COVER STORY LTE v WiMAX
laptop. You’ll get 2 – 300 kbps because there
are too many people trying to share too small
a resource.”
If LTE requires a couple of years to mature
before it is ready for deployment, then so
does mobile WiMAX—certainly if the companies
behind it want to see it evolve into a
technology that can take on cellular standards.
And this is something that the WiMAX
community does not seek to hide. “WiMAX
today is more of a broadband technology
than a mobile technology,” says Senior. “We
call it mobile WiMAX and, yes, you can drive
round and do handovers. But it’s not really
architected for mobility first. It will always
be about broadband capacity—whether you
could do that while travelling on an TGV
through France is going to be a secondary
concern, I think.”
This will change, he says, as the technology
evolves to the next iteration, 802.16m, where
mobility will be the trust of development
work. Even so, it’s a fact that could lend a
feeling of security to the LTE camp.
The voice legacy of this camp is important
to LTE. Voice revenues are still the major
breadwinner for cellular players and WiMAX
is a data technology. As the Forum itself says,
“WiMAX technology is designed to supply
data bandwidth only, increasing the bandwidth
without compromising voice service
quality, since voice services are not operating
on WiMAX bandwidth.”
Othmar Kyas sees this as a potential drawback
for WiMAX. “Nobody really knows how
well voice services are going to work over
WiMAX. This is the biggest unknown and the
biggest limitation. At the moment, the large
operators deploying mobile WiMAX plan to
only launch data services, which implies that,
in any case, for mobile voice you’ll have to
have another technology.”
Spectrum is another point of contention, one
that Vodafone’s Steve Pusey sees as a potential
obstacle for WiMAX. “WiMAX uses TDD spectrum
primarily, while LTE is FDD. Most of the
operators that are looking at these technologies
have an FDD footprint, like us,” he says. “There
is a natural choice for us and it’s difficult to
see, because of spectrum, how WiMAX could
play for us in our Western European footprint.
The spectrum we have naturally lends itself
to an evolution towards LTE.”
Vodafone is in both camps, though, and
committed to pushing both standards; a point
Pusey is keen to stress, although he won’t give
a view on which is the better technology. He
52
If LTE requires a couple of
years to mature before it is
ready for deployment, then
so does mobile WiMAX—
certainly if the companies
behind it want to see it
evolve into a technology
that can take on cellular
standards
also points out that LTE could be delivered
in a TDD flavour, and that an FDD WiMAX
could also be developed.”
Exactly when that will happen is a matter
for some debate. “The WiMAX Forum will
have an FDD profile for mobile WiMAX inside
six months,” Paul Senior says. “We’ve been
working on it for the last 12 months. We’ve
been a bit quiet about it because we wanted
to get the IMT 2000 decision. And if we had
gone to IMT with an FDD profile, we probably
couldn’t have got it through. We decided to go
for something that was a little less threatening,
which was a TDD profile.
“There will be an FDD profile, it will sit
at 2.5GHz FDD allocations just as well as
any other technology. And in terms of implementation,
we’re only 12 months away from
products. If our competitors are betting on
[the FDD/TDD issue] then they’re going to be
quite surprised,” he says. This could be big
news and, arguably, gives the strongest indication
yet that WiMAX is indeed going to be
positioned as a serious competitor to LTE.
But when these comments were run in
MCI’s weekly email newsletter, A Week in
Wireless, the resulting attention drew the
following from WiMAX Forum chairman, Ron
Resnick: “Contrary to any of the unofficial
statements made recently, the WiMAX Forum
has not made any Board-approved policy or
determination of when FDD mobile WiMAX
system or certification profiles will be created.
All profiles will be determined by the WiMAX
Forum, driven by market demand, and the
WiMAX Forum is exploring mobile profiles for
FDD certification and is defining a network
architecture to support FDD. However, no decision
has yet been made when to propose an
FDD evolution of the “WiMAX” IMT-2000 air
interface to the ITU, nor has it been decided
what specific profile might be proposed by
WiMAX Forum in the future.”
Spectrum is a crucial issue, as is technical
performance. Time to market advantages cannot
be underestimated. But in all probability, each of
these will be trumped by cost. In this industry
lower cost comes with scale and the perceived
enthusiasm among the operator community for
each of these technologies will play a part in
setting the vendors’ pricing strategies.
Othmar Kyas reveals that the engineering
budgets of the major vendors reveal “a clear
preference” for LTE. The leading vendor in
the mobile space, Ericsson, is a very visible
absentee at the WiMAX Forum, while its
competitors are all members.
Cost is a serious issue for the vendors too,
of course. And that’s why Steve Pusey reckons
the two technologies really will converge in
the end. “The vendors themselves will look at
the two portfolios and say that, basically, the
ingredients are very similar. The only difference
will be addressing different spectrum
needs so they’ll just aim for one solution with
different spectrum,” he says.
Obviously vendors will do what their customers
ask of them. But by the time LTE is being
deployed, and 802.16m (which Paul Senior
promises will do everything that LTE will do)
is ready, the respective roles of operator and
vendor may have changed significantly. Perhaps
by then, the operators will be increasingly
prepared to outsource decisions as to which
technologies are best to the vendors that are
running the networks day by day. �
Mobile Communications International | First for news, best for business
To view a Ceros magazine you need to have JavaScript enabled in your browser and have the flash player 8 or higher installed. To install the latest flash player, click the icon above, install the flash plugin and then click here to refresh this page.