View
8
Download
0
Category
Preview:
Citation preview
Prof. Roberto Verdone www.robertoverdone.org
Mobile Radio Networks NB-IOT
NB-IOT
Roberto Verdone www.robertoverdone.org
Prof. Roberto Verdone www.robertoverdone.org
Ø Generalrequirementssetby3GPP:o Coverage:Morethan20dBimprovementfromGPRS(164dB)o Throughput:Morethan160bpso Latency:Lessthan10secondso BatteryLife:Morethan10years(5Whbattery@MCL=164dB)o Deployment:OnlySWupdateo Capacity:Morethan52500devicespercell
LongRangeLowPowerTechnologies
Prof. Roberto Verdone www.robertoverdone.org
LPWANTechnologiesLPWAN
Technologies
ISMBand CellularBand
LTE Cat.0 3GPP: Rel. 12
LTE-M3GPP:Rel.13
NB-IOT3GPP:Rel.13
LoRa
SigFox
RPMAIngenu Weightles
s
EC-GSM-IoT
Prof. Roberto Verdone www.robertoverdone.org
Ø NB-IOT:anewclassofLTEdeviceso EnhancedCoverage->Narrowbando Reducedenergyconsumptiono Reducedcost/complexity
Ø Deploymentoptions
LTEGSM
InBand Guard-BandStand-Alone
LTE
1PRB=180kHz
NB-IOTOverview
Prof. Roberto Verdone www.robertoverdone.org
Ø 3CoverageClasses(Normal,Robust,Extreme)Ø RSSIMeasurementØ DecisionBasedonThresholds
CoverageClasses
ExtremeRobust
Normal
Prof. Roberto Verdone www.robertoverdone.org
Ø NarrowBandtransmissiono LessNoise
Ø TimeDiversity(TxRepetitions)
o Differentscramblingcodesoftxtocombine
Ø BPSKandQPSKModulationschemesØ HARQØ ULPowerControl
NoiseFloorWideBand
NarrowBandSamePower
BetterSNR
0 1 2 3
HowtoachieveLongRange?
Prof. Roberto Verdone www.robertoverdone.org
Ø PowerSavingMode(PSM)o UEconnectedtoNWbutunreachable
Ø eDRX(enhancedDiscontinuousReception)
HowtoconsumeLowPower?
Prof. Roberto Verdone www.robertoverdone.org
Ø ContentionbasedØ PseudorandomfrequencyhoppingØ AcollisionhappensiftwoUEstransmitpreamblefromthesame
subcarriero AttheendoftheRandomAccessProcedure(Msg4)onedevicewillreceivetheUL
Grant,theotherswillfailØ Preambleisrepeatedseveraltimes
PhysicalLayer-NPRACH
𝑆↓𝑁𝑃𝑅𝐴𝐶𝐻 Sub
carriers
Rep.1 Rep.2 Rep.3 Rep. 𝑃↓𝑁𝑃𝑅𝐴𝐶
𝐻
…
User1User3
User2
Prof. Roberto Verdone www.robertoverdone.org
Ø 1 NPRACH definition per Coverage Class Ø Remaining resources are used by NPUSCH
Ø BPSK or QPSK (from 96 to 288 bit per RU)
PhysicalLayer-Uplink
Prof. Roberto Verdone www.robertoverdone.org
Ø NPBCH(BroadcastChannel):Carriesbroadcastmessages(MIB)Ø NPDCCH(ControlChannel):CarriesUL/DLGrants(NCCE)Ø NPDSCH(SharedChannel):CarriesDataandotherbroadcast
information(SIB1,SIB2,…)
PhysicalLayer-Downlink
Prof. Roberto Verdone www.robertoverdone.org
NB-IoTDevicesfeatures(e.g.U-blox)Ø Numericalvalues:
o LinkBudget:164dBo Throughput:Peakdatarateof~250kbps,bettersuitedfor50kbpsuse
caseso Latency:Lessthan10secondso TransmitCurrent:~220mAat23dBmand100mAat13dBmo ReceiveCurrent:~40mAo Synchronization:Itmaintainessynchronousconnectionwiththecellular
networko ChipsetSize:~3cm2,ModuleSize:~1.6x2.6cmo Deployment:OnlySWupdateo Capacity:Morethan52500devicespercello CostHW:lessthan$10
Prof. Roberto Verdone www.robertoverdone.org
NB-IoTvsLoRaLoRa NB-IoT
Ecosystem LoRa Alliance 3GPP and GSMA
Modulation Proprietary standard by Semtech, based on Chirp Spread Spectrum
DL: OFDMA (15 kHz) UL: SC-FDMA (3.75 or 15 kHz) with BPSK or QPSK
Deployment ISM Bands (433, 868, 2400 MHz)
In-band & Guard band LTE, standalone
Coverage (@MCL) 155-170 dB, dep. regulation 164 dB
Data rate ~293 bps-50 kbps ~250 kbps in 2.4GHz band
UL: > 50 kbps, multi-tone DL: > 50 kbps-250 kbps
Power class (max) 14 dBm 23 dBm
Current consumption Max 84 mA in Tx Max 220 mA in Tx
Protocol Asynchronous Synchronous with eNB Duplexing HD with FDD HD with FDD
Recommended