I was surprised and pleased to receive some comments back today from my FTTH Council friend Katsu-san who is involved with FTTH installations for Sumitomo Electric in Japan. His email is very interesting from several aspects.
Thank you for the dispatch regarding the fibre optics and earthquakes.
I had lived in Sendai before and had experienced the earthquake measuring 7.2 Richter scale in 2003. It was a big shake, but luckily we had no damage by Tsunami. Maybe because the epicentre was close to the land. No man died, one house burned by fire. City tube operates without stopping services though they reduced the number of trains and operation speed.
The area is historically very famous for big earthquakes and tsunamis. They have them every 40 years in average for hundreds years. Many records are kept about the damage but this is the biggest one ever for 1,000 years. They are the most experienced citizens against the earthquake even in Japan. I’m sure nearly 100% of the toll will be explained by tsunami, not by the collapse of the buildings by shakes.
By the way allow me to express my comments on your article. Please note that it’s my personal opinion.
1./ Is the BIF strong against the risk of breakage?
I’m not sure about that. ITU-T and IEC specify BIF to be insensitive in terms of the bending induced optical loss (attenuation), however they didn’t specify anything about the strength. For our part (in case of Sumitomo) we apply higher proof stress level than the criteria specified in ITU-T (0.69 GPa), however we do it with our own policy.
2./ Underground or Aerial?
I’m not sure which is more reliable when the earthquake comes. The only damaged cable we had in 2003 in Sendai was underground cable because of the shift.
3./ Battery backup
I remembered you have mentioned about it before. We don’t have any battery backup on ONU in premises in Japan. Do I surprise you? I know it was highly controversial when NTT decided which way they go. Eventually they chose no-battery-back-up policy to make the system simple and cheaper. I couldn’t use the Internet for a couple of hours after the earthquake because of the power outage for a couple of hours. It was inconvenient but was not critical. It has recovered soon. The most serious issue was and still is the lack of capacity in wireless. In the situation of emergency mobile is quite useless.
It’s nearly the time for the annoying “planned power outage” of the day. I’m not sure if they really shut down the supply, but I’d better shut down my PC just in case.
Wataru Katsurashima (Katsu)
Sumitomo Electric Industries, Ltd