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Wireless Network Convergence and Wireless Network Convergence and Fi d M bil CFi d M bil C

Lecture #4

Fixed Mobile ConvergenceFixed Mobile Convergence

Dr. Kun YangUniversity of Essex, Colchester, UK

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Thursday 19th March 2009

Agenda

Network Convergence among Wireless NetworksWireless NetworksNetwork Convergence between Fixed and Mobile NetworksSummary, Q&A

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There are many different types of wireless access networks.There will be no perfect wireless system in terms various factors such as mobility, capacity, coverage, and cost. Instead, these networks, each with its unique features, will co-

Wireless Access Networks

Instead, these networks, each with its unique features, will coexist.

IEEE802.11a/b/g/n (Wireless LAN)

IEEE802.15.1(Bluetooth)

IEEE802.15.3a(UWB) IEEE802.15.4

(ZigBee)

IEEE802.16-2004(Fixed Wireless MAN)

3G Cellular(UMTS, CDMA2000,

TD-SCDMA)

RF-tag

Satellite

DVB-H

Wireless Access Networks

IEEE802.15.4a(low-rate UWB)DVB-T

IEEE802.16e(Mobile Wireless MAN)

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Technologies that enable users to seamlessly and easily use these networks are needed.

IEEE802.20(Mobile BWA)

2G Cellular(GSM, etc)

)IEEE802.21

(MIH)2.5G (GPRS)

2.75G (EDGE)

Wireless Mobile Internet – driven from mobile devices

2B cell phones vs. 500M Internet-connected PC in 2005 400M cell phones with Internet capability rising 400M cell phones with Internet capability, rising rapidlyWireless devices will be more portable, more intelligent, more functional and with multi-radio access capacity.

There is a historic shift from PC’s to mobile devices for Internet access.

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There is a historic shift from PC s to mobile devices for Internet access.

Mobile applications get more complicated.

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Wireless Convergence: Loosely Coupled

5www.vysoo.com/images

Heterogeneous Wireless for e-Health @ UEssex

“Always-on” lifeline using media-independent handover (MIH) across heterogeneous wireless networks (standardised within IEEE802.21)Video conferencing/VoIP to patient from home (also while mobile, but l ti l!)

Fall detector

GPS

Heart Monitor

Blood Oxygen

Blue

toot

h (1

00m

rang

e) WiMAX

WiFi

GPRS Blood Glucose

Sensors

MIH (802.21)

Router

Storage

HSDPA (3G)

less practical!)

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Linux low power

miniPC

Media Independent Gateway (MIG)

Ethernet (fixed broadband connection)

HSDPA (3G)Processor

LCD Monitor

Camera, mic, speakerVoIP/Video Conference

Mobile version

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7MIG Software ImplementationBy A. Bontozoglou

UEssex Research Network Testbed

Quality of Experience(QoE) Monitoring

Application and Service Manager

Network ResourceManagement

Routing and Dynamic Bandwidth Allocation

Quality of Service (QoS) Monitoring

rvic

e R

esou

rce

Man

agem

ent

Serv

ice

Laye

rSi

gnal

ling

Policy & Service LevelAgreement (SLA)

Management

Network Manager

Voice

Video(IPTV/VoD)

Storage

IP

Ethernet

cces

s N

ode

Quays South Courts

WiMAX

cces

s N

ode

WiFi

Betrand Russell

Campus Outskirts

Campus Perimeter (<10km)

Isolated WiFi Sports Car2-10Mbit/s

Central Campus

WiMAX3G

Wireless Backhaul

Future

Network Layer SignallingApplication Layer Signalling

DPI

DPI

Ser M S

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WDM

NG-SDH

Multi-Layer Switching Nodes (Circuit and Packet-Switched)

Mul

ti-S

ervi

ce A

c

GPON

Mul

ti-S

ervi

ce A

c

Ethernet

Fibre

Optical Splitters

Heterogeneous Access Technologies (Wired and Wireless)

