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The User Data Convergence (UDC) concept separates user data storage from the application logic in the 3GPP system, allowing remote access to profile data. This article discusses the UDC architecture, functional entities, and main characteristics of the User Data Repository (UDR) and Application Front-Ends (FEs).
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User Data ConvergenceCT4 specificationsJean-Jacques Trottin October 2009
User Data Convergence (UDC) Scope • From 3GPP Requirements : • "The User Data Convergence concept supports a layered architecture, separating the user datastorage from the application logic in the 3GPP system, • so that user data is stored in a logically unique repository (UDR) allowing access from core and service layer entities, named application front-ends. • Network elements and functionalities should be designed to access profile data remotely and without storing them permanently locally, i.e. the front-ends (FEs) shall work in a subscriber dataless configuration." UDC can apply to • HLR/HSS • Application servers • ANDSF • …..
TS 23.335 Stage 2 UDC architecture • UDC Functional entities • UDR : User Data repository • Front end (FE): executing the application logic • One reference point : Ud between UDR and Front ends e.g. HLR/HSS FE e.g. provisioning application FE e.g. 3td party application FE
TS 23.335 Stage 2 User Data Repository main characteristics • UDR is a single logical repository from FE perspective • a FE has only access to data relevant for it (application data view) • UDR may interact with several Application front ends • handling the same application logic or different application logics • Internal structure of UDR out of standardization scope • may be distributed over different locations or centralized, • may support geographical redundancy, replication mechanisms and back up functions to secure the storage of data • FE (and Ud interface) not aware of this internal structure • UDR supports transactions (Database meaning) • ACID (atomicity, consistency, isolation, durability) features
TS 23.335 Stage 2 Application front-end (FE) main characteristics • An Application FE executes an application logic • dealing with user data that are stored in the UDR • E.g. HLR/ HSS application logic, AS application logic • An application front-end interacts with other functional entities of the 3GPP system through existing 3GPP reference points • Those existing reference points (C, Cx, Sh, S6a…) shall not be modified by the introduction of the UDC concept • An application front-end may belong to a third party: • Application FEs which are equivalent may be grouped into a FE Cluster • Allowing distribution of requests
TS 23.335 Stage 2 UDC information flows • Generic information flow: • Data access + notification
FE UDR 1. Query data request 2. Perform access control 3. Fetch data value and format it according to the requesting application data view 4. Query data answer TS 23.335 Stage 2 UDC information flows • Ud is a Database access interface • Query, Create, Delete, Update procedures • Plus Subscription to notifications, notifications • Ud Query Procedure • Parameters • FE Identifier • user identity (e.g. IMSI, MSISDN, IMPU, IMPI • identification of the data (request) • data value (answer) (according to application data view)
TS 23.335 Stage 2Access Control • Access Control by UDR: it is based on • FE identity • FE Application type: FE can only access to data associated to a given application (application data view) • Type of procedure (Query, Update….) authorized • Authentication and Security aspects to be handled with SA3 • To be addressed
TS 29.335 UDC Stage 3 • Working assumption CT4 agreed (at previous CT4) • To use LDAP for Ud Query, Create, Delete, Update procedures • Ud Query -> LDAP Search • Ud Create -> LDAP Add • Ud Delete -> LDAP Delete • Ud Update -> LDAP Modify • Still a debate about Subscription/Notifications between • LDAP : that has limitations, so requiring extensions • Another protocol: SOAP / XML • To be decided in next CT4 (November) • Application data view -> LDAP Schema (SA5) • LDAP is Directory oriented data architecture • Tree /Subtrees • Naming aspects
ANDSF case • ANDSF (Access Network Discovery and Selection Function) • Simple example of an application that needs to read some HSS data • Eg list of access networks or their types a user can access • Methodology aspect : who is doing what? • Definition of the relevant data : SA2, CT1, CT4 • Modelling (application data view ) : SA5 • Pending points Are these data and associated application data view to be standardised? In rel9, rel10? • LS from CT4 to CT1
Time Schedule • CT4 meetings : • Nov 9th – 13th • Feb 22nd – 27th • Exception procedures for Rel9 up to March 2010 • Mainly on stage 3 • Authentication security aspects