Hi, Rob - That was an outstanding post: a concise overview of the factors pertaining to the emergence of coded OFDM networks.
"OFDM is a non line of sight technology"
There's been a lot of confusion in the public mind about that. I suppose the confusion hasn't been helped by the inevitable marketing efforts of various companies, which give the impression to the reader that they have solved the LOS issue, while others have not.
The issue is further complicated by the question of which frequency is being used. As the frequency drops, from 5 GHz down, the ability of the radio waves to penetrate walls and windows, and to be less affected by atmospherics, increases.
This should be apparent to any cell-phone user.
But the fact that coded OFDM is designed to achieve higher NLOS effectiveness (designed to use multipath reflections) is one that doesn't seem to have quite sunk in yet.
Anyway, the use of coded OFDM and frequencies at 5 GHz and below will mean previously unheard-of wireless reception/transmission.
Looking at the range of techniques being planned for these future networks, including MIMO, sectorization, new antenna technologies, macro/micro/picocell heirarchies, mesh topologies, and more, it's clear that the new networks will have, in time, ubiquitous reach.
While it is likely that the initial installations will gather the low-hanging fruit, there will be an evolution to higher densities, with conversion to RF/optical (augmenting or replacing wired) backhaul where heavy usage begins to degrade QoS.
There's not much to add to your excellent post, except that what is true of the United States is also true of the world, in general. While the US is an important market to any company with emerging technology, the importance of the world market to entrants should not be overlooked.
At MMDS frequencies, and in unlicensed spectrum, global efforts to develop high-capacity RF networks using coded OFDM, will, in the end, dwarf the American MMDS market. HiperLAN2 and IEEE 802.11a are both (primarily short-range) expressions of that potential.
China, for instance, is possibly destined for a jump straight to a fiber and fixed/mobile wireless connectivity model:
Message 15657272
Third-world countries will soon achieve the ability to replicate much of our "wired" infrastructure with relatively cheap, quickly-installed wireless installations.
You correctly point out the near-term uncertainties:
"I believe that FWBB is finally at the stage of development to explode onto the scene during the next two years. The climate for capital expenditure will probably continue to look bleak for at least six months. Meanwhile, major carriers are diligently evaluating the new systems and readying their plans for deployments expected to kick off by the 1st quarter of next year."
The explosive potential of this technology is global, and multi-spectrum. By 2005, the combination of Moore's Law, to which you refer, and economies of scale, will do to this technology what they did to the calculator.
Thanks for your excellent post.
Regards,
Jim |
