standardization and research in cognitive and dynamics spectrum access networks ieee-2010

IEEE Communications Magazine • January 2010 710163-6804/10/$25.00 © 2010 IEEE

The authors are membersof IEEE SCC41; however,the views presented hereinare those of the authorsand do not represent theviews of the IEEE SCC41or its projects.

IEEE STANDARDS IN COMMUNICATIONS ANDNETWORKING

Fabrizio Granelli, University of Trento

Przemyslaw Pawelczak, University of California, Los Angeles

R. Venkatesha Prasad, Delft University of Technology

K. P. Subbalakshmi and Rajarathnam Chandramouli, Stevens Institute of Technology

James A. Hoffmeyer, Western Telecom Consultants, Inc.

H. Stephen Berger, International Association of Radio and Telecommunications Engineers

Standardization and Research inCognitive and Dynamic Spectrum Access Networks: IEEE SCC41 Efforts and Other Activities

INTRODUCTION

The increase in computational abilities of cur-rent electronic devices, and recent developmentsin computer science and artificial intelligencehave permitted researchers to start thinkingabout introducing cognitive functionalities inwireless networks and devices. These functionali-ties allow wireless systems to become more flexi-ble. They also enable appropriate actions byadapting the internal parameters, after inferringfrom the environment, to best fulfill the needs ofthe user. It is expected that these cognitive-enabled wireless systems will be the dominatingforce in combating observed scarcity of the radiospectrum. Thus, the idea of cognitive radio(CR), as it is called in the literature, has attract-

ed considerable attention. Since the introductionof this concept in 1999 by Mitola [1], manyresearch results have been reported on thistopic.

Growing interest in CR was demonstrated bythe start in 2005 of the IEEE CommunicationsSociety Technical Committee on Cognitive Net-works [2]. Moreover, due to the importance ofCR, in 2004 the IEEE initiated a set of stan-dardization projects related to CR called IEEEP1900, which evolved in 2006 into IEEE Stan-dards Coordinating Committee 41 (IEEESCC41), “Dynamic Spectrum Access Networks”[3]. The activities of IEEE SCC41 aim at facili-tating the development of research ideas intostandards to expedite the use of research resultsfor public use. Now the IEEE SCC41 hasbecome the premier forum for standardizingconcepts related to CR [4].

CR standardization as well as research hasdramatically evolved since recent discussions onthe topic [4, 5]. For example, the utility of CRhas been recognized by the European Telecom-munications Standards Institute (ETSI) and theThird Generation Partnership Project (3GPP) asan important enabler for future wireless services.Therefore, this article reviews recent achieve-ments of IEEE SCC41 as well as unexploredissues in the field of CR standardization. It alsodiscusses non-IEEE SCC41 CR standardizationactivities, like those of the InternationalTelecommunication Union — Radiocommunica-tion Standardization Sector (ITU-R), ETSI,Object Management Group (OMG), SDRForum, and 3GPP.

The rest of the article is structured as follows.

ABSTRACT

Spectrum crowding, spectrum management,quality of service, and user support are the top-ics of vigorous research in the cognitive anddynamic spectrum access network communities.As research matures, standardization provides abridge between research results, implementation,and widespread deployment of such networks.This article reports recent developments withinthe IEEE Standardization Coordinating Com-mittee 41, “Dynamic Spectrum Access Net-works.” It outlines possible futurestandardization topics for IEEE SCC41, in theframework of other related standardizationactivities, and discusses open research issues thatpresent future challenges for the standardizationcommunity.

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IEEE Communications Magazine • January 201072

A detailed description of IEEE SCC41 is provid-ed in the next section, while the following sec-tion provides an overview of open issues inresearch and standardization of CRs that couldbe included in the future activities of IEEESCC41. We then provide descriptions of otherstandardization activities related to IEEESCC41. The final section outlines some ideas totighten interaction between the research andstandardization communities.

IEEE SCC41: GOALS, STRUCTURE,AND ROADMAP

This section provides an overview of the goals,structure, and roadmap of IEEE SCC41. Basedon a summary of IEEE SCC41 structure from [4,5], additional and updated information on recentdevelopments is given.

GOALS OF THE IEEE SCC41The objective of IEEE SCC41 is to develop stan-dards supporting new technologies for next-gen-eration radio and advanced spectrummanagement. The IEEE Communications Soci-ety and IEEE Electromagnetic Society begansponsoring, in 2004, initial projects related toCR in the IEEE 1900 series. In 2006 the IEEEStandards Association directed the reorganiza-tion of this effort as Standards CoordinatingCommittee 41 with dynamic spectrum access(DSA) networks as the assigned scope, where“the focus is on improved use of spectrum.” Inother words, IEEE SCC41 deals with an area oftechnological convergence, wherein radio engi-neering, wireless networking, computer science,software engineering, network management, andother disciplines contribute to the success of CRdeployment.

Active dialog between different standard bod-ies is crucial for IEEE SCC41. SCC41 initiatesand maintains interaction with relevant IEEEand external standards committees. For example,through the IEEE sector membership in ITU-R,IEEE SCC41 has provided inputs from its workto ITU-R. IEEE SCC41 also interacts with regu-latory bodies such as U.S. Federal Communica-tions Commission (FCC), the U.K. Office of

Communications, and other national regulatoryentities.

IEEE SCC41 believes that CR standardiza-tion can be considered an interactive process ofbusiness case, technology, and policy, as depict-ed in Fig. 1. Although research is typicallythought of as a technological component only,business cases and policy research must be takeninto account, especially in CR standardization. Abrief account of these aspects is discussed below.

