1. A survey on LPWA technology: LoRa and NB-IoT
Source: ICT Express , Volume 3, Issue 1,March 2017,Pages 14-21
Authors: Rashmi Sharan Sinha, Seung-HoonHwang , Yiqiao Wei
Speaker:Bo-Yi Shiu
Data: 11/09/2017

2. Outline Introduction Technical differences
Network architecture
MAC protocols
Contention-based Random Access
Comparison in terms of IoT factors
Conclusion

3. Introduction
Multi-mode

4. Network architecture(1/2)

5. Network architecture(2/2)

6. MAC protocols(1/3)

7. MAC protocols(2/3) Class-A : Bi-directional end-devices
Downlink communications from the server at any other time will have to wait until the next scheduled uplink.
Class-B: Bi-directional end-devices with scheduled receive slots
Class B devices open extra receive windows at scheduled times. In order for the End-device to open it receive window at the scheduled time it receives a time synchronized Beacon from the gateway.
Class C: Bi-directional end-devices with maximal receive slots
Class C have nearly continuously open receive windows, only closed when transmitting.

8. MAC protocols(3/3) NAS (Non-Access Stratum)
RRC (Radio Resource Control)
PDCP (Packet Data Convergence Protocol)
RLC (Radio Link Control)
MAC (Medium Access Control)
PHY (Physical)

9. Contention-based Random Access

10. Comparison in terms of IoT factors

11. Conclusion
Both LoRa and NB-IoT have their own advantages and disadvantages according to its different technological principles.
LoRa focuses on the low cost applications.
NB-IoT is directed to applications that require high QoS and low latency.