Saturday, 7 May 2011

What is Bluetooth´s prestanda?

What is Bluetooth´s prestanda?

Technical standards and performance levels
1. Bluetooth is based upon small, high performance integrated radio transceivers, each of which is allocated a unique 48-bit address derived from the IEEE 802 standards.
2. It operates in the unrestricted 2.45 GHz ISM "free band", which is available globally, although slight variation of location and width of band apply.
3. The range is set at 10 meters to optimize for target market of mobile and business user. The range can, however, be increased.
4. Gross data rate is 1Mbit/s, with second generation plans to increase to 2 Mbit/s.
5. One-to-one connections allow maximum data transfer rate of 721 kbits/s (corresponding to 3 voice channels).
6. Bluetooth uses a packet switching protocol, based on a frequency hop scheme with 1600 hops/sek. to enable high performance in noisy radio environments. The entire available frequency spectrum is used with 79 hops of 1 Mhz bandwidth, analogous to the IEEE 802.11 standard.
7. It has low power consumption, drawing only 0.3 mA in standby mode. This enables maximum performance longevity for battery powered devices. During data transfer the maximum current drain is 30 mA. However, during pauses or at lower data rates the drain would be lower.
Bluetooth has 2 transmission power levels

The Bluetooth radio is built into a small microchip and operates in a globally available frequency band ensuring communication compatibility worldwide. The Bluetooth specification has two power levels defined;
1. a lower power level that covers the shorter personal area within a room, and
2. a higher power level that can cover a medium range, such as within a home.
Software controls and identity coding built into each microchip ensure that only those units preset by their owners can communicate.

Bluetooth provides both circuit and packet switching

The Bluetooth baseband protocol is a combination of circuit and packet switching. Time slots can be reserved for synchronous packets. A frequency hop is done for each packet that is transmitted. A packet nominally covers a single time slot, but can be extended to cover up to five slots.
Bluetooth can support;
• an asynchronous data channel, or
• up to 3 simultaneous synchronous voice channels, or
• a channel which simultaneously supports asynchronous data and synchronous voice.

No comments:

Post a Comment