Business Cases: The current forecast is thatthe communication world, especially in theaccess loop, will be completely wireless. Thisimplies a growing need for spectrum resourcesfor many devices, which are anticipated to floodthe market. As a consequence, the developmentof efficient techniques to optimize spectrumusage and access is required. Thus, the userrequirements drive new business cases, which inturn drive the need for more spectrum. Newradio technologies, like ultra wideband andmethodologies such as policy radio, opportunis-tic spectrum access, CR, and networks that uti-lize these radio technologies are opening up newbusiness opportunities. The extra efforts in thedirection of reusing the spectrum as well as thestandardization of these aspects mainly dependon the business opportunities for various players(i.e., manufacturers and service providers).

Technologies: Businesses that generate newrequirements are responsible for promotingtechnology developmental activities. Thus, indus-try and academia are driven toward finding newmethods, in this case more efficient spectrumuse methods.

Policies: The technology alone cannot sup-port the requirements generated by new businesscases. The technology can prove what can bedone, but it does not account for the develop-ment of the business and reaching out to endusers. Thus, the above two steps can yield suc-cess only if supported by new initiatives in regu-latory procedures. In the CR scenario policiesare enforced by national regulators as well asinternational committees such as ITU-R.

Given the goals of IEEE SCC41, we nowdescribe in detail each work group (WG) in thenext section.

IEEE SCC41 STRUCTUREA schematic representation of all IEEE SCC41WGs is represented in Fig. 2 (top), while thetimeline of IEEE SCC41 (and other importantmilestones in CR standardization described inlater sections) is given in Fig. 2 (bottom). IEEESCC41 is currently structured into five activeWGs. Each WG is responsible for drafting astandard for a specific topic described below.

IEEE 1900.1: Definitions and Concepts forDSA: Terminology Relating to EmergingWireless Networks, System Functionality,and Spectrum Management — IEEE 1900.1,approved on 26 September 2008 by the IEEEStandards Association as an operative standard,acts as a glue to other IEEE SCC41 WGs byproviding common definitions of terms and con-cepts. This common vocabulary is critical to theCR community, ensuring common understand-ing of the technical terms. This was necessitated

Figure 1. Interaction between technology, policies, and business case scenariosas the drivers of CR system standardization.

Standards

Business cases - User requirements - Operators/service providers - Component manufacturers

Technologies - Radio components - Radio network architectures - Protocol specifications

Policies - Regulatory - Operational - Radio environment


IEEE Communications Magazine • January 2010 73

since various research groups and industrieswere using the terms in this arena merely fromtheir own viewpoints. Therefore, it is necessaryto have a common understanding to ensureaccurate and precise communication. IEEE1900.1 provides normative definitions supple-mented with informative text. This informativematerial is necessary because of the complexityand interrelation of the terms for which norma-tive definitions are provided. It further providesexplanations to germinate a coherent view of thevarious efforts taking place in the broad area ofCR.

IEEE 1900.2: Recommended Practice forthe Analysis of In-Band and Adjacent BandInterference and Coexistence betweenRadio Systems — IEEE 1900.2, approved on29 July 2008 by the IEEE Standards Association,documents all aspects of a framework for analyz-ing the interference and coexistence between dif-ferent wireless systems. The cost-gain trade-offsof using a particular system, the harmful inter-ference (and its thresholds), and their impactsare all considered in the analysis, since new wire-less technologies, while attempting to improvespectral efficiency by being flexible, collabora-tive, and adaptive, can cause interference and

coexistence issues. Therefore, this WG estab-lished a common standard platform on whichthe disputing parties can present their cases andresolve them amicably.

IEEE 1900.4: Architectural Building BlocksEnabling Network-Device Distributed Deci-sion Making for Optimized Radio ResourceUsage in Heterogeneous Wireless AccessNetworks — IEEE 1900.4 addresses DSA andnetwork operational issues in heterogeneouswireless networks. With the availability of multi-ple wireless systems on terminals, the network orthe terminals need to decide in a distributedmanner which system to use. Thus, distributeddecision making in such heterogeneous networksis an important characteristic. The network archi-tecture that enables reconfigurability of terminalsfor such a system, providing the QoS and increas-ing spectrum utilization, is addressed in the stan-dard. The functionalities and interaction betweenthe network and the devices are also addressed.This WG has strong participation from the EUfunded End-to-End Reconfigurability project, aswell as from industry. IEEE 1900.4 WG wasapproved by the IEEE Standards Association on27 February 2009. More detailed information onthis WG can be found in [6].

Figure 2. CR standardization: (top) IEEE SCC41 organization structure and its relationship with otherstandardization entities (for comparison see [4, Fig. 2]); note the missing WG3 (see text); (bottom) time-line of important standardization projects related to CR.

Other IEEE entities802.{16, 18, 19, 20, 21,22}

External to IEEEITU-R, SDR forum, OMG, 3GPP, ETSI

IEEE standards coordinatingcommittee 41

- Conferences- Journals

WG1Terminology and

concepts

Activestandard1900.1

WG2Interference and

coexistence


WG4Optimized spectrum

utilization


WG5Policy languages

Draftingstandard

WG6Spectrum sensing

interfaces

Draftingstandard

Proposals fornew standardsand technicalcontributions

Technical researchcommunity

IEEE 1900.2 complete27 March 2008

ITU-R Resolution 805published

November 2007

IEEE CommunicationsSociety technical

committees

IEEE 1900.3 withdrawnOctober 2008

IEEE 1900.4.1 and1900.4a startsMarch 2009

IEEE 1900.1 complete12 June 2008

IEEE 802.22 draft 1.3released

November 2008

ETSI RRS group starts19 February 2008

IEEE 1900.5 and1900.6 startsAugust 2008

IEEE 1900.4 complete30 January 2009

Liaisons asneeded

With the availability

of multiple wireless

systems on terminals,

the network or the

terminals need to

decide in a

distributed manner

which system to use.

