Realtime is measured in whatever you need to measure it in. Realtime means that the system will guarantee to perform its function within some timeframe. If it v

Realtime is measured in whatever you need to measure it in. Realtime means that the system will guarantee to perform its function within some timeframe. If it violates this (even by a nanosecond), it's failed. Think of the airbags in you car. If they function perfectly 2 seconds too late you simply don't care. There are plenty of realtime (often termed hard realtime) systems where that action can take minutes or hours, but if it isn't performed by then lives can be lost. The "realtime" people usually talk about is soft realtime. Trying to perform tasks as fast as possible (or within some average response time), but if the odd task takes longer that's OK. Anything involving a dynamic open network would be soft realtime.