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Kalogiros- Woice - - a Decentralized System for Ubiquitous VoIP Services
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Kalogiros- Woice - - a Decentralized System for Ubiquitous VoIP Services


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  • 1. WOICE - a Decentralized System for Ubiquitous VoIP Services Authors: Costas Kalogiros Costas Courcoubetis Panayotis Antoniadis
  • 2. Motivation
    • ‘ Voice is just another Internet application’
      • Multiple end-user identifiers at the same time
        • End-devices with multiple network interfaces
    • VoIP can be an antidote for ‘monopoly termination’ problem, but:
      • ubiquitous access to Internet is required
      • interconnection agreements must be promoted
  • 3. WOICE (Wireless vOICE)
    • A distributed system supporting ubiquitous VoIP services over WiFi networks
      • Flexible marketplace
        • Business opportunities for all participants
        • Semi-automated contract management
      • VoIP-peering accommodation
        • Community spirit establishment
        • Mapping system for end-user identifiers
          • Telephone number ↔ SIP address
  • 4. WOICE entities
    • WOICE WISPs : Hot-Spot owners setting the access network over which WOICE services can be provided to end-users by third parties.
    • WOICE ITSPs : ITSPs that use WOICE modules for offering and supporting VoIP services to their subscribers.
    • WOICE Aggregators : WOICE ITSPs that also set up bilateral agreements with WOICE WISPs.
    • Traditional providers : PSTN, cellular and VoIP providers being interconnected to WOICE.
    • End-users : Regular Hot-Spot users (like employees) or visitors that own dual WiFi/cellular handsets.
  • 5. WOICE network scenario
  • 6. WOICE service scenario
    • WOICE WISP collects mobile number of “User A” and assigns a temporary SIP address
    • WOICE WISP informs WOICE Aggregator about the new mapping
    • WOICE Aggregator advertises this mapping to WOICE network
    • “ User B” calls “User A” on her traditional mobile phone number
    • WOICE ITSP of “User B” routes the call to the temporary SIP address of “User A”
    • WOICE ITSP and WOICE Aggregator exchange accounting information
    • End-to-end VoIP call is being performed
    • WOICE ITSP and WOICE Aggregator rate each other and values are stored in WOICE network
    WOICE Aggregator F WOICE ITSP WOICE WISP Rest WOICE network User B User A
  • 7. WOICE modules (1/2)
    • Contract life-cycle management
      • Contract terms negotiation
    • Call routing information management
      • Collection of authenticated reachable numbers
      • Propagation of/search for supported numbers
    • Call management
      • … especially call routing & setup
    • Accounting :
      • Transaction tracking
  • 8. Contract terms negotiation
  • 9. Collection of authenticated reachable numbers
  • 10. WOICE modules (2/2)
    • Reputation mechanism
      • Distributed mechanism for storing a measure of participant’s aggregated behaviour
    • System rules
      • Distributed configuration of system parameters
    • Group membership:
      • Join/leave/expel procedures
      • Distributed partner search
  • 11. Non-peer Interoperation
  • 12. Peer Interoperation
  • 13. WOICE impact (1/2)
      • Core business becomes more attractive
      • New potential revenue streams
    • WOICE Aggregators, WOICE ITSPs
      • Advanced VoIP services roll-out
      • Lower termination costs
  • 14. WOICE impact (2/2)
    • Traditional providers
      • Lower termination costs
      • Higher competition from ITSPs
    • End users
      • Availability of advanced VoIP services
      • Lower charges due to increased competition
    • Regulators
      • Less need for ex-ante regulation
  • 15. Summary
    • WOICE is a collaborative marketplace allowing participants to implement a wide range of business models.
    • Sufficient levels of trust will be built through carefully designed incentive mechanisms.
    • “ Plug and play” functionality for effortless participation
  • 16. Thank you for your attention! Questions?