Thus, the distributed

decision making in

such heterogeneous

networks is an

important

characteristic.



On 19 March 2009 the IEEE 1900.4 WGstarted work on two new projects.

1900.4a: Architectural Building BlocksEnabling Network-Device Distributed Deci-sion Making for Optimized Radio ResourceUsage in Heterogeneous Wireless AccessNetworks — Amendment: Architecture andInterfaces for Dynamic Spectrum AccessNetworks in White Space Frequency Bands— IEEE 1900.4a is aimed at the definition ofarchitecture and interfaces for efficient utiliza-tion of white space (i.e., unused wireless spec-trum). Since the available white space differsfrom country to country, and is essentially anever changing context, this WG activity isfocused on creating a common system for whitespace devices to manage whatever availablewhite space they have.

1900.4.1: Interfaces and Protocols EnablingDistributed Decision Making for OptimizedRadio Resource Usage in HeterogeneousWireless Networks — This project providesdetailed description of interfaces and serviceaccess points defined in IEEE 1900.4, enablingdistributed decision making in heterogeneouswireless networks and obtaining context informa-tion for this decision making process. This stan-dard facilitates innovative, cost-effective, andmultivendor production of network and terminalside components of the IEEE 1900.4 system andaccelerates commercialization of this system toimprove capacity and quality of service in het-erogeneous wireless networks.

IEEE 1900.5: Policy Language and PolicyArchitectures for Managing CR for DSAApplications — IEEE 1900.5, started in August2008, aims at defining a policy language (or a setof policy languages or dialects) to specify inter-operable vendor-independent control, andbehavior of CR functionality for DSA resourcesand services. In other words, the purpose of theWG is to define a set of policy languages andtheir relation to policy architectures for manag-ing the features of CR for DSA applications.The initial work is concentrated on standardizingthe features necessary for a policy language tobe bounded to one or more policy architecturesto specify and orchestrate the functionality andbehavior of CR features for DSA applications.

IEEE 1900.6: Spectrum Sensing Interfacesand Data Structures for DSA and OtherAdvanced Radio Communication Systems— IEEE 1900.6, was also started in August 2008.The intended standard will define the informa-tion exchange between spectrum sensors andtheir clients in radio communication systems.The logical interface and supporting data struc-tures used for information exchange will bedefined abstractly without constraining the sens-ing technology, client design, or data linkbetween sensors and clients.

It is important to note that the IEEE P1900.3WG (Dependability and Evaluation of RegulatoryCompliance for Radio Systems with DynamicSpectrum Access), due to lack of volunteers, wasdismantled in 2008. The primary focus of this

WG was to provide a set of tests and evaluationmethods to be used in regulatory compliancetesting of CR devices.

ROADMAP OF IEEE SCC41Notwithstanding the work in all active WGs,IEEE SCC41 has taken an initiative to invitemore projects and potentially set up new StudyGroups (SGs) or WGs. SCC41 has developed aprocess for the evaluation of new project pro-posals. A new project proposal may first begiven SG status to further evaluate the viabilityof the project and interest from the community.However, if it is clear in advance that there are asignificant number of parties interested in astandardization topic, a Project ApprovalRequest will be submitted to the IEEE StandardAssociation Standards Board for approval as aWG without going through the intermediatestates such as the SG. Thus, IEEE SCC41 isactively working as an incubator and an umbrellafor supporting, facilitating, and encouraging theefforts for standardization of the multifacetedissues of cognitive communications.

OPEN ISSUES INIEEE SCC41 STANDARDIZATION

The scientific community, inspired mainly by thework on CR [1] and cognitive networks (CNs)[7], focused on the analysis of the specific issuesand the identification of possible architectures tosupport CRs as a way to improve spectrum uti-lization on one hand, and CNs as a suitableframework for network self-configuration andQoS provisioning on the other. In the standard-ization framework, the work of IEEE SCC41 isrelatively new with many challenges to beaddressed, some of those derived from problemsoutlined in the literature. We outline some ofthe potential and relevant issues to be addressedby IEEE SCC41.

REGULATION AND TESTINGRegulatory bodies must ensure that devices inthe CR field conform to contemporary andfuture requirements for radio equipment. Toachieve this goal, a conformity assessment appa-ratus must be developed using many compo-nents, such as equipment certification, qualitycontrol, and field monitoring. Providing regula-tors with the standards they require to fulfilltheir mandate is an area for many future pro-jects. Regulation documents would describemethods to measure the interference caused byCR and CNs, and quantify the intelligence ofsuch devices. With this background it is impor-tant to restore the work of IEEE P1900.3, whichhad some of these goals in mind.

SYSTEM DESIGN AND NETWORKINGThere are certainly many aspects of CN systemsthat need standardization. While wireless region-al access networks are covered by CR standards(e.g., IEEE 802.22), other wireless network typesare not standardized with respect to CR. Oneimportant aspect of network design is mediumaccess control (MAC). In the case of wireless adhoc and sensor networks, distributed MAC pro-

IEEE SCC41 is

actively working as

an incubator and an

umbrella for

supporting,

facilitating, and

encouraging the

efforts for

standardization of

the multi-faceted

issues of cognitive

communications.



tocols operating in an opportunistic spectrumaccess manner (on licensed and unlicensed chan-nels) are not yet covered by any standard. Con-temporary intelligent spectrum managementstandards, such as IEEE 802.11k, cover only theunlicensed bands. Therefore, there is a need fora generalized CR-MAC, which will take intoaccount many of the specificities of CR. It isenvisaged that many future versions of MAC willinherit from this generalized CR-MAC.

