baseband-devel September 2010

baseband-devel@lists.osmocom.org

10 participants
22 discussions

assignment command / status of RR
by Andreas.Eversberg 01 Sep '10

01 Sep '10

hi, as you can see in the git log, i checked in the "ASSIGNMENT COMMAND" processing. it modifies timeslot, subslot, and hopping sequence. this is required when the network assigns an SDCCH before the actual TCH is allocated: after receiving the "ASSIGNMENT COMMAND", the layer2 is release locally (without sending anything), the dedicated mode is released and established with a new parameters (e.g. TCH/F), and the layer2 is established again, finally the "ASSIGNMENT COMPLETE" is sent to the network. this process is incomplete, but it should work in most cases. (no "starting time" processing). in my local copy of the git, i already completed the assignment process. additionally "FREQUENCY REDEFINITION" is completed, "IMMEDIATE ASSIGNMENT" supports "starting time", MDL-error processing is added, and "HANDOVER COMMAND" parsing is done. the handover process is not completed, because it depends on unimplemented layer1 features, like RX-only channels or "4 successive HANDOVER ACCESS bursts on DCCH". except the handover process, the RR protocol for basic phone calls is complete now. before i can check it in, it depends on two things. first, there are additional messages to be defined in osmocore: "[osmocore] Adding handover and frequency redefiniton message headers" http://home.eversberg.eu/osmocore.patch second, it depends on "starting time" support for layer1: http://home.eversberg.eu/modify.patch it adds a L1CTL message to store modified frequency allocations (ma, ma_len, HSN, MAIO, TSC) for hopping and a "starting time". this starting time is the frame number at which the modified frequencies are used. if the frame number lies in the past, the new modified frequencies are used after the L1CTL message is received. sylvain already noted, that the event of "starting time" should be triggered by the scheduler. since i don't know how the scheduler exactly works, i would ask someone to change my patch. note that the dedicated mode can be released before the "starting time" elapses. as soon as both things above are in the master branch, i will commit my latest work on RR. regards, andreas

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Hi all, why osmocombb need Ti Calypso/Iota/Rita GSM baseband chipset
by John Wu 01 Sep '10

01 Sep '10

Hi all, from what i learned, osmocombb provide gsm protocol stack and dsp signal process code. So why need to use Ti Calypso/Iota/Rita. Is it possible to run on other common arm7+dsp chipset?

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baseband-devel September 2010