an overview of lora, sigfox, and ieee 802.11ah
TRANSCRIPT
AN OVERVIEW OF LoRa, SigFox, and IEEE 802.11ahFaheem ZafariComputer & Information TechnologyPurdue [email protected]
AGENDA• LoRa• SigFox• IEEE 802.11ah• Differences between LoRa, SigFox, IEEE 802.11ah• Use cases• Problem with IEEE 802.11ah• Co-existence problem
LoRa• Physical Layer LPWAN solution
• High range (max 15km), low power, low data rate (0.3-37.5 kbps), wideband, sub-GHz
• The architecture consists of • LoRa end-devices• LoRa Gateways• LoRa Network Servers (NetServer)
Taken from Centenaro et al.
LoRa• The MAC layer is basically ALOHA protocol controlled by
the LoRa NetServer.• The LoRa MAC is designed to mimic IEEE 802.15.4 Mac
to allow the accommodation of other protocols such as CoAP, 6LoWPAN etc.
Taken from Centenaro et al.
• SIGFOX• First LPWAN technology.• The physical layer uses
Ultra-Narrow Band (UNB) wireless modulation.
• Network layer protocols are ‘secret sauce’.
• Low throughput (~100 bps), low power, extended range (up to 50 km).
• The end device must use SIGFOX modem to connect to the SIGFOX network
• The device should initiate the communication.
• IEEE 802.11ah• Physical layer based on 802.11ac.• Low Data Rate (~100kpbs), extended range (up to 1km),
low energy consumption, sub-GHz. • One hop network topology.• Supports MIMO, Single user beamforming etc on the
Physical layer.• Three different types of stations supported
• Traffic Indication Map (TIM): Listens to AP for data transfer• Non-TIM stations: Directly negotiate with AP during
association process to obtain transmission time on Periodic Restricted Access Window (PRAW)
• Unscheduled Stations: does not listen to any beacons and uses poll to access channels.
• IEEE 802.11ah
MAIN DIFFERENCESParameter LoRa Sigfox IEEE 802.11ah
Data rate (kbps) 0.3-37.5 0.1 >100
Coverage (km) Rural: 10-15Urban: 3-5
Rural: 30-50Urban: 3-10
1
Nodes per BS
Frequency (MHz) Various, Sub-Ghz
969 or 902 902-928 (US)
Initiation Both node and NetServer
Device Both device and the AP
Energy Consumption
Very low low slightly higher
Dedicated Network
No Yes No
USE CASES
Technology Use Cases
LoRa Garbage collection bin fill level for pick up route optimization
Sigfox Smart meters, smoke detectors
IEEE 802.11 ah Backhaul network for Sensors, Video Surveillance, wearable consumer electronics
PROBLEM WITH IEEE 802.11ah• As pointed out by Adame et al., a potential challenge in
802.11ah is the performance of Non-TIM and unscheduled stations, and their integration with TIM stations in a single WLAN. The problem is interesting to explore for further research.
• The number of stations that IEEE 802.11ah is also much lesser than Sigfox and LoRa.
COEXISTENCE PROBLEM • One of the problems with the coexistence of Sigfox and
LoRa is that, Sigfox is based on UNB sub-GHz while LoRa is wideband sub-GHz. The wideband solution is prone to the interference from UNB technologies. This problem can be interesting to explore for further research.
REFERENCES• Adame, T., Bel, A., Bellalta, B., Barcelo, J., & Oliver, M. (2014).
IEEE 802.11 AH: the WiFi approach for M2M communications. Wireless Communications, IEEE, 21(6), 144-152
• Centenaro, M., Vangelista, L., Zanella, A., & Zorzi, M. (2015). Long-Range Communications in Unlicensed Bands: the Rising Stars in the IoT and Smart City Scenarios. arXiv preprint arXiv:1510.00620.
• Centenaro, M., Vangelista, L., Zanella, A., & Zorzi, M. (2015). Long-Range Communications in Unlicensed Bands: the Rising Stars in the IoT and Smart City Scenarios. arXiv preprint arXiv:1510.00620.
• Keysight Technology. Explosion of the Internet of Things: What does it mean for wireless devices? June, 2015
