Wimax vs. WiFi: WiFi is the inheritor to Ethernet's Manifest Destiny
Robert Berger writes that WiMax and 802.16 may be eclipsed by near-term 802.11 development: Robert is a veteran of several industries, moving from digital video to Internet to wireless, having spent the last five years thinking about and building wireless systems and companies. He now consults in the industry through his firm Internet Bandwidth Development, LLC. Robert has deep thoughts that come from this experience, and I wanted to pass on (with his permission) an email he sent to Dave Farber's IP list today.
I have been involved in these realms for the last 4+ years both in the hardware manufacturer and service provider realms. Here is my opinionated, but educated perspective on the WiMax vs Wi-Fi debate:
At this point in time, WiMax/802.16 is another Zero Billion Dollar industry. There are no WiMax Products today. There will be some WiMax products within the next 3 - 6 months, but they will be first generation and far from the promises that the WiMax forum has been promising. Wi-Fi/802.11 chipsets are already up the learning curve by several generations. Wi-Fi chipsets are already shipping in the high 10's of millions / year.
IMHO, 802.11 is recapitulating the evolution of Ethernet into the Wireless realms.
Ethernet was originally considered a "toy" technology by many of the industry leaders of the time. The manly technologies at that time were first Token Ring, then 802.12 AnyLAN VG, then ATM.
Wi-Fi is currently considered useful only for the home and some enterprise applications and a "toy" for outdoor Municipal Networks.
But Ethernet out evolved and kept delivering just enough functionality, at much lower cost than the too sophisticated QoS laden and expensive "heavyweights".
Wi-Fi/802.11 has taken on the mantle of Ethernet's Manifest Destiny (it uses almost exactly the same packet frame as Ethernet) and brings it into the wireless realms. There are many more companies, universities and hackers pushing the boundaries of what 802.11 can do and the volume is growing at an accelerating pace.
Today 802.11 is at a similar phase of evolution as early Ethernet was when there were only a shared contention medium via hubs and bridges. Ethernet really took off when switches became available and allowed the contention realm to be broken up to support parallel data flows. And that is what we can expect in the next stage of 802.11 evolution. This is what is needed to make mesh wireless networks viable with 802.11. There are already several companies developing mesh (though only a few are doing it in a way that will scale). There is also an 802.11s working group developing a standard for wireless mesh. And mesh is what will allow 802.11 to eventually cover municipal areas.
WiMax hype is extremely misleading. You hear that a WiMax basestation can create coverage of 35 - 70 miles, deliver 50 Mbps, will work in unlicensed and licensed frequencies, can deliver Non Line Of Sight (NLOS) through trees and buildings, will support mobility and CPE built into Laptops.
But this hype is misleading because they mush together all the claims for all the different frequencies from 2 GHz to 10 GHz, licensed and unlicensed, and projections of their roadmap for the next 8 years.
If you compare WiMax using the same 5.8 GHz unlicensed frequencies that 802.11a would use, there may be only 3 or 4 dB link budget advantage of WiMax over 802.11a. (I.E, the link budget is the total of receiver sensitivity and transmitter power, less losses between the two end points, thus it represents the distance that can be covered and/or penetration thru obstructions. So WiMax can deliver a link budget that is at most twice as good as 802.11a, and in the scope of things this is not very much compared to the total link budgets used in outdoor links).
If you say, ok, lets use licensed spectrum, then you can get long distances OR NLOS. If you really want to deliver multi MBps and be able to use laptops inside buildings as CPE, you'll still need microcell sites on the scale of 1- or 2-mile radius of coverage and use multiple WATTS of power. WiMax uses sophisticated base stations and relatively dump CPE. So each micro-cell basestation would be relatively expensive (compared to 802.11, but definitely cheaper than cellphone basestations).
AND you would have to buy the spectrum to create the coverage. At this point in time, in the US, the only spectrum that has half decent propagation characteristics and is available for this application in big enough chunks to be useful is the 2.5 GHz MMDS frequencies. These are already owned by primarily 3 corporations, plus a bunch of educational institutions (the later still holding on to it for "educational" distance learning TV).
So there is a customer base of maybe a handful of companies to buy and buildout licensed networks. Two of the license owners failed already in building out an MMDS network, the third is a "new" company, Clearwire, who bought spectrum from Worldcom. This does not represent a robust marketplace needed to drive a rapidly evolving technology. Its more like a legacy telco marketplace that will have to compete against DSL and Cable Modem in the urban/suburban markets that represent the bulk of the potential end user marketplace. It will not be subsidized by a parallel home / enterprise networking marketplace as will 802.11.
Finally, the WiMax industry has (in terms of active, as opposed to paper members) one giant company, Intel, and scores of small, mostly barely surviving wireless equipment companies that had already spent most of their efforts on proprietary LMDS or MMDS technology and then threw their hats into WiMax as a way to try to keep going. Most of these companies plan to offer proprietary enhancements to their WiMax products to "differentiate" from the competitors. So there are already way too many companies involved in WiMax than there will be demand for their products. So we can expect that when the hype dies down most of the companies will fail.
Sometime in the near future, I would expect that Intel will drop out of most activity with WiMax. They will realize that they need to get back to their "knitting" as AMD is challenging their core business and that there is never going to be the kind of volume in WiMax chipsets that is needed to keep Intel's interest.
There are a few WiMax companies, that will do very well for themselves. Companies such as Alvarian, who are already a leader in the outdoor, wide area wireless network equipment even before WiMax, who understand the market and have the distribution channel / customer base. This niche will grow with the lower costs for this style of rural and Multiple Business Unit (MDU) type network buildouts that can afford the price points that WiMax will end up with. But it will not be a mass market.
In conclusion, Wi-Fi will out evolve and deliver connectivity at costs dramatically lower than WiMax. WiMax / 802.16 is just starting on its path to evolution, has a much smaller base of innovators and chipset growth volume. Wi-Fi is already far along on its core learning curve, has an easy order of magnitude larger base of innovators / investors and chipset growth volume. WiMax hype will sputter out to reality of a niche backhaul and rural marketplace, Wi-Fi/802.11 will evolve and grow into many more realms and dominate the Local Area Network (LAN) / Neighborhood Area Network (NAN) / Metro Area Network (MAN).