Wireless Networking at Dartmouth College

Wireless Networkingat Dartmouth College

Case Study from theEDUCAUSE Center for Applied Research

Paul Arabasz, IDCJudith Pirani, Sheep Pond Associates

ECAR Case Study 9, 2002

4772 Walnut Street, Suite 206Boulder, Colorado 80301www.educause.edu/ecar/

Wireless Networkingat Dartmouth College

EDUCAUSE is a nonprofit association whose mission is to advance higher edu-cation by promoting the intelligent use of information technology.

The mission of the EDUCAUSE Center for Applied Research is to foster betterdecision making by conducting and disseminating research and analysis aboutthe role and implications of information technology in higher education. ECARwill systematically address many of the challenges brought more sharply intofocus by information technologies.

Copyright 2002 EDUCAUSE. All rights reserved. This ECAR Research Study isproprietary and intended for use only by subscribers and those who have pur-chased this study. Reproduction, or distribution of ECAR Research Studies tothose not formally affiliated with the subscribing organization, is strictly pro-hibited unless prior written permission is granted by EDUCAUSE. Requests forpermission to reprint or distribute should be sent to [email protected].

EDUCAUSE CENTER FOR APPLIED RESEARCH 1

Wireless Networking in Higher Education Case Study 9, 2002

© 2002 EDUCAUSE. Reproduction by permission only.

0Wireless Networking

at Dartmouth College

PrefaceThe EDUCAUSE Center for Applied Re-

search (ECAR) produces research to promoteeffective decisions regarding the selection,development, deployment, management,socialization, and use of information tech-nology (IT) in higher education. ECAR re-search includes research bulletins, shortsummary analyses of key IT issues; researchstudies, in-depth applied research on com-plex and consequential technologies andpractices; and case studies designed to ex-emplify important themes, trends, and ex-periences in the management of ITinvestments and activities.

ECAR has investigated the state of wire-less networking in higher education and hasissued “Wireless Networking in Higher Edu-cation.” This research was undertaken inthree phases:� an online survey of 391 EDUCAUSE

members to establish the state of wire-less networking in higher education andto understand its implementation char-acteristics;

� follow-up, in-depth telephone and on-site interviews, covering 17 selected in-stitutions, with IT personnel and univer-sity members who are directly involvedwith the creation, operation, or use ofwireless networks; and

� best practices cases studies with sixhigher education institutions about theirwireless network implementations.Between March and May 2002, ECAR

and IDC began with a list of approximately150 colleges and universities that had ex-perience implementing wireless networks.From this list, 20 were interviewed exten-sively by telephone, and six were selectedfor either on-site visits or extensive telephonefollow-up. On-site visits are rigorous and in-volve nearly two days of interviews andmeetings with the widest variety of institu-tional representatives associated with—oraffected by—the technologies or practicesbeing investigated.

This case study was undertaken to drawon the direct experience of others to pro-vide insights into what has—and, as appro-priate, what hasn’t—worked in wirelessimplementations. It is assumed that readersof the case studies will also read the mainreport, which incorporates the findings ofthe case studies within the generalized con-text of the report.

ECAR wishes to thank the leadership ofDartmouth College for their time, assistance,and diligence in support of this research. Wehope readers of this ECAR case study willlearn from their experiences.

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IntroductionLocated in Hanover, New Hampshire,

Dartmouth College is a private four-yearcollege with an enrollment of 4,200 under-graduates in the liberal arts and 1,500graduate students. With an annual budgetof approximately $425 million (for fiscal year2000), Dartmouth employs approximately3,115 staff and 2,250 faculty. A member ofthe Ivy League, Dartmouth offers 16 gradu-ate programs in the arts and sciences, as wellas a medical school (Dartmouth MedicalSchool), a professional school of engineer-ing (Thayer School of Engineering), and agraduate school of management (TuckSchool of Business). Dartmouth College isalso intimately associated with theDartmouth Hitchcock Medical Center, ofwhich the College and the Medical Schoolare members. In terms of information tech-nology, the two environments are closepeers, sharing various services, althoughDHMC maintains separate networking.

