Bluetooth

The target for Bluetooth is highspeed, very short distance, ad-hoc, wireless communication.

Examples of applications include PDA-PC, PDA-PDA, laptop-peripheral, phone-PDA, <digital devices>-computer, etc.

Major industrial backing: Ericsson, 3Com, IBM, Intel, Lucent Technologies, Microsoft, Motorola, Nokia, Toshiba, etc.

Technology overview

Radio frequency energy, omnidirectional

Range
10cm - 10m, indicating the low power levels of ?
Frequency range
80 MHz at 2.4 GHz, in the Industrial, Scientific, Medial (ISM) band
Same as 802.11 wireless LAN
Topology
Ad-hoc networks of nodes within range, point to multipoint.
Maximum 7 devices (3 bit address field, 000 reserved).
Multiplexing
Frequency hopped spread spectrum, 79 channels separated by 1 MHz
Time division multiplexing within a piconet.
Data rate
Up to 1 Mbps
Security
Done at data link level, with authentication (PINs) and encryption for piconets.
Interesting clash of goals: ad-hoc, automatic, transparent networking plus security.

Competition

IEEE 802.11 covers more range, at higher speed, and is squarely aimed at LAN replacement. Networks are more fixed, formal. Power consumption is much higher than Bluetooth, making target devices much "fatter".
IrDA (Infrared Data Association) is widely availabble (used?) in laptops and some PDAs and phones. Speeds from very slow to 4 Mbps. Near line-of-sight (30 degree cone) is major difference. No security at data link level.

Operation

Higher level functionality borrowed from existing standards and protocols.

File sharing

From IrDA, HomeRF SWAP