Wireless Options

In the nearly three years since Sept. 11,2001, much has been written and said about the critical role oftelecommunications in homeland security, and of the literallylife-and-death urgency of modernizing the communications networkslinking local, state and regional critical responders. Experts havelaid out bold visions of a new telecommunications era, when allrelevant security workers at all levels are seamlessly connected asneeded with interoperable equipment able to communicate fully, securelyand effectively in any imaginable emergency.

As homeland security professionals know, however, it is a far distance from the vision to the reality.

Take the nation’s capital, for example.

“Everyone knows Washington DC continues to bea major global target,” Robert LeGrande, deputy chief technologyofficer (CTO) for the District of Columbia said in a conversation with HSToday.“Yet despite the federal presence all around us, and all the speechesand media attention, our telecommunications remained unprepared incrucial areas. Our voice networks were not interoperable between fire,police, HAZMAT and EMS [emergency medical services] and, worst of all,we continued to have glaring coverage gaps inside buildings and in thecity’s major tunnels. Over two years after 9/11 if we had a majorexplosion or fire or other incident in any of our largest tunnels we’dhave held our breath, because we knew communications in there werenon-existent.”

LeGrande recalled the long, not always easypath toward modernization of public safety communications networksfaced not only by his city but across the country.

“The good news,” he continued, “is there areanswers, and we did finally solve the problem. The rub is there’s nosimple all-purpose foolproof solution that’s going to work foreverybody. You can’t just snap your fingers and, voila, have a perfectpublic safety communications network up.”

Federal focus

There’s certainly been no lack of federalfocus on helping locales. Project 25, for instance, a consortium ofgovernment, business and academia dating back to the early 1990s, is anongoing effort to achieve the ambitious goal of standardizinginteroperable radio gear and equipment for emergency responders acrossthe country.

The Federal Communications Commission (FCC)has also worked at allocating additional spectrum in the 800MHz rangefor local public safety and security uses. Further, the agencyannounced that additional portions of the 700 MHz spectrum, currentlyused for commercial TV broadcast, will be reserved exclusively forsecurity-related use once the migration to digital TV is complete, aprocess legally required by Dec. 31, 2006, but one many believe willactually extend far beyond that date.

This April the Department of HomelandSecurity (DHS) published its guide to interoperability requirements, akind of road map for future telecomm upgrade paths.

Still, despite federal encouragement, localsecurity managers face a confusing array of choices and challenges whensurveying upgrade options. Public cellular networks remain vulnerableto security failure, system paralysis due to excessive call volume and“catastrophic” shocks such as blackout or destruction of a cell tower.Public safety networks remain woefully fragmented, literally spread outover 10 frequency bands ranging from 30 MHz to 869 MHz. And publicspectrum remains scarce.

“One way to ensure state-of-the-arttelecommunications would be to just start from scratch and re-equipevery single local first responder nationwide with brand-new digitalradio hardware,” explained Ronny Haraldsvik, vice president of globalcommunications and marketing for Flarion, a wireless broadband companylocated in Bedminster, NJ. “This unfortunately is something not manycan pay for on a grand scale, as it would cost tens of billions ofdollars, minimum. What most communities are concerned with as theyconsider their upgrading options is not having to chuck their legacyinfrastructure wholesale.”

Emerging technologies and network solutionsare designed to help states and localities upgrade their communicationswithout abandoning their legacy systems. In different ways, eachprovides cross-patch links or audio bridges to assist interoperabilitybetween different kinds of devices and channels, allowing public-safetynetworks to enhance the functionality of existing infrastructure andhardware for both voice and data.


While the wireless systems provide speed andaccessibility for their users, they also bring with themvulnerabilities—although they are less vulnerable than the highlyhackable public wireless networks.

Before they’re used for mission-criticalcommunications between and among local and wide area networks on anational scale, some of these vulnerabilities must be closed. Somesystems have inadequate or no encryption or users may improperlyconfigure their hardware. Wireless systems can be tapped and subject tounauthorized access, passwords can be sniffed out, hackers canmasquerade as authorized users, messages can be modified and thesystems can be hit with denial-of-service attacks.

