It is mandatory to support it because MS may request a single block.
In this case the network must assign a single block.
It is possible to force single block allocation for all uplink requests
on RACH. (VTY option)
This is required because uplink assignment (PACCH) is done on a request
by mobile, so the mobile expects that it get this assignment in return.
After that we may assign downlink.
In order to do downlink assignment during uplink TBF, the content
resolution must be completed. It is completed when the first Packet
Uplink Ack/Nack message is transmitted to the mobile.
In order to send control blocks to MS and receive control blocks from MS
(polling), it is required to select one timeslot that the MS must be
able to send and receive. The allocation algorithm must take care of
selecting that slot.
The new data structure is required to define slot/TFI assigment for MS
with multislot capability.
Now there are two lists for TBFs: uplink and downlink. It is possible to
have different TBFs with same TFI in the same direction, as long as they
are assigned on different timeslots.
See tbf.txt for description.
Note: This does not implement any multislot support. It defines the new
data structure. Currently only the first slot is assigned.
The scheduler is triggered at ready-to-send-requesst. It schedules
control blocks, data block and dummy blocks, depending on priority.
It provides upstream ressource by setting USF. The ressources are
assigned, if required. The ressources are dispatched round-robin.
In case of polling, the upstream ressource is given to MS at the
time it will respond to polling request.
Andreas Eversberg