What does near-real-time vs. real-time mean?
A real-time signal is continuously being sent and received, with little or no delay, much like a newscast or program on TV. Near-real-time is delayed slightly because a communication link is established to send the data once an event occurs, much as one makes phone call to someone in order to give them a message. Near-real-time communication is generally more economical than a continuous data link, which makes it attractive for communication of infrequent events like the occurrence of earthquake shaking. Real-time communication is thought to be more reliable, but a big earthquake can interrupt many conventional communication pathways. To achieve the most robustness, all types of communication paths should be used achieve maximum redundancy (as is being done in CISN).
