Fiber interfaces at 10 Gbps and below at OOK (on/off keying), yes.
40 and 100 Gbps interfaces are frequently a form of CWDM (4 x 25 Gbps) or coherent modulated, QPSK, or 16QAM for example, this Cisco 100 Gbps linecard which uses a form of QPSK modulation. http://www.cisco.com/c/en/us/products/collateral/routers/carrier-routing-system/datasheet_c78-478689_0629.html On Thu, Oct 23, 2014 at 11:47 AM, Adam Moffett via Af <[email protected]> wrote: > Something came up in fiber training that I attended recently that I found > hard to believe. > > The instructor said that the signaling was simply on/off. I.E.: light on > = 1 and light off = 0. > > I would have *assumed* they would use some sort of more advanced > modulation than that. In fact, I'm sure I've read about creating an > optical carrier wave and modulating it. > > Was the instructor correct? Is it just blinky blinky on/off and that's > it? If so, then why the hell would they do that? Wouldn't they get > another order of magnitude of capacity by applying a more advanced > modulation scheme? >
