OMEGA leT project:Towards convergent Gigabit Home Networks

Jean-Philippe Javaudinl, Martial Bellecl

, Dimitris Varoutas2, Member, IEEE and Vincenzo Surace

1 France Telecom, R&D Division, 4 rue du Clos Courtel, 35512 Cesson-Sevigne BP 52, France

Emails:jeanphilippe.javaudin@orange-ftgroup.com.martial.bellec@orange-ftgroup.com

2University of Athens, Dep. Informatics & Telecom., Panepistimiopolis, Ilissia, GR15784, Athens, Greece

Email: D.Varoutas@di.uoa.gr

3 University of Rome, DIS department, via Ariosto 25, 00185, Rome, Italy

Email: vincenzo.suraci@dis.uniromal.it

Abstract- Gigabit home networks represent a keytechnology to make the Future Internet success a reality.The OMEGA European project [1] aims to define anddemonstrate such networks. Consumers will requirenetworks to be simple to install, without the need of anynew wire. To achieve this, gigabit radio links and wirelessoptics communications will provide wireless connectivitywithin the home and its surroundings. Power-linecommunications potentially combined with robust RF willprovides a home backbone "without new wires." To makethis network ubiquitous, seamless and robust a technology­independent MAC layer will ensure its global control andprovide connectivities to any number of devices the userwishes to connect to it in any room in a house or a Oat. Inorder to make this vision come true, substantial progress isrequired in the fields of optical-wireless and RF physicallayers, in protocol design, and in systems architectures.

Index Terms- Home Area Networks, Network Convergence,Business cases.

I. INTRODUCTION

The future Internet will require an extremely high-bandwidth"core" and "access" network, along with the associateddevelopments in transmission and switching that are requiredto achieve this. User expectations are high; the future Internetmust be as simple to use as other utilities (gas, water, andelectricity), high-capacity mass storage and other devices mustplug in and work; "no new wires" should be required; andaccess to information should preferably be wireless. Servicesmust be also portable and personalised, seamlessly followingthe consumer from place to place and device to device at anytime, with no delay or interruption of service. In the absence ofsuch an easy-to-install and easy-to-maintain HAN, theconsumer is required to have information technologies (IT)skills that are a major barrier to mass market broadbandpenetration.

978-1-4244-2644-7/08/$25.00 ©2008 IEEE

The future HAN must also enrich the lives of consumers, forexample by allowing visual communications with their friendsor relatives, by enabling interactive experiences throughentertainment, by assisting the consumers in maintaining theirindependence as they age, for example by offering remotehealthcare and by allowing them to communicate with theirfamily to reduce any sense of isolation they may have. Inessence they must have the ability to control their virtual aswell as their physical environment.

A. The OMEGA vision for a gigabit home area network

Given that FITH access promises symmetric data rates of atleast 100 Mbit/s, this implies a HAN supporting Gbit/s datatransmission and a latency time in the millisecond regime. Itimplies that the performance of the HAN must be high enoughto maintain several services simultaneously, each with verydifferent requirements. Furthermore, it must be low-cost andeasy to be manufactured in volume.

The OMEGA home network aims to deliver Gbit/s capacityand low latency within the home and to the access network,with either wireless transmission or transmission using existingwired home infrastructure, thus enabling access to and thedevelopment of new and innovative services.

Figure 1 illustrates the network concept. Data enters the homeand is routed by the home gateway. The gateway in tum isconnected to OMEGA hardware, which can deliver Gbit/s datatransmission. Room-area communications is provided throughultra wide band (UWB) radio and broadcasting by use ofvisible-light communications (VLC).

To extend UBB penetration, the gateway can also use lowerfrequency RF to connect to terminals, or use power-linecommunications (PLC) beyond state of the art 100 Mbps net toconnect to OMEGA bridges within the house. Bridges canalternatively or complementarily be networked by means ofhigh speed radio backbone, leading to the first hybridization ofwireline and wireless connectivities.

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2

(((.)))------((t:\))---.l:J ~ ::;: ~Bedroom

Lounge

1..........=1

Office

( (( • )) ) --PL-Cor Rad-iO___----,

tndoor Wireless

Optics and!or Radio

Figure 1: Gigabit home area network - OMEGA

ADSl - Asymmetric

Digital Subscriber Une

mH - Fiber To The Home

RlL - Radio in the local Loop

II. USAGES AND BUSINESS CASES FOR GIGABIT HOME

NETWORKS

A. Market status

For access networks, the deployment of broadband access(xDSL and beyond) will exceed 100 million sUbscriber~ inEurope in the near future [2]. The majority of the connect1~ns

will approach the Shannon limits of xDSL technology, ':lthultimate native asymmetry and limited (-50Mbit/s) downhnk.Optical fibres outperform xDSL in terms of data rate and fibre­to-the-home (FfTH) deployments are growing within Europeat rates depending on the economic models and financing ineach country, and are expected to reach a maximum 10 %penetration by 2010. At the end of 2007, t~e number.o~ FTTHsubscribers in Europe was already exceedIng one ml1hon andthe number of FTTH passed homes was around 5 millions [2].

