802.11 is used for short range high bandwidth

[cscott]

What is there about a particular protocol that defines its range of use? Is there such definition? i.e. 802.11 is used for short range high bandwidth, GSM/EGPRS for long range cellular communications and bluetooth for even shorter range communication on PANs.

Is it possible for 802.11 to be used across the world if the infrastructure was there? Even bluetooth? (Forgetting the potential uselessness of actually doing this for say bluetooth)

 

[LowEParticle]

I can really only think of two design parameters that limit the range of use in a particular protocol: latency and reliable propagation.

Latency is key in Carrier Sense Multiple Access protocols, where any node can initiate a transmission at any time. Arbitration of the network is handled by sensing packet collisions. If the latency is large relative to the transmission time of a packet, the network will statistically gradually grind to a halt.

Reliable propagation has to do with the transmission media (physical layer) choice. If the tiny milliwatt-level transmitter in a Bluetooth transceiver is working in New York, the chances of successfully communicating to London are small. :-) This is much different from the network design of "reliable end-to-end" or "reliable communication", which is a protocol layer-attribute that is not got anything to do with the physical layer.

Dave