Australian WiMax Pioneer Calls It a Disaster

Anonymous Coward writes "Garth Freeman, CEO of Australia's first WiMax operator, sat down at the recent International WiMax Conference in Bangkok and unleashed a tirade about the failings of the technology, leaving an otherwise pro-WiMax audience stunned. His company, Buzz Broadband, had deployed a WiMax network over a year ago, and Freeman left no doubt about what conclusions he had drawn. He claimed that 'its non-line of sight performance was "non-existent" beyond just 2 kilometres from the base station, indoor performance decayed at just 400m and that latency rates reached as high as 1000 milliseconds. Poor latency and jitter made it unacceptable for many Internet applications and specifically VoIP, which Buzz has employed as the main selling point to induce people to shed their use of incumbent services.' We've previously discussed the beginnings of WiMax as well as recent plans for a massive network in India.

Real life experience with WIMAX

For some time now I've been taking part in WIMAX trials here in Hamilton Ontario. [community-media.com] This too was trumpeted as a glorious thing that would change the face of our city, bring us into the high tech 21st century etc.

In practice although WIMAX seems to work OK (aside from a real lag much of the time, which may just be bad server configuration by Primus Communications), My sense is that the company isn't really committed to it. I doubt that there will be a serious public roll out.

The idea seems great - a wireless Internet connection that works wherever you are. The reality seems a bit less rosy, and my guess is that a city wide wireless network will need a good level of customer support - not Primus' strong point by a long shot.

Re:Real life experience with WIMAX

You found the problem and didn't even mention it really:

This too was trumpeted as a glorious thing that would change the face of our city

Never believe the hype. WiMax has a great deal of potential but it will never eliminate the common cold, nor compete with wired broadband for a mere pittance of what wired infrastructure costs. It does however have a niche market that is quite a bit bigger than what most people think. As point to point relay for a WiFi network it has some really good uses, just as microwave links are used between cellular sites in some areas.

If you use a Honda to haul gravel you too will be disappointed in the performance... perspective is everything and a damned good car analogy will explain anything

Re:Real life experience with WIMAX

They should be making deals with current access points for better coverage. Thats how a real wifi network will work. 1000s of access points.

and the cost of building and maintaining 10,000 access points will be what. exactly?

Re:Real life experience with WIMAX

the cost of building and maintaining 10,000 access points will be what. exactly?

Less than the cost of laying fiber to millions of homes.

Re:Real life experience with WIMAX

Myopic thinking. The value and the income from those access points will be a fraction of what can be carried over fibre. Namely voice, data, video, emergency services, business services like remote backup, et al.

But forget that, it's the least of your worries. Your real problem will be to make the access points and subscribers not all hear each other in the limited frequency available, drowning each other out, causing network brownouts (or blackouts), hurting efficiency, causing lag and re-registrations, etc. Go downtown Toronto and you'll see what I mean. It just doesn't work the way people want it to.

Who's fault?

>Not all WiMAX operators are unhappy.
>
>Internode says an Airspan-supplied network is providing consistent average speeds of 6Mbps at >distances up to 30km, with CEO Simon Hackett describing the platform as "proven."

So where exactly lies the problem? Implementation?

complaining about it for years

I remember when a bunch of wireless guys got invited down to Intel for a private overview three or four years ago and we spent most of the couple hours trashing most of their basic assumptions about the technology. Their major response was, "well by the time it is deployed we will have figured it out"

WIMAX isn't going to be the success that it should be because I think it was driven more by marketing than technology.

I'm going to fiddle my fingers until they have a few more disasters till they get it working. In the meantime mesh will definitely deflate the momentum WIMAX needs right now.

Re:complaining about it for years

The problem with a mesh network is that you have a serious chicken-and-egg problem. It's not going to do work well (or at all) until you get enough of your population using it, and you can't get enough of them to use it until it works well. Mesh networking will probably be piggybacked on the deployment some other wireless technology, and will be used to supplement it.

Re:complaining about it for years

Not really. Small meshes are easier to get working than large ones, so the first step in deployment is to dangle meshes off the ends of existing infrastructure. You'll find a static access point in, for example, a coffee shop, and then use a small mesh to extend the range out into the street by relaying via devices in there. Once enough people are carrying mesh-capable devices, you'll be able to extend the range all the way to (for example) the access point in the library. At the point, any computer in the mesh can have some of its traffic routed via either connection. Once enough meshes are deployed and overlapping then the existing static links are just for bulk traffic or fallback use. The problem is that the complexity of mesh routing does not scale well. If you've solved the routing problem, you can deploy easily. Until then, meshes are limited to small-scale use.

