"Wow", I said. Far faster than the 2.5 Gb/sec transmission that is currently fairly standard for long-haul fiber trunks. The ads say they are selling it - that doesn't mean shipping it... yet at least. (Note that my employer is a direct competitor of Lucent so I have a vested interest in setting the facts straight)
No comment :-) And I certainly don't presume to speak for Lucent.... Traditional fiber-optic technology is a hybrid between electrical and optical components - big hulking multiplexers feed a high-speed electrical signal to a laser, which sends optical pulses down the fiber. Every N km, a regenerator reads the photons, decides if it saw a 0 or 1, and feeds that as an electrical signal to an output laser. Repeat as needed. The means that if you want to upgrade the signal speed, you not only need to replace the muxes and lasers, you need to replace all the regens. That's more of a problem for long-distance companies than locals (the common FT Series G 1.7 Gb system uses them every 40 km.) The new optical amplifiers not only go farther (e.g. 120 km), but they do everything optically instead of dropping down to electrical so they support a wide range of data speeds. I don't know that they can support the 1Tb experimental stuff, but they work fine for the 8-color x 2.5Gb Dense Wavelength Division Multiplexing stuff AT&T will be using. This means that the first time you do an upgrade, you need to rip out a bunch of regens, splice around 2/3 of them, replace 1/3 with opamps, and optionally replace the equipment at the ends with even bigger hulkinger multiplexers. Depending on capacity needs, you may not fire up all 8 colors at once. The next time you want to upgrade the same route, replace the muxes if you didn't, or fire up more colors, or upgrade to the new Year 2005 model. And since you've got to pick _some_ framing technology, it might as well be SONET, which lets you build self-healing rings if you want (the FDDI-like configuration, which not everyone uses, burns half the capacity on restoration circuits, more than some of the less-healable SONET configurations or mux-based restoration like AT&T's FASTAR.) AT&T has announced that they'll be pouring lots of capital into this over the next few years, partly to keep up with demand, and partly to deploy SONET rings for faster restoration.
I was figuring they'd cut out silences...as well as echo-suppression cutouts. Do they still do this? Given modern fiber's capacity, I wonder if they bother.
Voice compression and silence suppression aren't done domestically (at least by most carriers.) Undersea cables still use this, though I don't know how much it's done on the newer fiber cables. Of course, people running private networks do whatever they want, and for overseas connections, people are often willing to trade lower-voice-quality compression for the cost savings, especially if the PTT on the far end is expensive.
I don't know that any number fiber cable is "standard" but 36-fiber cable is not unusual. To find the capacity of a cable, you have to cut the number of fibers in half (as you did) because generally each fiber is used only for a single direction of traffic. You then have to cut it in half again because phone companies have everything redundant.
A fairly common configuration for FT Series G is 8 fiber pairs (one fiber for each direction), with 7 in service and 1 protection pair to recover from mux-card and regen failures and other single-fiber hits. To restore whole-bundle hits (e.g. backhoe fade), some of the 7 pairs are typically dedicated to restoration - though seldom half. The restoration pairs are often used for short-time reserved applications such as TV connections for sports events, videoconferencing, or other applications where someone needs a lot of bandwidth for a short time and is willing to be pre-empted or blocked if there's a failure.
There's also a lot of 'dark fiber' out there, right? Fiber laid as part of a cable but not activated, because it's not yet needed.
That's _highly_ location and company dependent. Long-haul connections are likely to be used efficiently, because you can get economies of scale and because growth will fill them up (e.g. across the Rockies). Short-haul connections (e.g. around town) are more likely to have dark fiber because the big costs are digging up streets and paying for government officials\\\\\\\\ licenses and permits rather than the costs of the fiber you're putting in a trench once you dig it. And the short-haul doesn't need regens, and often uses lower bandwidth than the fiber can handle (OC3 muxes are much cheaper than OC48, though per-Mbps they cost more.) And of course, _everybody_ seems to want a T3 to the Bay Area or other Internet-heavy locations.
I would add that much of a phone companies cost is in billing and customer service, etc. Not the cost of installing and maintaining the fiber and equipement.
This suggests that there would be a market for a LD phone company that charged, say, a yearly payment of $200-300 for essentially unlimited use. (The main impediment to this would be regulatory; as I understand it LD companies have to pay local telco's for connections on a per-minute connect basis. Is that right? This needs to get fixed.) Their billing costs would be very small.
There's a lot of cost in switching equipment as well. A feature-rich voice telecom switch costs _far_ more per 64kbps voice circuit than the 1/(24*28*36=24192) fraction of a fiber that carries it. And big muxes, while cheaper than voice switches, are still expensive.
Internet telephony should make the use of bandwidth even more efficient - thereby cutting costs. The big guys who own the fibers will still make money - the pipes that carry internet traffic are still needed. But the little guys will get squeezed out. (until they become ISPs ;-). Internet traffic could theoretically be carried over this large amount of protection fiber (mentioned above) that is out there for a much lower marginal cost than the current T3 or OC3 pipes that are being used.
In addition to Internet telephony, ATM switch makers are doing voice compression, and some of the fiber vendors are starting to use their equipment to offer business voice services. And voice-over-frame-relay, which has more delay and therefore doesn't handle voice as well, also is getting some market, especially internationally. Pricing is a really difficult problem - if you price bandwidth proportional to the 64kbps voice circuits, it's either too expensive for most businesses to buy much or priced too low to make money on switched voice. But if you price high-speed circuit bandwidth much cheaper than proportional, it becomes cost-effective to buy customer-premises equipment and bulk bits and run your own phone services. Phone companies have been worrying about this for video services for years, but fortunately Moore's Law and research have let compression improve enough that you can run cheap video on 2*64kbps and good video on 6*64kbps, so they haven't been killed. But Internet and similar data needs are starting to demand high bandwidth at low costs, and the market will have to catch up somehow. # Thanks; Bill # Bill Stewart, stewarts@ix.netcom.com, +1-415-442-2215 # goodtimes signature virus innoculation