Consistent with its size, Dartmouth main-tains a highly centralized IT organization,known as Peter Kiewit Computing Services.In addition, there are smaller IT organiza-tions affiliated with each of the three pro-fessional schools. With a staff ofapproximately 150, Computing Services con-sists of� Academic Computing� Administrative Computing� Computing Support� Technical Services

Academic Computing focuses on provid-ing services to the student and faculty popu-lation. It includes three subgroups. TheAcademic Consulting Services group pro-vides general consulting assistance to fac-ulty and staff. The Research Computinggroup supports and develops computingapplications and information resources witha primary focus on supporting research. TheCurricular Computing group assists theDartmouth faculty in the use of information

technology for research and instruction.The focal point of support for most in-

stitutional administrative systems, Adminis-trative Computing provides systems needsanalysis, design, development or procure-ment, operations, and maintenance; dataadministration; information systems andcapacity planning; system security; and con-sulting on system use. This division formsclose partnerships with institutional effortsto improve the effectiveness and efficien-cies of local or campus-wide administrativeprocesses.

Computing Support includes ComputerSales, Service, and Support and Communi-cations and Telephone Services.

Technical Services develops and supportsDartmouth’s technical infrastructure for datanetworking and computing. The TechnicalServices division supports the school’sEthernet backbone and servers, connectionof the backbone to the Internet, and net-work applications.

The core of Dartmouth’s computing in-frastructure is an Ethernet backbone em-ploying Nortel routers that links all 161 ofthe school’s buildings. Dartmouth supportsapproximately 20 public computing clustersacross the campus, the largest of which arelocated in the Kiewit Computation Centerand the Baker-Berry Library. The school alsoprovides extensive computing facilities forfaculty, graduate students, and researchers,including several multiprocessor Unix andLinux servers for computational, statistical,and visualization applications.

Drivers of Dartmouth’sWireless Deployment

Dartmouth’s wireless initiative beganearly in the fall of 2000 with a series of smalldepartment-level pilot programs in the En-gineering and Computer Science depart-ments as well as parts of the student unionand library. While Computing Services hadsome involvement in the wireless initiative,



it was by and large a decentralized effort,enabled by the departments’ willingness totake ownership in the early stages. Thismeant not only installation, maintenance,and management of the 20 to 30 accesspoints (APs) that were initially deployed, butalso providing early funding from depart-ment budgets.

Since Dartmouth’s wireless initiativestarted out as a “bottom up” deployment,many factors are cited as drivers. However,the one basic driver common to all was theincreasing rate of laptop computer owner-ship in both the student and faculty popu-lations. For instance, from 1999 to 2001,the laptop share of computers purchased bystudents through the campus computerstore rose from 27 percent to 45 percent to70 percent. (At present, approximately 40percent of undergraduate students own alaptop.) Coupled with the fact that alllaptops sold in 2001 were factory-equippedwith wireless cards, a consensus began toemerge that wireless computing was becom-ing a viable option on campus.

Within Dartmouth’s Thayer School ofEngineering, the deployment of wireless wasseen as a low-cost means of expanding com-puting resources for its 400 undergraduateand 150 graduate students. As enrollmentin the school grew, the School of Engineer-ing could not accommodate—for reasonsrelated to both cost and physical space—the demand for more workstations. Thelogic of providing wireless access in Engi-neering was further buttressed by the factthat students in technical disciplines aremore likely to use laptops and thus wouldbe well positioned to take advantage of it.

Dartmouth’s pilot deployments werejudged a clear success by virtue of their popu-larity with students and faculty. Determinedto build on this success, staff fromComputuing Services began discussions withthe Deputy Provost for Academic Affairsabout making wireless ubiquitous across the

campus. According to Larry Levine, Direc-tor of Computing, the core value proposi-tion for wireless was its ability to enablenetworking for everybody, everywhere. “Wemade the case that wireless would produceabundant benefits to the overall academicprocess,” said Levine. “For faculty, we sawclear value for both teaching and research.”Under Levine’s vision, the role ofDartmouth’s IT organization was to workwith faculty to facilitate innovation, butleave it to faculty to drive innovation.

While presenting the benefits of wire-less in the lofty terms of the overall com-puting and communications environment,Computing Services also sought to providepractical demonstrations. In this way, keyDartmouth decision makers (principally theprovost) could see the value of wireless inaction. In addition, alumni from various ITsectors who serve as advisors toDartmouth’s IT environment strongly en-dorsed the notion of a wireless campus.

