Joining the Scatternet Club

It must be said that to date, most applications using Bluetooth have been one to one�"
a host and slave device (handset and earbud, for example). In practice, it is very hard
to develop consistent rules for joining and leaving a scatternet�"for instance, authentication
procedures. You could have 100 Bluetooth-enabled handsets all in the same
room, but you might not want them all to talk to each other. If the device is in discovery
mode, it would spend all its time interrogating other devices and inviting them to
join its scatternet club. All the other devices could potentially be doing the same. Who
decides which club to join?
Because there are potentially so many different hardware and software form factors,
it is difficult to define a common ontology that can be used for disparate devices to
communicate with one another. There is not a huge amount of point in getting a Bluetooth
earpiece headset to talk to a Bluetooth-enabled printer. It would not have much
to say. Just because something is possible doesn’t mean you should do it!
So as with wireless LANs there are physical layer performance issues. Bluetooth and
IEEE802 wireless LANs used together in the 2.4 GHz band add mutually to each
other’s noise floor. The Bluetooth device suffers from poor sensitivity anyway, so the
quality of the connection will be far from constant.