UWB
ULTRA WIIDEBANDUltra wideband (UWB) offers the promise of new radar andimaging services that can save lives by helping to rescuehostages, locate disaster victims trapped under the rubble ofa collapsed building, detect hidden flaws in the constructionof highways or airport runways, secure homes and businesses,and possibly even provide short-range high-speedInternet access to the classroom. UWB devices operate byemploying very narrow or short-duration pulses that resultin very large or wideband transmission bandwidths. Itsultrawide disbursement of ultra-low power bursts presentsnovel interference questions that must be addressed, includinghow to ensure that existing services are not adverselyimpacted—especially those services which support publicsafety—and whether widespread deployment would haveany appreciable effect on the noise floor. With appropriatetechnical standards, however, UWB devices can operateusing spectrum occupied by existing radio services withoutcausing interference, thereby permitting scarce spectrumresources to be used more efficiently.In early 2002, the Federal Communications Commission(FCC) issued standards designed to ensure that existing andplanned radio services, particularly safety services, are adequatelyprotected from UWB users. The FCC will enforce therules and act quickly on any reports of interference. Thestandards are based in large measure on standards that theNational Telecommunications and Information administration(NTIA) believes are necessary to protect against interferenceto vital federal government operations.On an ongoing basis, the FCC intends to review the standardsfor UWB devices, explore more flexible standards,and address the operation of additional types of UWB operationsand technology. Since there is no production UWBequipment available at this writing and there is little operationalexperience with the impact of UWB on other radioservices, the FCC chose to err on the side of conservatism insetting emission limits when there are unresolved interferenceissues.The FCC establishes different technical standards andoperating restrictions for three types of UWB devices basedon their potential to cause interference. These three typesof UWB devices are imaging systems, including groundpenetratingradars (GPRs), wall, through-wall, medicalimaging, and surveillance devices; vehicular radar systems;and communications and measurement systems. Imaging systems Provides for the operation of GPRs andother imaging devices subject to certain frequency andpower limitations. The operators of imaging devices mustbe eligible for licensing, except that medical imagingdevices may be operated by a licensed health care practitioner.At the request of NTIA, the FCC will notify or coordinatewith NTIAprior to the operation of all imagingsystems. Imaging systems includeGround-penetrating radar systems GPRs must be operatedbelow 960 MHz or in the frequency band 3.1 to10.6 GHz. GPRs operate only when in contact with orwithin close proximity of the ground for the purpose ofdetecting or obtaining the images of buried objects.The energy from the GPR is intentionally directeddown into the ground for this purpose. Operation isrestricted to law enforcement, fire and rescue organizations,scientific research institutions, commercialmining companies, and construction companies.Wall-imaging systems Wall-imaging systems must beoperated below 960 MHz or in the frequency band 3.1to 10.6 GHz. Wall-imaging systems are designed todetect the location of objects contained within a “wall,”such as a concrete structure, the side of a bridge, or thewall of a mine. Operation is restricted to law enforcement,fire and rescue organizations, scientific researchinstitutions, commercial mining companies, and constructioncompanies.Through-wall imaging systems These systems must beoperated below 960 MHz or in the frequency band 1.99 to10.6 GHz. Through-wall imaging systems detect the locationor movement of persons or objects that are on theother side of a structure such as a wall. Operation is limitedto law enforcement and fire and rescue organizations.Medical systems These devices must be operated in thefrequency band 3.1 to 10.6 GHz. Amedical imaging systemmay be used for a variety of health applications to“see” inside the body of a person or animal. Operationmust be at the direction of or under the supervision ofa licensed health care practitioner.Surveillance systems Although technically these devicesare not imaging systems, for regulatory purposes theyare treated in the same way as through-wall imagingand are permitted to operate in the frequency band1.99 to 10.6 GHz. Surveillance systems operate as“security fences” by establishing a stationary radio frequency(RF) perimeter field and detecting the intrusionof persons or objects in that field. Operation is limitedto law enforcement, fire and rescue organizations, publicutilities, and industrial entities.