In October 2000, the provost gave thegreen light to expanding the initiative underthe condition that most of the deploymentbe completed by spring of 2001. Underlyingthis speedy timetable was the idea that thesooner a leading-edge wireless environmentwas established, the sooner Dartmouth’s stu-dents and faculty would begin deriving ben-efits. This, in turn, would provide Dartmouthan opportunity to showcase these benefitsto the broader academic community. Indeed,the increasing press coverage and buzz cre-ated by the issue of campus wireless werefactors in Dartmouth’s decision to moveahead aggressively.

Wireless DeploymentIssues

In planning for its wireless expansion,Levine’s team consulted with schools (for ex-ample, Carnegie Mellon University) thatalready had advanced wireless implemen-tations, with the aim of sharing best prac-

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tices and lessons learned. The most valuablefeedback related to network topology, espe-cially the placement and configuration ofwireless APs. Of particular interest were is-sues surrounding “edge effects”—specifi-cally, understanding how wireless networksbehaved at the boundaries of coverage ar-eas between access points. The issue of edgeeffects was most relevant to how wirelessend-user devices “reassociate” (hand-off)from one AP to another. One of the key les-sons in this area, noted Levine, is the impor-tance of calibrating the transmission powerof APs in order to limit instability between“subnets” or coverage zones. “A messagethat came through loud and clear was thatAP placement is more of an art than a sci-ence,” said Levine. “We learned that whenit comes to signal power, less can be more—which wasn’t intuitive to us at first.”

In the weeks leading up to the roll-out,Computing Services took a hands-on ap-proach to AP placement, with teams fan-ning out across the campus to identify thebest locations. These teams—composed ofstaff and students using laptops, APs, andwalkie-talkies—employed a trial-and-errormethod that involved measuring signalstrengths under different placement options.

Technology and StandardsSelection

Another key lesson Dartmouth learnedfrom peer institutions was that wireless stan-dards had not fully evolved. For Dartmouth’splanners this implied that, for the immediatefuture, a single-vendor solution made the mostsense. At the outset of the project, Dartmouthhad short-listed Lucent, Cisco, and 3Com. Al-though Lucent’s WaveLAN AP was used in theinitial trial, Lucent was dropped from consid-eration due largely to delays in delivering itsnext-generation wireless local-area network(WLAN) products. Cisco, on the other hand,was viewed favorably by virtue of its recentacquisition of Aironet (a WLAN vendor) and

was seen as a more stable player. The mostimportant factor working in Cisco’s favor wasits willingness to underwrite a major share ofDartmouth’s infrastructure costs through do-nations and deep discounts. The influence ofa large contingent of Dartmouth alumni withinCisco also played a major role in the deal.

On the standards front, Levine saw IEEE802.11b as the most practical near-term op-tion. “802.11b was the most well-understood,most prevalent technology at the time wedeployed wireless,” noted Levine. “We foundit to be a robust and easy-to-deploy technol-ogy, with good end-user experiences.”

While currently examining the next gen-eration of standards, Dartmouth has voicedearly support for deploying 802.11g (versus802.11a) by virtue of its support for 802.11b.The major issue driving the move to the nextstandard will be increased user demands forhigher bandwidth and collaboration.

Funding WirelessDartmouth’s wireless expansion was

originally projected to cost approximately$400,000, with funds provided by the pro-vost and donations from Cisco. Going for-ward, Dartmouth has rolled the cost ofmaintaining the wireless network into itsgeneral IT budgeting practices. Under thesepractices, Dartmouth’s five major budgetcenters (consisting of its three professionalschools, the Office of Residential Life, andall other areas) are charged on a cost-per-port basis. Wireless costs, which includeadded support costs, are embedded in thesecost-per-port estimates.

Profile of Dartmouth’sWireless Deployment

Dartmouth’s wireless network provides100 percent coverage through a networkof 476 Cisco Aironet APs. These include amix of APs powered over the network(through injectors) and separately poweredunits. Dartmouth’s wireless network extends



over 161 buildings and all major outdoorareas and off-campus facilities (the stadium,boathouse, and facilities). Dartmouth’s APsoperate chiefly under an omnidirectionalantenna scheme and are arrayed in a mi-cro-cell pattern to enable frequency reuseand to mitigate range-related problems.Each access point connects directly to a lo-cal building’s wired subnet rather than intoa campus-wide wireless virtual LAN (VLAN).This was necessary due to the current archi-tecture of the campus backbone, and maychange when the campus wired network isupgraded during the coming year. The wire-less network delivers 11 Mbps coverage.

