WiFiNetNews, reprints an interesting opinion by consultant Robert Berger. He thinks WiFi will win over WiMax for metropolitan “city clouds”.
He has a few good points. His conclusions are dubious. Here’s his case against WiMax:
…”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)”…
But Intel CEO Paul Otellini believes WiMAX could overshadow DSL in much the same way that cell phones have supplanted many landline users. WiMax was designed for metropolitan area networks. WiFi was not:
- WiMax has polling architecture
- WiMax has dynamically adaptable modulation
- WiMax has QOS built-in (for VoIP)
- WiMax can use narrower channels that can concentrate signals
- WiMax can use both unlicensed or licensed channels in 5, 6, 10 or 20MHz channel widths
- Intel anticipates WiMax PC-Cards and WiMax phones in 2-3 years.
- WiFi mesh networking is proprietary with no interoperability between vendors.
Competition for “city cloud” architecture includes licensed wireless ISPs and carriers like those in Sydney and North Carolina (Arraycomm & Flarion), Seattle and Jacksonville, Florida (pre-WiMax) as well as EVDO everywhere (Verizon and Sprint) and 3G with HSDPA (Cingular).
Both WiFi and WiMax share the same power limitations (at 2.4Ghz and 5 Ghz). But WiMax can also use the licensed bands. With standardized adaptive modulation, narrower channels, polling and QOS, WiMax will deliver the goods where WiFi can’t.
WiMAX enables optimization of each subscriber s data rate by allowing the base station to set modulation schemes on a link-by-link basis. A subscriber station close to the base station can use 64QAM modulation, while the weaker signal from a more remote subscriber might only permit the use of 16QAM or QPSK. The 802.16 MAC can even use a different modulation method for each subscriber s downlink and uplink bursts.
Phone and cable companies will be out of the loop. That cuts costs – the infrastructure is mostly air. Antennas atop schools, community centers, gas stations or utility poles will be WiMax-compatible because the range is better and the average cost per user is less.
Mesh networking is proprietary. You must choose one vendor and stick with them.
Washington DC is experimenting with Flarion on the 700 Mhz band. They get better coverage than cellular with faster service. With MIMO designs, “smart antennas” like Motia or Navini and improved signal processing, even the 5.4Ghz band could become practical for mobility. Cities can merge the ajoining 4.9 GHz public service and 5.9 GHz highway information systems together to create a “cloud”. WiFi range is too limited. A proprietary WiFi mesh system would be expensive. Spending millions on the 2.4 GHz band also seems risky. It could be reduced to “junk” in no time. There just aren’t enough channels at 2.4 Ghz.
The Champaign-Urbana Community Wireless Network (CUWiN), is available on a bootable CD-ROM. A computer with a wireless card can be a node. It doesn’t get any cheaper (or simpler) than a $60 Linksys WRT-54G modified with Portless software or a $99 Sputnik Box . But how to network them?
Do the backbone in WiMax. Intel says WiMax clients or WiMax-linked hotspots should be about as cheap as WiFi gear is today by the time the infrastructure is built out (in a couple of years).
WiMax IS complicated and expensive (compared to WiFi). But it’s far cheaper than cellular. You can build it yourself. I recall thinking 802.11g was too complex and expensive, too. Now you can buy a card for $20.
Proprietary mesh networks are handy for many things. The ability to add a module on a light pole is a big deal. But you can mesh with WiMax, too. Fixed backbone, mobile everywhere. Forget the 2.4GHz band. WiMax seems the better bet for covering large areas, especially the 802.16e flavor with mobility. Faster, cheaper and standardized. It was designed for metropolitan area networks and travels further than WiFi.
Mr. Berger may change his tune when he’s got something to sell.
Circumstantial evidence appears to be overwhelmingly on the side of WiMax but lacking evidence, this case should be thrown out of court. (Theme from Perry Mason)
