Question regarding TS allocation algorithm(s)

Andreas Eversberg andreas at
Sun Sep 29 08:15:50 UTC 2013

Holger Hans Peter Freyther wrote:
> I have the suspicion that in case of algorithm A only the first
> PDCH will be used to assign to phones? And in case of algorithm B
> it is likely that the assignments are not spread equally across the
> available timeslots?
dear holger,

it is true tat algorithm A only assigns the first PDCH time slot. i
don't see any problems changing that by spreading TBF usage over all
available PDCHs.

in case of algorithm B it is a bit different. we want to assign a
certain PDCH time slot for uplink, so we can be sure that the phone is
able to receive all supported downlink PDCH slots, if an additional
downlink TBF is assigned. for a class 12 mobile (as used today), we can
assign up to 4 PDCHs for downlink. in this case we must assign the third
PDCH for uplink, otherwise semi-duplex operation is not possible with
all 4 time slots. but again, it would be possible to spread uplink and
downlink assignment, if we have more than 4 PDCHs. this makes the
algorithm more complex.



More information about the osmocom-net-gprs mailing list