Isolated WiFi hot-spots

Sports Grounds

Car Parks

Fibre

2 10Mbit/s Broadband

Access

ONU TrafficGenerator

Access Network Emulator

TrafficGenerator

Internet

Public IP address

Future

Campus Network

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iDorm – Digital Lifestyle Environments

iSpace (evaluation environment)

iDorm1 (development environment)

Single student bed-sit (work, sleep etc)

p ( )• Test‐bed for ambient intelligent and pervasive computing in a 

domestic setting (Full sized 2 bedroom apartment)

• Sensor, actuator, computer and network rich environment to enable open‐ended R&D

• £250,000 in IT related aspects (+£100,000 energy equipment)

• Capable of supporting evaluations with long‐term occupants

9For further information, contact Prof Vic Callaghan (vic@essex.ac.uk)

A Closely-coupled HWN: Motivation

Current cellular systems are limited in flexibilities in that

As a result, some cells could be congested

cellular architectures are fixed and bandwidth allocation

cannot dynamically adapt to instant network change.

gbecause of temporary events, such as traffic accidents and sports events.

Proposal: introduce MANET over cellular networks to divert traffic

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Proposal: introduce MANET over cellular networks to divert traffic.

Existing work:iCAR: diversion station has only cellular interfaceUCAN: high-date rate, within a cell

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Physical Characteristics of the HWN system

MH2

Mobile Host #1

MH3

MH4

Base Station #1 BS2

Traffic DiversionStation #1

TDS2

TDS3

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MH3 MH5

Cellular Interface Ad Hoc Interface

BS: no change from the current UMTS BSTDS: with both cellular and ad hoc interfaces, deployed close to the borders of a cellMH: with only A-interface, C-interface, or both interfaces.

QoS: QoS MappingHeterogeneous

Wireless NetworkHome WLAN

aDSLIP InternetTDS

BS

aDSLRouter(RSVP/DiffServ/

MPLS)

Home Server(video)

EgressRouter

Wiredinterface

C-interface

A-interface

End to end QoS

Internet QoS RoutingHWN QoS Routing

C-to-Amapping

A-to-Cmapping

AP

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End-to-end QoS

K. Yang, et. al. “QoS-Aware Routing in Emerging Heterogeneous Wireless Networks”, IEEE Communications Magazine, Feb. 2007. Page(s): 74-80.

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Adaptive Routing

MHs initiates a requestbut blocked

Transmit data from MHsusing route r

Start End

Not needed in normal routing

Source SelectionDestination SelectionRoute discovery & selection

but blocked

Is there a TDS nextto MHs?

Source Selection Procedure:find a MHj in the same cell as

MHs

Route SelectionProcedure: r=r

Is MH’ empty?

MHj releases channel;MH’ uses the channel;

YES

NO

YES

NO

using route r

YES

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Is MHj empty?

MH’=MHs;MHs=MHj;

Destination SelectionProcedure

Route DiscoveryProcedure:

discover routeR={rk|k=1,..,|R|}

Is R empty?

Procedure: r=rkfailure

NO

YES

YES

NO

Evaluation

BB C

CCC

C

D

D D D

D D

D

D

A

B

B

B

B

C

CC

C

C C C

D

D

D

D D D D

D

D

D

The whole networkenviroment

The structure of asingle cell

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8

Further Integration with DVB

DVB BaseStation

Focus is on the network architecture and its service-driven adaptation and mngt

DVB-H: Digital Video Broadcast-Handheld

• Three types of nets

MH1

MH2

Base Station #1 BS2

MH4

MH5Cellular

Cell

DVBCell

MH9

adaptation and mngt. • Unicast+broadcast• Uplink for DVB via cellular net.

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MH3

MH6

Base Station #1 BS2

MH7

Cellular Interface Ad Hoc InterfaceDVB-H Downlik

MH8

It utilizes a policy-based mngt (PBM) approach in combination with fuzzy control theory, aiming to maximize the overall effectiveness, flexibility, and robustness of the network.

