Transcript Fast Intra-Network and Cross-Layer Handover (FINCH) for

IEEE Transactions on Mobile Computing, vol. 8, no. 4, pp. 558-574, 2009.
Fast Intra-Network and
Cross-Layer Handover (FINCH)
for WiMAX and Mobile Internet
J.-H. Yeh, J.-C. Chen, and P. Agrawal
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Outline
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Introduction
Related Work
Design Principles
Proposed FINCH
Performance Analysis
Numerical Results
Conclusion
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Introduction
• 802.16 standardizes physical (PHY) layer and Media Access Control
(MAC) layer only.
• To build a complete system, higher layers are necessary.
– One of the major objectives of WiMAX Forum is to promote conformance
and interoperability of the IEEE 802.16 standards.
• The Access Service Network (ASN)
– provides radio access to WiMAX subscribers.
– consists of one or more ASN Gateways (ASN GWs) and Base Stations (BSs).
• ASNs are connected by Connectivity Service Network (CSN)
– provides Internet Protocol (IP) connectivity services.
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• Mobile IP (MIP, IETF RFC 3344) is adopted by WiMAX Forum.
– The Home Agent (HA) of a Mobile Station (MS) is located in the CSN of the
MS’s Home Network Service Provider (H-NSP).
– ASN GW supports the Foreign Agent (FA) functionality.
• intra-ASN mobility  no need to update MS’s care-of-address (CoA).
• inter-ASN mobility  the MS needs to update its CoA.
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• MIP is simple and effective
– to deal with interdomain mobility management in the network layer.
• MIP’s deficiencies
– frequent location update,
– long handover (HO) delay, and
– long end-to-end latency.
• route optimization has been proposed,
– can result in latency, which is highly variable.
– may not be suitable for intradomain mobility
• especially for real-time services
• IPv6 might be more efficient than IPv4,
– it is not widely deployed.
• this paper only focuses on the IPv4 over Ethernet-like link model [6]
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[6] J. Jee, S. Madanapalli, and J. Mandin, IP over IEEE 802.16 Problem Statement and Goals, IETF RFC 5154, Apr. 2008.
– the Address Resolution Protocol (ARP) can incur significant delay for both
packet delivery and HO
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The proposal
• for interdomain mobility (inter-CSN mobility)
– use MIP only.
• for intradomain mobility (intra-CSN mobility)
– a new protocol, Fast Intra-Network and Cross-layer Handover (FINCH),
• which can achieve fast HO, especially for real-time services.
• paging extension is designed
– to conserve the energy of MS and
– reduce the signaling overhead for location update
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Outline
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•
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•
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Introduction
Related Work
Design Principles
Proposed FINCH
Performance Analysis
Numerical Results
Conclusion
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Related Work
• Interdomain
– MobileIP, SessionInitiateProtocol, HostIdentityProtocol
• Intradomain
– Tunnel-based
• HierarchicalMIP
– E. Gustafsson, A. Jonsson, and C. Perkins, “Mobile IPv4 Regional Registration,” IETF Internet draft, work in
progress, Oct. 2006. (RFC 2007)
– Host-specific-routing-based
• Cellular IP
–
A. T. Campbell, J. Gomez, S. Kim et al., “Design, implementation, and evaluation of cellular IP,” Personal Communications,
IEEE, vol. 7, no. 4, pp. 42-49, 2000.
• Handoff-Aware Wireless Access Internet Infrastructure (HAWAII)
– R. Ramjee, K. Varadhan, L. Salgarelli et al., “HAWAII: a domain-based approach for supporting mobility in widearea wireless networks,” TON: IEEE/ACM Transactions on Networking, vol. 10, no. 3, pp. 396-410, 2002.
• FINCH
– Fast HOs for MIPv4
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R. Koodli, and C. Perkins, "Mobile IPv4 Fast Handovers," IETF, RFC 4988, 2007.
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HMIP
• Tunnel-based
Gateway FA
Regional
Foreign
Agent
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Cellular IP
• intends to minimize the usage of explicit signaling messages
• a layer three routing protocol
– identifies MS with its home address and
• MHs use the IP address of the gateway as their MIP care-of address.
– directly routes packets without tunneling or address conversion
– Uplink packets
• sent to the gateway in a hop-by-hop manner.
• each node on the path will cache
the source direction of the MS.
– Downlink packets
• be forwarded back to the MS
with the routing caches.
– When there is no data to send,
MS must send a special IP packet
toward the gateway
to indicate its current location.
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HAWAII
• Use MIP to handle macro-mobility (interdomain)
• Network nodes maintain mobile-specific routing entries on the
legacy routing tables.
• MS creates, updates, and modifies the location information with
explicit signaling messages.
• The forwarding scheme
– buffers packets forwarded to the
old access point and redirects them
to the new access point.
• the nonforwarding scheme
– drops the packets sent to the
old access point. (?)
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Design Principles
• Propsed Fast Intra-Network and Cross-layer Handover
(FINCH)
– Fast HO
– Cross-layer
– Scalability
• avoid using centralized nodes
– Paging support
– Timely for deployment
– Flexibility
• not be limited to tree-based topology only
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Outline
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Introduction
Related Work
Design Principles
Proposed FINCH
Performance Analysis
Numerical Results
Conclusion
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Mobility Management in WiMAX
• when an MS leaves its home network, the HA tunnels packets
to the MS’s current anchor ASN GW, which is essentially the FA
– further tunnels the packets to the MS
• If the serving BS and target BS belong to different IP subnets,
the MS needs to perform L3 HO
– acquire an NCoA and register the NCoA with the HA
• problems
– suboptimal problem may happen in a nontree network topology
– most of the protocols operate on or above the IP layer.
