Software defined and virtualized wireless access open issues and
perspectives
Software defined and virtualized wireless accessopen issues and
perspectivesFabrizio Granelli ([email protected])
FP7 PACE Project Workshop on "Path Computation Element and
beyond: innovating control and management functions towards fully
reconfigurable software-centric networks"Table of
ContentsIntroductionSDNWirelessExtending SDN over
wirelessVirtualizing wireless accessNFVTest case: SDN for
interference controlE2E
SDNStandardizationConclusionsIntroductionComputer networks play a
very important role in our day to day lifeAs the number of users
increases so does the number of network
devicesChallenges:Configuration and managementbecomes costlySystem
updates are verydemandingLowers the pace of innovation
Introduction (contd)Why?The control logic (intelligence) is
embedded to every deviceHow it could be solved?Software-Defined
Networking (SDN)
What is SDN?Newly emerging network architecture paradigmPromises
innovation in terms of:Network programmabilityHigh-level of
abstraction
Introduction (contd)How is it achieved?By separating the
control-plane and data-plane with a well-defined programmable
interface to provide:Centralized global view of the networkEasy
configurability and manageabilityFlexibility, scalability and
capability of reconfiguration of different network segments
Introduction (contd)
Why wireless?Mobile data traffic is also booming due to:
Why wireless?
Why wireless? (contd)Device bandwidth consumption profile*Growth
in the number of devices growth in mobile data
trafficDeviceTrafficM2M6 * Wearable Devices7 * Smartphones49 *
Tablets127 * Laptops227 *
To account these issues, programmability of mobile networks is
needed:Allocating non-overlapping frequency bandsMonitoring
interferenceCoordinating handoversConfiguration and
management*Cisco and/or its affiliates, Cisco Visual Networking
Index: Global Mobile Data Traffic Forecast Update, 20132018, White
Paper, February 5, 2014 Extending SDN to wireless
Extension of the NaaS concept to include wirelessGoogle Project
Fi
Wireless access virtualization perspectivesFlow Oriented
PerspectiveAlso, mobile network virtualizationManagement and
scheduling of different flows on different slicesImplemented as
overlay (OpenRoads, vBTS) or via internal scheduler (NVS,
vLTE)Protocol Oriented PerspectiveCustomize and manage multiple
wireless protocol instances on the same radio HW (OpenRadio,
SORA)Spectrum Oriented PerspectiveRF bands and raw spectrum are
slicedWireless virtualizationExtension of Service Awareness and
Functions Modularity to the wireless domainDecoupling of management
and data planes (CAPWAP)Virtualization using SDRsBaseband
processing divided into programmable processing and decision
planesWLAN VirtualizationConnecting NICs to different
networksCloudMACCellular Base Station VirtualizationDifferent
schedulers for different slicesWireless Spectrum
VirtualizationSpectrum reshaping (Spectrum Virtualization
Layer)
Enabling SDN over wirelessThe idea is to augment the
capabilities of WiFi (Virtual WiFi)14Enabling SDN over wireless
(contd)
Efficient management and allocation of network resources
(NetShare)Enabling SDN over wireless (contd)
- Additional flexibility and efficiency in resource
allocation16Enabling SDN over wireless (contd)
CROWD architecture (www.ict-crowd.eu)Extremely dense and
heterogeneous scenarioMitigation of intra-system interference,
opportunistic channel usage, energy efficiencyControl through CROWD
Regional Controller and CROWD Local Controller17Enabling SDN over
wireless (contd)
Enhancing IP multicast over 802.11 networksMultiflow converts
multicast tx into unicast, to optimize channel availability18Test
case: SDN for Interference controlEven though the problem of
interference was studied for decades at both PHY and MAC layers, so
far no satisfactory solution emerged.
Objective:To come up with a framework for interference control
(i.e., manage and avoid) to mobile networks by adopting the SDN
paradigm
(*) Anteneh A. Gebremariam; Leonardo Goratti; Roberto Riggioy;
Tinku Tasheed; Fabrizio Granelli, A Framework for Interference
Control in Software-Defined Mobile Radio Networks, IEEE CCNC 2015.
