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Ethernet Via Electric Conduits
windows bios world writes "From a CNet article NYC businesses will be able to get internet access via ethernet routed through electrical conduits from a subsidiary of Con Edison. CEC is targeting business customers and telecommunications carriers with its PowerLan Ethernet services as part of a larger strategy to become the premier provider of high-bandwidth transport services for New York." Interesting that a non-telecommunications firm can parley a single asset (right-of-way in existing conduits in the crowded tunnels under Manhattan) into a business.
Back in the mid-80s I was doing networking down on Wall St. and we needed to connect ethernet LANs in two buildings that were about 100 yards apart.
We looked into running cable, but the rights-of-way were not available. We looked into getting dark fiber, but NY Telephone said they were not tarrifed to let us have it (although there was in fact dark fiber already in the buildings).
Then we talked to a company that would run the cable using their right-of-way. That company was (if I recall correctly) called "Metropolitan City Subway" and had nothing whatsoever to do with the subways. Their sole reason for existence, so far as I could tell, was to rent people parts of their right-of-way, which they had obtained I have no idea how.
They proposed letting us run a cable between the buildings but not directly. We would have to go down to the tip of Manhattan and back again. Instead of 100 yards it was about 4 miles. They also wanted to charge us $20K per month, and had few safety provisions in place to guarantee that our cable wouldn't suddenly be cut by their or other workers.
Based on the long cable run, the costs, and the uncertainty, we passed, and I ended up installing the first microwave ethernet link in Manhattan instead (24GHz microwave between two ethernet bridges). Which worked fine and required no right-of-way...
Sprint was created when the Southern Pacific Railway realized that they could take advantage of their railway rights-of-way to lay fiber-optic cable.
Then, several years after the fiber had been installed at a cost of God-only-knows-how-many hundreds of millions of dollars, someone discovered their rights-of-way were for the surface and the fiber was buried... where Southern Pacific's rights-of-way didn't extend. I mean, after all, they were intended to allow them to lay track, period.
Oops.
(Whatever happened to that whole brouhaha anyway? I haven't heard anything about it in forever...)
Using power lines for data transfers is rather stupid - those lines just aren't designed to transmit high frequencies. Losses are high, and cabling acts as a bad antenna. If taken in use in high scale, this will bring up the RF noise levels in areas where it is in use.
For radio amateurs, this means that reception will be bad, and only way to get through is to use high power levels.
These mentioned interference problems were solved by spreading the used spectrum more - which only distributes the noise into wider band.
Eavesdropping will be also ridicilously easy with PLC.
Those who get allergic symptoms from electric fields, might want to react on this also, as PLC radiates a lot from cabling meant to use with low frequencies only. (50Hz in here)
So, tell me this isn't a real-world application of the technique to send data over power lines, is it? They're using their control cables or stuff instead?
Yeah, the article sure was unclear on that. I think it is safe to assume this is NOT running over power lines, but something like fiber. It just takes advantage of the conduit/right of way they own.
The only athletic sport I ever mastered was backgammon - Douglas William Jerrold
From the way it was explained to me, Sprint (then called United Telecom) in the early 80's was only a local telco (small one at that), and there was a partnership between United Telcom (local telco operations), GTE (long distance), and Southern Pacific Railroad (they had the right of way for the fiber drops).
They started building this network before the breakup of ATT. Once the breakup of ATT. The network that was being built was a long distance network, and GTE wanted out since it could provide long distance now since ATT was required to lease out part of its network to competitors. Souther Pacific wanted out since, it is a railroad company, not a telecom company.
The partners were slowly bought out by United Telecom, and this is where the name Sprint was picked up, because Sprint was the old name of GTE's Long Distance.
A similar thing happened with Sprint PCS, it was originally a partnership between Comcast, TCI, and Sprint. Sprint sold off their old Analog Cellular network (I think to Alltel). The cable partners joined because they feared the Baby Bells power, and want in on an alternative solution. As time went on, the cable companies were bought out by Sprint. I guess the cable partners started to realize that with the possibility of cable modems, they already owned an alternative to the baby bells.
This is how it was explained to me, let me know if there are any mistake in it.