Fiber

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RKG
Posts: 2629
Joined: Mon Dec 10, 2001 4:00 pm

Fiber

Post by RKG »

We need to light and mux some point-to-point fiber; looking for about 24-48 "pairs" over 2-3 mile hops. Anyone have any good experience with equipment?
RFdude
Posts: 149
Joined: Thu Sep 13, 2001 4:00 pm

Fibre

Post by RFdude »

Thats like asking: "I want to buy a car. What model should it be?"

Can you be more specific what you have in mind? 24 to 48 pairs of E+M that you must somehow convert and transport using a channel bank? Data? Voice? Order Wire? Ethernet? DS1? DS3? OC3? Redundant lasers? Single mode or multi-mode? What kind of a MUX? AC, DC power, etc? If you want some help, make an effort to be more specific!

In the mean time, look at ADTRAN, among others. Good telecom grade equipment that is guaranteed for 10 years, even if you buy from ebay. Price is excellent.

Sorry for the rant. I've seen this a bit too many times on this board. I'll never reply like this again. I have to chuckle that I've taken the bait and already exceeded your two sentences with my reply.

RF Dude
RFDude
k2hz
Posts: 531
Joined: Tue Mar 01, 2005 7:27 am

Post by k2hz »

I will second RFdude's comments. If you do not know specifically what type of equipment you need, you probably do not have the experience or equipment to install and maintain it.

I would suggest you find some local vendors that can support the system and see what they recommend. Then, if need be, come back here with some specific questions to compare alternatives.
RKG
Posts: 2629
Joined: Mon Dec 10, 2001 4:00 pm

Post by RKG »

You guys are quite correct; my query was a bit vague.

For a new installation, we had originally been promised some 50-pr copper pair cables between the critical points, and that isn't going to happen; as a consolation, we've been offered a couple of strands of dark, single-mode fiber instead. The lines we need are simple 2- and 4-wire audio lines for such things as connecting TRC cards or receiver cards to remote radios. Also need a couple of contact-closure lines for remote manually-operated relays. Max hop length is under 5 miles.

After some investigation and recommendations, we are zeroing in on a device called TC8000 from TC Communications, in Irvine, CA. Seems to fit the bill nicely; seems to be reasonably priced; will work nicely with our main and standby power systems; and is easily adapted to fiber hot standby. Had a couple of conversations with their tech people, and they seem to be responsive and knowledgeable.

Anyone have any experience with this Company or their stuff?
k2hz
Posts: 531
Joined: Tue Mar 01, 2005 7:27 am

Post by k2hz »

OK, you did do your homework and know what you want. I am not familiar with the company but I just looked at the specs on their website and I agree that it looks appropriate for your needs.

The fact that you only need basic 2/4 wire audio and some contact closure circuits simplifys things and this unit seems to do what you need. This unit will support both single and multimode fiber so it should interface with whatever you have available.

Power supply redundancy is always a good thing.

The fiber hot standby may not be worth the extra cost of you do not have diverse routed fibers. It looks like the other electronics in the unit are not redundant so the only protection would be for a failure of the optical transceiver in the unit. If you do have fiber route diversity then hot standby to protect against a fiber cut makes sense.

The other concern I would have, depending on the criticality of the circuits to be carried, is maintenance and support issues. Will you have the ability to make prompt repairs with the assistance of remote tech support from the vendor or will you need availability of a local service contractor?
RKG
Posts: 2629
Joined: Mon Dec 10, 2001 4:00 pm

Post by RKG »

1. The reason we were offered the fibers is because the Town has a large over-capacity, to virtually all Town-owned facilities. I intend to try to get diverse redundant paths, so that one falling tree or one flooded manhole doesn't take down a hop, and I believe that at the moment "they" feel like they "owe us one" for renegging on the Telco copper. If that works, then adding fiber hot standby to the TC8000 series is pretty easy.

2. It is an item on the "to do" list to see if the regular service shop will add these units to the contract. Regardless, they are inexpensive enough that I have in mind sparing one or two and, if need be, sending one that goes south back to the manufacturer. That is what we presently do with CEB cards and the like. Frankly, since they are less exposed to lightning transients and since we have superb isolation from utility transients, I expect that once the units survive burn-in, they should last for a long time. The warranty is 5 years.

But I'd still be interested to hear if anyone has any experience with TC Communciations or the TC8000 series.
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