AW: 3GPP - paging references

Stefan Bauer stefan.bauer at cubewerk.de
Thu Jan 12 23:10:55 UTC 2012


-----Ursprüngliche Nachricht-----
Von:	Sylvain Munaut <246tnt at gmail.com>
> When the phone sees he's being paged, he will initiate the channel
> request procedure.
> 
> He sends a RACH at a given time fn with a random reference (8bits).
> And then he looks for assignement matching his RACH (i.e. the time fn
> and random reference are repeated back by the network in the
> assignment so that a phone knows the channel was for it).

Sylvain,

so it goes like this: ?

1. BSC starts paging MS by either TMSI/IMSI
(Paging1: Normal paging chan any to imsi M(262073948077454))

2. MS sends channel request procedure to BSC over RACH
(MS uses special(random) parameters inside this request)
(is there a way to see the RACH-traffic in the "air" with regular tools?)

3. BSC sends Immediate Assignment message to MS and repeates the random
parameters from request
(GSM48 IMM ASS (ra=0x0f, chan_nr=0x49, ARFCN=667, TS=1, SS=1, TSC=5))

Greetings

Stefan




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