NB IoT is a low power wide area network technology that allows connectivity of devices using a small part of the LTE spectrum bandwidth. It enables connectivity for a large number of devices using less battery power and provides better building penetration compared to previous technologies. NB IoT reuses existing LTE infrastructure and can support wide area connectivity for devices with low throughput but long battery life up to 10 years. It is well suited for applications like smart metering, asset tracking and wireless sensor networks.

1. Introduction to NB IoT
Nicolas Tribie – ntribie@sequans.com
Copyright © 2018 Sequans Communications
MKT-FM-016-R01

2. LTE (4G) for IoT Usage
Copyright © 2018 Sequans Communications2
Nokia
3GPP

3. NB IoT versus LoRaWAN
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Licensed Spectrum
 Users need to register with an operator.
 Guaranteed QoS
Reuses existing 4G base stations network
 NB IoT support : By software upgrade,
 Network is costly , but shared with 4G usage
 Natural replacement for GPRS M2M
Higher power consumption
 Protocol overhead (QoS)
Unlicensed Spectrum
 Private networks are possible
 Also deployed by operators
 Spectrum shared with other devices
New network deployment required
 But Low cost base stations.
Lower power consumption
 Small protocol overhead
NB IoT LoRaWAN
Similar Data Throughput
Similar coverage performance

4. NB IoT Performance
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50 000 to 800 000 devices per base station (eNB)
~ 10 new connexions / second per base station
< 10 s latency
Coverage :
 ~1.5 km urban (Need to reach basement water/electricity meters )
 20 km free range
 3x GSM / legacy LTE ( 164 dB MCL)
10+ years battery life
 200 Bytes upload, 20 bytes download / day / 5WH battery Coverage (km) . 3GPP

5. LTE Signal: OFDM Modulation
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5 to 20 MHz BW for LTE
Sound Analogy: Multiples notes of a piano chord
 Message = intensity of a single note + notes sequence
Light Analogy: White light decomposition in a rainbow
 Message = intensity of each monochromatic source + sequence
Usages: LTE, WiFi, DVB-T (digital TV) , ADSL , PowerLine, ..

6. LTE signal structure
Copyright © 2015 Sequans Communications6
P-SCH - Primary Synchronization Channel
S-SCH - Secondary Synchronization Channel
PBCH - Physical Broadcast Channel
PDCCH - Physical Downlink Control Channel
PDSCH – Physical Downlink Shared Channel
Reference Signal – (Pilot)
64QAM16QAM QPSK
Frequency
Time
Agilent

7. OFDMA : Spectrum Sharing Between Users
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Agilent

8. NB IoT in the LTE signal
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One Physical resource Block (PRB) is assigned to NB IoT traffic : 12 subcarriers
NB IoT devices will only listen to this tiny 180 KHz bandwidth
 Simpler Radio , lower power
 Only 1 % of the total LTE bandwidth
NB IoT
Frequency
Time
Agilent

9. In Real Life : LTE Spectrum
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Frequency
Time
Signal from an Enode-B (base station) , seen from a spectrum analyzer
NB IoT

10. Messaging sequence
• Wake up
• Synchronize with Network
• Get Network Info
• Request Access
• Setup session
• Data exchange
• Close Session
• Re-enter deep sleep
3GPP

11. NB ioT vs LTE Coverage enhancements
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LTE signal originally designed for :
 High Data throughput (> 100 Mbps) , fair reception conditions
 Fairly complex receiver (costly)
 “High” power consumption (mobile battery : 8 WH)
NB IoT is targeted for :
 Low cost and Low Power Devices,
 Low data throughput , bad reception conditions
Solution : Transmission repetitions:
 Simpler coding : “simpler” receiver,
 Signal is compatible with LTE freq/time grid
 Signal / Noise is improved across repetitions
 Throughput / coverage tradeoff tailored to each case :
 -100 dBm (fair RX conditions) : 1 repetitions : ~ 56 Kbps
 -144 dBm (worst RX condition) :256 repetitions : ~ 400 bps
Analogy with Astronomy Photography
(faint Galaxy image acquisition)

12. Energy savings Enhancements
Copyright © 2015 Sequans Communications12
Concept : stay idle as long as possible
 A periodic RendezVous is negotiated
with the base station :
 Base station keeps the device registered
 Device remembers network parameters
 Shorter attach time
 Device goes into sleep mode,
 Device wakes up quickly at each RDV:
 Data exchange happens
 QoS : NBioT claims less energy spent per
message than LoRaWAN
Device can request uplink at anytime
 Example : sensor alert
3GPP

13. Sequans NB IoT Platform
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• Hardware : Paris
• RF : Reading (UK) / Kista (SW)
• SW / DSP : Sophia/ Paris
Pycom “FiPy”module for Makers
WiFi/BT CatM NB-IoT
Sequans Monarch Platform
PyCom
Sequans

14. Towards 5G..
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Source: ITU
Cat-M and NB-IoT fulfill 5G mMTC requirements:
mMTC : Massive Machine Type
Communications
MultiCast capability added
Even more power savings features

15. 15
Thank You !
References :
 www.sharetechnote.com/html/Handbook_LTE.html
 Book: Cellular Internet of Things:
 Slideshare: Tdd lte training material
 3GPP: www.3gpp.org

16. Annex 1 :NB IoT Frame
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Time view
User control
User Data

17. Annex 2.1 : Energy consumption Lora / NB IoT
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Actility

18. Annex 2.2: Energy Timeline
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19. Annex 3 :Link Budget details
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20. Annex 4 : Throughput
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