While its network is effectively fully de-ployed, Dartmouth’s wireless strategy is farfrom static. Computing Services constantlymodifies the network to maximize perfor-mance by either adjusting transmitter sig-nal strengths or moving APs. WhileComputing Services monitors the opera-tional status of the wireless network re-motely, most feedback comes from studentsand faculty.

Applications SupportedBy and large, Dartmouth’s wireless appli-

cations mirror those used on the wired net-work. Among general-purpose applications,messaging, Web browsing, and productivityapplications constitute the most widely usedapplications. Within the Thayer School of En-gineering, key applications supported (bothwired and wireless) include computer-aideddesign (CAD) applications such asProENGINEER and MathLab. Likewise, at theTuck School of Business, students use wire-less to access e-mail, the Web, and a com-prehensive array of intranet services.

Wireless Security ProfileAt present, Dartmouth’s wireless network

security is token at best. To access the wire-less network, a user needs to enter a non–user-specific service set identifier (SSID).

Levine sees the present weak security regimeas a temporary—yet necessary—fact of lifein what is now the “early phase” ofDartmouth’s wireless history. “We didn’twant a solution where everyone has to reg-ister a MAC [media access control] address,mostly because the MAC address canchange frequently,” explained Levine. “Ul-timately we’re moving toward using ourLDAP [lightweight directory access protocol]name directory for sign on, but a cross-ven-dor standard does not exist for that rightnow.” Levine does not see unauthorizedaccess as a problem right now, althoughDartmouth will nonetheless move swiftlytoward required login and other securitymeasures.

Dartmouth does not plan to deploy acampus-wide virtual private network (VPN)because of the difficulties and complexi-ties of providing client software for all cli-ents. In the area of encryption, wiredequivalent privacy (WEP) is enabled andoptional on the wireless network.Dartmouth chose to make it available be-cause it was supported by the access points,yet chose to make it optional because itwas not supported by all wireless cards.

Wireless UsagePatterns

At present, wireless use on campus fallsunder two broadly defined categories: gen-eral-purpose access (the vast majority) andtargeted, customized wireless applications.Based on incidence of use, the most com-mon usage of wireless is for student-to-stu-dent and student-to-professor e-mail,principally through Dartmouth’s BlitzMailmessaging platform (discussed below). Thisis followed closely by Web browsing, includ-ing the use of the Web to conduct library-based research. Some other generalobservations about wireless usage on theDartmouth campus, drawn from a March2002 study, follow:

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� Roaming is limited, with most users lim-iting their activities to a few key sites intheir daily routine.

� Overall, residential activity dominates,with most usage coming from residencehall rooms, even though all residencehalls are also wired.

� Residential and social-space use is heavierin the evening hours, academic and ad-ministrative usage is highest during theday, and library-based use is spread moreevenly.

� Most sessions are short (with a medianof 16 minutes), probably reflecting stu-dents checking e-mail at periodic inter-vals.

� Buildings with large lecture halls and theBaker-Berry Library have the most con-centrated activity, implying the need toconfigure APs accordingly.The next two sections profile two of the

more prominent department-specific wire-less applications deployed at Dartmouth,one fostering engagement and the other,collaboration.

Increasing Engagementthrough Wireless

One of the earliest and most innovativeuses of wireless at Dartmouth involved PDAs,enabling all students to simultaneously re-spond to a professor’s question. Under theapplication, which was developed by G.Christian Jernstedt, professor of psychologi-cal and brain sciences, students can directtheir answers to a Jernstedt question ontoa large screen. The application also enablesJernstedt to continually ask students ques-tions during class and have every studentanswer every question (with anonymitywhere appropriate).

Jernstedt sees the main benefit of hisapplication as a marked increase in students’level of engagement in the classroom expe-rience. “Research shows that in traditional

lecture environments, students are very of-ten not actively engaged, since taking notesamounts to passively receiving and storinginformation,” said Jernstedt. “This approachprovides students with truly interactive ex-perience, thus increasing the overall qualityof the time spent in the classroom.”

