hi,
currently i am working on radio ressource layer and the sub processes for 1) network selection, 2) cell selection, and 3) location update trigger process. i have problems expecially with the cell selection task. since it requires measurements and detection of carriers (for some time depending on the slot configuration), it must work together with the layer 1 (radio part). here are some examples of messages what i think must exist between layer 1 and cell selection process:
(the primitive names are just examples and do not conform to GSM specs.) L1CTL_DM_EST_REQ (which already exists) tune to a channel in dedicated mode (by given channel, frequency and later hopping sequence) L1CTL_IM_EST_REQ tune to a BCCH channel in idle mode (by given frequency) L1CTL_IM_EST_CNF confirm valid carrier signal. L1CTL_IM_INFO_IND info when reading of BCCH was enough for a cell selection (depends on the channel configuration), shall include measurement L1CTL_MEAS_IND periodic info of measurements from the selected channel. (required for cell reselection)
take these only as examples, not as required messages. while reading GSM 05.08, this is what i think is required to do cell (re-)selection process or abort radio connection if fails (below minimum level).
any help/ideas/suggestions?
andreas
Hi Andreas,
On Tue, Apr 06, 2010 at 02:19:20PM +0200, Andreas.Eversberg wrote:
currently i am working on radio ressource layer and the sub processes for 1) network selection, 2) cell selection, and 3) location update trigger process.
Andreas, as indicated in my other mail, I am currently working on those parts that are needed for cell (re)selection anyway, so it would be good to not duplicate work here.
However, the required changes to our current layer1 are probably a bit more than I hoped for, so it definitely won't be ready in a day or two.
Meanwhile, if you want to test location updating and other higher level parts, I suggest you simply use a fixed ARFCN for testing.
Please also note that the current lapdm.c code is far from being complete, there are no retransmissions, etc. yet.
Also, layer1 TX side still has a problem where it transmits the bursts all off-by-one timeslot, i.e. only 3 out of 4 bursts of a message are received correctly by the BTS, the other burst is sent at a different (wrong!) point in time, disturbing some other phone on the same cell.
But as indicated, I was on holidays for four weeks, so everything is quite stalled.
Harald.
baseband-devel@lists.osmocom.org