Another issue is cross-layer design, meant asan interlayer interaction of CN entities. Whilethis aspect is included in the concept of CNs as ameans to support user and application require-ments, no relevant and comprehensive analysis isavailable to address the performance and behav-ior of applications and networks based on CRand CN technology [8]. Unique signaling archi-tectures are needed in order to enable internalor network-wide exchange of information andcommands between cognitive devices or amongdistributed devices constituting a single cognitiveentity. While the debate on cross-layering hasalready gained maturity, even with conflictingideas [9], it is worthwhile to address signalingarchitecture as a relevant point to support cross-layer or general optimization solutions.

SECURITYAlthough existing wireless security standards canbe used in CR networks for certain aspects (e.g.,encryption), there are several unique challengesthat arise merely due to the opportunistic natureof spectrum access [10, 11]. For example, inorder to accurately sense white spaces, as well asto securely transmit this decision to all nodes inthe secondary network, it is not only necessaryto design standalone optimal sensing techniques,but also authenticated encryption enabled proto-cols that will allow a reliable, joint, and speedydecision for the entire network. Hence, a moreholistic approach is needed while designing theseveral components of the CR network. A gooddesign will result in accurate and secure primaryuser (PU) detection [10], resilience to non-jam-ming denial of service (DoS) attacks on the sec-ondary user (SU) [11], efficient and fairspectrum sharing, accurate authorization, andcomputational efficiency.

In order to understand the components need-ed to design a secure CR network, it is necessaryto understand the threats a CR network couldface. The problem of spectrum opportunitydetection is intimately connected with the prob-lem of detecting PU activity in any given band. Ifthis key functionality is not accurately imple-mented, one of the following undesirable situa-tions could occur.

DoS Attacks on the Secondary Network —If a set of malicious agents can impact the deci-sion on PU activity so that nonmalicious agentsrepeatedly come to the conclusion that a prima-ry is present when indeed it is not, it could resultin several missed opportunities for the nonmali-cious SU network. Furthermore, because thenonmalicious SU will resume the search for anavailable band until it finds an empty one, thiscould potentially lead to quick power depletionfor the SU. The problem gets even more compli-

cated when the SU node is a participant in anestablished secondary communication. This isbecause the node will have to tear down its exist-ing connections and set up an agreement withcommunicating nodes for a rendezvous channel.If a dedicated channel is not available for ren-dezvous, each node will have to asynchronouslysearch for a common available channel toresume communication. If the DoS attack iscoordinated, the algorithm for the rendezvousmay not converge quickly, or at all. Hence,emerging standards need to consider this impor-tant problem in the specification of the sensingprotocol, decision protocol (especially when cen-tralized decisions are made), and rendezvousprotocol.

DoS Attacks on the Primary Network —This problem arises when the malicious entitiesrefuse to leave the band when a PU arrives,which potentially affects the decision of otherSUs (with no malicious intent) by propagatingfalse notions regarding the return of the PU. Inlight of the fact that the U.S. FCC has recentlydiscontinued the use of interference tempera-ture (IT) as a metric for measuring the disrup-tion caused by any node, IT-based solutions toautomatically exclude errant nodes may not bepossible. Besides, it would be ideal to isolatethe malicious nodes rather than the nodes thatwere inadvertently fooled. Although this is aharder goal, this may be important in order toprevent an accidental partial DoS on the SUnetwork when defending against DoS on thePU network.

To summarize, it is important to define met-rics that can be used to capture the level of secu-rity in a DSA and CR network. In order toachieve a high level of security, a variety of solu-tions would have to be co-adopted in the upcom-ing standards, including those that are used incryptographic security and authentication, gametheory, fault tolerance, statistical signal process-ing, and so on.

CR RELATED STANDARDSGiven the description of IEEE SCC41 it is alsoimportant to look at other standardizationendeavors, inside and outside of IEEE. For asimilar discussion we refer to [5].

IEEE 802.22To make universal broadband access a reality, toallow the Internet service industry to grow, andto make consumer Internet access competitive,the TV white spaces were opened for unlicenseduse in the United States by the FCC in 2008.Luckily, already in 2005 IEEE 802.22 took theinitiative to define a standard to use TV whitespaces [12].

IEEE 802.22 is thought of as an alternativetechnology to IEEE 802.11, operating in a spec-trum range that allows better and further prop-agation (54–863 MHz). The physical and MAClayers of IEEE 802.22 are similar to IEEE802.16 with the amendments related to theidentification of the PUs and defining thepower levels so as not to interfere with theadjacent bands. The two important entities

To make universal

broadband access a

reality, to allow Inter-

net service industry

to grow, and to

make the consumer

Internet access

competitive, the TV

white spaces were

opened for unli-

censed use in USA

by the FCC in 2008.

Luckily, already in

2005 IEEE 802.22

took the initiative to

define a standard to

use TV white spaces.



defined in the standard are the base station(BS) and customer premises equipment (CPE).BS controls all the CPE’s decisions as to whento send data and the channels to use. CPE sens-es the spectrum in its vicinity, helping in dis-tributed detection of PU activity. At the time ofwriting this article, IEEE 802.22 was still in thestandard drafting phase. The document reachedversion 2.0 in May 2009.

