1. Towards a harmonised Tispan Subscription model TISPAN WG8 – 3GPP SA#5 Joint meeting Sophia Antipolis, May14th - 15 th 2007. Source: Steve Orobec BT

2. © British Telecommunications plc Contents The Challenge – part 1 The Challenge – part 2 TISPAN Problem Space Bringing it together Result Summary

3. © British Telecommunications plc The Challenge – part 1 3GPP’s fine for the management of mobile networks but is not rich enough to cater for next generation networks (NGN’s) The challenge is to capture the useful aspects of 3GPP with NGN needs –Agree consensus with both Tispan AND 3GPP –Protect existing investment in 3GPP –To create a whole new SOA architecture model for the management of NGN services –Do this in an agile way such that it reduces integration barriers –Can be Implemented in current industry standard tools along with industry best practice leverage the work of W3C, OASIS and OMG –Harmonise with other strategic standards e.g. TMF SID & MTOSI

4. © British Telecommunications plc The Challenge – part 2 Service providers are looking to structure their OSS around TMF SID, MTOP & eTOM. Service providers are looking for a solution to fixed- mobile convergence and to develop value add services To do this we need a SOA model with a contract API between OSS e.g. CRM, Service BSS and IMS –This implies standard operations defined and understood on both sides - verbs –Data binding objects, which are defined and understood by both sides – nouns –A method to integrate these data binding objects into the existing models at either side of the interface

5. © British Telecommunications plc 3GPP Observations Multiple-Inheritance (Use of Top as root class): implementable in C++, requires use of workarounds in Java and C# and not supported in XML Schema. Cyclical dependency (Class A depends on Class B and vice-versa) – Far too many associations, reduce the number by applying ‘Law of Demeter’ i.e. each class talks only to it’s neighbour. Each association is an attribute in a class, each m-n relation is a list Not aligned with eTOM 3GPP Model uses UML 1.5 –This UML is obsolete and non standard – current version is 2.1 –Tolls supporting UML 1.5 like Rational Rose no longer exist – I can’t buy it!

6. © British Telecommunications plc TISPAN Problem Space Problem is that the 3GPP model is different architecturally from the TMF model that BT and many OSS vendors are adopting and IMS will need to integrate with Implementation detail not clear to outside integrator – e.g. ME! Current TISPAN documents are only high level. E.g. Powerpoint 3GPP has a concept of an IMS but it is limited in scope –Limited support for Subscriber & multiple Users using different access technologies such as DSL and Mobile –Inheritance hierarchy problematic e.g. Service ‘is-a’ Managed Element –Inconsistent use of eTOM layered architecture It’s too tightly coupled – TISPAN vision is a distributed, loose coupled SOA –Each association or aggregation increases coupling –Re-structure according to Law of Demeter

7. © British Telecommunications plc Bringing it together BT vision is the creation of a ‘master’ TISPAN model in OMG UML 2.x which is line with use of Industry trends taking the best of 3GPP – this should be derivable from the TISPAN model The short term goal is to take the best of both models along with the TMF SID Using an Agile development driven approach develop a prototype constructed from a hybrid 3GPP-TISPAN UML model to validate ideas This will allow certain concepts to be proven plus technical issues with the models to be discovered and resolved As an added bonus – it deepens the model understanding!

8. © British Telecommunications plc Summary Move the TISPAN model debate away from high level discussion to hands on UML development Promotion of UML 2.x as the technology neutral descriptive language, this supports the use of meta-models to describe SOA contracts plus automatic generation of technology specific models e.g. Java, C++, IDL etc Goal is to have TISPAN as the technology neutral and overarching model and generate the 3GPP model as a subset – possibly in C++, alternatively to generate a full Java solution for NGN. Further goal is harmonisation with TMF – initially by mapping but in the long term by defining a multi standard meta-model from which others can be derived Use of tools such as Borland/IBM allow for rapid prototype generation to test ideas and challenge existing dogma New models and ideas can be trialed – currently prototyping SID OSS to IMS interaction – the results of which will feed back to both TISPAN and TMF Agile UML modeling offers future promise of harmonising all our Business OSS models under a single meta-model, with the ability to generate artefacts such as Java, WSDL directly from the UML