• They do not address link-layer mobility.
– The broadcast-and-reply nature of ARP wastes bandwidth and causes
extra latency
– ARP messages may wake up the MSs in sleep/idle mode
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Cross-layer Design
• a special table-lookup technique for both link layer and IP
layer to update the location.
– location updates in the link layer and IP layer are coupled
together.
• Consequently, ARP is no longer necessary
• The mobility management and packet routing within the
domain are done by replacing the necessary routing table
and bridging table with a Forwarding Table (FT).
• assume that all nodes have L3 functionality
– they are capable of processing IP packets.
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• When MS 1 enters the CSN-2 domain
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Handover and Location Update
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Characteristics
• All source nodes (in the domain) know the new location of the
MS after the location update is complete.
• The triangular routing in MIP is eliminated (Lee, “partially”)
– no need for route optimization.
• the new path may be the one with least congestion or
shortest path
– the new forwarding address is updated by the first arrived frame
• Not necessary to trigger L3 HO after L2 HO is done if it is an
across IP subnet HO.
– The proposed scheme deals with HOs and location update and leaves
address configuration to other protocols.
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• Breaks the layer structure
– eliminates the redundancy of doing two HOs and location
updates in both link and IP layers.
• the FT needs to maintain a list of all terminals in the
domain.
– Each domain does not expect to support millions or billions of
terminals.
– The table searching can also be implemented in hardware
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Paging Extension, P-FINCH
PG: paging group
PC: paging controller
• The proposed P-FINCH is also compatible with the mobile WiMAX standards.
• P-FINCH can significantly reduce signaling overhead and efficiently conserve the
energy of MSs.
• Scalable and robust
– paging is initiated by each PC instead of a centralized paging initiator
– Comparing with the protocols that have only one single node to buffer packets
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Outline
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•
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Introduction
Related Work
Design Principles
Proposed FINCH
Performance Analysis
Numerical Results
Conclusion
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Performance Analysis
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Handover Latency and Packet Loss
Location Update Cost
Over All Cost
Energy Conservation
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Handover Latency and Packet Loss
• Handover latency
– DL2 is the L2 link switching delay
– DIP is the IP connectivity latency.
• the duration of IP layer movement detection,
• IP address acquisition, and configuration
– DLU is the location update latency.
• the latency for binding update and
• the latency to forward packets to the new IP address.
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Handover latency
Packet loss
200 ms
200 ms
200 ms
10 ms
200 ms
200 ms
10 ms
15 ms
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Location Update Cost
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ρ  the MS call-to-mobility ratio (CMR). defined as λ/μ,
U  the average cost of location update to its HA in MIP.
S  the cost for setting up a single link when the intradomain mobility management
protocol sets up the path in the intradomain.
A  the cost of ARP operations.
L  the cost for setting up the direct connection between the NAR and PAR in F-MIP.
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U=10000
L=500
S=500
A=1000
V=200
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Overall Cost
• the overall cost adds up location update cost and packet
delivery cost.
• M  the packet delivery cost of MIP.
• F  the packet forwarding/routing cost in the intradomain (or CSN).
• T  the additional re-encapsulation and decapsulation cost of MIP, F-MIP, and
HMIP.
• B  the cost for buffering packets at NAR in F-MIP.
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Energy Conservation
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Outline
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•
•
•
•
•
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Introduction
Related Work
Design Principles
Proposed FINCH
Performance Analysis
Numerical Results
Conclusion
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Handover latency and packet loss
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Location Cost and Overall Cost
17%
high
mobility
low
• when P-FINCH is applied, the cost is reduced significantly
• When the mobility rate is low, the cost of HMIP is larger than that
of HAWAII and MIP due to the hierarchical tunneling cost
• the paging extension should be turned on when CMR is less than 1 33
Energy Conservation
high
mobility
low
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Conclusion
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MIP is adopted as the mobility management protocol by WiMAX Forum.
– cannot support HOs well when mobile nodes move frequently and/or when the coverage area of a
subnet is small.
– even exaggerated for real-time services,
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which require very fast HOs in mobile WiMAX networks.
a fast HO protocol, FINCH, for intradomain (intra-CSN) mobility management is proposed
– discussed with examples
– The analytical models and extensive simulations show that it can support fast and efficient link layer
and intradomain HOs.
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reduces location update cost and overall cost because of the cross-layer design
a scalable paging extension for FINCH, P-FINCH, is proposed
– analysis also shows that it significantly reduce the signaling overhead and energy consumption
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if the size of the paging area is well configured.
Comparing with MIP, the proposed FINCH does NOT
– need IP encapsulation and
– have triangular routing problem.
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also reduces the overhead caused by registering CoA with the HA
the overhead and latency in interfacing conventional mobility management protocols in
the two layers are eliminated
– By unifying the mobility management in layer 2 and layer 3,
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comments
• Does ARP really has to propagate to the entire intra-CSN?
• The analysis is complete.
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