Smart Caching in Mobile IP enabled Networks

1. 13. ComNets-Workshop 2006 Smart Caching in Mobile IP enabled Networks Stephan Göbbels Chair of Communication Networks RWTH Aachen University, Germany 13. ComNets-Workshop, Mobil- und Telekommunikation March 31st, 2006, Aachen, Germany

2. Overview Overview– Introduction – Smart Caching – Simulation - Outlook • Motivation and Introduction • The Smart Caching Approach • System Concept • Simulation • Scenario • Results • Conclusion and Outlook

3. Strong development towards All-IP networks Heterogeneous network structure Combination of wired and wireless networks Ambient Networks Integration of various wireless networks Always Best Connected Intersystem handovers Different performance characteristics of involved communication technologies Maximum and average throughput Packet delay and latency QoS … Goal: Improve user satisfaction and network performance New upcoming services Video on Demand Online VCR IPTV Motivation Overview– Introduction – Smart Caching – Simulation - Outlook

4. Aggregation of mobile communication networks Integration of buffer on aggregation level Closest point between IP gateways (SGSN, gateway router, …) Smart Caching: Caching Media Port (CMP) Decoupling of backbone and radio subsection of the end-to-end connection Optimal utilization of available wireless bandwidth Virtually continuous broadband connection (for non real-time services) Hierarchical Mobile IP shows similar structure to Smart Caching Integration of Mobility Anchor Point (MAP) and CMP Introduction Overview– Introduction – Smart Caching – Simulation - Outlook

5. Aggregation of discontinuous high bandwidth wireless links (WiFi) and continuous basic coverage (Cellular networks – GPRS/UMTS) Idea: Buffer data if wireless link is overloaded Forward data if radio bandwidth is available on top of current traffic Full utilization of wireless link – maximum throughput Store enough data at the end device in order to bridge idle gaps and pretend a continuous service Buffered video data Cached WWW sites … CMP between SGSN and WLAN Gateway router Integration with Mobile IP Micro mobility by MAP and Macro mobility by Home Agent MAP can trigger data delivery of CMP MAP switched => new CMP The Smart Caching Approach Overview– Introduction – Smart Caching – Simulation - Outlook

6. Caching node (CMP): Client entity to communicate with service provider Server entity to forward traffic to end device Continuous traffic on first hop Major part of control traffic only on second hop Better performance of communication (TCP, ARQ,…) and session management protocols Location update triggers data delivery System Concept Overview– Introduction – Smart Caching – Simulation - Outlook

7. Applied service: Video streaming (400 kbit/s) CMP and MAP are collocated in one gateway node Simulation Scenario Overview– Introduction – Smart Caching – Simulation - Outlook • Heterogeneous network structure by only partial coverage of 10 WLAN Access Points (802.11b – 11 Mbit/s) • Varying coverage ratio (10 – 75%) • Consummation rate 300 kbit/s • Legacy network technology for reference reasons

8. Currently perceived user throughput Optimization of wireless link utilization Increased throughput after first coverage gap Simulation Results Overview– Introduction – Smart Caching – Simulation - Outlook • Note: • Session recovery delay • Full utilization of wireless link

9. Average throughput for long-term session Increase of average throughput Comes close to the maximum reachable throughput Doubles Throughput in 50% coverage scenario Effect is amplified if coverage ratio decreases (as long as coverage zones are not fully utilized) Simulation Results Overview– Introduction – Smart Caching – Simulation - Outlook

10. Decreasing performance with sinking coverage ratio But: Improvement if compared to reference level Difference between full utilization and partial utilization (25% coverage is lower limit) Below 25% only partial improvement (buffer overflow) Simulation Results Overview– Introduction – Smart Caching – Simulation - Outlook

11. Fill level of user equipment buffer Decides whether an virtual continuous service can be provided. In reference scenario usually not possible Even 30% network coverage is almost enough In 50% case an overspending of resources Simulation Results Overview– Introduction – Smart Caching – Simulation - Outlook

12. Integration towards ALL-IP networks will cause several problems for service provisioning Smart Caching is suitable protocol to enhance network performance in new heterogeneous network structures Support of mostly unidirectional services Allows prefetching of user data Benefits from integration of Hierarchical Mobile IP and Smart Caching Virtual continuous broadband connection in patchy coverage areas (suitable for video services like IPTV) Future improvements: Stronger integration of Mobile IP and Smart Caching protocol Combined GPRS – WLAN scenario Switching of MAP/CMP Conclusion and Outlook Overview– Introduction – Smart Caching – Simulation - Outlook

13. Thank you for your attention ! Stephan Göbbels sgs@comnets.rwth-aachen.de Any questions?