Faster Data Transfer With Bluetooth and Contactless Communicatio
Bluetooth technology allows two devices near each other to communicate at a maximum speed of 3 Mb per second. In the grand scheme of wireless communication, Bluetooth is roughly two times faster than the data throughput of a 3G wireless phone but still 10 to 20 times slower than today's Wi-Fi speeds.
More than one billion Bluetooth-enabled devices are currently on the market, and Bluetooth does a good job of transferring files that are smaller than 10 MB in size. However, due to the inherent nature of most wireless communication protocols, Bluetooth devices need to discover other Bluetooth devices, even if both devices are right next to each other. Finding a remote Bluetooth device is great, but what services does that remote Bluetooth device offer? If the remote device is a printer, does it offer the commonly used Basic Printing Profile (BPP) or the more advanced printing service known as the Hard Copy Cable Replacement Profile (HCRP)?
To find the available services on a remote Bluetooth device, you also need to search for a service. Bluetooth device-discovery and service-searching capabilities are great when you are trying to find any remote Bluetooth device in the vicinity that can suit your needs.
But device discovery and service searching are extremely time-consuming and frustrating to use when you're trying to communicate with a device that's right in front of you. This article shows you how to get Bluetooth applications to completely bypass the device-discovery and service-searching processes simply by using Near-Field Communication (NFC) technology and JSR 257: Contactless Communication API.
Contents
Introduction to NFC Technology
What exactly is NFC technology? NFC is a radio communication standard that enables wireless data transfer between two devices at a very short distance -- less than 10 centimeters. NFC devices include a certain class of radio-frequency identification (RFID) tags and contactless smart cards. NFC devices operate within the 13.56 MHz frequency range, and they support extremely low data rates -- a maximum of 0.42 Mb per second.Compared to Bluetooth and Wi-Fi, NFC technology operates at drastically reduced transfer rates and only within a very small proximity. If that's the case, why use NFC technology? Here are three reasons:
- Setup time. NFC devices communicate instantly -- in less than 100 milliseconds -- when placed within range.
- Power consumption. NFC tags and cards do not consume power, so their lifespan can be unlimited.
- Cost. NFC tags and cards are inexpensive to manufacture compared to other wireless technologies.
- Wireless payments. Traditional smart cards have been used for cashless payments for years. The short setup time for NFC devices allows mobile payments to be even easier.
- Smart magazines and posters. Want to get more information about something you read in a magazine or see on a poster on the street? Just tap the page to get more information, or get the URL to store the bookmark for later use.
- Transit tickets. When used in scenarios for mass transit, NFC-enabled phones are simple and convenient.
- Business-card exchange. Because setup times for communication between NFC devices are very short, NFC devices are ideal for business-card exchanges.
Table 1: A Comparison of Wireless Communication Standards
International Standard
|
Operating Frequency
|
Maximum Data Rate
|
Maximum Distance
|
Power Consumption Rate
|
|
|---|---|---|---|---|---|
 | |||||
Bluetooth 3.0
|
IEEE 802.15.1
|
2.4 GHz
|
22 Mb/s
|
100 m
|
hours/days
|
Bluetooth 2.1
|
IEEE 802.15.1
|
2.4 GHz
|
3 Mb/s
|
100 m
|
days
|
NFC
|
ISO 14443
|
13.56 MHz
|
0.42 Mb/s
|
10 cm
|
∞
|
Wi-Fi B
|
IEEE 802.11b
|
2.4 GHz
|
11 Mb/s
|
100 m
|
hours
|
Wi-Fi G
|
IEEE 802.11g
|
2.4 GHz
|
54 Mb/s
|
100 m
|
hours
|
Wi-Fi N
|
IEEE 802.11n
|
5 / 2.4 GHz
|
144 Mb/s
|
100 m
|
hours
|
ZigBee
|
IEEE 802.15.4
|
2.4 GHz
|
0.25 Mb/s
|
100-1200 m
|
months/years
|
| |||||
As you can see, NFC technology is definitely not suited to transferring large amounts of data over long distances -- that is definitely a job for other wireless communication protocols such as any of the flavors of Wi-Fi.
But if you want to provide a small amount of information in a very short amount of time, then NFC may be for you. And a Java technology API is available that allows developers to interact with NFC devices: the JSR 257 API.
Introducing JSR 257: Contactless Communication API
JSR 257, the Contactless Communication API, is the Java ME API that allows mobile phones to communicate with a variety of devices within proximity. The Contactless Communication API allows your Java ME MIDlets to read and write data to the following entities:- External contactless smart cards
- NFC tags
- Generic RFIDs
- 2D barcodes
- Other NFC-capable phones
- Internal secure elemen
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