Overall architecture

UWW

D Service G

ateway

16K. Yang, et al. “A Flexible QoS-aware Service Gateway for Heterogeneous Wireless Networks”, IEEE Networks, March 2007. Page(s): 6-12.

WLAN overlays UMTS. UMTS and DVB-H networks operate separately but connected via a pair of signalling gateways.UWD Service Gateway monitors the UWD network status and conducts network selection and configuration to satisfy user-perceived services.

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Operations

MH UMTS BS UWD Service Gateway WLAN DVB-H BS

(1) Service request (2) QoS not satisfied,invoke service gateway

(3) Decisionmaking

(4b) Configure WLAN

(4c) Configure DVB-H

(2) QoS satisfied, requestserved by UMTS

(4a) ConfigureUMTS(5a) service

execution via UMTS

(5b) service execution via WLAN

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( )

(5c) service execution via DVB-H

How the three types of networks collaborate to fulfill a service as coordinated by the USG.

Network Environment

CCCD

D D D

D

D DVB-H BaseStation

A

B

B

B

B

B

B

C

C

CC

C

C

C C C

D

D

D

D

D D D D

D

D

D

D

The structure of asingle cellular cell

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Agenda

Network Convergence among Wireless NetworksNetworksNetwork Convergence between Fixed and Mobile Networks: EPON+WiMAXSummary, Q&A

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K. Yang, et al. “The Convergence of Ethernet PON and IEEE 802.16 Broadband Access Networks and its QoS-aware Dynamic Bandwidth Allocation Scheme”, to appear in IEEE JSAC

Background

IEEE 802.16 provides wireless broadband access with high bandwidth capacity, large network coverage, strong QoS support. But how to backhaul its traffic? -> EPON (Ethernet Passive Optical But how to backhaul its traffic? > EPON (Ethernet Passive Optical Network), a point-to-multipoint optical access network technology. The most popular EPON topology is tree-based architecture where transmission occurs between an optical line terminal (OLT) and multiple optical network units (ONUs).

The OLT is usually connected to the core networks whereas each ONU locates at either curb (thus the so called fiber-to-the curb or FTTC), within a residential building (i.e., fiber-to-the-building or FTTB), or even to the home (i.e., fiber-to-the-home or FTTH)

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home or FTTH).Of course, an ONU can be connected to an IEEE 802.16 base station (BS).

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Illustration of an EPON Network Backhauling IEEE 802.16 Access Networks

OLT ONU BS SS

OLT1:n

splitterONU

802.16 BS

VOD ClientSS

ONU802.16 BS

...

...

VOD Server

SS

SS

Core

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We assume that an EPON ONU is integrated with an 802.16 BS into a converged box called Virtual ONU-BS (VOB).

We call it “virtual” because there is not such an integrated box physically.

Residential BuildingONU

VOD Server

Why this Convergence?

Firstly, most 802.16 BSs are equipped with Ethernet interface as such can be easily connected to EPON. Secondly, both technologies share many similarities in terms of bandwidth request/allocation and QoS supporting mechanisms. Thirdly, EPON and 802.16 also complement each other in that the convergence of two has the potential to combine the bandwidth advantage of optical networks with the mobility feature of wireless communications. Furthermore, this integration enables the design of joint bandwidth allocation/reservation, connection admission control and transmission scheduling schemes.

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These collaborative schemes are more likely to provide a close-to-optimal solution to system’s overall resource management, including both wired optical resources and wireless radio resources. In return, a better support of end-to-end QoS guarantee and improvement of overall system performances such as throughput and delay can be expected. But how to design such schemes is still an open and challenging issue!We endeavor to make a first-step attempt towards this challenge by focusing on bandwidth allocation.

