Networklayer mobility in wireless ad hoc access networks

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Network-layer mobility in wireless ad hoc access
networks

• Robert Brännström

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Outline of the presentation

• Project goal and focus
• Research issues
• Background
• Publications and contribution
• Outcomes
• Conclusions and future work

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Overall project goal

• To improve the efficiency of wireless Internet
  access for roaming users

Current focus

• The thesis work focuses on network-layer mobility
  and connectivity of wireless multi-hop ad hoc
  networks to the Internet

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Scenario
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Research issues

• Network-layer metrics
• - Evaluation of gateway selection and handover
  decisions
• Multihomed global connectivity
• - How to deploy Multihomed Mobile IP in MANETs
• Gateway connectivity in global connectivity
  networks
• - How to maintain gateway connectivity
• Destination locality in global connectivity
  networks
• - How to decide locality

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Introduction - Wireless Internet access

• Wireless access could be provided by many
  different network types with different coverage
  and capacity
• Access networks to wired All IP backbone
• Heterogeneous access network

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Introduction - Mobile Ad hoc Networks (MANET)

• Global connectivity network, gateway bridging
  routing differences
• Multi-hop network, direct peer-to-peer
  communication
• Ad hoc routing, hop count
• Extended service area

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Introduction - Mobility

• Addressing and routing problem - dual meaning of
  IP address
• Identifier for endpoint and location
• User mobility migrate sessions
• Network mobility switch network attachment

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Introduction - Mobile IP

• Provides network-layer mobility
• FA advertise its service on the foreign network
• MH registration with HA through FA
• Tunneling between HA and FA

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Background - network-layer metrics (WLAN)

• Overlapping service areas
• Gateway selection
• Current solution SNR
• Problem High SNR ? high throughput

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Background - network-layer metrics (ad hoc)

• Ad hoc routing
• Current solution Hop count
• Problem Lower hop count ? higher throughput

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Background - network-layer metrics

• Mobile IP agent advertisements sent with discrete
  intervals from FA
• Mobile Host measures variance in arrival time
• Running Variance Metric (RVM)
• Include RTT to HA gt Relative Network-layer Load
  (RNL)

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Background - network-layer metrics

• Related work challenging discrete models
• - Statistical modeling of ad hoc links
• - Stable links
• - Load balancing
• - Join procedure

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Background - multihomed global connectivity

• Gateway implements MIP foreign agent
• MIP needs to be adapted for the multi-hop
  environment
• Ad hoc networking enables connectivity to more
  than one gateway at a time
• M-MIP enables multiple registrations

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Background - multihomed global connectivity

• Just rebroadcast advertisements?
• Forwarding condition needed

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Background gateway connectivity

• Internet traffic gtgt local traffic
• Mobile hosts roaming around, keeping sessions
  active
• Importance of maintaining gateway connectivity

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Background destination locality

• Ad hoc routing protocol proactively or on-demand
  finds the route to a destination.
• Proactive discovery gives high overhead
• On demand discovery gives high latency

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Background destination locality

• Related work
• - Reactive destination discovery
• - Advertisements solicitation
• - Single hop prefix matching

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Publications road map
Running Variance Metric for evaluating
performance of Wireless IP Networks in the
MobileCity Testbed (Chapter 4)
Agent Selection Strategies in Wireless Networks
with Multihomed Mobile IP
M-MIP extended Mobile IP to maintain multiple
connections to overlapping wireless access
networks (Chapter 5)
Maintaining Gateway Connectivity in multi-hop Ad
hoc Networks (Chapter 6)
Implementing multi-hop ac hoc Internet access in
the MobileCity testbed (Chapter 7)
Mobility Management for multiple diverse
applications in heterogeneous wireless networks
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Publications and contribution

• C. Åhlund, R. Brännström, and A. Zaslavsky.
• Agent Selection Strategies in Wireless Networks
  with Multihomed Mobile IP
• In Proceedings of The First International
  Workshop on Service Assurance with Partial and
  Intermittent Resources ( SAPIR 2004 ). August
  2004, Fortaleza, Brazil.
• C. Åhlund, R. Brännström, and A. Zaslavsky.
• Running Variance Metric for evaluating
  performance of Wireless IP Networks in the
  MobileCity Testbed.
• In Proceedings of The First International
  Conference on Testbeds and Research
  Infrastructures for the DEvelopment of NeTworks
  and COMmunities (Tridentcom 2005). February
  2005, Trento, Italy.
• C. Åhlund, R. Brännström, and A. Zaslavsky.
• M-MIP extended Mobile IP to maintain multiple
  connections to overlapping wireless access
  networks.
• In Proceedings of the 4th International
  Conference on Networking (ICN 2005). April 2005,
  Reunion Island, France.

