If this is the initial attachment in the new PLAN, then the SIGNS shall communicate with the HAL in the Home PLAN. At this point the user is validated as to whether they are allowed to roam or not. If the user is allowed to roam, then the VASS shall confirm this to the MS. Once the user is attached, then MO and MAT SMS transfer can take place. The user can then decide to perform a “PDP Context Activation”. This procedure, together with the data sent by the MS and the subscribed data stored in the SIGNS, ill determine which “roaming scenario” the user will activate.
This will be explained in detail in subsequent text. AIRY version 3. 1. 0 page 5 of 15 Once the “PDP context” is activated, then GAPS data transfer can commence. This is detailed in GSM 03. 60 . The mandatory “PDP type” in the roaming environment will be ‘P. (I. E. Not X. 25 or APP) 2. Roaming Scenarios 2. 1 . Scenario 1 – MS registered on PLAN using VASS and HIGHS This scenario applies to: – inbound roamers outbound roamers visited network – the VASS. The user shall then activate a context using a SIGNS in their home network – the HIGHS.
There will be data and signaling exchanges across the Inter PLAN Backbone in order to establish the context (Gap Interface required. ) To allow networking via Gap interface between foreign Plans having different GUNS suppliers, it is necessary to agree on compliance to a certain level of GSM specifications. As a baseline, roaming operators shall conform to GAPS Release 97 level SMOG#29 or higher. This scenario is shown in Figure 2, and requires: – ASSN – HAL interactions via the Gar interface, using Inter network CA/SCUP links Inter network DNS exchanges and possible “. Pros root” DNS exchanges.