Bluetooth And 802.11 Coexistence

By Ezurio Ltd., A Unit Of Laird Technologies

Both Bluetooth and 802.11 work in the same portion of radio spectrum at 2.4GHz. This means that in cases where both are operating at the same time and within range of each other, there is scope for interference between the two radios, which will result in a loss of performance for both systems. Given the success of both technologies, this is now an inevitable reality.

The effect of interference will depend on the relative location of the two transceivers, the frequency with which they transmit and also the type of data that is being transmitted. Bluetooth employs a frequency hopping scheme, where a burst of data is contained within a segment of spectrum 1MHz wide, which randomly changes to a different frequency 1,600 times every second. 802.11 transmitters do not hop, but transmit at a static frequency, using 22 MHz of spectrum. Both have mechanisms to deal with interference from another similar system, although in each case this results in steadily degraded performance. However, when they are mixed together, the opportunity for disruption increases.