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
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