Device Discovery Illustrated
Last updated
Last updated
Device A wants to search for stations
Device A wants to search for stations.
A does an inquiry (page with ID 000).
Devices B,C,D are doing an inquire scan.
B answers with FHS packet.
Contains DeviceID and Clock.
A does an inquiry again.
C e D answer at the same time with FHS packet.
Packets are corrupted.
A does not answer.
C and D will wait an random number of slots.
A wants to search for stations.
A does an inquiry again.
C answers with FHS packet.
A wants to search for stations.
A does an inquiry again.
D answers with FHS packet.
A has all the information it needs about the units in the cell.
Inquiry scanning has a common address.
and a common frequency pattern (from 32 frequencies).
All devices can page this address (and become masters).
All machines hearing an inquiry will answer the inquiry request.
There is a detector (correlator hit) in the slaves, that detects inquiries, before answering with a FHS providing:
Device ID and Clock
A machine in low power waits a random time before answering again to a scan.
If there is a collision on answering to a scan, they also wait a random period before answering again.
Inquiry requires two packets before the slave answers.
