Re: Dropping LLC frames due the TBF destruction

(just ignore my last mail. somehow i hit the wrong key...) hi holger, hi harald, i looked at the TS 08.18. the LLC-DISCARDED.ind message does not contain any reference to the frame(s) that has been discarded, so SGSN cannot resend specific frames that are dropped. also a resend does not seem to be specified. it is task of the PCU to be sure to deliver LLC frame. during a downlink TBF, lost downlink blocks are resent by the RLC/MAC protocol, but assignment is not. (at least not correctly) here is my suggestion: if assignment fails, the PCU should resend downlink TBF assignment several times. the number of retries should be a config option. it may happen that the assignment on PACCH fails, while the MS is in packet transmode. if the MS switches back to packet idle mode in the meantime, the retry must be performed on AGCH. it may also happen that the assignment on AGCH fails because the MS is establishing an uplink TBF. if this happens, the retry must be performed on PACCH. if the number of maximum retries is reached, the LLC frame (or list of) should be discarded and the an LLC-DISCARDED.ind message should be sent to SGSN. regards, andreas