To tackle these issues, an organizationcalled Project Mesa (which stands for Mobility for Emergency and SafetyApplications), located in Mesa, Ariz., was formed to establishuniversal wireless security standards for next-generation data devices,services, systems and applications. The organization, founded in May2000, includes participants from academia, government and business.

The project is currently developingspecifications for a three-tiered security architecture that includescrypto engines, application protocol interfaces and public keycryptography. MESA specifications also envision identifying securitystandards that government agencies, vendors, responders andpublic-safety organizations can incorporate in their acquisition plans.


Although the populist, grass-roots,inventor-in-a-garage spirit swells American hearts, we really like big,bold, comprehensive technological solutions like the Manhattan Projector the Apollo moon program. It’s natural that, faced with a problem ofthe magnitude of global terror and providing the telecommunicationstools for ensuring the effectiveness of our public-safety networks, thepublic similarly would demand a crash program for technical progress ona mass scale.

Those looking for a one-size-fits-all magicbullet, however, will be disappointed. In fact, despite theindispensable importance of federal funding and other assistance, trueprogress in modernizing the public safety telecommunicationsinfrastructure should be seen as a process of continuous learning andimprovement rooted in customized local innovations built throughcollaborations among local, regional and—finally—national firstresponders and emergency managers. HST

Ethernet bridges

In the past, wide area voice and data networks(WANS) required dedicated leased or owned fiber or cable connectionswell beyond the financial reach of most locales. A point-to-pointethernet radio system encodes, multiplexes and modulates signals over awireless link at 99.999% uptime and is designed to be impervious toweather and environmental stress. Additionally, the system can be setup on existing equipment infrastructure using portably mounted basestations, enabling quick deployment indoors or outdoors.

Proxim, a wireless networking firm located inSunnyvale, Calif., has developed ethernet bridge technology calledTsunami wireless broadband for public security providers. As Jeff Orr,Proxim’s product marketing manager, describes it, “The wirelessbroadband network is designed for facilitating communication betweenmultiple towns or counties, and can scale from a few square miles toover a thousand square miles. Traditionally, towns have had veryfragmented communications systems and very limited bandwidth. Byproviding bridges, we can connect county planning offices, 911facilities and courthouses. By putting laptops into vehicles, emergencymanagement systems can stream data from critical databases directly tofirst responders.” The broadband solution supports e911, two-way dataand voice, Internet and video.

Early this year, the city of Concord, NC,began to use Tsunami as the basis of a private network linking 15locations in three North Carolina cities to deliver video-basedtraining to firefighters and first responders. With the application,the city conducts large-scale training sessions for all firefighterswithout their having to leave the station. Point-to-multipoint radioscapable of carrying voice over IP (Internet protocol), data and videowill connect the city’s fire stations, administrative and operationaloffices, local health department and major hospitals.

Mesh networks

“The problem with the FCC’s plan to open upmore public spectrum,” said Rick Rotondo, vice president of technologyat Maitland, Fla.-based Mesh Networks, “is that public safety agenciesstill compete with the public network. So emergency responders arestill competing with a guy sending pictures of his dog. Ask acommercial cellular operator how he can prioritize traffic and theanswer is they don’t have the capability. After last year’s Super Bowlgame, when the Patriots won, police and fire departments throughout NewEngland could not use the system for several hours. Imagine if therehad been a bigger incident coinciding with that. So it’s not surprisingmore communities and regions are trying to find ways either eschewingor radically augmenting the public network.”

Dissecting the problems of most commercialwireless networks, Rotondo observes: “With the current hub-and-spokenetworks you need to talk to the tower first. That creates a singlepoint of failure. Disable one tower and you’ve seriously weakened thenetwork. What we’ve designed is a system with more paths and fewerbottlenecks. Think of the cell tower as Goliath. One well-placed rockwill knock it all down. Mesh, on the other hand, is like a swarm ofbees.”

