# Survey on Wireless Technology Trade-Offs for the Industrial Internet of Things
## 6 Conclusions  
LoRa, IEEE 802.11 ah, NB-IoT, BLE, WirelessHART, ISA100.11a and TSCH can provide site-wide network coverage if configured and deployed accordingly, at the cost of data rate and/or latency and/or scalability. The trade-offs of the evaluated technologies are basically equivalent qualitatively but greatly vary in quantity, as elaborated in Section 4. NB-IoT and LoRa have potential to serve non-critical class 4-6 systems. On top, NB-IoT is more suitable for frequent downlink traffic because of LoRaWAN's downlink limitations, which makes it eligible for class 3 systems, as well as latency insensitive class class 2 systems (regulating very slow processes). However, NB-IoT typically comes with a subscription fee and due to the operator involvement, maintenance is slower. Thus, both have pros and cons, as well as similarities. BLE could serve supervising non-critical systems given its inherent unreliability in mesh topology and range limitations in star. TSCH, on the other hand, provides necessary reliability for critical services but its scale and latency are limited by the typical industrial fieldbus topology. WirelessHART, 802.15.4e TSCH and ISA100.11a are similar in terms of both reliability and latency. They all operate in the same frequency band and they all employ channel hopping to improve coexistence. Although they provide high data rates in comparison to other technologies, mesh topology increases the latency and limits the scalability. Still, these technologies  
Figure 5: Battery lifetime of a device (both radio and microcontroller) transmitting once every 10 min for mid-range technologies (>1 km).  
Figure 6: Battery lifetime of a device (both radio and microcontroller) transmitting once every 10 min for long-range technologies (<10 km). (**b**) is a subset of (**a**) where LoRaWAN SF7 is omitted for clarity.  
are being deployed in class 2-6 systems. Finally, Wi-Fi HaLow trades data rate for range and latency but can still support the lowest latencies compared to reviewed technologies in networks of limited scale. Its star topology and novel MAC design contribute to high energy efficiency. Other technologies exhibit various trade-offs as well, ergo the choice of appropriate technology for a certain application is very challenging, given the number of options. This paper quantitatively evaluates the aforementioned technologies, outlining their main advantages and disadvantages and enabling the appropriate choice of the technology for an IWSAN of interest, considering the specific latency, reliability, scalability, energy consumption, data rate and coverage requirements.  
Conceptualization, A.S., E.D.P. and J.H.; validation, A.S., J.F., E.D.P. and J.H.; investigation, A.S.; resources, A.S., J.F., E.D.P. and J.H.; writing-original draft preparation, A.S., writing-review and editing, A.S., J.F., E.D.P. and J.H.; visualization, A.S., J.F.; supervision, E.D.P. and J.H.; project administration, E.D.P. and J.H.; funding acquisition, E.D.P. and J.H. All authors have read and agreed to the published version of the manuscript.  
This research was funded by Fund for Scientific Research-Flanders (FWO-V) grant number S004017N in the context of Strategic Basic Research (SBO) project IDEAL-IoT (Intelligent DEnse And Longe range IoT networks) project.  
The authors would like to thank [PERSON], [PERSON], [PERSON] and [PERSON] for assisting in setting up the energy consumption measurement experiments.  
The authors declare no conflict of interest.