Jernstedt’s wireless application was derivedfrom an older wired system that had provenunmanageable due to the need to string wiresin the classroom. The emergence of suitablewireless technology allowed Jernstedt to getaround these issues. A grant from Handspring,which donated 80 Visor PDAs for the class,helped him make it happen.

Jernstedt noted that while wireless in theclassroom can lead to distraction in classeswith low levels of engagement, the converseholds true in classes with good engagement.“When the class is taught in an engagingmanner, the issue of wireless distraction is anon-issue,” stated Jernstedt. “Wirelesstends to amplify the existing climate of learn-ing in a particular classroom—not changeits direction.”

Fueling Team-basedCollaboration

Dartmouth’s Thayer School of ThayerSchool of Engineering, an early pioneer, haswoven wireless tightly into its curriculum.Some of the more common applications in-clude using PDAs to download course-re-lated materials and lecture notes, and toview relevant Web content (such as the lat-est semiconductor technology from IBM).Engineering has deployed wireless to makethe learning process more compelling.

Ted Cooley, Director of Computing forthe Thayer School of Engineering, also seesan ideal platform for supporting research.“Wireless enables students to work moreproductively in a laboratory setting becauseit leverages the inherent collaborativestrengths of wireless and the teamwork ori-



entation that tends to prevail in a researchenvironment,” said Cooley. “Students caninput data as they generate it, downloaddata to the laptop, crunch numbers, andwrite their laboratory report in real time.That’s a real improvement in efficiency.”

Cooley also pointed to the more generalbenefits of wireless in the classroom—mostnotably the efficiency with which professorscan deliver data to students. “Wireless ben-efits the teaching process because it allowsstudents to focus less on transcribing lec-ture content and more on learning throughcompelling presentation,” explained Cooley.“But to capitalize on wireless’s capabilities,instructors will need to change their teach-ing styles—enabling more flexibility and flu-idity in the student-teacher exchange.”Examples cited by Cooley include the down-loading of class notes, so students can goalong with—and make annotations to—apresentation as a professor delivers it.

Gauging the Impactof Wireless

While still a relatively new phenomenon,wireless has already had a marked impacton communication, learning, and teachingpractices across the university. Of these threedomains, communications practices—stu-dent-to-student and student-to-professor—has undergone the most significantevolution since the introduction of wireless.Not surprisingly, the frequency and ease withwhich messages can be checked and sentenabled (and catalyzed) this evolution.

Discussing their use of wireless on cam-pus, Dartmouth undergraduate studentssaw messaging (via the BlitzMail system) ashaving the most pervasive impact on theiracademic and social lives. The commontheme cutting across the different uses ofwireless messaging is an increase in controlof their social and academic agendas.

Some key observations on the impact ofwireless messaging follow:� Scheduling. Wireless messaging allows

students to better “fine tune” theirschedules because it enables a muchshorter planning horizon. This affectsboth the academic sphere (for example,how study groups congregate and inter-act) and the social sphere. One seren-dipitous finding was that intensive wire-less messaging users often elected tokeep their planning horizons short(hours) and avoid excessive longer-termscheduling commitments. This is seen asa reflection of the greater flexibility af-forded by wireless messaging. Someother common scheduling-related mes-saging practices include sending “persis-tent” e-mail to oneself and receivingevent notifications via BlitzMail.

� Collaboration. Wireless messaging hasmade it easier for work groups to col-laborate on projects. Message threadsare seen as a useful way of tracking thehistory, direction, and flow of a subjectmatter discussion.

� More intensive, but less intrusive, mes-saging. Wireless messaging leads tomore intensive (that is, frequent) mes-saging than would occur using cellphones (the equivalent channel for ubiq-uitous messaging). In short, students feelunconstrained in sending frequent (or re-current) e-mails without inducing “mes-sage fatigue.”

� RSVP. The pervasiveness of messaginghas given rise to a “messaging etiquette”on the Dartmouth campus, the mostimportant element of which is a promptresponse to messages.In addition to messaging, wireless has

also led to an increase in students’ mobilityas they conduct nonmessaging wireless ap-plications. While the ability to do remote

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work is more a function of portable com-puting capability (like having a laptop), thewireless component provides students withthe all-important ability to stay “plugged in.”Among students interviewed, one of the keyvalues of wireless computing is the abilityto perform work in a common-area setting,such as the Green or in social and diningspaces. In the words of one student, wire-less computing breaks the trade-off betweenhaving to get work done and being aroundpeers. “With a wireless laptop, students cannow work in a social setting, which is seenas very desirable,” said the student. “Over-all, it’s a better experience because there’smore freedom and happiness in the workprocess.” Ironically, students working in so-cial settings point to the need for music todrown out background or crowd noise—aneed satisfied by downloading streamingmusic via their wireless laptop.