Products such as the Telef6nica Home Gateway and OrangeLivebox are early, highly successful examples of convergence,and the emergence of efforts such as the Home GateWayInitiative [3] and work within the ITU [4] shows theimportance of HANs and the demand for convergent services.

B./mpact

OMEGA will demonstrate a proof of concept UBB HAN andevaluate roll-out scenarios that create mutual benefits for

society and industry. The disruptive capabilities of such anetwork will open up new business opportunities for the entirevalue chain, from manufacturers to network operators, serviceand content providers up to the end users.

The goal of the OMEGA project is to provide significantcontributions to standards especially in the fields ofconvergence layer, power line and wireless opticcommunications. These objectives are shared by a strongconsortium of major companies and institutions, ranging frommanufacturers, network operators R&D centres and theacademic domain. This vertically integrated group ofcontributors has the knowledge to ensure that outcomes fromOMEGA take into account the requirements of all the'stakeholders' in the industry.

In terms of impact on the European society the OMEGAproject addresses several important challenges. Firstly it willease and encourage the development of new advancedcommunication services to the benefit of both the society andindustry. The expected impact for the citizen is the availabilityof new services due to UBB penetration to the device. From asocietal perspective, OMEGA will enable the emergence of anew 'level of experience' of communication, entertainmentand instant services.

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3

20072006

Year

20052004

10

Figure 3: Access to Internet and PC-based Internet access in EUI5,EU25 and EU27 countries. PC-based Internet access dominates in thehome environment.

70,------------------------,

further elaborated by using financial, economic and socialcharacteristics, in order to get a better insight of HANpotential.

60

Total access to Internet and access via PC

Minimising power consumption due to home electronic devicesis a major expectation. The OMEGA network will provide thelowest power consumption connection (of the several possible)to a device, due to the efficient cooperation that the integratedapproach will bring. In addition there is the potential to 'build­in' energy consumption as a core parameter in the newprotocols and techniques that OMEGA will develop.

c. Business models

According to market analysts, more than 50% of US houseswith a home network are equipped with a router or residentialgateway. This market is addressable from operators andservice providers aiming to offer converged gigabit homeaccess using a dedicated multi-service gateway.

In addition, 50% to 60% of the customers are interested instreaming PC videos to TV set in other rooms or to a primaryTV set equipped with DVR. Therefore an increasing interestfrom telecom and media operators as well as from serviceproviders appears towards the business opportunities arising inthe home environment.

Technology penetration In EU15 households Number of Dwellings, House occupancy and Internet access In EU15 countries

! 80% o SOd<70%.

Ogr1 15 60%

~1~% 0, Oie1840%

°0-_ 30%

j 2O"k

10%

0"102 2,25 2,5 2,75 3,25 3,5

Average pel'lDns per dwelling

100"lo-r------------------------,

90%

200620052004Year

20032002

10

..~ 70

! 60!'0 50

i 40

i 30

l 20

80

100••••••••90

Figure 2: Average values of technology penetration in EUI5countries

Figure 4: A classification of EUI5 countries in terms of internetpenetration, average number of persons per dwelling and totalnumber of HAN market potential (number of dwellings)

As different technologies appear in European homeenvironment (Figure 2), the opportunities for converged homenetworking services are high and especially those related toTV streaming to other devices, content storage and contentacquisition/downloading.

On the other side, services such as home automation andbrowsing/chatting using TV sets are of limited interest mainlyto the high penetration of PCs and its dominance as theInternet access terminal (Figure 3).

In Figure 4, the situation in EU 152 in terms of PC-basedinternet penetrations, the average number of persons perdwelling and the total number of dwellings per country isillustrated. It can be denoted that using these parameters, aclassification of countries in terms of HAN potential can beoccurred: countries with large internet penetration perhousehold and an average number of 2.5 persons per dwellingand countries with moderate internet penetration with morethan 3 persons per dwelling. This first classification can be

OMEGA will also permit to address market segments of theaccess networks that are not strictly home network. Indeed, itsgeneric low cost technology will make it easily to be on boardto solutions for business enterprise solutions, as well as hotspot infotainment and electronic kiosks.

III. CHALLENGES FOR TRANSMISSION TECHNOLOGIES

The general objective of the OMEGA is to distribute in allrooms 1 Gbitls over heterogeneous technologies. Three maintechnologies without need of new wires in the home will beinvestigated and optimised in order to meet this challengingtarget: radio, power line communications and wireless optics.