Mesh networking allows devices to interactwith multiple base stations, essentially hopping seamlessly from thebase station regardless of the user’s coverage zone. In a mesh network,voice and data signals are broken down into electronic packets and, aswith the Internet, packets are routed over the most efficient path totheir destination. Each end-user device can also act as a router.

The town of Medford, Ore., was looking for ahigh-bandwidth mobile solution that would provide interoperablecommunications among first responders from multiple agencies in thecase of a catastrophic event in the Pacific northwest. As DougTownsend, the city’s technology director, recalled, “It was not ourintent to abandon current radios but to supplement each group’s currenttechnology with a solution capable not only of reliableinteroperability during emergencies but of sustaining high-bandwidthapplications like voice over IP and video in a way that GPRS (generalpacket radio service) cannot.

“We identified several advantages of meshover alternatives,” Townsend continued. “Currently, most solutions outthere are not really mobile. They’re hot-spot technologies that don’toffer seamless roaming. In addition to emergency voice and datacommunications, we’re using mesh to reduce radio traffic, enhancevehicle-to-vehicle communications, conduct records searches from thefield, determine optimum routing with mapping solutions, locatevehicles and view preplans of structures.”

Mobile Satellite

“First responders and emergency workers are avoice-driven group,” said Austin Comerton, channel manager of MobileSatellite Ventures, a developer of satellite communications systems forsecurity and safety systems headquartered in Ottawa, Ontario. “Thebiggest problem in coordinating emergency communications is that overlarge distances, especially in rugged or remote areas, signalsdeteriorate. When you have an incident out in a remote area, there’s notime to put up a cell tower.”

Satellite dispatch radio differs fromtraditional two-way one-to-one radio in that a single network providesmobile communications regardless of location. To place a dispatch callor establish a conference call, the user selects the desired talk groupand pushes a button on the handset. Signaling channels identifying thecall type and talk group are transmitted to the satellite and relayedto the ground signal, where they are assigned a communication channel.The average call setup takes just 2.3 seconds. Visual and audio signalsindicate when a conference call is established and prompt the call’sinitiator to begin speaking. The speaker is identified on eachparticipant’s handset. Systems contain cross-band functions that enableusers to switch over to terrestrial systems.

“The reason we first looked into satellite,”recalled Kerry Flaherty, director of Connecticut’s Office of EmergencyManagement (OEM), “was that our cellular and traditional private mobileradio networks, though they work OK for routine purposes, have a poortrack record when the system gets stressed, which, after all, is whatemergencies are often about. Once we saw how our emergencycommunications systems just went black on us during the blackout ofAugust 2003, it was a no-brainer. We needed a system unreliant on celltowers.”

Connecticut’s Department of Public Healthchose MSV’s satellite radio for a state wide communications systemlinking the department’s headquarters to all of the state’s 32hospitals, the state OEM operations center, mobile bioterrorismresponse units and two bioterrorism centers of excellence at HartfordHospital and Yale New Haven. It’s called MEDSTAT and is funded throughthe state’s public health Bioterrorism Preparedness and Response office.

Narrowband PCS Messaging

“We hear all the time about high-tech,”reflected Paul Deastlov, communications manager at Arch Wireless ofWestborough, Mass. “But the ironic thing is that emergency workers insituations like the Pentagon on 9/11 found out it wasn’t the high-techcommunications that worked. In fact, the only man left standing wasgood old-fashioned messaging. Sometimes simpler really is best.”

Wireless messaging systems encompass anetwork backbone, air interface and simple handheld end-user devices.Messages may come from a customer-service operator, an Internet oremail user, or — most germane to emergency first responders — from userto user by way of a two-way message. A messaging server authenticatesusers, tracks movement and, perhaps most crucially, manages deliveryand receipt of messages.

Most messaging systems today use a satellitedata backbone, and support up to 40,000 users per single forwardchannel. The number of channels can be modified based on traffic volumeand user density. Messaging is also more “intelligent” than a cellularor traditional land radio system in recognizing and acknowledgingfailure when signals or calls, for whatever reason, are not beingreceived. The group messaging function of systems like Arch’s allowscommunications from one source to many users. Each user devicepossesses a unique forward address as well as a broadcast address.Users can then be pre-defined in specific groups, with messages goingto one group, all groups or selected groups on an as-needed basis.