STANDARDS RELATED TO IEEE 802.16The IEEE 802.16 group has its own set of stan-dards that support CR-like functionalities. IEEE802.16.2-2004, which superseded IEEE 802.16.2-2001 in March 2003, describes engineering prac-tices to mitigate interference in fixed broadbandwireless access (BWA) systems. This documentexplained methods of efficient coexistence ofmultiple BWA systems. IEEE 802.16a-2003, asan amendment to IEEE 802.16-2001 and com-pleted in March 2003, described the operation ofthe wireless MAN interface of BWA networks inlicense-exempt bands. It also discussed interfer-ence analysis and coexistence issues for BWAnetworks in these bands. Finally, improved coex-istence of IEEE 802.16-based networks workingin the unlicensed bands is covered by the IEEE802.16h WG. At the time of writing this article,IEEE 802.16h is in the IEEE Standards Associa-tion sponsor ballot stage.

STANDARDS RELATED TO IEEE 802.15Wireless personal area networks, covered by thework of IEEE 802.15 group, work in the license-exempt bands and also have their own set ofstandards related to coexistence. These includeIEEE 802.15.4-2003 (completed in May 2003),which describes dynamic channel selection mech-anisms, and IEEE 802.15.2-2003 (completed inJune 2003), which describes general coexistenceguidelines.

STANDARDS RELATED TO IEEE 802.11Coexistence mechanisms are also included inIEEE 802.11 standards: IEEE 802.11-2007 andIEEE 802.11y-2008. IEEE 802.11-2007, pub-lished in July 2007, describes dynamic frequencyselection and transmit power control for coexis-tence with satellite and radar systems operatingin the 5 GHz band, first described in IEEE802.11h. IEEE 802.11y-2008, approved inSeptember 2008, is an extension of IEEE 802.11to the 3650–3700 MHz frequency range, which isshared with satellite Earth stations.

IEEE 802.19This standard defines general coexistence met-rics for all IEEE 802 networks working in theunlicensed bands. Although focusing on IEEE802 networks, the guidelines of the standard canbe applicable to other unlicensed wireless sys-tems. Currently, the IEEE 802.19 technical advi-sory group is evaluating coexistence betweenIEEE 802.11y and IEEE 802.16h.

ITU-R ACTIVITIES RELATED TO CRStandardization bodies outside of IEEE are alsoworking on their own sets of standards related toCR, and ITU-R is particularly active. In the CRimplementation domain, in 2007 ITU-R pub-

lished ITU-R Report M.2117, “Software DefinedRadio in the Land Mobile, Amateur, and Ama-teur Satellite Services.” In ITU-R Resolution805 (Agenda for 2011 World Radiocommunica-tion Conference) in Agenda Item 1.19, ITU-Rdecided “to consider regulatory measures andtheir relevance, in order to enable the introduc-tion of software-defined radio and cognitiveradio systems, based on the results of ITU-Rstudies, in accordance with Resolution 956(‘Regulatory Measures and their Relevance toEnable the Introduction of Software-DefinedRadio and Cognitive Radio Systems’).” In a sim-ilar Resolution 951 (“Enhancing the Internation-al Spectrum Regulatory Framework”), ITU-Rconcluded “that evolving and emerging radio-communication technologies may enable sharingpossibilities and may lead to more frequency-agile and interference tolerant equipment andconsequently to more flexible use of spectrum.”To address WRC-11 Agenda Item 1.19, StudyGroup 1 (Spectrum Management) has beenassigned to be the lead organizational entitywithin ITU-R.

ITU-R Study Group 5 (Mobile, Radio Deter-mination, Amateur, and Related Satellite Services)Working Party 5A (Land Mobile Service Exclud-ing IMT-2000; Amateur and Amateur Satellite Ser-vices) will continue its work on the developmentof an ITU-R Report entitled “Cognitive RadioSystems in the Land Mobile Service.” This workis in response to two Questions on SDR andCRS assigned to ITU-R Working Party 5A:ITU-R 230-2/5 (Software Defined Radios) andITU-R 241-1/5 (Cognitive Radio Systems in theMobile Service). Note that in ITU-R terms aQuestion “is a statement of a technical, opera-tional, or procedural problem, generally seekinga Recommendation, Handbook, or Report.”

SDR FORUM ACTIVITIESThe SDR Forum is also involved in several activ-ities related to CRs, CNs, and DSA. The opera-tion plan from January 2009 described thefollowing activities:• The CR WG is initiating preparation of a

literature survey to identify and presentquantifiable metrics that objectively mea-sure the benefits of CR technology. Initialwork on this report was expected to con-clude in 2009.

• The group Test Guidelines and Require-ments for Secondary Spectrum Access ofUnused TV Spectrum will aim at use casesand test requirements for the use of CRtechniques to allow unlicensed secondaryspectrum access for unused TV bands.

• A “Test and Measurement of Unique Fea-tures for Software-Defined/CognitiveRadios” report is being prepared by theTest and Measurement Task Group to iden-tify the unique test challenges created bysystems with SDR/CR features and proposesolutions in such a framework.

• The CR Market Study will represent a mar-ket study focused on CR and white spacecommunications, to be delivered during2010.Apart from this, in the course of 2009 and

2010, the SDR Forum will aim at projects relat-

IEEE 802.16.22004,

which superseded

IEEE 802.16.2-2001

in March 2003,

describes

engineering practices

to mitigate

interference in fixed

Broadband Wireless

Access (BWA)

systems. This

document explained

methods of efficient

coexistence of

multiple BWA

systems.



ed to different topics such as certification of CRtechnologies, CR architecture recommendations,design processes and tools, and a hardwareabstraction layer for CR.

