Transcript slides

Software-Defined Networking in Heterogeneous
Radio Access Networks
TNC 2014 Conference, Dublin
Hao Yu, DTU/NORDUnet
May 21, 2014
Agenda
Introduction
Some concepts
Background of the problem
Problem
Leveraging SDN in HRAN for Seamless Handover Across Multiple
Domains
Summary
Questions
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Introduction – RoF and HRAN
RoF = radio-over-fiber
Allows radio signal to be modulated and transmitted over optical
fibers in order to expand the reach of a base station
(NodeB/eNodeB) or a wireless router
Allows various signals over the fiber to the remote radio head,
providing different access simultaneously.
One universal access method for mobile devices is no longer a valid
scenario. Instead, multiple access methods are available in the radio
access networks (RANs):
4G (LTE)
3G (W-CDMA, TD-SCDMA,
CDMA2000)
WLAN (Wi-Fi)
Therefore, a heterogeneous RAN
(HRAN).
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Introduction – Handover
Surrounded by different signals, mobile devices switch between them
either to receive better signal or to save data usage.
Switching from one access type to another is referred to as
vertical handover, while keeping the access type unchanged is called
horizontal handover.
Problem of handover (mainly in VH): disturbance in user experience
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Introduction – Handover Problem
(mobility management problem)
The disturbance problem can be found in
both handover types.
Caused by the change of the IP address
acquired by the mobile device from the
attached network.
Problem rooted in the dual roles of IP
address when it comes to mobility:
Locator: by means of routing, how to
reach the node that is using a specific
destination address.
Identifier: used by upper-layer protocols
to identify the endpoints of a
communication channel.
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Switch from one access type to
another, e.g. LTE→Wi-Fi
Change of IP address assigned to
the mobile device
Reestablishmenf the all TCP
traffic
Disturbance in user experience,
e.g. need for re-login.
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Introduction – PMIPv6
Proxy Mobile IPv6 standardized by IETF
in order to provide Network-Based
Localized Mobility Management support
in IP networks. (Host-based has security
problems)
For building a common and access tech
independent mobile core, cooperative
with different access techs (3GPP,
WLAN, etc.)
Tech terms:
LMD: Localized Mobility Domain
MAG: Mobile Access Gateway
(>1 per LMD)
LMA: Local Mobility Anchor
(1 per LMD)
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Introduction – PMIPv6
Principle is to maintain the
Home Address unchanged
regardless of the change of
attachment point of the
mobile node.
Bi-directional tunnels
between LMA and MAG
In a handover situation, the
LMA updates the Binding
Cache entry with the Proxy
CoA of the new MAG,
updating also the tunnel.
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Problem
PMIPv6 seems a pretty good solution for mobility management in a
localized domain.
But what about multiple domains?
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Leveraging SDN in HRAN for Seamless
Handover Across Multiple Domains
Use case:
Students/teachers using mobile learning
applications on their mobile device moving
to/from LTE network from/to university
eduroam Wi-Fi network.
Seamless handover using PMIPv6 with SDN
assistance is proposed.
SDN = Software-Defined Networking
Decouple the control plane
from the data plane
Centralize the control function
into one controller
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Leveraging SDN in HRAN for Seamless
Handover Across Multiple Domains
A SDN controller connecting to LMA and MAGs per domain.
Interdomain tunnels needed.
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Leveraging SDN in HRAN for Seamless
Handover Across Multiple Domains
PMIPv6 to be
enhanced for
signaling path.
Agreement
between domains.
West- east bound
APIs of SDN
controllers need to
be standardized.
Interdomain
tunnels jointly set
up be the SDN
controllers on data
path.
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Some Details About the Proposal
Guest LMA needs to send PBU[MN-ID, (MAG B.LMA B)] to Home LMA
Home LMA considers the Guest LMA-MAG combination as a MAG.
Tunnel needs to be established between Home LMA and Guest MAG
(SDN controller’s help).
Downlink traffic received by Home LMA first and then Guest LMA-MAG,
resulting in longer traffic delay.
Home Address of the mobile node is preserved.
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To Summarize
PMIPv6 provides network-based mobility management support in IP
networks.
However, there lacks the ability to provide multidomain mobility
management support in PMIPv6.
How to provide a seamless handover in multidomain HRAN is
challenging and needs to be solved.
Propose to enhance the PMIPv6 (signaling path) with the use of SDN
approach (data path) to assist in solving the problem.
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Questions?
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