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A bit of state-of-the-art on FMC

Application Layer: IMS (IP Multimedia Sub-system)/SIP (Session Initiation Protocol) -> loads of workPhysical Layer: Radio over Fibre (RoF) -> tons of workPhysical Layer: Radio over Fibre (RoF) > tons of workMAC Layer

C. Qiao. et al. appears to consider FMC in a layer other than physical layer or application layer. However, this seminal work does not reflect too much the flavor of 802.16 networks. IEEE OFC March 2006 – seminal workShen et al. recently summarize the architecture issues arising in the integration of EPON and 802.16. but not concrete algorithm details

d R f IEEE C M A 2007 k hl h

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presented. Ref. IEEE ComMag, Aug. 2007 – work at roughly the same timeline as ours.

Our work endeavors to design a QoS-aware dynamic bandwidth allocation (DBA) scheme at the MAC layer for a converged network of EPON and 802.16.

Technical Focus

Firstly, to propose converged network architecture of EPON and 802.16 (especially the concept of VOB) and identify the unique research i lt f thi issues as a result of this convergence. Secondly, to investigate a DBA scheme that is specifically designed for the WEN networks. This DBA scheme takes into consideration the specific features of the converged network to enable:

(1) a smooth data transmission across optical and wireless networks, (2) an end-to-end differentiated service to user traffics of diverse CoS(Class of Service) requirements. Here the end-to-end means from a connection originated from an 802 16 SS to the OLT

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connection originated from an 802.16 SS to the OLT. • This QoS-aware DBA scheme shall ensure certain fairness under network traffic

saturation condition along both station dimension and CoS dimension. • CoS fairness specifically means that the low-priority traffic (such as best effort

traffic) shall not be significantly disadvantaged under network saturation condition.

The proposed DBA scheme, called WE-DBA for WiMAX-EPON DBA

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A bit practical work first …

Feasibility Study: ExperimentsRef.: S. Ou, K. Yang, M. P. Farrera, C. Okonkwo, and K. M. Guild, "A Control Bridge to Automate the Convergence of Passive Optical Networks and IEEE 802.16 (WiMAX) Wireless Networks," Proc of BROADNETS 2008 London UK Sept 8 11 2008Proc. of BROADNETS 2008, London, UK, Sept. 8-11, 2008.

QoS Mapping

Control Bridge

Bandwidth Allocation Control Control API

Interface to higherlevel managemententities, such as

service managers

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BS Control ModuleOLT Control Module

Interface to GPON OLT Interface to 802.16 BS

The GPON equipment used: one Ericsson EDA 1500 (OLT) and three T050G ONUs. IEEE 802.16: one Airspan MicroMAXB BS (AS.MAX MicroMAX-SOC) and three SSs (AS.MAX ProST).

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GPON and 802.16 Upstream Packet Classification and QoS Mapping

SS QueuesGPON 802.16

UGS

ertPS

ONU T-CONT Buffer

UserTo

Control Bridge

T-CONT 1ertPS

rtPS

nrtPSBE

SSClassifierONU

Scheduler

SDUsSSScheduler

ONUClassifier BS

ToONU

OLT

802.1Q/pUser Priority

765 UGS

802.16Services

a. QoS Mapping

SSBW Request

ONUBW Request

Control FlowData Flow

T-CONT 3

T-CONT 4

T-CONT 2

Lowest-Cost-First Mapping Algorithm

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Classified by other parameters(such as source/destinationMAC address, VLAN ID, IP

protocol, etc.)

43210

DSCPEF

AF4xAF3xAF2xAF1xBE

UGSertPSrtPS

nrtPSBE

b. An Example of Packet Classification inSS Classifier

T-CONT 1

ONU T-CONTBuffer

T-CONT 3

T-CONT 4

UGSertPSrtPS

nrtPSBE

802.16Services

T-CONT 2

c. An Example of Packet Classification inONU Classifier

Dynamic Bandwidth Control

VOD Client(SS)

VODServer

ControlBridge

GPONOLT

802.16BS

ServiceManager

1. VOD service request

2 i t d/ j t d

a. V O D serv ice w eb page

2. service granted/rejected

3. Invoke Control API toprovide just-enough BW

4. Resize the CIR of theservice flow

5. Resize the max. BWallocated for the T-CONT6. Inform VOD

server to provideservice to the client

7. VOD service begins

b. se rv ice m anager

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8. VOD service ends

9. Invoke ControlAPI to release BW

10. Release allocated BW

11. Release allocated BWc. contro l b ridge daem on

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Some results

4 5

5

5.5

6

st (

per

MB

)