Frequency, not just technology

NLOS performance depends on a number of things, including how well the underlying technology can handle multipath and otherwise distorted signals. But the main thing is probably frequency; the higher the frequency, the worse the NLOS performance. WiMax is designed to run at many different frequencies, and the article fails to mention which one was in use.

The issues with latency and jitter, though, probably aren't as dependent on frequency.

Re:Frequency, not just technology

I am no RF expert either, but I have been on the receiving end of WiMax-ish technology, and the jitter was so bad, it was completely unusable for VoIP and even made ssh annoying at times.

This was kit designed to work for up to 10 km (6 miles) and I had line-of-sight to the base station, which was about 150m (500 ft) away.

Sky.. sky.. SkySomething. SkyPilot? Some kind of wierd meshy-network, I was also connected to the "master" tower, not a leaf.

The problem, as it was explained to me, was that it has a collision/backoff algorithm not unlike that of 10-base-2 ethernet ("thin net"). So, the 50 (or so) neighbours I had, plus the leaf towers (2 of them, I think) were causing me to not get "slots" with the master on a timely basis. Hence, introducing jitter.

So, your L2 protocol hypothesis is reasonable from my perspective, although we can eliminate poor radio performance as a direct cause. Changing the radio from broadcast to something like time or code division multiplexing would be a good solution for reducing jitter, but probably causes other problems (like decreased burst bandwidth and range).

My solution? "*sigh* - cancel the wireless link and order me a up a T1"

Wireless is nice because it's easy. But it sure ain't there yet.

My real-life experience with WiMax (Mexico City)

I chose as my ISP in Mexico City E-go [ego.net.mx], co-owned by Alestra [alestra.com.mx], the Mexican AT&T subsidiary. It started offering WiMax connection in 2003 in limited areas of Mexico City (I understand nowadays it covers most of the Central, Western and Southern parts), before even WiMax was standardized. Clients get a NextNet [nextnetwireless.com] RSU unit [nextnetwireless.com], which is basically a network bridge.
The latency complaints you state are simply not true - I get consistent ping response times of 100ms in average (with minimum response times of around 50ms) to hosts in Mexico City, 200ms to hosts in the USA. Yes, this is about 80ms higher than wired equivalents - but it's not so much of a killer. What I do get, of course, is way higher packet loss - About 5% when things are optimal, and it sometimes gets up to 50%. But yes, I'm located at a relatively poor reception area, at one of the lower-income (this means, no incentive to place many antennas nearby) neighbourhoods in the South of the city, where the mostly flat valley where most of the city is located begins to become quite hilly. The RSU unit does not provide any means (for the client) for monitoring connection, to help choose the best possible location. It only has five LEDs (and no, they are not blue, just an unfashionable old green. Bummer.) indicating signal strength, and I always get one or two of them. I have seen signal quality significantly better when at a five-leds connection.
Prices and speed are more or less in-par with Mexico's near-monopoly TelMex; I'm paying about US$40 for a nominal 1Mbps/128Kbps connection (512K guaranteed, whatever that means). The upstream data flow _is_ shaped to 128k, but the downstream speed is not - when the network smiles on me, I get up to 2Mbps. It is not common, though.
I understand E-go (back then called I-go, don't ask me why) was praised as the world-first massive WiMax deployment - Even before the standard was finalized. There are several aspects of the installed network that show clearly the gear is pre-standard (i.e. extreme sensibility to position changes - If I move my RSU over two centimeters, it has to resynchronize with the antenna. This process takes around two seconds, so no big deal).
To me, clearly, the reason it hasn't got more popular is because it is owned by a relatively small company, and has not had the muscle to stand in front of Telmex's publicity machine.
Of course, we benefit more than DSL users from having a low client density :) E-go owns 20MHz of spectrum, which allows it to give a theoretical maximum of 70Mbps to a given area. If many too people were to subscribe, each client would have much less effectibe bandwidth alloted.

Nothing just magical about WiMax

There's nothing magical about WiMax. Other frequency ranges, other protocols, that's about it.

The only interesting thing about it is that it's not operated by traditional telcos.

But remember, what traditional telcos sell is not telecom, they're SELLING UBIQUITOUS telecom.