Wireless is also seen as a powerful toolin library research, with the “killer app” be-ing research in the stacks and accessing ofdigital media (such as netLibrary, which letsstudents obtain digital versions of certainbooks). Under one of the more collabora-tive scenarios, students can find researchmaterials via the Web, mark it, and forwardit either to themselves or to others on theirresearch team.

Wireless has also radically changed theway students communicate with their pro-fessors by making such communication vir-tually 24 × 7. For students, the key benefithas been increased accessibility and fasterproblem solving, as well as a more conve-nient and efficient way to schedule time withprofessors. For faculty, the key benefits aretwo-fold. First, wireless messaging improvesmanagement because instructors can bulkmail answers to a class as a whole, share ques-tion threads, and so forth. Second, instruc-

tors have more flexibility as to where or whenthey answer students questions (in the of-fice, at home, in class, or while traveling).

Professor Cooley sees the use of wire-less messaging as a variant on the customerrelationship management (CRM) model.“Like CRM, messaging allows me to addressmore routine queries as they come in so thatI can focus on more involved inquiries orproblems during office hours,” said Cooley.“Overall, it makes my office hours more valu-able and manageable.”

The second key benefit for faculty hasbeen the feedback that wireless inquiriesprovide. Professors can infer from the con-tent of messages which areas or subjectsneed clarification. More broadly, professorscan use this feedback as a way to reshapetheir teaching curriculum.

Lessons LearnedMany of Dartmouth’s lessons learned

relate to technology or deployment issues.Among the more practical observations isthe need to more accurately account forelectrical and wiring costs in the develop-ment of the wireless infrastructure.Dartmouth far outspent its original budget($400,000) largely because wiring costs (theneed to prepare sites for APs) far exceededoriginal expectations. However, more than100 APs were donated by Dartmouth alumniat Cisco and by the Dartmouth Alumni As-sociation of Silicon Valley, which greatlyhelped in keeping the project a financialsuccess.

Ted Cooley sees a broader lesson learnedduring Dartmouth’s wireless initiative as theneed to acknowledge the subsidiary role ofwireless vis-à-vis the wired network. “It’s im-portant in the design stage to realize thatwireless should not be considered a replace-ment for the wired network,” said Cooley.



“In our case, it’s truly a supplemental net-work—with bandwidth capabilities beingthe major factor.”

On the usage front, a key lesson learnedis that students often choose wireless net-work access even when wired network portsare available. Stan Pyc, IT Director for theTuck School of Business, pointed out thateven though Tuck’s facilities are some of themost heavily wired on campus, MBA stu-dents find the wireless network very conve-nient. “All Tuck students are required to owna notebook computer, and the wireless net-work enables them to move from room toroom very easily without regard for the avail-ability of wired network ports. It’s amazingto observe just how popular the wirelessnetwork has become in such a short periodof time,” observed Pyc. “All of the studentsarriving next fall will have notebook com-puters with wireless networking, so we ex-pect usage to double.” Pyc sees the mainchallenge arising from this projected increaseas the management of expectations regard-ing network performance.

The Future of Wirelessat Dartmouth

With its infrastructure roll-out practicallycomplete, Dartmouth plans to focus on thecontinuing task of optimizing coverage—adding, adjusting, and reconfiguring APs asneeded. Consistent with its long-held policy,Computing Services will continue to workwith Dartmouth’s academic departments tofacilitate their plans for using wireless to en-hance teaching practices.

The two biggest items on Dartmouth’swireless agenda—likely to take place overthe next 12 to 18 months—will be a movetoward a more robust security frameworkand a migration to the next-generationWLAN standard (most likely 802.11g). Thelatter anticipates the significant growth inhigher bandwidth activities, such as stream-ing video, that is likely to characterizeDartmouth’s wireless network

Documents

Wireless Networking at Dartmouth College