How?By exposing/abstracting the lower layers of the protocol stack
(i.e., PHY and MAC) in order to make system parameters available to
the controller or applicationsProviding an efficient resource
scheduling scheme to control interference
System Architecture
Interference control frameworkSDN for Interference control
(contd)The Goal is the design and implementation of the
interference control framework20
The selection of H is doneby the central controller based on the
channel feedbackinformation of the UEsY can be represented by
atuple of parameters, , representing an abstraction of the
resources assigned to a data stream X
PORTIG represented by a pair (V, E)IG construction:Based on the
historyMicro-probing
Interference Graph (IG)SDN for Interference control (contd)The
details of each block in the interference control frameworkPORT :-
motivated by the switch port concept, where the switch input ports
are mapped in to an output port based on the forwarding table.In a
similar manner we can use the same concept in the wireless domain
to provide the flexibility of selecting the mapping H from the
centralized controller.
Interference Graph (IG) :- models the interference among
communication links. Its represented by two tuples (V, E); where V
represents the UEs and E represents the edge connecting the
interfering transmitter to the receiver (i.e., UE). From the figure
above, the purple lines represent the IG and the black solid lines
represent the connectivity graph.IG construction:I, By collecting
information for a certain period from all communication linksii,
Micro-probing: by injecting traffic to the network (accurate and
very demanding)
21
Conflict Graph constructionWhat are weights assigned for each
edge?
The maximum allowed interference level at the receiver (using
Physical Interference Model) is:The maximum allowable interference
contributionof the kth interfering link on terminal XR(i):Conflict
Graph (CG)Sm represents a set of communication links that could be
active at the same time, considering the following expression is
satisfied:
SDN for Interference control (contd)Where is the threshold SINR,
2 is the additive noise, Xi and XR(i) represents the transmitter
and receiver location 22The optimizer:Goal: to reduce the weights
in a certain transmission link in the CGHow? Efficient resource
scheduling: Integer Linear Problem (ILP)Objective function
minimization of the weights (i.e., minimizing the aggregate
interference)
Constraints :
decision binary variable, which is 1 if link li uses MCS
(modulation and coding scheme) m in RB (resource block) r or 0
otherwiseSDN for Interference control (contd)Where: L- represents
the transmission links (UE, eNB) pairs R- represents the resource
blocks (RBs) (frequency, time, space) M-the Modulation Coding
Scheme
i,k,r,m :- is a decision binary variable, which is 1 if link li
uses MCS m in RB r or 0 otherwisethe power constraint sets the
interval for the transmission power levelTP constraint makes sure
that each link achieves its throughput demands23End-to-End SDNTo
enable combined management of wireless and wired segments of the
networkAdvantages:Unified management of the networkUnified policy
enforcementEnabler for NaaSPerformance improvementVendor
interoperabilityCustomized applications through SDN (northbound)
APIsCurrent Standardization Efforts on SDNIETF Forwarding and
Control Element Separation (ForCES) WGOpen Network
FoundationPushing OpenFlowInterfaces between (1) applications and
controller and (2) controller and switching infrastructureITU-T
SG13 (Future Networks) and SG11 (SDN signaling)IRTF Software
Defined Networking Research GroupETSI SDN/NFV
Standardization of wireless NVFsSeveral interesting scenarios of
wireless in the future5G calls for heterogeneous wireless
networkingSDN could come in the picture to enable efficient
management of 5G infrastructuresStandardization could be
two-fold:Standardizing WHAT is virtualizedStandardizing the WAY we
compose virtualized entitiesConclusionsSDN is expected to be hot
both in wireless as well as in wireless-cum-wired scenarios5G could
represent a suitable scenario, including hetnets and
softwarizationDifferent opportunities for standardization
For more info: F. Granelli, et al. Software Defined and
Virtualized Wireless Access in Future Wireless Networks: Scenarios
and Standards, IEEE Communications Magazine, in press
Software defined and virtualized wireless accessopen issues and
perspectivesFabrizio [email protected] Any
questions?