration process. Instead, you can just tap your phones, and the NFC connection will authenticate your phones and let you immediately share a faster type of connection, such as Bluetooth or WiFi.

Want to print a photo that's on your phone? Tap your smartphone to an NFC inkjet printer and you can quickly start the print job. Or skip the printer and place your phone right next to your smart HDTV, and watch as your images appear on the screen without the need to set up a connection.

Now you know some of the ways that NFC might just live up to its hype in the next few years. While you're anxiously awaiting these marvelous new technologies, you can stay up to date on the latest NFC news and speculation at NFC Rumors.com, which details the many products and services that will put the power of NFC to use.

You can also jump into the fray and find an NFC -capable phone using this handy list. These phones might be your first taste of a wireless standard that will likely wow you and millions of others with its capabilities for a long time to come.

How Bluetooth Technology Works

Bluetooth is a high-speed, low-power microwave wireless link technology, designed to connect phones, laptops, PDAs and other portable equipment together with little or no work by the user. Unlike infra-red, Bluetooth does not require line-of-sight positioning of connected units. The technology uses modifications of existing wireless LAN techniques but is most notable for its small size and low cost. The current prototype circuits are contained on a circuit board 0.9cm square, with a much smaller single chip version in development. The cost of the device is expected to fall very fast, from $20 initially to $5 in a year or two. It is envisioned that Bluetooth will be included within equipment rather than being an optional extra. When one Bluetooth product comes within range of another, (this can be set to between 10cm and 100m) they automatically exchange address and capability details. They can then establish a 1 megabit/s link (up to 2 Mbps in the second generation of the technology) with security and error correction, to use as required. The protocols will handle both voice and data, with a very flexible network topography.

This technology achieves its goal by embedding tiny, inexpensive, short-range transceivers into the electronic devices that are available today. The radio operates on the globally-available unlicensed radio band, 2.45 GHz (meaning there will be no hindrance for international travelers using Bluetooth-enabled equipment.), and supports data speeds of up to 721 Kbps, as well as three voice channels. The bluetooth modules can be either built into electronic devices or used as an adaptor. For instance in a PC they can be built in as a PC card or externally attached via the USB port.

Each device has a unique 48-bit address from the IEEE 802 standard. Connections can be point-to-point or multipoint. The maximum range is 10 meters but can be extended to 100 meters by increasing the power. Bluetooth devices are protected from radio interference by changing their frequencies arbitrarily upto a maximum of 1600 times a second, a technique known as frequency hopping. They also use three different but complimentary error correction schemes. Built-in encryption and verification is provided.

Moreover, Bluetooth devices won't drain precious battery life. The Bluetooth specification targets power consumption of the device from a "hold" mode consuming 30 micro amps to the active transmitting range of 8-30 milliamps (or less than 1/10th of a watt). The radio chip consumers only 0.3mA in standby mode, which is less than 3 % of the power used by a standard mobile phone. The chips also have excellent power-saving features, as they will automatically shift to a low-power mode as soon as traffic volume lessens or stops.

Bluetooth devices are classified according to three different power classes, as shown in the following table.

Power Class	Maximum Output	Power
1	100 mW	(20 dBm)
2	2.5 mW	(4 dBm)
3	1 mW	(0 dBm)

But beyond untethering devices by replacing the cables, Bluetooth radio technology provides a universal bridge to existing data networks, a peripheral interface, and a mechanism to form small private ad hoc groupings of connected devices away from fixed network infrastructures. Designed to operate in a noisy radio frequency environment, the Bluetooth radio uses a fast acknowledgment and frequency hopping scheme to make the link robust. Bluetooth radio modules avoid interference from other signals by hopping to a new frequency after transmitting or receiving a packet. Compared with other systems operating in the same frequency band, the Bluetooth radio typically hops faster and uses shorter packets. This makes the Bluetooth radio more robust than other systems. Short packages and fast hopping also limit the impact of domestic and professional microwave ovens. Use of Forward Error Correction (FEC) limits the impact of random noise on long-distance links. The encoding is optimized for an uncoordinated environment.

