Well George, ready for long answer that may not actually answer your
question? I'd prefer to give you the full story.
First,...so, is Alvarion building UL WiMAX? Of course, and I personally
lots of potential for it. When will it come? A few things are in line
so there is no firm date but we'll have it roughly around the same time as
other main suppliers. If I could give a better and more useful date, I
Second, WiMAX is not a simple story. Here are the issues revolving around
1. 3650MHz is a better UL band for WiMAX than 5.8GHz:
Vendors and operators know that this band is more favorable for a scaled
deployment than 5.8GHz for both reasons of physics, higher power
and less interference. So far, the only UL profile for WiMAX is
5.725-5.850GHz. But most vendors are not eager to invest too much in that
profile while 3650MHz is up in the air. If 3650MHz goes UL, as it most
likely will, at least in part, then that would take the wind out of 5.8GHz
WiMAX's sales and a new profile will have to be created to support
2. The UL profile is limited to upper 5GHz only:
The UL WiMAX profile excludes 5.25-5.35GHz, as well as 5.47-5.725GHz. That
is 355MHz of spectrum that the WiMAX Forum so far does not support. Who
wants to build a UL WiMAX network that only uses 5.8GHz? The profile needs
to be broadened.
3. The scheduled MAC of 802.16 is designed for licensed:
The reality is that the 802.16 MAC was originally developed for licensed
LMDS bands. In order to push through a standard quickly, when 802.16 was
amended to be applicable to sub-11GHz frequencies, they co-opted that same
MAC. Now it's a great MAC...for licensed. Scheduled MAC's are highly
efficient, but they are intended to be used in licensed where the only
interference risks are self-inflicted. With a scheduler, when your slot
comes to talk, you talk, regardless of what is happening in the spectrum.
the UL world where there is contention for the spectrum, a scheduler
in lost packets AND hurts the other systems already in the air.
The IEEE knows this is a problem, so they formed a new task group about 9
months ago called 802.16h, or TG H. The charter of this task group is to
come up with a mechanism that somehow enables UL co-existence of systems
using shared (UL) spectrum. The idea of the TG is to find some type of
technology neutral soft patch that can be overlaid atop not just any .16
device, but any 802.11, or even proprietary system. Alvarion chairs this
It is a tough nut, because we and the IEEE are trying to make this a joint
TG with the 802.11 crowd, but so far the 802.11 groups in the IEEE refuse
joint. The challenge is that the TG can come with some super slick
technique, maybe some time sharing mechanism, but unless other systems in
the air adopt it, it will not be as effective as it would otherwise be.
Suppliers are aware of all this and it adds to the reluctance to release
WiMAX as it exists today.
4. The UL WiMAX profile was designed for PMP backhaul, NOT last mile
Most may not be aware of this, but if you take note that the
options in the 5.8GHz UL profile are 10MHz and 20MHz, you come to realize
that the intention is to make big pipes. Consider that the current
efficiency of WiMAX is a bit better than 3.5Mbps NET usable throughput per
megahertz used and you'll see that in UL WiMAX you can create pipes
delivering over 70Mbps NET in a 20MHz channel. Then note that the last
centric licensed profiles deal in 3.5MHz and 7MHz wide channels. You
begin to realize that UL WIMAX is intended for backhaul only, for things
like mesh clouds, hotspots, and outdoor PMP enterprise bridging.
What does this mean? This means that the market is scrambling to build
residential CPE for UL WiMAX. Instead, the CPE will be that you would
at the remote end of an enterprise bridge or backhaul. In other words, we
are not talking about sub-$200 devices.
5. There will be no indoor only, self-install UL WiMAX CPE:
Unlike licensed WiMAX, for which the power and bands are suitable to
a no-truck-roll CPE, we have no such luck in 5GHz. This leaves us with the
same installation paradigm we live under today in the UL world.
6. UL WiMAX profile in only supported in the fixed WiMAX standard of
802.16-2004. There is no profile for 802.16e-2005:
While we and a handful of others remain excited about fixed WiMAX, most of
the large telecom suppliers are bypassing it entirely and going straight
802.16e-2005. Now, and this is key, while the -2005 standard is about
mobile, IT CAN be used also for fixed and it WILL be the basis of nomadic
and portable (semi fixed, self-install) CPE. So that is where all the big
R&D money is at now and vendors planning to participate in the main WiMAX
market (the 802.16e-2005 world) have to invest to stay ahead. This makes
802.16-2004, and all the profiles that go along with it, including the UL
profiles, a lesser priority, at least relative to 802.16e-2005.
So the net result of all these issues is that the suppliers are cautious
not certain about the market size for UL WiMAX, or even who will be the
buyers. Is there a large enough market to drive down prices? Who knows,
currently the main growth in the UL BWA market is happening at the Wi-Fi
muniwireless level and there is a sense that this needs to play out, even
while WiMAX may make a good PMP backhaul solution for those projects.
I continue to hear that some vendors out there continue to say something
like, "we have UL WiMAX just around the corner!" the fact is that as of
last WiMAX Forum meeting (in Paris last month), not a single vendor had
submitted UL WiMAX product for certification testing. And keep in mind
it takes three to submit before any testing can even begin.
I do not hear enough suppliers being blunt to WISPs and others about all
these issues revolving around UL WiMAX and the WiMAX Forum itself needs to
be more clear about the different types of WiMAX.
Also, as operators you really have to ask yourself, what do I want out of
WiMAX? Can you get that with other or current gear? Finally, when UL WiMAX
product first hits the market, if it comes from a new entrant with no
current customers to piss off, approach it with healthy skepticism and see
if it addresses the issues put forth above. Heck, do that even if it comes
from respectable long term players like us.
Lastly, I'd advise that while you keep an eye out for progress on the UL
WIMAX front, you continue to deploy and put your faith in current
technology. From our end, solutions like BreezeACCESS VL are developed
specifically for the UL world and they are mature (over 300,000 installed
units) and ever improving. We will continue to invest in VL for the
foreseeable future, including making sure it supports ALL the 5GHz ranges
operators have choice and can scale. And to lend weight to the "continue
invest" claim, we have a firmware version entering beta right now that
blow the doors off you. We have basically stripped it down and rebuilt it.
Not only is it enabling a massive packet per second increase, but we have
added a prioritization feature that allows an operator to prioritize
types of traffic network wide. For example, it can be configured to let
voice (or video) traffic from all CPEs be transmitted first, with less
sensitive traffic like basic data released second. This is true no matter
the users' placement geographically in the network -- on the edge or near
the base station. At the same time, we have a starvation prevention
algorithm to make sure other apps are not starved out. This all happens
dynamically. We have tentative (lab) data showing this improves concurrent
voice sessions per sector from 40'ish to over 250. We'll see how this
out in our voice and video betas.
In addition, we have added QinQ VPN ability, so individual clients can
create secure VPN tunnel within an operators own VPNs. And there are a
of other new features.
Obviously, this is the one example I can speak about with authority, but I
am sure the other vendors will continue to invest and support their own
current UL technologies for a long time to come.
From: George [mailto:[EMAIL PROTECTED]
Sent: Monday, April 17, 2006 5:52 PM
To: WISPA General List
Subject: Re: [WISPA] Quick note of hello
Welcome back Patrick
How is Alvarion doing concerning UL WIMAX?
Patrick Leary wrote:
I just wanted to drop you guys a note that I have re-subscribed after
being off the list for maybe two years. Hope all is well.
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