Stacy DrakeBluetooth Vs. Wi-Fi

What is Bluetooth?

• Bluetooth is define as a specification for the use of low-power radio

communications to wirelessly link phones, computers and other

network devices over short distances.

• Bluetooth technology was designed primarily to support simple

wireless networking of personal consumer devices and peripherals,

including cell phones, PDAs, and wireless headsets. Wireless

signals transmitted with Bluetooth cover short distances, typically up

to 30 feet (10 meters). Bluetooth devices generally communicate at

less than A1 Mbps. Although the Bluetooth standard utilizes the

same 2.4 Ghz range as 802.11b and 802.11g, Bluetooth technology

is not a suitable Wi-Fi replacement. Compared to Wi-Fi Bluetooth is

much slower.

What is Wi-Fi?

• Wi-Fi (short for “wireless fidelity”) a local area network that uses

high frequency radio signals to transmit and receive data over

distances of a few hundred feet; uses ethernet protocol. Using IEEE

802.11

What’s the difference?Bluetooth and Wi-Fi are both wireless networking standards that

provide connectivity via radio waves. The main difference:

Bluetooth's primary use is to replace cables, while Wi-Fi is largely

used to provide wireless, high-speed access to the Internet or

a local area network.

Interferences issuesInterference issues between Bluetooth and Wi-Fi technology are,

both occupy a section of the 2.4 GHz ISM band that is 83 MHz-

wide. Bluetooth uses Frequency Hopping Spread Spectrum

(FHSS) and is allowed to hop between 79 different 1 MHz-wide

channels in this band. Wi-Fi uses Direct Sequence Spread

Spectrum (DSSS) instead of FHSS. Its carrier does not hop or

change frequency and remains centered on one channel that is 22

MHz-wide.

Interferences issues Cont’dWhile there is room for 11 overlapping channels in this 83 MHz-wide

band, there is only room for three non-overlapping channels. Thus

there can be no more than three different Wi-Fi networks operating in

close proximity to one another. When a Bluetooth radio and a Wi-Fi

radio are operating in the same area, the single 22 MHz-wide Wi-Fi

channel occupies the same frequency space as 22 of the 79

Bluetooth channels which are 1 MHz wide. When a Bluetooth

transmission occurs on a frequency that lies within the frequency

space occupied by a simultaneous Wi-Fi transmission, some level of

interference can occur, depending on the strength of each signal.

• When a Bluetooth device encounters interference on a channel, it

deals with the problem by hopping to the next channel and trying

again. In this manner it can attempt to avoid interference from a

Wi-Fi network.

• Wi-Fi acts like a wireless Ethernet™, and it deals with interference

like Ethernet does.