The D standard does not include support for diversity, though nothing technically prevents a company from making a D product that could (except money!). Our position is just that is adds major CAPEX to the build-out beyond the justification for most WISPs. Plus, there are elements of E that WISPs would be better off without, especially the built in techniques that increase latency and lower net capacity. In an E deployment, you are literally paying for features that can work to your detriment in our view.
I am very familiar with the theory the E users may someday benefit from lower cost due to economies of scale. To that, I would politely say, "What economies of scale?" LTE has won and a number of major telecom vendors have already dropped E development entirely. And anyway, the economies of scale, if any, are going to benefit 2.5 GHz users who have hopes of obtaining USB dongles, cards and maybe even laptops with built in WiMAX clients. Yay for them!...but that's not going to do a hill of beans for 3.65 GHz users. Those users still require outdoor CPE where much of the cost is embedded in the power amplification, just as happens in a 2.5 GHz outdoor CPE. You'll never see any cost benefits on the base station side of E from any possible economies of scale -- there you can still expect to pay maybe 2:1 or more for the same capacity as a D-based system. Which of you are up for that? No many as far as I can see...not unless Uncle Sam dumps big dollars into your lap. Patrick Leary Aperto Networks 813.426.4230 mobile -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Tom DeReggi Sent: Friday, September 11, 2009 4:12 PM To: WISPA General List Subject: Re: [WISPA] Which WiMAX Are You? Patrick, Always great to see your list posts filled with good info. Responses inline... > The E standard does enable use of diversity, but it comes at a high > cost and is of limited benefit for rural operators. The truth is that > diversity is designed to increase link budgets to support self-install. Can you clarify? Are you saying D Spec does not support Diversity? Or that most D vendors focusing on price chose not to include implementation of it? Even most Wifi chipsets supports diversity. My understanding was D supported diversity, because the early Pre-Wimax Aperto supported all types of Diversity. Please clarify. I'd like to add... I'd like to see more FIXED products support Diversity at the AP. Trials have shown that Polarity diversity yielded much better results than Spacial diversity for NLOS. BUT, that data does not consider spectrum availabilty and congestion. Many Metro deployments can't afford to waste a polarity, with limited spectrum and lots of noise, and forced to abandon the idea of Polarity diversity. Spacial Diversity at teh AP is an enhancement that can be used without any trade-off other than Colo fees if can't avoid paying colo per antenna. Actually in newer MIMO designs Spacial Diversity on its own showed signficant improvements in range. This could becaome even more important in 3.65 with few channels. > Basically, each standard has its place, E is for people in 2.5 GHz > doing self-install, like Clearwire, and we all know the low service > (especially low upstream) packages offered in Clearwire's service. D > is better and cheaper for rural fixed operators, and especially for > public safety video type networks and definitely for voice-centric > users. D is better for enterprise, where many users sit behind the > CPE. E is better for roaming individual users with modest expectations. I'd agree. And I'd agree "D" is most appropriate for most WISPs. I think the biggest factor in deciding though isn't technology specs? People want to pick the technology with the longest life span. Many WISPs might prefer D, but are afraid D might be discontinued sooner, since the big dollar might have followed E. Just like is happening right now. I think the number one factor that will lead WISPs to pick D is acknowledgement that Vendors understand and see the long term potential and MArket for D, so we can be confident about our vendors. So far, I think the primary vendors have done a good job showing their supprot for D. The other number 1 barrier to WiMax is price, so once again many have chosen D for price reasons. But that is a fake benefit, because technically there is no reason that E product couldn't be sold just as Cheap if it came down to it. If anything, E has the potential to drop to lower prices, because of economy of scale and diverse use for WiMax chipsets. So what I'm saying is... Wimax E is killing themselves by pricing their products to high. Right now D has the potential to regain its market share because its price advantage. However, one good way for E to protect its market share is to try and influence the discontinuation of D. Thus important to support the continued development of D. Tom DeReggi RapidDSL & Wireless, Inc > We'd like to hear your opinions, and if you like to discuss this with > us while at 4G World, please drop me a note. > > Regards, > > Patrick Leary > Aperto Networks > > > Patrick Leary > Aperto Networks > 813.426.4230 mobile > > > ---------------------------------------------------------------------- > ---------- > WISPA Wants You! 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