Even thought this thread is a bit old, couldn't help but add my 2 cents (as there seems to be a resurgence of "puff" in this space)
DISCLAIMER: I am also a vendor of various WiMAX 802.16d systems - so feel free to apply your necessary 'BS' filter Benefits of Wimax in 3.65ghz 1. Spectral efficiency ( 4.85 gross bp/hz ) On a six sector configuration with only 25mhz of spectrum, you can effectively deliver approx 20mb per sector or 120 mb / per pop, 240 mb when all 50 mhz is supported. Support for thousands of subscribers is possible off the same BSU. This isn't all too exciting, IMO - there are plenty of systems out there that have similar (if not better) spectral efficiency characteristics as to what the WiMAX 802.16d standard offers...also, with the uncertainties of 3650 licensing, which is, from an interference protection perspective, not that much different that Part-15, higher order modulation schemes don't do much in the presence of noise Case in point: Why does everyone keep using Canopy 900 MHz systems when you can get an 802.11a OFDM-based down-converted system that delivers 3-4x the throughput? Well, it's a matter of what's actually going to work in the crowded 900 MHz band. 2. multiple vendor support ( currently you have Redline, Aperto, Airspan, Alvarion, all with FCC approved equipment ) The "concept" of interoperability is one of the most "oversold" features of WiMAX which needs to be explained... Fictitious Scenario: Say I had deployed Brand A system for my business users, and in order to enable VoIP services, I enable a variety of the more advanced MAC features (rTP for my VoIP)...I set up a variety of service flows that are customized to each user...blah blah blah Problem is, Brand A system, for whatever reason, didn't support UGS and a few esoteric service flow / packet filtering features, but at the time, I'm really not too concerned because (a) my customers don't demand UGS from me right now and (b) the concept of "WiMAX interoperability" story gives me the conclusion that if I really need UGS, I could just buy / upgrade to Brand X system and retain all of my Brand A CPEs that I've deployed. Now, 6 months later, I've deployed 50 CPE in the field, and business is doing good...so good in fact that 2 customers want to upgrade to a "premium" service that requires features not currently supported on Brand A AP. Luckily, I have a "WiMAX" system so I go upgrade Brand A AP with Brand X. Common sense would lead me to believe that Brand X would support all of my CPE's features, plus supporting the enhanced feature of UGS that I need Sorry, isn't going to work As things turn out, the only "interoperability" testing done between Brand A CPEs and Brand X APs were done at the Best Effort feature set (basic Ethernet connectivity)...additionally, Rf interoperability was done at a 3.5 MHz channel size, and I've been running Brand A at 10 MHz to maximize my throughput (oh, and Brand X only supports 3.5 MHz, 5 MHz & 7 MHz channel sizes)...so to get this interoperability, I lose all of my rTP / VoIP prioritization for my entire network, or I have to go out and replace my 20 Brand A CPEs that are running VoIP with Brand X CPEs Oops What's the moral of the story? Ultimately, unless you're willing to run your network at the lowest common denominator, you're basically buying into a proprietary system. 3. Better RF performance ( even with siso systems ) Better RF performance as compared to what? And in what vein? I can easily "slant" the argument the other way by bringing up an example where a proprietary system outperforms WiMAX Noise Immunity: Are you saying that WiMAX has better noise immunity that Canopy (OFDM vs. FSK...yeah right) NLOS: Are you saying that WiMAX can do better NLoS than 900 MHz? Urban Reflective NLOS: Are you saying that WiMAX can do better Urban NLoS than a MIMO-based 1024-FFT OFDM system? 4. NLOS performance ( OFDM+OFDMA = More difficult shots obtain link ) See above 5. Better QOS support, and service flows ( UGS, NRTPS, ETC can be ) There can be an argument made that the WiMAX MAC is much more sophisticated than the Canopy / Alvarion VL / Trango / Tranzeo / CSMA-CA systems on the market today...that said, don't forget that there is a $$$COST$$$ for this sophistication...namely, you effectively lock yourself into a "proprietary" implementation of your WiMAX system 6. Greater scalablity ( Single sector can support hundreds of subscribers, our platform supports 30,000 pps ) WiMAX in it's true tested and interoperable state maxes out at an aggregate "throughput" range of ~10 Mbps per AP To get better performance (up to 20 Mbps / AP), I give up interoperability 7. Support for multiline VOIP out of box ( UGS + 30K PPS ) At the expense of interoperability 8. Sub 350 cpe shipping today ( in 100 packs, less with frame order commitments putting your cost sub 300 ) Ubiquiti Lightstations are sub-$100 Tranzeos / Deliberant / whatever are in the $100-200 range Motorola Canopy / Alvarion is in the $200-300 range Oh, and they (just like WiMAX) are basically proprietary 9. Carrier class systems vs Wisp class ( True 99.999% uptime solutions available for base station equipment, reducing downtime and truck rolls ) Carrier Class = $10k APs If you're willing to spend $10k for an AP - you can get a proprietary 'WISP' system that has all the "carrier-class" features of "WiMAX" 10. Carrier class network management systems that simplify provisioning and management of subscribers and base stations. Lol...I find this amusing...as the WiMAX specification "overcomplicates" the provisioning process, so you now have the need to purchase a system to simplify provisioning so it will work like a Canopy / Trango / Tranzeo / Alvarion =) Supply and Demand at its best =/ That said, if you are still interested in WiMAX after this "cold dose of reality," we have plenty of radios in stock =) -Charles -------------------------------------------------------------------------------- WISPA Wants You! Join today! http://signup.wispa.org/ -------------------------------------------------------------------------------- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
