This is required, since we may change slot allocation. In case of a
change, we do not want to be unable to change, if the same TFI on one of
the other slots is already in use by a different TBF (having same TFI, but
on different slot).
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)
Both flags can be used to determine wether assignment must be sent on PCH
or on AGCH. Before contention resolution is done, mobile will ignore
downlink assinment. When final uplink acknowledge was sent, the mobile
will go back to PCH after reception of akcnowledge.
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.
If the mobile misses assignment, it changes back to idle mode. In this
case we must kill the pending downlink TBF, because it is not used by
mobile and we can assign a new downlink TBF for new downlink data.
(We may not have two downlink TBF with same TLLI!)
If lifetime expires of queued LLC frames, they are discarded. The number
of discarded frames and the sum of their octets are reported to SGSN
via LLC-DISCARDED message.
The lifetime can be overridden via VTY. The value can be centi-seconds
or "infinite".
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.
It turned out that the final ack flag may not be set, but all packets
have been acknowledged. This patch will finish transfer in case all
blocks are acknowledged.
The slot must be the control channel TS, which is selected by the
allocation algorithm. The MS must be able to respond at this TS.
The counter to trigger polling is incremented until polling has to be
performed. Then the counter stops. When the transmission of data block is
requested on control channel TS, the counter is reset. The counter-value
is also used to poll immediately when the transmission has finished.
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.
Andreas Eversberg
Holger Freyther
Harald Welte