https://www.meetup.com/DigAnt-Cafe/events/235817676/

1. PUBLIC
LORAWAN – A VERY BRIEF INTRODUCTION
JOHAN BERGS
IMEC – IDLAB – UNIVERSITY OF ANTWERP

6. AIRBEZEN & CURIEUZENEUZEN - PRO AND CONTRA
Pro
Both projects draw the attention of the public
Large scale (hundreds of ”sensors”)
Cheap (good sensors are expensive!)
Contra
Relatively short duration (strawberry plants or signs)
Labour-intensive (leaves/dust needs to be collected, correctly labeled & analysed)
Only long-time average results, but no real-time peaks or periodical information
6
THIS IS MY PERSONAL OPNINION!

7. CAN WE HAVE THE BEST OF BOTH WORLDS?

8. 8

9. 9

14. SOME LORAWAN KEYWORDS
14
1. Long range
2. Low power
3. Robustness to interference
4. Low Data rate (250 bps – 50 kbps)
5. Two-way communication

15. ARCHITECTURE
15 Image source: LoRa Alliance

16. ARCHITECTURE
16
1. Nodes are not associated with a specific gateway
2. Gateways simply foward all received packets
3. The Network Server contains all complexity
1. Select the optimal gateway for downlink messages
2. Set ADR parameters
4. No handovers required for moving devices

17. ARCHITECTURE
17 Image source: LoRa Alliance

18. 18

19. BATTERY LIFETIME
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1. Asynchronous communication (send when you want to send – Aloha)
1. Sleep for as long as you want
2. Wake up and transmit
3. Go back to sleep
2. No synchronization needed

20. ROBUSTNESS TO INTERFERENCE
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Image sources:
- http://www.link-labs.com/what-is-lorawan/
- https://revspace.nl/DecodingLora

21. 21 LoRa-Alliance.org
Adaptive Data Rate (ADR)
SF12 11 10 9 8 7
14km 10km 8km 6km 4km
290bps 530 970 Avg bitrate ~1300bps
2D simulation (flat environment)

22. 22 LoRa-Alliance.org
Data rates, Time On Air and Sensitivity
Data rate Payload Data
rate (bit/s)
Time on
Air (mS)
Gateway
sensitivity
(dBm radiated)
End-device
sensitivity
DR0 (SF12 / 125kHz) 293 1400 -147 -138
DR1 (SF11 / 125kHz) 540 740 -144.5 -135.5
DR2 (SF10 / 125kHz) 980 370 -142 -133
DR3 (SF9 / 125kHz) 1760 200 -139.5 -130.5
DR4 (SF8 / 125kHz) 3125 100 -137 -128
DR5 (SF7 / 125kHz) 5470 56 -134.5 -125.5
DR6 (SF7-250kHz) 11000 28 -131.5 -122.5
DR7 (FSK50) 50000 6 -116 -107
Gateway figures assume +6dBi antenna
User applicative payload = 10 bytes

23. DEVICE CLASSES
23 Image source: LoRa Alliance

24. 24 LoRa-Alliance.org
Bidirectional communication, class A
Receiver Initiated Transmission strategy (RIT)
END DEVICE
BASE STATION
PACKET
Received by ALL base
stations in range
END DEVICE SLEEPS Rx slot 1 Rx slot 2
Cloud Network Server
(MAC Controller) selects
best base station

25. 25 LoRa-Alliance.org
Bidirectional communication, class B
Coordinated Sampled Listening (CSL) :
Network may send downlink packet to node at any Rx slot
END DEVICE
BASE STATION
Received by all base
stations in range
128 seconds
Rx
Cloud MAC Controller
selects best base station
BEACON
BEACON
Rx Rx Rx Rx Rx Rx Rx

26. BIDIRECTIONAL COMMUNICATION
26
Class A
Class B
Class C

27. PUBLIC