[MLB-WIRELESS] WiMAX to go Australia wide?

[Steven Haigh]

>> -----Original Message-----
>> From: melbwireless-bounces at wireless.org.au [mailto:melbwireless-
>> bounces at wireless.org.au] On Behalf Of Steven Haigh
>> Sent: Monday, 18 June 2007 10:05 AM
>> To: Gary Winder
>> Cc: melbwireless at wireless.org.au
>> Subject: Re: [MLB-WIRELESS] WiMAX to go Australia wide?
>>
>> I agree - a WiMAX rollout will be pretty much useless....

Quoting Dean Collins <Dean at cognation.net>:
> That's a ballsy statement - want to explain why?

Easy. For the infrastructure required, the operator may as well run  
ADSL. Hell, as there's no reason it can't be ADSL2+, do that. 4Mbit  
speed is about half of what an ADSL1 spec connection can do. 12Mbit -  
about half of what an ADSL2+ connection can do. "But wait" I hear you  
think. "Those ADSL speeds are theoretical maximums!" - and you're  
quite correct - they are - but so are these WiMAX speeds.

Now lets have a look at the rollout infrastructure required vs  
finance. You want to serve quite a few customers to make each 'cell'  
worthwhile. You have to run a backhaul to the radio equipment (either  
fibre, ATM, STM etc) so that you have enough bandwidth for the  
customers on that cell.

After you've done all this, you've just replicated what you would do  
for an ADSL rollout. Replace radio with DSLAM and you have ADSL - at  
comparable or faster speeds. Keep in mind that ADSL1 can do ~6.5Mbit  
over 3.5Km of copper. That's a lot of range you just added from your  
radio/dslam point. Your backhaul will cost the same if you use ADSL or  
wireless.

So what about the people further out? The answer is already there. A  
Minimux. This is a small ADSL DSLAM in a cabinet that can service up  
to a few hundred people.

Now lets look at it from a technical side. The radios are a shared  
spectrum - think a hub or your local cable segment. The more nodes you  
have in the same area, the more retransmits, the more errors, the  
slower the connection. I'd tip that with any serious use to have any  
ISP make a profit with WiMAX that your speeds will be well under 4Mbit.

Now lets add a dash of reality. A lot of these places in the bush  
don't even have a working GSM phone network. There are places where  
people can't make mobile phone calls - and we all know that is a  
priority over broadband. Now using this same logic, unless the WiMAX  
system can magically cover more area than a mobile phone network via  
higher node density (and higher rollout costs), then I don't see it  
standing a chance in a wide scale deployment.

A lot of people call Wireless great for the "last mile" delivery of  
connectivity, however it's only really useful as a simple point to  
point system. When point to multipoint starts getting implemented on a  
large area, it quickly gets overloaded.

For some people that want to see an already existing wireless network,  
iBurst and Unwired do a fair job of this and have fairly good  
coverage. However as soon as these networks get under load, the  
quality of the service plummets. I've done some testing on our works  
test iBurst connection, and sometimes been lucky to get 5Kb/sec. Good  
enough for an SSH connection, but certainly not broadband.

-- 
Steven Haigh

Email: netwiz at crc.id.au
Web: http://www.crc.id.au
Phone: (03) 9017 0597 - 0404 087 474