AW: status layer 3

Andreas.Eversberg Andreas.Eversberg at versatel.de
Mon Mar 8 18:26:01 UTC 2010


 
> L3 sends RSL RLL ESTABLISH REQUEST with LOC UPD REQ as L3_INFO
> L2 converts this in SABM with LOC UPD REQ as payload
> L1 sends the packet to the GSM network
> L1 receives response from the GSM network
> L2 generates RSL RLL ESTABLISH CONFIRM to L3

hi,

just to see if i understand it right, here is my view of how it should
work:

(for reference, see Fig. A.4 in GSM 04.07 in the appendix A.)

mobility management layer requires to send an location update, so it
does the following things happen:

- a msgb is created with payload, large enough for LOC UPD REQ, and a
headroom to encapsulate it into other messages...
- LOC UPD REQ is assembled by mobility management layer
- the msbg is "pushed" to add radio ressource header in front of it
- the radio ressource primitive RR EST REQ is written to radio ressource
header
- the msgb is now transferred using a function call to radio ressource
layer
- the radio ressource routes the message according to the state and the
primitive to the appropiate handler of this message. (state machine)
- there the msgb is "pulled" to remove that header
- the handler of "RR EST REQ message in IDLE mode" stores the msbg until
an IMM ASS is received, and starts channel request procedure...
...
- when handling the IMM ASS, the radio ressource layer takes the stored
msgb and pushes the RSL RLL header in front of it
- the RSL RLL header gets informations about channel to establish, and
the RSL EST REQ primitive is set
- the msgb is sent down from radio ressource layer to layer 2, in this
case the RSLms layer, using a function call.
(RSL EST REQ represents the DL-ESTABLISH REQUEST primitive)

while the message is walking from radio ressource layer down to layer 1,
the primitives for inter-layer communication are added by the sending
layer and removed by the receiving layer.

is this procedure correct? (of course, more things are done at radio
ressource and mobility management layers in the procedure above, but i
just wanted to explain what happens to the msgb.

regards,

andreas
 




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