[2] The difference between a hard and soft real-time communication system is the consequences of incorrect operation.
Hard real-time communication systems are frequently electromechanically linked to a physical mechanism, often one that interfaces directly with people or property, which often contributes to or defines the potential danger of a fault.
Due to their safety-critical nature, the communication protocols defined in a hard real-time system generally must be deterministic.
[4] Hard real-time communication systems are particularly common in the transportation, industrial, and medical sectors.
[8] Data transmitted over a soft real-time communication system is not stored in a centralized server, and peers are connected directly to one another rather than through a server, although intermediary connecting nodes between peers are allowed when a direct link cannot be established.