Dear Pix, thanks a lot for your patience 🙂
So there is no much difference between BBH and RH (except BCCH-tre, of course) – they use same principle (basically).
But now I can’t understand this part of “Alcatel BSS description”:
… Synthesized Frequency Hopping functions in a similar fashion to Baseband
Frequency Hopping, but is performed at a different location. Instead of
switching each time slot between traffic channels, the channel assigned to a
time slot is assigned to a fixed Carrier Unit (or TRE).
The Carrier Unit/TRE changes frequency with each TDMA frame in accordance
with the HSN algorithm selected, in the same manner as above. Thus, instead
of the channel hopping from one fixed transceiver to another, the transceiver
itself hops from one frequency to another, in both cases, according to the
algorithm and parameters selected.
Synthesized Frequency Hopping has the advantage of allowing an FHS to
contain one more frequency than the number of Carrier Units/TREs in the
system. This is particularly useful in some microcellular applications where only
one transceiver is available for Frequency Hopping.
Note: Normally, in both Frequency Hopping schemes (Baseband and Synthesized),
time slot 0 (TS0) is not available for Frequency Hopping. This is because
it carries the BCCH, which must always be at maximum power and on a
frequency known to mobile stations in Idle mode in the cell…
And questions:
1) What does it mean – “Instead of switching each time slot between traffic channels”? In BBH we have a certain TS on certain tre – and each frame this TS is emitted on different frequencies the procedure is similaar to RH,as I understand.
2) “Thus, instead
of the channel hopping from one fixed transceiver to another, the transceiver
itself hops from one frequency to another, in both cases, according to the
algorithm and parameters selected.” It sounds like that: in BBH channel (and consequently – MS) hops between different transceivers. But maybe I’m not right :(((