ETSI STANDARDS RELATED TO CRIn February 2008 ETSI started a new technicalcommittee on reconfigurable radio systems(RRS), with liaison with IEEE SCC41 and SDRForum. RRS has four groups: WG1 (SystemAspects), WG2 (Radio Equipment Architecture),WG3 (Functional Architecture for CognitivePilot Channel), and WG4 (Public Safety). WG1issued two drafts related to technical recommen-dations: DTR/RRS-01002, “Cognitive Radio Sys-tem Concept,” and DTR/RRS-01003, “SpectrumAspects of Cognitive Radio and SoftwareDefined Radio Systems.” WG2 issued three doc-uments: one complete technical recommenda-tion, TR 102 680, “SDR Reference Architecturefor Mobile Device,” and two draft recommenda-tions, DTR/RRS-02003, “Radio Base StationSoftware Defined Radio Status, Implementationsand Costs Aspects, Including Future Possibili-ties,” and DTR/RRS-02004, “Multiradio Inter-face for Software Defined Radio Mobile DeviceArchitecture and Services.” WG3 published twodraft recommendations, DTR/RRS-03004,“Functional Architecture,” and DTR/RRS-03007,“Cognitive Pilot Channel Design.” Finally, WG4issued two draft recommendations: DTR/RRS-04005, “System Aspects for Public Safety,” andDTR/RRS-04006, “User Requirements for PublicSafety.”

OMG ACTIVITIESThe OMG is also involved in activities related tonext generation radio systems, with the SoftwareRadio Special Interest Group and Software-Based Communication (SBC) Domain TaskForce (DTF). The mission of the SBC DTF isthe development of specifications supporting thedevelopment, deployment, operation, and main-tenance of software technology targeted to soft-ware defined communication devices. The SBCDTF mainly targets issues related to the use ofUnified Modeling Language (UML) and modeldrives development technology for SDR, inter-operability and exchangeability of software-defined components, and, in general, attempts tobroaden the scope to new related technologies(e.g., CR, digital intermediate frequency, spec-trum management).

3GPP ACTIVITIES AROUND CR3GPP is also interested in standardizing CR-likefeatures in its future releases. In particular,3GPP plans to enhance Long Term Evolutionstandard (radio interface of the Universal MobileTelecommunications System [UMTS]) inRelease 10 with CR functionalities. For examplethe idea of a cognitive reference signal is pro-posed through which each radio access networkcan broadcast the interference level, frequencybands, and radio access technologies of othernetworks, and other information that can helpnewly joined user equipment to choose the bestradio access network.

We summarize different aspects of standard-ization for CR in Table 1.

CONCLUSIONS

IEEE SCC41 is providing a timely effort to stan-dardize the frameworks of CRs and CNs. As wehave shown, many additional issues require stan-dardization and offer future work for IEEESCC41. As given in Fig. 1, standardizationshould represent a melting pot of three aspects:technology, policy, and business. To achieve thisgoal, all the above topics should converge withinthe working groups of any standardization effort.

To support proper balance among these threeaspects, the IEEE Communications SocietyTechnical Committees are collaborating with theIEEE Standards Association. This facilitatesinteraction between the standards developmentprocess and the research community. In thisframework it will be useful to further increaseinvolvement of researchers by building tighterlinks between IEEE Societies, their TechnicalCommittees, and IEEE Standards Associationactivities. In this regard, a good starting pointwould be to identify a reference person to act asstandards liaison in each committee, followingwhat is currently done by the IEEE Communica-tions Systems Integration and Modeling Com-mittee. An alternative or complementary processfor standardization committees would be to con-tact IEEE Technical Committees in order tosolve specific problems within their researchdomain. Such action would activate a processwhere contacted Technical Committees will acti-vate specific WGs to produce a report for dis-cussion with respective standardization WGs.Good examples of discussion fora for the inter-action of technology, policy, and business in aCR framework are IEEE DySPAN and ICSTCrownCom. They represent the premier eventsdealing with DSA networks, regulations, stan-dardization, and implementation for CRs, inter-ference and coexistence analysis, and alsoongoing research and development efforts world-wide.

Summarizing, IEEE SCC41 represents a sig-nificant effort to foster standardization in theframework of next-generation wireless systems

Table 1. Summary of CR activities in standardization and open issues.

Functionality Covering organization

Definitions IEEE SCC41, ETSI, ITU-R

Coexistence IEEE 802.19, IEEE SCC41

SDR IEEE SCC41, SDR Forum, ITU-R, OMG

Radio interfaces IEEE 802.22, 3GPP

Heterogeneous access ETSI, IEEE SCC41

Spectrum sensing IEEE 802.22, IEEE SCC41

Testing —

Networking (CR-MAC) —

Security —

GRANELLI LAYOUT 12/16/09 1:33 PM 7


by bringing together experts in technology, poli-cy, and business cases. The results achieveddemonstrate the capability of the working groupsand project coordination as well as relevantpotential for further activities on the open issuesidentified in this article.

ACKNOWLEDGMENTSThe uthors would like to thank the IEEE SCC41working group chairs and officers for valuablediscussion, and Piotr Cholda for important com-ments.

REFERENCES[1] J. Mitola III, “Cognitive Radio for Flexible Mobile Multi-

media Communications,” Proc. IEEE MOMUC ‘99, SanDiego, CA, Nov. 15–17, 1999.

[2] IEEE Technical Committee on Cognitive Networks, 2009;http://www.eecs.ucf.edu/tccn

[3] IEEE Standard Coordinating Committee 41, 2009;http://www.scc41.org

[4] R. V. Prasad et al., “Cognitive Functionality in Next Gen-eration Wireless Networks: Standardization Efforts,”IEEE Commun. Mag., vol. 46, no. 4, Apr. 2008, pp.72–78.