An untraditional telco would have to sell at a nonzero price ubiquitous. If they sell at zero price (or truly flat rate), a smartass will monopolize all access and resell it at real market price (what people are truly willing to pay). If the service is only sporadically available, no one will want to pay for it, or they would be better off setting up a fix line connection at the only place it works. If they comply to the two conditions, they are definitely traditional telcos.

In the long run, WiMax is bad for the consumer. As I explained above, the business model behind WiMax can only be the "traditional telco model". But now we have two technologies with incompatible end user hardware, incompatible operator hardware. Nokia and Alcatel Lucent will sell less copies of their products to operators, thus the price will rise. Nokia and Alcatel Lucent will ask for higher fees from the opco, guess who will pay the bill. Nokia and Motorola will sell less copies of their products to end users, guess who will pay for the relatively higher cost.

Furthermore, with WiMax vs 3G, there are now not one, but two markets for mobile data and voice. Barrier to jump from one to the other market is nonzero for the consumers. Each of the individual markets is also smaller, hence less competitive.

Fuck WiMax

Re:The real dissaster is spectrum regulation.

Why is it that we still have broadcast TV and AM radio?

Stations of relatively modest power can provide services to distances of about 100 miles.

Receivers are cheap, portable and ubiquitous.

The AM radio is as accessible and familiar to the four year old as it is to the centenarian.

Re:The real dissaster is spectrum regulation.

Add to that the fact that AM radio is robust, understood and ubiquitous technology. The shit could it the fan tomorrow. Major economic collapse, dying infrastructure or whatever. AM radio would still be around and working. There is something to be said for a civilization having enough depth and legacy in its technology that there become no single point of failure.

Re:The real dissaster is spectrum regulation.

AM? I have never ever listend to a readiostation in my life. It is all FM here in Europe.

Medium-Wave broadcasting in the U.S. evolved when the country was still significantly rural.

Distances in the U.S. can defeat the European imagination.

The 50,000 watt "clear channel" station could be heard across several states - and to istances of 1,000 miles under favorable conditions.

AM radio had a distinct local or regional identity which persists to this day.

Re:The real dissaster is spectrum regulation.

Because my old tube radios will survive the EMP, I'll still be able to listen to the static.

Re:The real dissaster is spectrum regulation.

In event of natural disaster, I'd rather have an AM radio than VoIP.

AM radio is a really durable technology. You can listen to solar powered broadcasts on crank powered radios.

Re:The real dissaster is spectrum regulation.

You don't even need that. One diode and some high impedance headphones is all you need. You don't even need any kind of power. There is no amplification, but I dare you to find one other broadcast technology that can draw all the power it needs from the signal its self.

Even if we switch off of AM and FM and such to fancy digital encodings, every radio should have the ability to tune into old-fashioned AM signals built in. It's trivial to add, and functions no matter what if they need to put stations up in an emergency.

Re:The real dissaster is spectrum regulation.

Why are you looking into other /.er's cars?

Re:AM Radio = Range

AM radio spans roughly 1 MHz (IE: approx 530KHz to 1.6 MHz.) You CANNOT fit a broadband wireless service into that space ... furthermore, the resonant antenna length for 1/4 wave varies between (approx) 150 metres to 40 metres. Like to see you stick that out of the back of your Laptop.

doubtful if you could effectively get one 54mbit channel in that space, plus, because it is NOT line of sight, someone a few miles away WILL interfere with your local transmissions.

Low frequencies (below about 2 MHz) hug the ground, this means AM does not have line of sight issues. Some AM broadcast stations have service areas of hundreds of miles (kilometers) (radius)

FM is 88.. 108 MHz. 1/4 wave here is roughly around 1 metre. Still a thumping huge antenna! These frequencies are considered line of sight, however, there is a small area extending beyond line of sight. Enough bandwidth for a few 54mbit channels.

WiFi is generally at 2.4 GHz. Same band as Microwave ovens use. Has to do with the frequency of maximum absorbance of water. (Thus used in ovens!) 1/w wavelength approx 4 cm ... okay for Laptop, (easy)

To get sufficient bandwidth, only UHF and up is really useful. But, get too high in the microwave band and the signal wont even get through a thin wall.

So, there are trade offs that genuinely make sense for wireless broadband. (lots more reasons as well ...)