The challenges to be faced by these technologies in order tobuild a successful Gigabit Home Network concept depend ontheir respective maturity and current deployment.

A. Radio communications

2 EU15 corresponds to the 15 countries composing the European Unionfrom January 1st 1995 to April 30th 2004.

Current und future services and contents in home networks putdiverse demands on the underlying transmission technology.

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4

L ~

Figure 6: Convergence at MAC layer: the Inter-MAC functionalities.

MANAGEMENTPLANE

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:... SEMANTIC ./.........................................-..-.....~

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i-G~~~;~:hPOWER LINE i NTH !

COMM. ! TECHNOLOGY!TECHNOLOGY : DEPENDENT :DEPENDENT : MAC :

MAC LAYER L__~~_~~...J'--__.---_----1

HYBRID RADIOW. OPTICSTECHNOLOGY TECHNOLOGY

DEPENDENT DEPENDENTMAC LAYER MAC LAYER

NETWORK PROTOCOL LAYER I/'!'" SIGNALLINGL....- •••;.~••• PLANE

The OMEGA project will pioneer a new method of inter-MACconvergence, identifying the advantages and the limits of suchan approach in terms of performance, reliability, stability,backward compatibility, costs, and potential impacts ontoexisting standards.

Figure 5: Inter-MAC Reference Architecture

The QoS Control manages the resource allocation of specificflows guaranteeing QoS parameters: Bandwidth, Delay, Jitter,Loss Ratio and Error Ratio. Different classes of service can behandled by the Inter-MAC that translates them in a-compliantservice requirements. The QoS Control performs a completescan over all MACs to estimate which of them can handle thespecific flow belonging to that class of service.

The Path Selection selects all the possible paths to connecttwo or more nodes among various networks. It considersmulti-hop solutions and takes care of load balancingtechniques. Load balancing is needed whenever the QoSparameters could not be assured using only one available path.Existing solutions for multi-hop routing are tailored forhomogenous networks and thus not suited for theheterogeneous home gigabit architecture. Implementing multi­hop connection in the home heterogeneous environment isnovel, and will be undertaken by this functional component.This will consider factors including class-of-service

been any research efforts so far, concerning the convergenceof wired (PLC) and wireless (radio and HWO) technologies inthe challenging scenario of a multimedia and high-data-rateHAN..-o~.;g~ -D~;i~; ---------------------------------:

I/'!'" OmegaAPPLICATION LAYER ..•;../ Infrastructure

MIDDLEWARE LAYER I<~:~::

Current PLC standards provide throughput below 200 Mbpsand over a maximum of 30 MHz, see [7]. OMEGA aims toincrease the current frequency range for power linecommunications up to 100 MHz, a bandwidth for which thechannel capacity exceeds 1 Gbps, see [8]. A tight investigationof medium impairments as well as electromagneticcompatibility in this enlarged spectrum will help to defineadvanced modulation schemes based on multi-carrierapproaches that best fit this wider communication pipecontaining a higher number of carriers.

C. Optical wireless communications

OMEGA aims to combine optical wireless communicationstechniques in order to provide a range of communicationschannels, which together can provide robust optical wirelesscommunications. Infrared optical wireless will be used toprovide Gbps line-of-sight communications, while visible lightcommunication will provide broadcast coverage at lower datarates, see [9].

B. Power line communications

IV. CONVERGENCELAYER

Much research work has been carried out addressing theconvergence of heterogeneous networks, and many Europeancollaborative projects have developed complex softwarearchitectures. All these efforts have in common that theyassume that IPv6 as a minimum common factor for next­generation networks. Many open and lightweight middlewarearchitectures have been designed to handle QoS, resourcemanagement, and security aspects in heterogeneous networks,again assuming heterogeneous IPv6 networks, [10]. Makingthis assumption makes it easy to achieve such architectureswithin a single research project. But, on the other hand,working at such a high OSI level of the protocol stack does notoffer control of other key aspects, such as energy consumptionand optimal use of the network resources. Some research onintegrating PLC and WiFi in a home control network at lowerlevels has been undertaken, but the low target data rate hasmade this effort relatively straightforward and limited impact

The OMEGA project aims to enable the cooperation ofcommunication technologies by developing an inter-MACconvergence layer located between layer 2 (MAC) and layer 3(Network Protocol), with the main idea of switching betweenaccess technologies as proposed in [1]. This approach is totallynew because, to the best of our knowledge, there have not

Due to the trade-off between data rate and coverage rangeinherent to radio systems, only a mixture of different radiotechnologies trimmed to the different classes of applicationscan fulfil all the requirements to the desired extent. To avoidinefficient and cumbersome solutions with coexistenceproblems as experienced today, OMEGA will integrate variousappropriate radio devices into a converged heterogeneousradio network, which meets the customer's demands withrespect to quality of service, reliability, throughput, ubiquity,and self-configuration. In addition to the crucial aspect ofconvergence at the radio layer, advanced PHY, MAC, andcross-layer mechanisms will be developed, [5]-[6].