[5] M. Sherman et al., “IEEE Standards Supporting Cogni-tive Radio and Networks, Dynamic Spectrum Access,and Coexistence,” IEEE Commun. Mag., vol. 46, no. 9,July 2008, pp. 72–79.

[6] S. Buljore et al., “Architecture and Enablers for Opti-mized Radio Resource usage in Heterogeneous WirelessAccess Networks: The IEEE 1900.4 Working Group,”IEEE Commun. Mag., vol. 47, no. 1, Jan. 2009, pp.122–29.

[7] R. Thomas, L. DaSilva, and A. MacKenzie, “CognitiveNetworks,” Proc. IEEE DySPAN ‘05, Baltimore, MA, Nov.8–11, 2005.

[8] F. Granelli, D. Kliazovich, and N. L. S. da Fonseca, “Architec-tures and Cross-Layer Design for Cognitive Networks,” inHandbook on Sensor Networks, Y. Xiao, H. Chen, and F.Haizhon Li, Eds., World Scientific, 2009.

[9] V. Kawada and P. Kumar, “A Cautionary Perspective onCross-Layer Design,” IEEE Wireless Commun., vol. 12,no. 1, Feb. 2005, pp. 3–11.

[10] C. Nanjunda and K. Subbalakshmi, “Security Issues inCognitive Networks,” in Cognitive Networks: TowardsSelf-Aware Networks, Q. H. Mahmoud, Ed., Wiley,2007.

[11] Z. Jin, S. Anand, and K. Subbalakshmi, “Mitigating Pri-mary User Emulation Attacks in Dynamic SpectrumAccess Networks using Hypothesis Testing,” ACMMobile Comp. Commun. Rev., 2009.

[12] C. R. Stevenson et al., “IEEE 802.22: The First CognitiveRadio Wireless Regional Area Network Standard,” IEEECommun. Mag., vol. 47, no. 1, Jan. 2009, pp. 130–38.

BIOGRAPHIESFABRIZIO GRANELLI [SM] ([email protected]) received hisLaurea (M.Sc.) degree in electronic engineering from theUniversity of Genoa, Italy, in 1997, with a thesis on videocoding, awarded the TELECOM Italy prize, and his Ph.D. intelecommunications from the same university in 2001.Since 2000 he has been an assistant professor in telecom-munications and co-founder of the Department of Informa-tion Engineering and Computer Science, University ofTrento, Italy, and coordinator of the Networking Laborato-ry. In August 2004 he was a visiting professor at the StateUniversity of Campinas, Brazil. He is author or co-author ofmore than 90 papers published in international journals,books, and conferences. He is guest editor of ACM Journalon Mobile Networks and Applications Special Issues onWLAN Optimization at the MAC and Network Levels, Ultra-Wide Band for Sensor Networks, and Recent Advances inIEEE 802.11 WLANs: Protocols, Solutions, and Future Direc-tions. He is General Vice-Chair and Founder of WICON ‘05,General Chair of CAMAD ‘06, and General Co-Chair andFounder of MOBILIGHT ‘09. He is TPC Co-Chair of IEEEGLOBECOM 2007–2009 Symposia on Communications QoS,Reliability, and Performance Modeling and IEEE CAMAD‘08. His main research activities are in the field of network-ing, with particular reference to network performancemodeling, cross-layering, medium access control, wireless

networks, cognitive radios, and networks. He is Chair ofthe IEEE Communications Society Technical Committee onCommunication Systems Integration and Modeling (CSIM)and Associate Editor of IEEE Communications Letters, IEEECommunications Surveys and Tutorials, and InternationalJournal on Communication Systems.

PRZEMYSLAW PAWELCZAK obtained his M.Sc. degree in elec-tronics and telecommunications engineering from WroclawUniversity of Technology, Poland in 2004 and his Ph.D.degree from Delft University of Technology, the Nether-lands in 2009. Between 2004 and 2005 he was a staffmember at Siemens Software Development Center, Wro-claw, Poland. During fall 2007 he was a visiting scholar atthe Connectivity Laboratory of the University of California,Berkeley. He is currently a postdoctoral researcher at theCognitive Reconfigurable Embedded Systems Laboratory ofthe University of California, Los Angeles. He is the origina-tor and organizing committee member of the IEEE CogNetworkshops, collocated with IEEE ICC 2007, 2008, and2009. He is also a voting member of the IEEE SCC41 Stan-dardization Committee.

R. VENKATESHA PRASAD received his Bachelor;s degree inelectronics and communication engineering and M.Tech.degree in endustrial electronics from the University ofMysore, India, in 1991 and 1994. He received a Ph.D.degree in 2003 from the Indian Institute of Science, Ban-galore. During 1996 he worked as a consultant and pro-ject associate for ERNET Laboratory of Electrical andCommunications Engineering at the Indian Institute of Sci-ence. While pursuing a Ph.D. degree, from 1999 to 2003he also worked as a consultant for CEDT, IISc, Bangalorefor VoIP application developments as part of a Nortel Net-works sponsored project. In 2003 he headed a team ofengineers at Esqube Communication Solutions Pvt. Ltd.Bangalore for the development of various real-time net-working applications. Currently, he is a part-time consul-tant to Esqube. From 2005 to now he has been a seniorresearcher at the Wireless and Mobile Communicationsgroup, Delft University of Technology, working on the EUfunded projects MAGNET/MAGNET Beyond and PNP-2008,and guiding graduate students. He is an active member ofTCCN and IEEE SCC41, and a reviewer of many transac-tions and journals. He is on the TPC of many conferencesincluding ICC, GLOBECOM, ACM MM, and ACM SIGCHI.He is TPC Co-Chair of the CogNet Workshop in 2007,2008, and 2009, and E2Nets (2010) at IEEE ICC. He hasalso run the PerNets workshop since 2006 with IEEECCNC. He is Tutorial Co-Chair of CCNC 2009 and DemoChair of IEEE CCNC 2010.

