Transcript Mobile IP

Seamless Handover in Terrestrial
Radio Access Networks:
A Case Study
第5組 彭瑱瑞
李政穎
陳冠男
郝晉杰
Outline
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Motivation
Mobile IP
Mobile IP in WLAN-GPRS environment
Interworking between mIP and GPRS
entities
Simulation
Conclusion
Motivation
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An ever-increasing traffic flows over wireless
network
Existed wireless technology
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WLAN, Bluetooth, GPRS, ….
Two of largest deployed packet-switch technology
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802.11 (WLANs)
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High bandwidth, covers small areas
GPRS (WWANs)
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Low bandwidth, covers large areas
Motivation (cont.)
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Compare between various wireless technology
Motivation (cont.)
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Roaming between GPRS/WLAN
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Interface change
IP Address change
Upper layer application (TCP/UDP) disconnect
How to
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Vertical Handovers with Mobile IP
Mobile IP
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Component
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MN
HA
FA
Operation
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Agent Discovery
Registration
Tunneling
Mobile IP (cont.)
Vertical Handovers with mIP
Vertical Handovers with mIP (cont.)
Vertical Handovers with mIP (cont.)
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Vertical handover vs Mobile IP
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Vertical handover
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The mobile node registers its new location while it is still
connected through its old access interface
Datagrams buffered into the old network that old interface can
still reach
Very efficient in terms of datagram loss
Mobile IP
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Handover occurs delay and data loss between different IP
networks but over the same interface
Requires additional mechanisms to reduce delay and data loss
Target Usage Scenario
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Foreign Agent
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Help MN detect movement
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Broadcast periodic advertisements and respond to solicitation
message
Two scenarios
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Foreign agent lend its IP address as CoA to MN
MN can detect movement through other means and
acquire an IP address by itself
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DHCP, PPP
Target Usage Scenario (cont.)
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Another case
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MH allocated in private IP address
Datagram traffic to and from the private CoA is
transported over the Internet through IP-in-IP tunnels
established between public endpoints
Interaction between MH and GPRS
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Interaction between MH
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Emulate laptop and GPRS handset as a PPP connection
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To get IP address
PPP phase
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LCP (Link Control Protocol)
PAP (Password Authentication Protocol)
IPCP (Internet Protocol Control Protocol)
Foreign agent discovery
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Standard ICMP router discovery cannot be employed
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Different protocol stack between IP Network and GPRS
long-haul message
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Derives from standard ICMP message
Unicast message
Interaction between MH and GPRS
TE
MT
GGSN
Radius
Server
FA
LCP negotiation
PCP negotiation
PDP context activation
Radius authorization
FA notification
Long-haul unicast agent advertisement
Mobile IP registration
Interaction between the mobile node, foreign agent, and GGSN
Simulation
Simulation (cont.)
Simulation (cont.)
Simulation (cont.)
Simulation (cont.)
Conclusion
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Seamless communication in a heterogeneous
networking environment
Mobile IP: ensure IP-level connectivity
Vertical handover: ability to use multiple access
interfaces at one