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Gigabit wireless in a few years -- maybe




>About the OFDM, is it sustainable, in the long run? 2.4GHz and the ranges

Almost all of the wireless ISP system providers agree that this is a great 
improvement on the slower algorithms.  Alvarion has written a white paper 
explaining the improvement.  If you look at how quickly the wireless speeds 
are increasing in the last five years, and the investment in this 
technology -- then you can plan for gigabit wireless in a few years!

The radios we are selling now can operate in the licensed frequencies from 
2.5GHz to 2.7GHz -- so it is just like any other licensed microwave system 
for the protection of your frequency.  Also, the whole 5GHz range will not 
be completely un-licensed and we support any center frequency with 20MHz 
channel.

When you consider the short time it takes to install a wireless link and 
the low cost, this is the way to bring service NOW to customers.  Fiber is 
good, but if it five years off, then that if five years that people can't 
use broadband Internet.

Once you get some experience with wireless compared to leased lines, you 
start to think it is so good, there must be a little magic in it...

John



>within it have not been very successful in several parts of Africa, as a
>long term WAN service strategy, from the mere fact that many service
>providers, ISPs and private businesses/individuals will pretty much hook up
>anything that runs on 2.4GHz. It is quite easy to get interference from
>competing users, and even GSM networks that will over-power and flatten your
>transmissions. Tanzania, Uganda, Kenya, Nigeria, are just a few of the
>countries I can name that have experienced these kinds of problems with
>wireless.
>
>As for the 5GHz, yes, the issue about regulation can be a daunting one.
>Needless to say, the range for both the 2.4GHz and the 5GHz is not very
>inviting, when compared to fibre optic. When you compare the SNR and
>attenuation properties each carry, over distance, fibre still looks like a
>more scalable and sustainable solution.
>
>Now, OFDM on telephone cables, as the research continues to grow, would be a
>good idea, but there's quite a limitation amounts of copper in Africa, and
>then again compared to fibre, copper may not have that wide a band even 100
>years from now.
>
>Now, with fibre, you can go the traditional SDH/SONET protocols that have
>been used for a while now. But with DWDM, no need to change fibre cable,
>just intelligent boxes at the cable ends and you go from 2.5Gbps to 200Gbps
>plus. You can even have separate media formats such as ATM and SONET running
>on the same fibre.
>
>All in all, while Africa is trying to battle the digital divide, I don't
>think we are in such a rush that we should go for technology that may not
>support the user needs in the long run. Do it slow, do it right, would be
>the better approach, don't you think?
>
>Regards,
>
>Mark Tinka - CCNA
>Network Engineer
>Africa Online Uganda
>5th Floor, Commercial Plaza
>7 Kampala Rd,
>Tel:   +256-41-258143
>Fax:   +256-41-258144
>E-mail: mtinka at africaonline.co.ug
>Web:     www.africaonline.co.ug
>
>
>-----Original Message-----
>From: owner-afnog at afnog.org [mailto:owner-afnog at afnog.org] On Behalf Of John
>Tully
>Sent: Tuesday, May 13, 2003 5:10 PM
>To: afnog at afnog.org
>Subject: Re: Tanzanian ISPs move closer to establishing an Internet exchange
>
>
>
> >Against that must be weighed:
> >- the cost of getting a circuit to the IX (especially if the local
> >   infrastructure is poor-quality copper only, and local leased lines in
> >   Africa can be very expensive)
>
>Wireless is the way!  The new OFDM stuff is so fast that you could only
>consider fiber/laser as an alternative.  We will have OFDM (around 55Mb/s
>throughput is common) from 2.4GHz - 2.7GHz (2.5GHz to 2.7GHz are safe
>licensed frequencies) or all the 5GHz range for less than $1000 a side!  Of
>course it depends on the regulations in each country.
>
> >- the cost of extra equipment at the IX
>
>At the EAIF meeting last year it was pointed out that a CISCO for $2000 can
>do the job if you take some good advice on exactly what to buy (also a
>MikroTik router can do it cheaper).
>
> >- the cost of IX administration (shared between members)
>
>Of course you need some clever people like Brian working on it.
>
> >which generally means that you have to get above a certain size before
> >it becomes economically feasible to join an IX.
>
>I don't really know, but most likely the telecom lease line (for backhaul)
>are not coming down so quickly and the usage is surely growing in
>Africa.  So, everyday the economy should become more feasible.
>
> >I don't dispute that IXes are good things. But you should beware
> >exaggeration, as it only weakens the argument. I imagine that if there
> >was $400m being poured down a drain every year, there would be people
> >ready to get their hands on it. Building an IX would be an attractive
> >commercial proposition.
>
>How that was calculated is interesting.  As a former student of economics,
>I don't trust any statistics unless it is accompanied by a detailed
>description of the calculations.  Generally, you can see if you agree with
>the main idea and don't rely on vague statistics.
>
>John
>www.mikrotik.com
>
>
> >Cheers,
> >
> >Brian.
>
>
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