 |
Physical
Characteristics
|
1. What is the range of Bluetooth?
Bluetooth is designed for very low power use, and the transmission range will only be 10m, about 30ft. High-powered Bluetooth devices will enable ranges up to 100m (300ft). Considering the design philosophy behind Bluetooth, even the 10m range is adequate for the purposes Bluetooth is intended for. Later versions of the Bluetooth spec may allow longer ranges. 2. What are the differences between Wi-Fi (802.11b) and the Bluetooth? Bluetooth
wireless technology and Wi-Fi are complementary technologies that do different
things: 3. Is Bluetooth harmful? Wireless phones and Bluetooth devices both emit non-ionizing radiation, typically at frequencies from 1 to 2.5 GHz. The data results on health hazards from wireless phone radiation are not clear-cut, with some studies showing a measure of risk and some showing no problems. But because it’s a good idea to err on the side of caution in such matters, regulatory bodies have set exposure standards. These are expressed in terms of the “specific absorption rate” (SAR), which attempts to measure the radiation actually reaching body tissue. The U.S. and Canadian governments have set a maximum SAR of 1.6 watts per kilogram, while the European Union permits a slightly higher level. In the real world, emissions generally stay well below the maximum allowed. According to data from BlackBerry-maker Research in Motion (RIMM), SARs for GSM BlackBerry devices fall in the range of 0.25 watts per kilogram when used at your ear. Bluetooth radios operate at much lower power levels than phones so, not surprisingly; the radiation added by a Bluetooth device is insignificant by comparison. A study by William G. Scanlon of Queen’s University in Belfast found that a typical Ericsson (ERICY) Bluetooth radio module generates an SAR of just 0.001 watts per kilogram. 4. Will using Wi-Fi and Bluetooth technologies together cause interference? Studies by a number of companies indicate that if the separation is more than two meters, in most cases there is no perceptible degradation in transmitting data in either device. From two meters to about a half-meter, there is a graceful degradation. As the devices are brought into very close proximity, the degradation can be quite noticeable. Fortunately, this scenario only happens when the two systems are in the same device, and in those cases, Bluetooth hardware and Wi-Fi hardware can collaborate to dramatically improve performance. In addition, all Bluetooth desktops from Logitech include Adaptive Frequency Hopping (AFH) technology, making them an ideal solution for the growing number of customers who work on a wireless network, because it minimizes interference between Bluetooth wireless technology and Wi-Fi wireless technology. 5. Difference between Bluetooth 1.2 and Bluetooth 2.0 EDR (Enhanced Data Rate) The main motivation
for the release of the new version was to improve existing usage scenarios
that require increased data throughput. Scenarios requiring higher throughput
may be image transfer, printing and synchronizing. In these cases the
new release makes the Bluetooth wireless technology faster and better
for the consumer to use. 6. What is the data throughput speed of a Bluetooth connection? Bluetooth transfers data at a rate of 721 Kbps, which is from three to eight times the average speed of parallel and serial ports, respectively. This bandwidth is capable of transmitting voice, data, video and still images. 7. How secure is a Bluetooth network? Bluetooth is extremely secure in that it employs several layers of data encryption and user authentication measures. Bluetooth devices use a combination of the Personal Identification Number (PIN) and a Bluetooth address to identify other Bluetooth devices. Data encryption (i.e., 128-bit) can be used to further enhance the degree of Bluetooth security. The transmission scheme (FHSS) provides another level of security in itself. Instead of transmitting over one frequency within the 2.4 GHz band, Bluetooth radios use a fast frequency-hopping spread spectrum (FHSS) technique, allowing only synchronized receivers to access the transmitted data. |
| Bluetooth Definition | Physical Characteristics | |
| ©2006
The Tech Geek. All rights reserved. The Tech Geek is not responsible for typographic errors. The Tech Geek reserves the right to change the terms and conditions of sale at any time. |
|