Transcript Network Initiated Handovers

Network Initiated
Handovers
T. Melia, J. Korhonen, R. Aguiar,
S. Sreemanthula, V. Gupta
Based on draft-melia-mipshop-niho-ps-00
Motivation
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Deployment of heterogeneous access systems
combined with IP convergence (WLAN, WiMax, 3G)
requires enhanced network controlled mobility
Inter system handovers
WLAN deployments lack network control of roaming
users
Steering of roaming: NAPs do not belong to mobile
operators (inter domain)
We have solutions for Mobile Initiated and network
assisted (L2 triggers, FMIv6 alike solutions)
Need to understand Network Initiated Handover
i.e. the trigger generates in the network
NEED for a flexible framework supporting both kind of
handovers
Definition of network initiated
handover
Action taken in the network to initiate the handover based on:
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Link events originated in the mobile node:
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radio link variations (e.g. RSSI, SNR)
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powering on of new network devices
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new service requirements
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…
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Events generated in the network:
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resource management reasons
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optimization based on location/services
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multi homed devices
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…
Assumptions (i)
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Reusing existing security mechanisms as much as possible
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All mobile nodes within the scope of this document are
expected to support at least one (potentially modified) existing
or future IP mobility enabling protocol.
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MNs and mobility management nodes are expected to
understand or support network initiated and assisted
handovers. CNs may not.
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The network initiated handover concept relies on the
presence of a functional entity.
Assumptions (ii)
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To provide adequate scalable support, additional distributed
functions are required to support the functional entity.
 See functional components described in the document
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It is envisioned the presence of multi wireless access, such as
802.11, 802.16, UMTS, forming an heterogeneous
composition of macro and micro cells.
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Performing network initiated handover has the main
implication that the network has first to assess the terminal
view of the network. Signal level evaluation is a important
matter when coming down to user mobility.
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Neighborhood discovery relates to the above assumption
when neighborhood scanning is requested from the network.
It is expected these functions to be available on the terminal
side.
Issues to consider for NIHO
feasibility:
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Mobility Application Area:
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Resource Application Area:
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Efficiency of measurement functions for signal level reports
Location of decision functions (RTT)
Network can control the handover
Overlapping and Coverage of (different) wireless access
technologies
Resource optimization or administrative decisions
Network can trigger the handover
Application for inter-domain handover
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Steering of roaming
NIHO with IEEE 802.21
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IS, ES and CS as enablers for network initiated and
assisted handover scenarios
Consider the Mobility and Resource Optimization
(opportunistic handover) application area
Two steps approach:
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Network selection
 MIHF at the terminal discovers available networks
 MM in the network decides which is favorable
Handover control
 MM sends a CS-switch request to initiate the handover
 Simulation results available on request
Goals
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Independent of the IP mobility management mechanism
Work over administrative domains e.g. in inter-domain
handover cases or when a multi-homed host is attached to
multiple ISPs
Provide inter technology handover
Provide similar degree of security as existing with the
current solutions.
Non Goals
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Designing a new security framework in order to enable
network initiated and assisted handover triggering.
Initial bootstrapping problem -- The mechanism to gain the
initial access to some network is out of scope of.
Questions?
Scenarios
Single administrative domain
MRMH
NIHO Triggers
generated in the
home network
Mobile Operator
Home Network
ISP
NIHO Triggers
generated locally in
the access network
Transparent to the
home network
NAP A
NAP B
PDA
Scenarios
Multiple administrative domain
NIHO Triggers
generated in the
home network also
over administrative
domain
Mobile Operator
Home Network
MRMH
ISP
NIHO
Triggers
generated
locally in the
access
network
Transparent
to the home
network
ISP
GMP
NAP A
NAP B
PDA
NAP B