Motorola MC40 - Bluetooth; Adaptive Frequency Hopping; Security

5Bluetooth
Bluetooth-equippeddevicescancommunicatewithoutwires,usingfrequency-hoppingspreadspectrum(FHSS)
radiofrequency(RF)totransmitandreceivedatainthe2.4GHzIndustryScienticandMedical(ISM)band
(802.15.1).Bluetoothwirelesstechnologyisspecicallydesignedforshort-range(10meters(32.8feet))
communicationandlowpowerconsumption.
DeviceswithBluetoothcapabilitiescanexchangeinformation(e.g.,les,appointments,andtasks)withother
Bluetoothenableddevicessuchasprinters,accesspoints,andothermobiledevices.
5.1AdaptiveFrequencyHopping
AdaptiveFrequencyHopping(AFH)isamethodofavoidingxedfrequencyinterferers,andcanbeusedwith
Bluetoothvoice.Alldevicesinthepiconet(Bluetoothnetwork)mustbeAFH-capableinorderforAFHtowork.
ThereisnoAFHwhenconnectinganddiscoveringdevices.AvoidmakingBluetoothconnectionsanddiscoveries
duringcritical802.11bcommunications.AFHforBluetoothconsistsoffourmainsections:
•ChannelClassication-Amethodofdetectinganinterferenceonachannel-by-channelbasis,orpre-dened
channelmask.
•LinkManagement-CoordinatesanddistributestheAFHinformationtotherestoftheBluetoothnetwork.
•HopSequenceModication-Avoidsinterferencebyselectivelyreducingthenumberofhoppingchannels.
•ChannelMaintenance-Amethodforperiodicallyre-evaluatingthechannels.
WhenAFHisenabled,theBluetoothradio“hopsaround”(insteadofthrough)the802.11bhigh-ratechannels.
AFHcoexistenceallowsMotorolaEnterpriseTabletstooperateinanyinfrastructure.
TheBluetoothradiointhisdeviceoperatesasaClass2devicepowerclass.Themaximumoutputpoweris2.5mW
andtheexpectedrangeis10meters(32.8ft.).Adenitionofrangesbasedonpowerclassisdifculttoobtaindue
topoweranddevicedifferences,andwhetheronemeasuresopenspaceorclosedofcespace.
ItisnotrecommendedtoperformBluetoothwirelesstechnologyinquirywhenhighrate802.11boperation
isrequired.
5.2Security
ThecurrentBluetoothspecicationdenessecurityatthelinklevel.Application-levelsecurityisnotspecied.
Thisallowsapplicationdeveloperstodenesecuritymechanismstailoredtotheirspecicneed.Link-levelsecurity
occursbetweendevices,notusers,whileapplication-levelsecuritycanbeimplementedonaper-userbasis.The
Bluetoothspecicationdenessecurityalgorithmsandproceduresrequiredtoauthenticatedevices,andifneeded,
encryptthedataowingonthelinkbetweenthedevices.DeviceauthenticationisamandatoryfeatureofBluetooth
whilelinkencryptionisoptional.
PairingofBluetoothdevicesisaccomplishedbycreatinganinitializationkeyusedtoauthenticatethedevicesand
createalinkkeyforthem.Enteringacommonpersonalidenticationnumber(PIN)inthedevicesbeingpaired
generatestheinitializationkey.ThePINisneversentovertheair.Bydefault,theBluetoothstackrespondswith
nokeywhenakeyisrequested(itisuptousertorespondtothekeyrequestevent).AuthenticationofBluetooth
MN000111A01-August2013
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