Hi Jack,
The line of sight systems from TGNT, WCII, etc. are more limited in bandwidth relative to the LU OpticAir system's, but since they operate in the RF region they are far more reliable, if distanced properly, than those based on Infrared. One needs to assess the tradeoffs and the probabilities of inclement weather's effects on operations in determining the actual levels of risk for any given situation.
If the Infrared link is only required during rare occasions, such as those which are designed for disaster recovery, then one can make some assumptions that the likelihood for both systems (main and backup) being down at the same time is low. But even this assumption is fair game, subject to treatment by Murphy's Law, from time to time. Very rare, but I could tell you some stories of other backup schemes which have disappointed during the moment of truth.
In fairness, however, "bad weather" is but one form of threat. Optical systems running through central offices may find their own form of "bad weather" in the form of administrative error at the hands of craftspeople, system failures, etc. In other words, there are no entirely failsafe systems out there. None that I am aware of, in any event.
But if I had to grade IR against those of fiber and other wireless forms, today I would have to rank IR last in terms of reliability, despite their many other advantages outside the realm of meeting strings of nines (e.g., 99.9999% uptime).
Even though much higher speeds can be attained through the Infrared system approach, even for day to day use, one must take into account the maximum period of time that they could sustain their ongoing operations at the reduced speeds, or forego the IR link altogether, during severely inclement weather.
If the much higher speeds are only required for several hours per day, say, for backups of servers and NAS files, then perhaps IR offers a viable solution, if there is some slippage allowable in the scheduling of these tasks.
But if the criticality of a link is such that it cannot be down for more than a couple of minutes before it begins to impact the bottom line, then... well, you can take if from there.
Regards, Frank Coluccio |
