A communication(s) channel (also called a circuit or line) is
- "a medium by which data is transmitted (e.g., physical via Universal Serial Bus (USB), wireless, wired, verbal, etc.)."
Basic properties, assumptions, recommendations, and general statements about communication channel include:
- 1. Communication channels move data between computing, sensing, and actuation.
- 2. Since data is the "blood" of a NoT, communication channels are the "veins" and "arteries", as data moves to and from intermediate events at different snapshots in time. . . .
- 3. Communication channels will have a physical or virtual aspect to them, or both. Protocols and associated implementations provide a virtual dimension. Wires provide a physical dimension.
- 4. Communication channel dataflow may be unidirectional or bi-directional. There are a number of conditions where an aggregator might query more advanced sensors, or potentially recalibrate them in some way (e.g., request more observations per time interval).
- 5. No standardized communication channel protocol is assumed; a specific NoT may have multiple communication protocols between different entities.
- 6. Communication channels may be wireless.
- 7. Communication channels may be an offering (service or product) from third-party vendors.
- 8. Communication channel trustworthiness may make sensors appear to be failing when actually the communication channel is failing.
- 9. Communication channels can experience disturbances, delays, and interruptions.
- 10. Redundancy can improve communication channel reliability. There may be more than one distinct communication channel between a computing primitive and a sensing primitive.
- 11. Performance and availability of communication channels will greatly impact any NoT that has time-to-decision requirements. . . .
- 12. Security and reliability are concerns for communication channels.
- "Overview" section: NIST Special Publication 800-183, at 7-8.