I’ve been reading about this now for about 2 weeks, and frankly, I wanted to have more to talk about.  In this link to the National Weather Service, you can read the official announcement, and here is a nice article in the Wall Street Journal. Having lived in the St. Louis area for over 35 years, I’ve seen lots of floods.  Of course, the flooding in 1993 was the worst (so far).

So, why am I posting this? A couple of reasons;

First, I know that not everybody pays attention to the weather service, or the news for that matter, and I wanted to “spread the word” in my own way.

Second, I wanted to reinforce maintenance and systems preparedness.

Some of the things that I have come across in my experience that happens during flooding and chronic wet conditions can really create headaches. You really don’t want to be troubleshooting a communications issue while trying to dispatch sand trucks or trying to maintain a switching station.

Things to look for primarily are weatherproofing issues.  Some may be beyond your control.  Water creeps into telephone cables all the time. This can cause noise and cross talk in analog circuits, and can cause errors on T1 lines. While fiber is somewhat immune to the water, the electronics are not. Additionally, if the fiber handholds and electronics are under water, the circuits will fail.

Water also does interesting things to microwave paths. Water has a high reflection coefficient. This is why we design in diversity when paths travel over large bodies of water. These ties back to overall system design.

So, my question is, when was the last time you tested your hot standby systems? Have you recently busied out your T1 and accepted calls on your backup trunks? For that matter, when was the last time you tested your UPS on some of your smaller sites or non-generator systems?  Have you forced a ring direction switch on your fiber or ring microwave system?  If you are running a simulcast system, how does this affect the timing and the system retraining time? Are your people trained and experienced enough to notice and respond to equipment alarms appropriately?

For some of my customers, these items are standard operating procedure, but for some, the network is taken for granted.  Let’s not take things for granted.

When to check your nuts

OK, so a pithy headline can get anybody’s attention, but when it comes to tower maintenance, it really is about nuts and bolts.

Towers are like bridges – they all need maintenance, but unless they break or are visible, they tend to get neglected. Oh, sure, the big ones, the ones with lights and alarms get some attention, but when was the last time you checked the ones that don’t get painted or lit? Would you be worried if the nuts at the base of your tower were like the ones in this video??

OK – so, not fair; this was a new tower. BUT we discovered this during our final punch list.  This tower was lighted, and had all antennas installed.  In fact all the civil was completed.  We only needed to install electronics at the site.

However, this photo

is not of a new tower, but one that is up.  Notice the concrete? Over time, everything fatigues, even concrete and steel.  The forces of heating and cooling naturally work parts loose, and if not checked regularly, could lead to a major catastrophe. The crack in the concrete was found while adding antennas to this tower.  The crack leads right to one of the anchor bolts.  This is a serious repair.

As part of this post, I went out to Rohn, Sabre, and Valmont to try and find the recommended maintenance intervals and practice.  Unfortunately, my search of their respective web sites was not fruitful. I’m sure an email or phone call to them with the model number of your installation would get you quick results.

The point here is to make sure that you include tower inspections and routine maintenance in your budget.  I know things are tight from a fiscal perspective, but like your communications system, a minor failure can multiply, and over time become a real issue.  And we all know that it’s during the critical times that systems tend to break down.

One of the best things of being in business is the access to free trade articles. I regularly get NASA Tech Briefs – what can I say, I’m a tech junkie. They have, from what I can discern, a few other sister publications.  One of these sister publications is Photonics Tech Briefs.  Most of the time, this has articles specific to hardware design; lasers, OTDR‘s and other serious technology and fiber optic discussions.

However, this months feature article is on Ethernet over Fiber Optics.  Titled “Demystifying Optical Ethernet Networks” this really gives an excellent basic understanding of how Ethernet works in carrier networks for the uninitiated.

These networks are becoming more and more predominant – particularly for larger customers, or customers in areas that have a better technology infrastructure. Ethernet is becoming a more common access method for everybody.  What I really like about this paper is how it’s broken up in to the PHY layer (or physical) versus native Ethernet and long haul carrier Ethernet over SDH networks.

This is also just a technology paper, not published by any specific vendor. I recommend that everybody go out an take a few minutes to read about Ethernet and how it all works together over a wide area to provide services, and what happens in the middle.