K. P. SUBBALAKSHMI is an associate professor in the Depart-ment of Electrical and Computer Engineering at StevensInstitute of Technology. Her research interests are in cogni-tive radio, wireless, and information security. Her work isfunded by the U.S. National Science Foundation, U.S. Intel-ligence Systems Support Office, U.S. Army ARDEC, NationalInstitute of Justice, and other sources. She was an invitedPanelist at IEEE ICC 2008 on Security Issues in CognitiveRadio Networks. She was a co-organizer of the Symposiumon Selected Areas of Communications at IEEE ICC 2009.She is a Guest Editor of the EURASIP Journal on AppliedSignal Processing Special Issue on Dynamic SpectrumAccess for Wireless Networking (2009). She was the found-ing co-organizer of the First Workshop on Security Privacyand Authentication in Wireless Networks, IEEE WoWMoM2008. She was a Special Sessions Co-Chair for CROWNCOM2007. She was a Co-Chair of the Network Security Sympo-sium of the IEEE International Conference on ComputerCommunications and Networks in 2007 and 2008. She wasa Co-Organizer of the Symposium on Network and Infor-mation Systems Security 2006. She is the Chair of theSecurity Special Interest Group of the IEEE MultimediaTechnical Committee. She is also the Co-Founder ofinStream Media, LLC, a start-up company developing inter-active video technologies. More information is available athttp://personal.stevens.edu/ksubbala

RAJARATHNAM CHANDRAMOULI is the Thomas Hattrick ChairProfessor of Information Systems in the Department ofElectrical and Computer Engineering at Stevens Instituteof Technology. His research spans the areas of wirelessnetworking and security, human factors in Internet securi-ty and forensics, and applied probability theory. Projectsin these areas are supported by the National ScienceFoundation, U.S. Army, Office of Naval Research, Air

IEEE SCC41

represents a signifi-

cant effort to foster

standardization in

the framework of

next generation

wireless systems by

bringing together

experts in

technology, policy,

and business cases.

The results achieved

demonstrate the

capability of the

working groups and

project coordination.



Force Research Laboratory, National Institute of Justice,and other Department of Defense Agencies. He is Found-ing Chair of the IEEE Communications Society TechnicalCommittee on Cognitive Networks (TCCN), a keynotespeaker at the Wireless Communications and Signal Pro-cessing Conference 2009, a member of the IEEE Commu-nications Society Standards Board, Associate Editor ofAdvances in Multimedia Journal and Journal of Communi-cations, and International Advisory Committee Member ofWCSP 2009. He was on the Steering Committee ofCROWNCOM, General Co-Chair of CROWNCOM 2007,IEEE GLOBECOM 2007 Wireless Communications Sympo-sium Co-Chair, Technical Program Vice-Chair of IEEE CCNC2007 and 2008, Co-Chair of the Workshop on CognitiveNetworks and Communications held with IEEE ICCCN2009, Multimedia Communications Symposium Co-Chairof CHINACOM 2008, and Associate Editor of IEEE Transac-tions on Circuits and Systems for Video Technology. Hiswork on cognitive wireless networks has won an IEEEGLOBECOM 2008 Best Paper Award and an IEEE CCNC2006 Best Student Paper Award. He is also a recipient ofthe NSF CAREER Award and IEEE Richard E. MerwinScholarship. He also the co-founder of inStream Media,LLC, a startup company developing interactive video tech-nologies. More information is avai lable athttp://www.ece.stevens-tech.edu/mouli

JAMES A. HOFFMEYER is president of Western Telecom Con-sultants, Inc. and was previously employed by the NationalTelecommunications and Information Administration wherehe managed a group of up to 25 engineers and scientists.He has over 25 years’ experience in wireless telecommuni-

cation. His current areas of interest include cellular sys-tems, software-defined radio, cognitive radio systems,radio regulation, and international telecommunicationsstandards development. He has held numerous standardsleadership positions as Chair of the predecessor of the SDRForum, and as Chair of working groups in the ITU and theIEEE Standards Association. He has published over 40 tech-nical papers and reports, and has developed more than 45input contributions to the ITU and IEEE. He was awardedthe Department of Commerce Silver Medal while workingfor the NTIA Institute for Telecommunication Sciences. Hisinvolvement with the IEEE Standards Association includesserving on the IEEE SCC41 Management Board, IEEE Com-munications Society Standards Board, IEEE 1900.1 Chair,and IEEE 1900.5 Vice Chair.

H. STEPHEN BERGER is president of TEM Consulting, an engi-neering services and consulting firm dealing in regulatorycompliance, wireless, and EMC. He is the current co-chairof IEEE SCC41, Dynamic Spectrum Access Networks, andchair of the IEEE EMC Society Standards DevelopmentCommittee. He is also President of the International Associ-ation of Radio and Telecommunications Engineers. Beforeforming TEM Consulting he was a project manager atSiemens Information and Communication Mobile, Austin,Texas, where he was responsible for standards and regula-tory management. He has worked in EMC and RF safety for20 years. More recently he has been active in the area ofdisability access to telecommunications and informationtechnology products. He has written numerous technicalpapers and holds several patents in the areas of wireless,EMC, and access technology.

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