Charging and QoS Aspects for Service Outsourcing in Inter-Domain IMS Frameworks Candidate: Vitalis G. Ozianyi Supervisor:Neco Ventura Electrical Engineering University of Cape Town South Africa

Introduction Next Generation Networks (NGN) are characterized by wireless overlaps (WO) Ubiquitous mobile computing required in NGN Handoff decisions are mainly influenced by signal strength and network congestion To achieve price-influenced ubiquitous mobile computing

Objectives Maintain the same (predictable) charge for the user Analyze financial implications of service outsourcing Facilitate pricing in NGN for the success of the IMS

Service Outsourcing Basics Provide services to users over a federated operator network Home network experiencing congestion Session QoS negotiated based on offer price Several operators bid for outsourced service UE directed to attach to specific network

Related Work Roaming – higher and unpredictable charges Dependent of signal strength and network congestion Some recent work investigates user profiles and other context information for handover decisions

Useful Definitions Custodian network (home network) – Holds user subscriptions Candidate network (visited network) – Federated to custodian IMS registration and session setup Network capacity and congestion Service request blocking Service outsourcing negotiations between custodian and candidate network – –QoS and outsource offer price Handover to candidate network X Session re-establishment: – –Update registration – –Re-invite – –Start/resume media flow

Conditions and Requirements Custodian network (N1) and candidate network (N2) would be federated Access networks AN1 and AN2 are reachable by UE (Overlapping) N2 can meet QoS requirements for the session

Financial Requirements User Pricing function – satisfaction influenced by SLA Network price functions – profit maximization Local resources in an Access Domain (Fixed capacity over medium time frames) – sold to users Inter-domain resources (Less resources for off- peak times) – bought in blocks from ISP; price controlled by ISP Utility function Cost function Satisfaction Revenue Expenditure Profit users sessions Time-frame

Financial Conditions Time Frame No. of Resourc e blocks Congestion charge factor Profitable no. of users No. of reque sts Outsourced requests 0-30 min hr h30 min h30-2hr Profitability for custodian network: PN > 0 Revenue from user payments Cost of 1 st block Cost of subsequent blocks Net Revenue

Financial Conditions Extra block to service one user session – not profitable (More radio spectrum in AN) Outsource new request to candidate network Share user payments with candidate operator Select cheapest candidate network in multi-operator scenarios

Outsourcing Triggers and Benefits Triggers –Unserviceable requests from UE on AN1 –N1 wants to admit high profile requests on AN1 – outsource of low profile requests Benefits –Ubiquitous service delivery to users – enhanced satisfaction –Retention of subscriptions – important for advertisement and AAA revenue in IMS

Financial Implications Extra revenue due to outsourcing P Σ > P N Net Revenue Outsource revenue

Deliverables Extend the UCT IMS client to support and service outsourcing Extend the Fokus OSIMS Core to support service outsourcing Questions and Suggestions are Welcome…!

Next Steps Implement charging in OSIMS Develop outsource messaging for IMS Outsource signaling optimization through aggregated outsourcing

Published Work Integrating pricing profiles in NGN – Elsevier journal paper –Use of the platinum, gold and silver pricing profiles to influence selection of access network Virtual network capacity expansion – WCNC 2008 paper –Definition of generic user and network pricing functions for service outsourcing Service outsourcing to support virtual home environments – LCN-P2MNet Route selection impacts on achieving IMS QoS – SATNAC 2008