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identification, policy-based routing table derivation, dynamicbandwidth allocation, protection, reservation, priority routing,and priority queuing.

In order to provide access to different communications systemsan efficient vertical Technology Handover mechanism isrequired. A technique that uses the common semantic todescribe the available channels and chooses between them willbe developed. The technology handover switches between twodifferent technologies and is recalled whenever a networkcongestion, link failure or device mobility occur.

The Monitoring & Event Manager represents the link-up pointfor the functionalities described above. Its task is to triggerdecisions, based on Signalling & Management Planeinformation. Since every Inter-MAC functionality is related toeach other, if Monitoring & Event Manager detects that aparticular link of the Home Network cannot support theservice class imposed by QoS Control, then it will trigger PathSelection module in order to choose a better link. So,information produced from monitoring and event manager willbe used by Inter-MAC to cast its main functionalities.

The Inteifaces with Technology dependent MAC layersinterrogate the underlying MAC layers using special Inter­MAC adapters. The adapters provide the information in aproper and compatible format with the data obtained from theInteiface with Network Protocol Layer. The adapters receiveas input parameters that are different for every MAC(technology-dependent information), and translate them togive in output always the same specifications (technology­independent information). This interface has two main tasks.The first one is to provide a complete set of basic commonfunctionalities: medium sharing, channel allocation, back-offalgorithm, duplexing, flexible access, prioritized access, errorhandling and frame aggregation. The second purpose is re­utilizing this set of basic functions and the informationreceived by the adapters to implement the enhanced Inter­MAC features previously described.

The Inteiface with Network Protocol layer allows the Inter­MAC to communicate with upper layers. It has to be intendedas a standard interface, aiming to not modifying the existentinteraction with the IP layer.

The Inteiface with Signalling and Management Plane. Thekey role of the Inter-MAC is to conveniently translate theinformation received in order to re-arrange data and toimplement the functions previously introduced. Inter-MACprovides a set of management plane elements that can beaccessed by the other layers to optimize their ownfunctionalities. Signalling plane elements are used to establishand release connections as well as to set QoS parameters.

A successful project will develop a future-proof scalable inter­MAC layer that will provide the 'glue' for the OMEGAnetwork and developments after the completion of the project.

5

v. CONCLUSION

In this paper, we describe a project that will have a numberof significant outcomes. It will provide a substantial consumer"pull" for next-generation broadband by enabling the sharingof large-date user-generated content, which will, in turn, raisethe expectation for higher data rates.

Among all aspects investigated in the FP7 OMEGA project,this paper focuses on future usages and business cases for theGigabit Home Networks as well as on the convergence amongheterogeneous transmission technologies to be used in futureHome Networks.

Home Area Networks based on the OMEGA concepts willgive the possibility of delivering new high-bandwidth servicesto the user throughout the home, by offering access to novel"emotional" experiences or virtual services.

ACKNOWLEDGEMENT

The research leading to these results has received funding fromthe European Community's Seventh Framework ProgrammeFP7/2007-2013 under grant agreement n° 213311 also referredas OMEGA.

REFERENCES

[1] ICT OMEGA project, http://www.ict-omega.eu

[2] Source IDATE, http://www.idateJr/.

[3] Home Gateway Initiative, http://www.homegatewayinitiative.orgl

[4] ITU Study Group 15- Home Network Initiative http://www.itu.int/ITU­T/jca/hnlindex.phtml

[5] 1. Lorincz and D. Begusic, "Physical layer analysis of emerging IEEE802.11n WLAN standard" International Conference on AdvancedCommunication Technology, ICACT 2006

[6] Su Khiong Yong and Chia-Chin Chong, "An Overview of Multi-gigabitWireless through Millimeter Wave Technology: Potentials andTechnical Challenges", EURASIP Journal on Wireless Communicationsand Networking, Volume 2007, Article ID 78907

[7] HomePLug Power Line Alliance, http://www.homeplug.org/home

[8] Ouzzif, Meryem; Le Masson, Jerome; "Channel Capacity StatisticalAnalysis for Indoor Power Line Transmissions", Signals, Systems andElectronics, 2007. ISSSE '07. International Symposium on July 302oo7-Aug. 2 2007 Page(s):575 - 578

[9] K.-D. Langer, J. Gubor, "Recent developments in optical wirelesscommunications using infrared and visible light," Proc. ICTON 2007,Vol. 3, pp.146-151.

[10] G. Fodor, A. Eriksson and A. Tuoriniemi, "Providing QoS in AlwaysBest Connected Networks", IEEE Communications Magazine, Vol. 41,No.7, pp. 154-163, June/July 2003.

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