Bluetooth guarantees security at the bit level. Authentication is controlled by the user by using a 128 bit key. Radio signals can be coded with 8 bits or anything upto 128 bits. The Bluetooth radio transmissions will conform to the safety standards required by the countries where the technology will be used with respect to the affects of radio transmissions on the human body. Emissions from Bluetooth enabled devices will be no greater than emissions from industry-standard cordless phones. The Bluetooth module will not interfere or cause harm to public or private telecommunications network.

The Bluetooth baseband protocol is a combination of circuit and packet switching. Slots can be reserved for synchronous packets. Each packet is transmitted in a different hop frequency. A packet nominally covers a single slot, but can be extended to cover up to five slots. Bluetooth can support an asynchronous data channel, up to three simultaneous synchronous voice channels, or a channel, which simultaneously supports asynchronous data and synchronous voice. It is thus possible to transfer the date asynchronously whilst at the same time talking synchronously at the same time. Each voice channel supports 64 kb/s synchronous (voice) link. The asynchronous channel can support an asymmetric link of maximally 721 kb/s in either direction while permitting 57.6 kb/s in the return direction, or a 432.6 kb/s symmetric link.

Modes of operation

An interesting aspect of the technology is the instant formation of networks once the bluetooth devices come in range to each other. A piconet is a collection of devices connected via Bluetooth technology in an ad hoc fashion. A Piconet can be a simple connection between two devices or more than two devices. Multiple independent and non-synchronized piconets can form a scatternet. Any of the devices in a piconet can also be a member of another by means of time multiplexing. i.e a device can be a part of more than one piconet by suitably sharing the time. The Bluetooth system supports both point-to-point and point-to-multi-point connections. When a device is connected to another device it is a point to point connection. If it is connected to more that one (upto 7 ) it is a point to multipoint connection. Several piconets can be established and linked together ad hoc, where each piconet is identified by a different frequency hopping sequence. All users participating on the same piconet are synchronized to this hopping sequence. If a device is connected to more than one piconet it communicates in each piconet using a different hopping sequence. A piconet starts with two connected devices, such as a portable PC and cellular phone, and may grow to eight connected devices. All Bluetooth devices are peer units and have identical implementations. However, when establishing a piconet, one unit will act as a master and the other(s) as slave(s) for the duration of the piconet connection. In a piconet there is a master unit whose clock and hopping sequence are used to synchronize all other devices in the piconet. All the other devices in a piconet that are not the master are slave units. A 3-bit MAC address is used to distinguish between units participating in the piconet. Devices synchronized to a piconet can enter power-saving modes called Sniff and hold mode, in which device activity is lowered. Also there can be parked units which are synchronized but do not have a MAC addresses. These parked units have a 8 bit address, therefore there can be a maximum of 256 parked devices.

Voice channels use either a 64 kbps log PCM or the Continuous Variable Slope Delta Modulation (CVSD) voice coding scheme, and never retransmit voice packets. The voice quality on the line interface should be better than or equal to the 64 kbps log PCM. The CVSD method was chosen for its robustness in handling dropped and damaged voice samples. Rising interference levels are experienced as increased background noise: even at bit error rates up 4%, the CVSD coded voice is quite audible.

Mobile Phones as a Medical Diagnostic Platform

 Many people die every day due to lack of access to basic medical measurements, such as blood pressure, and corresponding diagnoses. In order to combat this, a medical diagnostic platform is being designed which will use low-cost sensors and utilize the proliferation of mobile phones in emerging regions for computational power.

Broadly speaking, the Mobile Phones as a Medical Diagnostic Platform project can be divided into an electronics phase and a software phase. The electronics phase involves selecting a suitable pressure sensor, amplifying its output, and modulating the signal for transmission to the phone. The software phase involves demodulating the signal, calculating the blood pressure, creating a GUI for the phone targeted for the regions in which it will be deployed, and creating a database with basic diagnostic information correlated to the blood pressure calculated.

