Fiber-to-the-something:  Which is which?

Twisted wire, xDSL, coaxial, wireless or fiber??
DSL-like technology has done an admirable job of keeping up with cable, but fiber's signficant advantages are becoming reality for many homes and businesses. Also, the portability of wireless service with 3.5G-and-faster speeds could soon make this technology the exclusive broadband choice for many.



Fiber to the node, cabinet, curb, building, or home.
FTTx: Fiber-to-the-node, fiber-to-the-curb, fiber-to-the-cabinet, fiber-to-the-building and fiber-to-the-home are all slight variations of a theme: Fiber is coming in a big way!

When backbones catch-up, customers will have virtually limitless data speeds, up and down, that not even cable or wireless can match. Too expensive? Too difficult to roll out?? No, and no, to both questions.




How many turns or splices can you place?
One of the challenges of fiber is splitting and combining, bends, and interfaces. Fiber is pulled like any cable, but the last mile-to-quarter mile, particularly in commercial or residential high-rises, has some special challenges: Attenuation, the stress in bends, limits on the number of splices, etc. can all be optimized with carefull planning in advance. New construction should always try to incorporate the proper plenums and guides for fiber.



Did you know?


Chances are you own two, three (or more?) of these: a flash memory card. Flash memory was invented by Dr. Fujio Masuoka of Toshiba in 1980, and even though they knew it was something big, it's unlikely anyone then would foresee what would happen next.

Smaller than the size of your fingernail, a 4GB microSD card like the one below stores 4 billion bytes of data.

That's 2³² or 4,294,967,296 bytes.

Courtesy of SanDisk®.

How many transistors is that? Well, there's 8 bits in a byte. And certain varieties of NAND flash use only 1 transistor per bit, while others use as many of 8 transistors per bit. Curiously, despite using more transistors, the 8 transistor/bit design often uses up less space than the single transistor/bit because of the physical design, which requires fewer lead connections to the outside world. However, 8 transistors/bit can consume more power to operate. Because the actual designs are trade secrets, we don't know for sure how many transistors per bit are used in any given microSD card, so let's just assume the lowest number of 1 transistor per bit, which would give us:

4,294,967,296 bytes x 8 bits per byte x 1 transistor per bit =

34,359,738,368 transistors!

On less than the size of your fingernail! And that doesn't even include the circuitry needed for the memory controller, interfacing or error checking circuits. Plus it's reliable, with literally tens of millions of these cards sold every year, and virtually nil rejects at the retail level. But perhaps the best part is, we just bought a 4GB microSD card much like the one pictured above for $18 at a local office supply store, including tax -- less money than it takes to eat out for an average dinner or to buy a few gallons of gasoline. That's about 2 billion transistors per dollar!

Now consider a state-of-the-art microSD, such as the 32GB version (as of mid 2010), or one that does use the design of 8 transistors per bit. That card, which would have the exact same physical dimensions as the one pictured above, has 8 times the number of transistors, or 274 billion, 877 million, 906 thousand, 944 transistors.

Dr. Evil and images from the
Austin Powers films are trade marks
of New Line Cinemas.

Imagine the disappointment of an evil extortionist, demanding a ransom of some 274 billion transistors, only to find out their actual value of only $18 (and dropping...).