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5177 Brandi n Court, Frem ont, CA94538 | Tel : +1 51 0 -4 9 2 -4044 | Fax : +1 510 -4 9 2 -4001 | www.l o ra -al l i anc e.org IPv6 LoRaWAN Adaptation Layer FAQ This makes it particularly adapted to transport IPv6/UDP datagrams over LoRaWAN, but it can also compress upper layers like CoAP, DLMS application on top of IPv6/UDP, ... 4. What can SCHC over LoRaWAN not do? LoRaWAN is a long range, low power consumption and long distance, but low bitrate protocol (250 bits/s to 50 kbit/s). SCHC provides an adaptation of IPv6 and upper protocols over LoRaWAN by means of fragmentation and header compression. However, SCHC always transmits at least one LoRaWAN frame per IPv6 packet, therefore it does not reduce the chattiness of an upper protocol. Furthermore, SCHC usually does not reach into the application payload data, therefore the latter is not compressed. As a consequence: 1- Like any other LoRaWAN applications, IPv6-based applications using SCHC should limit the amount of messages they are exchanging. Specifically, it is recommended to have them work in end-device push mode, as opposed to network-pulled mode. 2- Like any other LoRaWAN applications, IPv6-based applications using SCHC should be conservative in the data volume they are exchanging. For example, the bit rate of non-compressed audio or video streams is simply not compatible with LoRaWAN, no matter how well SCHC compresses the protocol headers. 3- Like any other LoRaWAN applications, IPv6-based applications using SCHC should be aware of and tolerate the latency introduced by the LoRaWAN network. 5. What additional resources are necessary on the end device? SCHC is the IPv6 adaptation layer for LoRaWAN. As such, it is expected that the end-device implements IPv6/UDP functionalities. The end-device will require some memory resources (Flash/ RAM) to apply compression/decompression and fragmentation/reassembly on the packet. The amount of memory resources depends on the SCHC implementation and the target hardware. 6. What is the impact on the power consumption of the end device? SCHC compression reduces the size of the packet, and thus reduces the time-on-air. This will lead to significantly lower power demand compared to sending uncompressed packets. SCHC also provides fragmentation mechanisms when the packet is greater than the LoRaWAN MTU. In case of fragmentation, as explained in 13. How does SCHC affect traffic? Efficient acknowledgement message(s) (small size messages) are generated to ensure the reliability of the fragmentation mechanisms. Overall, SCHC provides IP interoperability over LoRaWAN at payload sizes similar to that of custom application IoT protocols, thanks to the compression mechanism. The associated computation cost is affordable even for constrained IoT devices. 7. How to manage the rules for SCHC? SCHC operates based on rules that describe the context for a point-to-point connection between the SCHC instance in a device and the corresponding SCHC instance in the SCHC gateway on the

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