A chief design difficulty in this project has been the implementation of amplitude modulation (necessary to transmit DC information to the mobile phone) on the 3.2V provided by the phone battery. An analysis of the standard modulation IC, ON Semiconductor’s MC1496 balanced modulator, is presented, along with modifications and design decisions that demonstrate optimized operation for low-power, DC input, and minimal harmonics.

Wirless Led

Definition

Billions of visible LEDs are produced each year, and the emergence of high brightness AlGaAs and AlInGaP devices has given rise to many new markets. The surprising growth of activity in, relatively old, LED technology has been spurred by the introduction of AlInGaP devices. Recently developed AlGaInN materials have led to the improvements in the performance of bluish-green LEDs, which have luminous efficacy peaks much higher than those for incandescent lamps. This advancement has led to the production of large-area full-color outdoors LED displays with diverse industrial applications.

The novel idea of this article is to modulate light waves from visible LEDs for communication purposes. This concurrent use of visible LEDs for simultaneous signaling and communication, called iLight, leads to many new and interesting applications and is based on the idea of fast switching of LEDs and the modulation visible-light waves for free-space communications. The feasibility of such approach has been examined and hardware has been implemented with experimental results. The implementation of an optical link has been carried out using an LED traffic-signal head as a transmitter. The LED traffic light (fig 1 below) can be used for either audio or data transmission.

Audio messages can be sent using the LED transmitter, and the receiver located at a distance around 20 m away can play back the messages with the speaker. Another prototype that resembles a circular speed-limit sign with a 2-ft diameter was built. The audio signal can be received in open air over a distance of 59.3 m or 194.5 ft. For data transmission, digital data can be sent using the same LED transmitter, and the experiments were setup to send a speed limit or location ID information.

The work reported in this article differs from the use of infrared (IR) radiation as a medium for short-range wireless communications. Currently, IR links and local-area networks available. IR transceivers for use as IR data links are widely available in the markets. Some systems are comprised of IR transmitters that convey speech messages to small receivers carried by persons with severe visual impairments. The Talking Signs system is one such IR remote signage system developed at the Smith-Kettlewell Rehabilitation Engineering Research center. It can provide a repeating, directionally selective voice message that originates at a sign. However, there has been very little work on the use of visible light as a communication medium.

The availability of high brightness LEDs make the visible-light medium even more feasible for communications. All products with visible-LED components (like an LED traffic signal head) can be turned into an information beacon. This iLight technology has many characteristics that are different from IR. The iLight transceivers make use of the direct line-of-sight (LOS) property of visible light, which is ideal in applications for providing directional guidance to persons with visual impairments. On the other hand, IR has the property of bouncing back and forth in a confined environment. Another advantage of iLight is that the transmitter provides easy targets for LOS reception by the receiver. This is because the LEDs, being on at all times, are also indicators of the location of the transmitter. A user searching for information has only to look for lights from an iLight transmitter. Very often, the device is concurrently used for illumination, display, or visual signage. Hence, there is no need to implement an additional transmitter for information broadcasting. Compared with an IR transmitter, an iLight transmitter has to be concerned with even brightness. There should be no apparent difference to a user on the visible light that emits from an iLight device.

It has long been realized that visible light has the potential to be modulated and used as a communication channel with entropy. The application has to make use of the directional nature of the communication medium because the receiver requires a LOS to the audio system or transmitter. The locations of the audio signal broadcasting system and the receiver are relatively stationary. Since the relative speed between the receiver and the source are much less than the speed of light, the Doppler frequency shift observed by the receiver can be safely neglected. The transmitter can broadcast with viewing angle close to 180 . The frequency of an ON period followed by an OFF period to transmit information is short enough to be humanly unperceivable; so that it does not affect traffic control. This article aims to present an application of high-brightness visible LEDs for establishing optical free-space links.