Re:AM Radio = Range

Minor nitpick: 2.4 GHz is not the frequency of maximum aborbance of water. The frequency of the maximum is temperature dependent, and the absorbance peak is very broad. Thus there is no need to use any special frequency. 2.4 GHz is used in microwave ovens due to that it was free to use, being an ISM band, and that the penetration depth is useful for cooking.

Re:The real dissaster is spectrum regulation.

I think part of the argument is legitimate, in that we're stuck in the unlicensed bands, where there is significant opportunities for interference both within those bands and from licensed bands sitting on the borders at each side.

2.4ghz and 5.6ghz/5.8ghz are good bands for line of sight transmission. Unfortunately, these frequencies are increasingly noisy and all of the fancy algorithms in the world can't help you when some of son-of-bitch with a home-made outfit is spewing out at obscene power levels.

As to non-line-of-sight, well, the higher bands just don't do so well. It's one thing to have a wood-framed house with drywall, which doesn't offer much of an obstacle, but apartment buildings and the like, where there's significant amounts of steel and concrete aren't going to cut it too well, at least without tons of access points all over the place (translation: $$$). The 900mhz band is pretty good at non-line-of-sight, but this section of the spectrum has been utterly poisoned by cordless phones (2.4ghz is getting that bad too).

What WiFi needs is some protected chunks of spectrum at the low, middle and high. Without that, forget about it. Maybe this latest auction will open some stuff up, but I doubt it.

Re:The real dissaster is spectrum regulation.

I think part of the argument is legitimate, in that we're stuck in the unlicensed bands, where there is significant opportunities for interference both within those bands and from licensed bands sitting on the borders at each side.

This is WiMax, not Wi-fi. Despite the first two letters, and the fact they're both 802.x standards, these are completely unrelated technologies, which for some reason geeks in particular tend to get overly excited and confused about conflating the features of one with the other. WiMax is generally run on licensed spectrum, and is about as useful as Wi-fi on unlicensed spectrum, if you can even get certified equipment. So far as I'm aware there are no commercial operators trying to run it on unlicensed spectrum: there's no point, Wifi is cheaper and just as effective for non-LoS use.

2.4ghz and 5.6ghz/5.8ghz are good bands for line of sight transmission. Unfortunately, these frequencies are increasingly noisy and all of the fancy algorithms in the world can't help you when some of son-of-bitch with a home-made outfit is spewing out at obscene power levels.

Again, you're assuming WiMax is generally run on unlicensed frequencies. But your point is worth addressing because the bands WiMax is generally licensed in to tend to be greater than 2GHz, though it is being considered by a number of operators for use on the 700MHz spectrum recently auctioned.

Anyway: 2-3GHz has roughly the same characteristics as PCS, the 1900MHz spectrum used by Sprint PCS and T-Mobile USA, and it's in this area that WiMax is usually offered - though I have heard of it being deployed in the 3.5GHz range. It's generally pretty strong outside, while indoor coverage generally deteriorates relatively quickly, though not to the point of unusability.

WiMax is an interesting technology but it suffers from being "first" and from being designed by the computer industry with almost no input from the telecoms industry. The latter may be a bunch of Luddites but they do put a premium on reliability, something our industry is absolutely abysmal at. Which is partially why I'm betting on LTE being the path forward to universal internet connectivity.

Re:Clearwire

Lots of people seem to be confused about whether Clearwire is WiMax.

My Clearwire device has an FCC ID of PHX-RSU2510F. The FCC docs say that it operates on 2.496-2.690Ghz. The chipset leads me to believe that it is an implementation of the Motorola Expedience [nextnetwireless.com] Wireless Broadband CPE.

The Motorola RDM specs say that the device can operate in Expedience (up to 2W) or WiMax (up to 0.5W) modes. They also say that in Expedience mode it is a layer 2 smart bridge, while in WiMax mode it is a router with NAT, DHCP and firewall functions.

Since my device acts like a layer 2 bridge, I conclude that it is in Expedience mode. Having just checked the Wikipedia article, I see that the first paragraph agrees:
"Clearwire currently uses Expedience wireless technology, dubbed Pre-WiMax, transmitted from cell sites over licensed spectrum of 2.5-2.6 GHz in the U.S. and 3.5 GHz in Europe."

So no, they use the WiMax frequency range, but they can transmit a stronger signal. That seems to be the main difference between the technologies.

This Motorola promotional video [motorola.com] talks about some of the infrastructure and business justifications for using their Expedience gear: