hi harald,
must random value in chan_request change on every resend or only on every RR establishment? (currently it changes on every RR establishment only.)
as far as I know, it has to change on every retransmission. Dieter is probably the person who knows all RACH aspects in detail, maybe he can comment on this.
from the specs it is quite clear that every access burst has different random number when resending. but how does the network know if the burst is from the same phone but retransmitted? in case of poor uplink many bursts may be resent. will the network allocate a channel for every burst received and waits for timeout? (if this is the case, emergency calls could quickly 'evacuate' the cell.)
OpenBSC: if tx-msg fails during process, the msg must be freed to avoid memory leak.
I don't understand, can you please explain this further?
it is something to remind me that there are memory leak problems. in some functions of gsm_04_08.c there are messages allocated at the beginning and sent at the end. sometimes during processing, the function returns due to error conditions, but the message is not freed before return. i will check that later together with my new code.
as far as i can see right now, it just happens in gsm48_cc_tx_setup().
regards,
andreas
On Mon, Mar 29, 2010 at 01:39:21PM +0200, Andreas.Eversberg wrote:
hi harald,
must random value in chan_request change on every resend or only on every RR establishment? (currently it changes on every RR establishment only.)
as far as I know, it has to change on every retransmission. Dieter is probably the person who knows all RACH aspects in detail, maybe he can comment on this.
from the specs it is quite clear that every access burst has different random number when resending. but how does the network know if the burst is from the same phone but retransmitted?
it does not know, and I think according to the spec it should not know.
The rationale might be that if two phones chose the same random value and keep retransmitting it, they will never get out of their collision.
in case of poor uplink many bursts may be resent. will the network allocate a channel for every burst received and waits for timeout? (if this is the case, emergency calls could quickly 'evacuate' the cell.)
yes, this is the case. however, RACH retransmissions are spaced large enough that a phone will detect the immediate assignment on the downlink before sending the next RACH burst.
baseband-devel@lists.osmocom.org