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Publications and contribution

• R. Brännström, C. Åhlund, and A. Zaslavsky.
• Maintaining Gateway Connectivity in multi-hop Ad
  hoc Networks.
• In Proceedings of the Fifth International IEEE
  Workshop on Wireless Local Networks (WLN 2005).
  November 2005, Sidney, Australia.
• R. Brännström, R. Kodikara E, C. Åhlund, and A.
  Zaslavsky.
• Implementing Global Connectivity and Mobility
  support in a Wireless multi-hop ad hoc Network.
• To appear in Proceedings of the 4th Asian
  International Mobile Computing Conference (AMOC
  2006). January 2006, Kolkata, India.
• R. Brännström, R. Kodikara E, C. Åhlund, and A.
  Zaslavsky.
• Mobility Management for multiple diverse
  applications in heterogeneous wireless networks.
• To appear in Proceedings of the IEEE Consumer
  Communications and Networking Conference (CCNC
  2006). January 2006, Las Vegas, USA.

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Implementation - network-layer metrics

• Evaluation of RNL compared to SNR
• Evaluation of RNL compared to hop count
• Implementation in
• GloMoSim 2.0

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Implementation - network-layer metrics

• Confirming results with prototype
• Implemented in C on Linux

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Results - network-layer metrics

• Real-world

• Simulator
• Enables the mobile host to select the gateway
  with best performance

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Implementation - multihomed global connectivity

• Gateway implements Mobile IP foreign agent
• One agent advertisement - RVM
• M-MIP Registration
• Default gateway

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Implementation - multihomed global connectivity

• M-MIP over AODV including RVM and RNL
• Simulator implementation (GloMoSim)
• Implementation in Linux
• - Hooks into protocol stack
• - Routing table manipulation
• - Gateway IPC - MIP and AODV

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Results - multihomed global connectivity

• Updated information - select the best gateway
• Old registrations soft state
• Multiple registered FAs enables soft handover

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Implementation - gateway maintenance

• Mobile IP over AODV
• MH install routes based on agent advertisement
  broadcast
• - Uplink neighbors (previous hop)
• - Gateway (via best previous hop, RVM)
• Creates a tree structure
• Reverse route from MIP registration request

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Results - gateway maintenance

• Routes to gateways proactive
• Routes discovery delays avoided

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Implementation - destination locality

• Combines reactive and proactive approaches
• Prefix matching with default gateway (known by
  advertisements)
• Match gt RREQ.
• Mismatch gtTunnel to GW
• Mobility adds complexity
• RREQ
• - Host respond with RREP
• - Gateway respond with Proxy RREP for away
  hosts
• Tunnel to default GW
• - Gateway forward packet to Internet destination
• - Gateway respond with ICMP redirect for
  visiting hosts

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Results - destination locality

• Avoids route request delay (on demand routing)
• Uses established links to gateways (Tunneling)
• Uses gateway knowledge (Mobile IP)

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Outcomes

• An analysis of gateway selection and handover
  decision based on network-layer metrics. The
  analysis is carried out for both single-hop and
  multi-hop networks
• A deployment proposal of multihomed Mobile IP in
  global connectivity networks with an enhanced
  interconnection with the reactive routing
  protocol AODV
• A proposal to maintenance of gateway connectivity
  in global connectivity networks based on Mobile
  IP messages
• A destination locality decision strategy for
  mobile hosts in global connectivity networks
  based on advertised information and foreign agent
  knowledge.

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Prototypes

• Global Connectivity

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Prototypes

• Multihomed Mobile IP (WLAN and GPRS/UMTS)

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Conclusions

• Mobile IP
• Network layer
• Fast mobility detection
• Deployment MIPv4
• Ad hoc
• Extended service area, multiple gateways
• Ad hoc routing, radio channel
• Gateways

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PhD plans

• PhD Polis project, collaboration with Monash
  University
• Two years to PhD
• Mobility support in heterogeneous access networks
• Mobility support system
• Combining MIP and SIP
• Cross layer mobility detection
• Mobility adoption of multimedia
• Ongoing work, one publication within Polis
  project
• Target
• 1-2 conference publications
• 1 journal publication in a year

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PhD plans

• Heterogeneous access
• Cross layer context awareness, Ruwini (MU)
  Polis project
• Communication between moving vehicles
• Vertical handover
• Using multiple access networks
• Ongoing work within Polis project
• Target
• 1-2 conference publications
• 1 journal publication in two years

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Thank you! lt/presentationgt