Re: Equalization and benefits of Parallel Optics.
The parallel technique will add more skew than a single fiber to further
restrict the distance and cost.
NetWorth Technologies, Inc.
If you have 75% support for 6-PMDs to include parallel-interconnect, I will
vote for parallel, since I support all VCSEL technologies. Otherwise,
is sufficient already.
The Parallel approach is mainly for up to 20 meter connections. It is not
designed for 100 meter to go through ducked, or underfloor pipe
installations, because a ribbon fiber is not jacketed enough for those
punishing pulling environment. Furthermore, at the patch panel connections,
the fibers are all single (duplex fibers) fibers, but not 4-parallel
fibers. For a parallel fiber to connect to an existing single (duplex)
at the patch panel, one has to perform field termination, to which a
fiber is not designed for due to the tight tolerance of spacing between
adjacent channels. Normally, the parallel ribbon fiber cable is factory
However, if the parallel fibers are used just as a jumper cable to
interconnect closely located nodes -- 5 meter, 10 meter,-- the ribbon cable
can do the job. Then, how about the serial 850 nm approach, which is
cheaper, and easier eventually to reach more than 20 meters?
I was a member of OETC consortium in early 1991, which promoted the parallel
interconnect in industry with the blessing from ARPA. The project failed
several years later due to the lack of interest from industry. The reason
was too expensive, difficult in termination and alignment, and expensive
I was a big fun for, the industry first commercial parallel interconnect,
OCTOBUS. I tried very hard to implement to my company's equipment. After
several years, the product never reach production stage, and was canceled,
due to the lack of interest from industry. The reason was the same as OETC.
There was only two ribbon cable suppliers and was expensive that time. The
factory only termination was very inconvenient for users. It implies there
is no flexibility in modifying the cable lengths, when an equipment, or
terminals are rearranged to a different location. One has to go back to
order new set of cables?
For last 10 years, parallel interconnect was highly valued; however, it was
never motorized as a contender for the top interconnect solutions. I hope
will this time?
NetWorth Technologies, inc.