ARINC Specification 853:2024

This specification defines the Cabin Secure Media-Independent Messaging (CSMIM) Protocol. CSMIM is intended to provide an industry standard open platform approach to defining networks and the elements contained within them for use within aircraft cabin systems. CSMIM is built upon existing protocols that support Constrained RESTful Environments, for example, Concise Binary Object Representation (CBOR) for data representation and Message Queue Telemetry Transport (MQTT) for transport. At the core of CSMIM is the philosophy that supporting the interoperability of equipment from many suppliers on a common communications platform is key. Components that are envisioned to be users of CSMIM in the future will include lighting, sensors, seats, and other cabin systems. The protocol provides device classifications, use cases, and reference architectures to aid developers in adopting and developing networks and hosted elements that will leverage CSMIM. A CSMIM compliant system will provide common services, which are defined in the document, to allow system components to securely join and share data across the network.