Without Control Bridge

With Control Bridge, U=5MBWith Control Bridge, U=50MB

With Control Bridge, U=100MB0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Cha

nnel

Util

izat

ion

(%)

Without Control Bridge (Maximum)

Without Control Bridge (Average)With Control Bridge

Channel utilization

0 20 40 60 80 100 1201.5

2

2.5

3

3.5

4

4.5

Traffic Load (%)

Ave

rage

Pac

ket

Del

iver

y C

os

0.85

0.9

0.95

1

Rat

io

0 25 50 75 100 125 1500

0.1

0.2

0 3

Traffic Load (%)

Delivery cost

290 25 50 75 100 125 150

0.5

0.55

0.6

0.65

0.7

0.75

0.8

Traffic Load (%)

Ave

rage

Pac

ket

Del

iver

y R

Without Control Bridge

With Control Bridge, U=50MB

Delivery ratio

30

A bit theoretical work …

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Virtual ONU-BS (VOB) Box

hardware layout

logical architecture

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Bandwidth Request & Grant

• The VOB queues are presented as virtual queues by dashed lines because these queues represent the bandwidth requested instead of the real data.

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q p q• EPON: Multi-Point Control Protocol (MPCP); IEEE 802.16 has similar mechanism and procedure. • These standardised mechanisms have defined the precise format for bandwidth request and grant messages as well as their processing. However, no DBA algorithm is specified.• Note that VOBs employ MPCP for bandwidth request and the 802.16 mechanism for bandwidth grant.

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Illustration of Bandwidth Request and Allocation

Grant per CoS

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Refer to the attached paper for technical details and discussion.

DBA at OLT

nRTnT

B gcycleVOB ×

××−=

8)( EPON

avg n: # of VOBs; Tg: guard timeR Mbps: EPON trans. raten×8

∑=

=3

1

req,

req

jjii BB i: VOB; j: CoS

)(|)( reqavgreq

1

avgexcessiVOBi

n

iVOB BBBBB >−= ∑

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1i=

),min( reqexcessavggiiVOBi BBBB +=

RBt ii /)8( glen ×= Written in the MPCP GRANT message

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DBA at VOB

avgmin BB ×= α BEBE BB ×= α

rBErBE TrafficB ,avg

1, =+

2/)( ,avg

1,avg

1, rBErBErBE TrafficBB += −+

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Evaluation Design

Benchmarks:DBA1: both the OLT and VOBs statically allocate bandwidth (equal share) to its client stations(equal share) to its client stations.DBA2: EPON static whereas 802.16 dynamic (the other way round is less common)

Test design:To evaluate against benchmark to show the benefit of dynamic

• in terms of throughput and delayTo evaluate itself under different conditions.

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• In terms of throughput and delay under different serving cycles, types of services, channel utilization, and BE windows

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Overall Throughput of WEN under different DBA schemes

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Average Delayof WEN under different DBA schemes

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Thoughput under different Serving Cycles

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Delay under different Serving Cycles

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Average Delay for Types of Services

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Channel Utilization

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Effect of minimum bw allocated to BE

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Conclusions

PON+802.16 at MAC appears to be beneficial though just some very limited preliminary work being carried j y p y gout.However, this is a massive research topic and much more effort is needed.

Other topics such as scheduling and admission control, a comparative study on the performance differences between a centralized control mechanism (carried out by the OLT) and a cascading decision making strategy

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cascading decision making strategy.Investigation into the effect of mobility on network performance. Long-term work includes research into a fully unified hardware VOB.

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Contact，Q&A

Dr Kun YangSchool of Computer Science & Elec. Eng. (CSEE),University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK

Email: kunyang@essex.ac.ukhttp://privatewww.essex.ac.uk/~kunyang/

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