<SilkRoad tech>
I took a look at the SilkRoad link. Tis pretty annoying and pretty
much devoid of technical content. Essentially what SilkRoad claims
is to have implemented an external EO (ElectroOptical) Modulator
which works at OC-48 speeds (2.5 Gbps) and it is able to AM modulate
that stream. This simply means they can form light pulses that carry
information, "0"s and "1"s at 2.5Gbps. That's all they say and claim
to have implemented a photodiode receiver that works at that speed.
Well, a lot of folks do similar already, directly with the laser diodes, without external EO Modulation, and they do it at OC-192.
DWDW technology uses multiple wavelengths in the same fiber, which means multiple narrowband (much narrower than what SilkRoad uses)
sources and all the special passive optics that go with it, like
gratings and the like.
Optical transmission for long distances invokes many effects that
can cause "crosstalk" in DWDM systems. There are a plethora of
non-linear optical effects that affect all high power optical systems
and these include such things as ASE (Amplified Spontaneous Emission),
4 wave mixing, all in addition to the modal and chromatic dispersive
effects which require the use of repeaters to re-time and re-form the
optical pulse train that carries the info.
So what does all this mean ?? Given what I have seen on what is in
the SilkRoad Link, and I am not a technical expert on SilkRoads offerings, my bet is on DWDM technology-- the CIENs, the LU's the
NT's, the Alcatels, the Pirelli's, the UNPH's. I'd rather have a
40 or even 80 channel DWDM box at OC-48, or even OC-192. |
