Wednesday, October 17, 2007

Wifi or Wimax (or both)?

Some followers of my blog and people that know me personally will have an idea on my position in the whole Wifi versus Wimax debate. As far as I am concerned there is no "versus" argument for the foreseeable future and the two technologies will compliment each other for quite some time.
Today I noticed a post on one of the many mailinglists (remember those you feed-junkies?) that I subscribe to. It was made by Cor van de Water a very knowledgeable guy who happens to work for Proxim. Cor's post concured with my opinion but added an extra bit of technical insight. Rather than quote from the post I have asked Cor for permission to post the whole message, so here it goes:

"Mr Cohen describes very accurately something that we also see
happening: Many customers come to us with the requirement for a WiMAX certified product, especially when they are working from a greenfield situation.
We then explain what our WiMAX certified products can do and check with the customer if this fits their needs.
The amazing thing that develops every time is that the customer starts explaining their needs and it appears that this absolutely does not fit with what WiMAX can offer.
For example, they want ubiquitous mobile high-speed wireless access. That is 3 acronyms that do not combine in WiMAX, while they are the core of standard WiFi.
WiMAX is either mobile (802.16e) but that variant of the standard is so much optimized for range that the throughput severely suffers and the ubiquitous availability is questionable, because this standard competes head-on with 3G style cellphone standards.
The 2004 variant (802.16d) can achieve a decent throughput, especially in the non-standard 7 MHz mode, but is not mobile and is also not ubiquitous.
The only ubiquitous mobile wireless de-facto standard is WiFi.
It is so much a standard, that when you buy a new laptop it is not mentioned as a feature, because *every* laptop has WiFi.

So, then the customers make the step that, yes, they want WiMAX still as backbone, but they want to add WiFi access to capture the market of ubiquitous available client devices.

Next stumbling blocks then appear: how about the availability of frequencies, licenses or unlicensed operation of the backhauls and the throughput requirements on the backhaul network.
Suddenly the customer realizes that none of their clients will be interested in which technology is used for the backhaul of their data, just like you don't care how the cell phone company feeds their towers, as long as you can use your phone.

So, in the contracts that we typically see with major customers we rarely see the work WiMAX back, except with a qualifier such as WiMAX-alike or pre-WiMAX.
We would like to sell our WiMAX gear to more customers, and we indeed see interest and sell to some customers, but they are a niche in our big wireless market and my personal opinion is that WiMAX signed its death certificate when it decided to focus the 802.16e variant so much on range, to allow it to be used for multimedia handsets in the same market segment that is targeted by so many cellphone technologies, which have the power of installed base and upgrade path.
WiMAX has gone the opposite direction of the rest of the wireless market, in search of higher throughputs.

Now look at how WiFi has finally decided to triple the air speeds without consuming more spectrum by putting the 802.11n stake in the ground and going for products.
The additional benefit of 802.11n will be the increased range, simply by smart switching between either higher throughput or using the additional bandwidth and antenna polarization for redundancy.
Indeed, with WiFi speeds now being higher than Fast Ethernet when AP and client benefit from 802.11n, we see that WiMAX is severely lacking in providing the bandwidth, where it started with an advantage by originally providing 256QAM modulation in the 802.16d version, so it is now unacceptable as backhaul.

To make an even stronger case for license-exempt products, with the addition of 255 MHz more bandwidth in the 5.4 GHz band and the regular approval of more radios by the FCC that allow a selection of any frequency in the 5.3, 5.4 or 5.8 GHz band, a whopping 480 MHz of spectrum is available for outdoor use in the USA, products are available today and plentiful, with high throughput, built-in mobility and competitive prices.

We see that once our customers understand the many orders of magnitude difference between WiFi and WiMAX installed base and they realize that the backhaul technology is unimportant as long as it provides high throughput, low latency and where applicable mobility, QoS and other WiMAX-alike features, we see that they always select a non-WiMAX solution for their access network and a WiMAX-alike solution for their backhaul.

I realize this may be controversial and painful for some, but I simply do not see the big market for WiMAX in the form it has now."

kick it on

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