The Federal Aviation Administration (FAA) hasimplemented wireless messaging to connect an expanding network of morethan a dozen operation-control centers. Emergin Inc., based in BocaRaton, Fla., and an Arch partner, installed wireless messaging softwareat major FAA operations centers, allowing facility managers tobroadcast critical conditions, security alerts, utility outages andauthorization breaches while sharing information between centers.Compared to pre-9/11 paging systems, the two-way wireless systemreduced broadcast delivery time from over an hour to just a couple ofminutes. It also provided a centralized system log of all message setsreceived, and can handle group messaging to over a thousand deviceusers simultaneously.


Flash-OFDM (Orthogonal Frequency DivisionMultiplexing) is a “spread-spectrum” technology developed by FlarionTechnologies, which divides spectrum into equivalently spacedfrequencies or tuners. Flash-OFDM can operate in any spectrum,including those stymied by chronic interference. Capable of peak datarates of 3 megabytes per second (MB/s), OFDM-enabled systems enable notonly web access but real-time video.

OFDM PC cards are plug-and-play compatiblewith existing IP devices such as laptop or handheld computers, personaldigital assistants and handsets. Flarion, a leading provider of thistechnology, produces “radio routers,” base stations that can beoverlayed onto existing radio networks and spectrum.

This past April, Washington, DC, launched thefirst tower of a prototype 10- tower private Flash-OFDM wirelessbroadband system. The network, due to be completed by late 2005, willlink hospitals and ambulances with real-time video, enable officers inthe field to download mug shots or even convey detections of a chemicalweapons attack via wireless devices. The network allows police, fire,transit and homeland security personnel to remain connected at 1 to 2MB/s even in moving vehicles.

“We view the network as a pilot project thatcan be replicated in other metropolitan areas,” said Le Grande,Washington’s deputy CTO. Along with other members of the SpectrumCoalition for Public Safety, he hopes the pilot’s results will motivateCongress to provide 10 MHz of additional spectrum for similar projectsnationwide.

Software-defined radio

If most current solutions focus on ways ofbridging differing hardware and channel frequencies, one solution,admittedly in its infancy, takes a software rather than hardwareapproach. SDR (software-defined radio) is based on the premise that,instead of locking radios into one fixed frequency and modulationconfiguration, existing radios can be changed at will by downloadingthe proper software into them.

As defined by research scientist JosephMitola, who coined the term, software radio is a radio whose channelmodulation waveforms are defined in software. In SDR, waveforms aregenerated assampled digital signals, converted from digital to analogvia a wideband digital to analog converter and then upconverted fromintermediate frequency to radio frequency.

“The promise of our technology,” explainedJohn Chapin, CTO of Vanu, an SDR developer based in Cambridge, Mass.,“is to combine multiple separate devices into a single device.” “Ratherthan spend the tens of billions of dollars that a mass investment innew radios would require,” Chapin said, “our technology provides themuch more cost-effective approach of virtual patching, using softwareto patch together frequencies that need to talk to one another.”

Vanu has demonstrated a prototypepublic-safety interoperability system that patches together severalwidely used radio systems (VHF, UHF analog FM, APCO Project 25, GSM andSINCGARS).

By using the system, a local policedepartment could take a police vehicle’s FM voice-over-radiotransmission and automatically retransmit it as a Project 25 standardtransmission, which is the federal frequency range.

(Visited 12 times, 1 visits today)

The Government Technology & Services Coalition's Homeland Security Today (HSToday) is the premier news and information resource for the homeland security community, dedicated to elevating the discussions and insights that can support a safe and secure nation. A non-profit magazine and media platform, HSToday provides readers with the whole story, placing facts and comments in context to inform debate and drive realistic solutions to some of the nation’s most vexing security challenges.

Leave a Reply