Problems with understanding packet downlink assignment

jolly andreas at eversberg.eu
Thu Jun 28 12:52:32 UTC 2012


hi,

i try to unterstand downlink assignment. there are two ways to perform it:

- on AGCH/PAGCH when mobile is in packet idle mode
- on PACCH when mobile is in packet transfer mode (currently ongoing
uplink TBF)

(for establishment of uplink TBF in packet idle mode, the mobile repeats
channel requests after one second timeout.)

i don't see any procedure how the networks repeats a downlink
assignment, if there is no response from the mobile (if downlink
assignment got lost, hence it was not received by mobile). the only
logical procedure i can see is that the messages from SGSN will get
dropped during release of downlink TBF. (the release happens, because
there is no response from mobile to polling of downlink acknowledgements.)

regards,

andreas


 




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