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Standard Bluetooth criteria have five principles: low cost, low power waste, small coverage, global standardization as well as robustness. These, by now, still provided developing directions for Bluetooth.
1. Bluetooths are devided into three groups according to power consumption, the most popular type is type 3.
Power Level |
Max Output Power |
Min Output Power |
Communication Range |
1 |
100mW (20dBm) |
1mW (0dBm) |
100m |
2 |
2.5mW (4dBm) |
0.25mW (-6dBm) |
16m |
3 |
1mW (0dBm) |
N/A |
10m |
Anyway, Bluetooth consumes relatively high power, for which reason, it is beaten by Infrared-Ray on some occasions. Fortunately, there emerged a new technique called Wibree, ULP (Ultra-Low-Power) Bluetooth as well. It is said, it can work up to 10 years with a bottom battery. ULP¡¯s main idea is to make Bluetooth work only when required, which on the other hand, brings down the quick response performance.
2. It was ever widely broadcasted that, Bluetooth exists safety problem. Though safety strategy and encryption have been considered in designing Bluetooth framework, but it can¡¯t be very effective, merely for two reasons. One is that higher safety means higher expense, and the other is that Bluetooth devices work in piconet, in which it is hard to determine the connecting topology and detect all devices within 10M range. In order to bring up security, sufficient identification before connection is necessary and connection should be declared to other devices initiatively rather than connected passively.
3. The expense of Bluetooth chips stays higher than others, which in a great sense limits its commercial use. In USA, the price of Bluetooth chips is brought down to 5-8 dollars with great effort, which is still a little bit too luxurious to embed such a chip in a mobile with total cost of 50-80 dollars. If the expense isn¡¯t to be brought down greatly so as to satisfy commercial command, Bluetooth will face the most bitter winter. Below is the price estimation of Bluetooth chip.
4. The last but no the least, the main weak point of Bluetooth is transferring rate. After many years, it is still hard for Bluetooth to overcome 10Mb/s. When the technical group of 802.11 is purchasing higher and higher transferring rate, 54Mb/s for example, there is hardly any reason to insist on the low communication method if there is no revolutionary breakthrough made on Bluetooth.
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