1)What is exchanged between VLR_HLR on D interface i.e MAP-D?
2)In 3G networks there is absence of Gs interface between SGSN and MSC allowing simultaneous circuit switching voice call and GPRS.However in 2G this is not allowed.Could anybody let me know the the signalling procedures enhance in 3G agains 2G which does not support simultaneous voice/data calls?
Regards
Ranjeet
1) Lots of MAP messages are used to pass info between HLR and VLR over D interface.
Example:
MAP_UPDATE_LOCATION ---- used by VLR to update the location information in
the HLR.
MAP_CANCEL_LOCATION ----- Used by HLR to delete a subscriber info.
MAP_SEND_AUTH_INFO ----- Used by VLR to reterive authentication information
from HLR.
MAP_PROVIDE_ROAMING_NUM --- Used by HLR to provide roaming no from VLR to
route incoming call.
MAP_RESTORE_DATA
MAP_READY_FOR_SM
MAP_PURGE_MS
MAP_ERASE_SS
MAP_REGISTER_SS
MAP_ACTIVATE_SS
You can find details of these MAP messages in 29.002 spec.
2) The function SGSN in PS domain and MSC/VLR in CS domain are somewhat similar.
Ex: Both MSC/VLR and SGSN handle IMSI attach/detach but for diffrent domain.
It is possible to combine the functionality of both to save radio resources using o ptional Gs interface.
Thanks for the MAP message information . I wonder if you could throw some light or suggest some reference on Radio Control Points in VLR with reference to the information fetched by VRL from HLR.