Smart Caching in Mobile IP enabled Networks
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Transcript of Smart Caching in Mobile IP enabled Networks
Stephan Goebbels, ComNets, RWTH Aachen University
Smart Caching in Mobile IP enabled Networks
Stephan Göbbels
Chair of Communication Networks RWTH Aachen University, Germany
13. ComNets-Workshop, Mobil- und TelekommunikationMarch 31st, 2006, Aachen, Germany
13. ComNets-Workshop 200613. ComNets-Workshop 2006
2Stephan Goebbels, ComNets, RWTH Aachen University
• Motivation and Introduction• The Smart Caching Approach• System Concept• Simulation
– Scenario– Results
• Conclusion and Outlook
OverviewOverviewOverview – Introduction – Smart Caching – Simulation - Outlook
3Stephan Goebbels, ComNets, RWTH Aachen University
• 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
MotivationMotivationOverview – Introduction – Smart Caching – Simulation - Outlook
4Stephan Goebbels, ComNets, RWTH Aachen University
• 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
IP world
GPRS
CMP MAP
Server
Backbone
AggregationLevel
AggregationRouter
RadioLevelWLAN
IntroductionIntroductionOverview – Introduction – Smart Caching – Simulation - Outlook
5Stephan Goebbels, ComNets, RWTH Aachen University
• 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 ApproachThe Smart Caching ApproachOverview – Introduction – Smart Caching – Simulation - Outlook
6Stephan Goebbels, ComNets, RWTH Aachen University
• 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 ConceptSystem ConceptOverview – Introduction – Smart Caching – Simulation - Outlook
Server Caching Client Caching Server Client
Data request
Sending data
… Caching…Data forward
Packet request
Ack
Packet request
…
No ack
Stop
deliveryLocation update
Packet request
…
Data forward
7Stephan Goebbels, ComNets, RWTH Aachen University
...160m0m 1440m
AP1 AP2 AP10
d
IP world
CMP / MAP
Simulation ScenarioSimulation ScenarioOverview – Introduction – Smart Caching – Simulation - Outlook
• Applied service: Video streaming (400 kbit/s)• CMP and MAP are collocated in one gateway node• 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
8Stephan Goebbels, ComNets, RWTH Aachen University
0 50 100 150 200 250 300 350 400 450 5000
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Location [m]
Cu
rre
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hro
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kbit/
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Throughput
Coverage
Simulation ResultsSimulation ResultsOverview – Introduction – Smart Caching – Simulation - Outlook
• Currently perceived user throughput
• Optimization of wireless link utilization
• Increased throughput after first coverage gap
• Note: – Session recovery
delay– Full utilization of
wireless link
9Stephan Goebbels, ComNets, RWTH Aachen University
Simulation ResultsSimulation ResultsOverview – Introduction – Smart Caching – Simulation - Outlook
• 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)
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Reference
maximum Throughput
average Throughput
10Stephan Goebbels, ComNets, RWTH Aachen University
0 500 1000 15000
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Simulation ResultsSimulation ResultsOverview – Introduction – Smart Caching – Simulation - Outlook
• Decreasingperformance with sinking coverage ratio
• But: Improvement ifcompared to reference level
• Difference between full utilization and partial utilization (25% coverage is lower limit)
• Below 25% only partial improvement (buffer overflow)
11Stephan Goebbels, ComNets, RWTH Aachen University
Simulation ResultsSimulation ResultsOverview – Introduction – Smart Caching – Simulation - Outlook
• 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
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Caching 50%
Reference 50%
Caching 30%
Reference 30%
12Stephan Goebbels, ComNets, RWTH Aachen University
Conclusion and OutlookConclusion and OutlookOverview – Introduction – Smart Caching – Simulation - Outlook
• 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
13Stephan Goebbels, ComNets, RWTH Aachen University
Thank you for your attention !
Stephan Gö[email protected]
Any questions?