LoRaWAN

This document updates the Static Context Header Compression (SCHC) and fragmentation protocol (RFC 8724) and the corresponding YANG module (RFC 9363). It defines a SCHC Compound Acknowledgement (ACK) message format and procedure, which are intended to reduce the number of response transmissions (i.e., SCHC ACKs) in the ACK-on-Error Mode, by accumulating bitmaps of several windows in a single SCHC message (i.e., the SCHC Compound ACK).

Both the message format and procedure are generic, so they can be used, for instance, by any of the four Low-Power Wide Area Network (LPWAN) technologies defined in RFC 8376, which are Sigfox, Long Range Wide Area Network (LoRaWAN), Narrowband Internet of Things (NB-IoT), and IEEE 802.15.4w.

The Static Context Header Compression and fragmentation (SCHC) specification (RFC 8724) describes generic header compression and fragmentation techniques for Low-Power Wide Area Network (LPWAN) technologies. SCHC is a generic mechanism designed for great flexibility so that it can be adapted for any of the LPWAN technologies.

This document defines a profile of SCHC (RFC 8724) for use in LoRaWAN networks and provides elements such as efficient parameterization and modes of operation.

This document defines the Static Context Header Compression and fragmentation (SCHC) framework, which provides both a header compression mechanism and an optional fragmentation mechanism. SCHC has been designed with Low-Power Wide Area Networks (LPWANs) in mind.

SCHC compression is based on a common static context stored both in the LPWAN device and in the network infrastructure side. This document defines a generic header compression mechanism and its application to compress IPv6/UDP headers.

This document also specifies an optional fragmentation and reassembly mechanism. It can be used to support the IPv6 MTU requirement over the LPWAN technologies. Fragmentation is needed for IPv6 datagrams that, after SCHC compression or when such compression was not possible, still exceed the Layer 2 maximum payload size.

The SCHC header compression and fragmentation mechanisms are independent of the specific LPWAN technology over which they are used. This document defines generic functionalities and offers flexibility with regard to parameter settings and mechanism choices. This document standardizes the exchange over the LPWAN between two SCHC entities. Settings and choices specific to a technology or a product are expected to be grouped into profiles, which are specified in other documents. Data models for the context and profiles are out of scope.