Broadcom Accuses Atheros Of WiFi Pollution

eggboard writes "We just posted a story at PC World about 802.11g chipmaker Broadcom's claims that the high-speed 108 Mbps mode available in rival Atheros's AR5004G chipset disrupts all nearby Wi-Fi networks. The Turbo mode, part of Atheros Super G, uses two Wi-Fi channels (5 and 6) to double bandwidth, but Broadcom says this can lead to 'an enormous degradation in the speed of nearby 802.11b and 802.11g networks.'. D-Link and NetGear are shipping Super G-based devices. If Broadcom is right, Atheros gear would pollute neighbors' networks. If wrong, they're putting out a pretty heavy marketing smokescreen just before Comdex - where Broadcom says they'll be demonstrating the Atheros problem."

Comments

The "not my problem" problem

[SeanTobin]

Don't you just love the joys of unregulated spectrum usage? If someone can get 108Mbps out of thier wireless by using more spectrum, I say let them do it. As long as its within power regulations, I can fine tune my wireless around it. If I get really upset I suppose I can buy one of the super-g systems for myself.

When the FCC sais that anyone can use this swath of the spectrum for anything within these power levels, and someone makes a gadget that does so, people have no right to complain if it interfears with thier gadget.

Re:The "not my problem" problem

[Jameth]

To the contrary: People have every right to complain, but no right to legal action.

This is a very distinctive difference, because bad press and legal action are about equally harmful in the US.

Of course, the bad press might do nothing. However, it might do something.

Two words...

[EmagGeek]

So what!? It's unlicensed spectrum and they can do with it what they wish as long as they don't violate any FCC rules, which Atheros is clearly not.

Part 15 devices must accept any interference, including that which may cause undesired operation.

I'd personally like to see point-to-point 2.4GHz hardware that uses the ENTIRE spectrum for extremely high bandwidth applications... that'd be very cool

Re:Two words...

[squiggleslash]

So what!? It's unlicensed spectrum and they can do with it what they wish as long as they don't violate any FCC rules, which Atheros is clearly not.

Wait, because they can you believe they should?

Part of living in a harmonious society involves cooperating with others to ensure what you're doing does not impair the freedom of others. This, at a very high level, is one of the reasons why we go around inventing protocols - clear, agreed-upon, protocols ensure that everyone can benefit from a technology rather than whoever has the most costly design.

There's a difference between what's legal, and what's right. Damaging the ability of others to use an established technology for minor bandwidth gains on your part is a Tech-world example of what may be legal but what most certainly isn't a decent thing to do.

Re:Social trap.

[Bishop]

You probably have a legitamate complaint for the FCC.

Re:Atheros Linux driver

[kju]

Your post ist not Insighful, but Clueless. So you say almost everything is GPL'ed. Yes, exactly, with the totally small exception of the COMPLETE hardware abstraction layer. Yes, everything which deals with the hardware is binary only and NOT gpl'd. The rest of the driver is worthless, the heart and core would be the HAL. So this driver is better than nothing but not really acceptable.

Atheros is as bad as Broadcom is. Dump both and buy Intersil PrismGT. Not even did they support a linux driver effort, they even sponsored the developent!

Re:Guilty Party

[Anonymous Coward]

1. Some of the displeasure with Broadcomm in the OSS community concerns the use of Linux in their base-stations without respecting the GPL license that accompanies it. If they did take GPL code (as some have claimed, I have no knowledge of this) to create a product and are making money off of it without respecting the license, that is wrong! and no amount of "wordly experience" excuses that!
2. Most of the OSS community has never asked manufacturers to create drivers for their chipsets for OSS; they merely ask that they release specifications for their chipsets to allow them to write drivers! Which you think would be a financial incentive for them.
3. It is certainly not naive to express your displeasure with a company's policies by "voting with your feet"; i.e. taking your business elsewhere.

Re:Just a quick question

[jerde]

What limits throughput on a wireless connection? Is it broadcast power, frequency, amount of spectrum, or "c"?

All of the above!

The most limiting factor is the amount of spectrum -- the bandwidth allocated to the signal. If you're restricted to a very narrow set of frequencies, you can't send as much data in a given amount of time.

But, once you've picked the bandwidth to use, broadcast power and frequency each affect how well the transmitted signal can be received. Lower frequencies pass through solid objects more easily, for example, but often require more broadcast power. There are myriad details affecting the quality of a signal as it passes from the transmitter to the receiver, not the least of which is interference from other transmitters.

And finally, "c" ultimately affects the latency of your signals. NASA's conversations with the Voyager spacecraft would be an extreme example: it takes about 25 hours now for a signal to make a round trip from Earth to Voyager 1 and back. Closer to home, even Earth satellites are far enough away that the speed of light becomes a limitation -- the round trip to a geosynchronous satellite is 0.239 seconds. If your signal is mostly one-way, this has very little impact. Television, for example, isn't hindered by this. But any kind of interactive connection like online gaming or even telephone conversations are adversely affected by that amount of latency.

I still think that the emerging spread spectrum technologies are our best bet for wireless computer networking.

- Peter

This is not new news

[puzzled]

If you place Adtran Tracers anywhere near an 802.11b cell the effect is rather like sandblasting a soup cracker. The Tracers split the band with one end using the lower half and the other using the upper. They bridge ESF T1 frames so their utilization of spectrum is always 100% whether they're idle or not.

Broadcom is just producing either a concatenated 108 mbits by using two channels at once or they're producing a full duplex 54 mbit 802.11g connection.

The FCC will not do anything about this sort of thing. As an unlicensed band user they'd prefer that you just drop dead.

Unlicensed band may work well in unpolluted rural areas with one carrier but in metro areas it is pretty much a disaster in the ISM band and the same troubles are starting to happen in the UNI (5.8) band as well.

If your business plan depends on flawless throughput in the ISM band please send me your home address - I'll come over, kick your ass in your driveway, steal a bunch of stuff from your house, and we'll call it good - the financial effects and suffering are the same but you get it all compressed into a few short minutes of fun, instead of spending a year of your life flushing your money along with investor's dollars.

Obvious solution

[Master_Wu]

Since probably at least half of your twenty neighbors plug the things in and go, just use their wi-fi points and vpn into your network if you need to - no bandwidth loss for you (it's all bonus, and free) and you can switch to the next guys nextwork if your current one gets slow.

Maybe mesh networks would help

[bonds]

Right now all of our wireless devices work on the "shout as loud as you can so people can hear you principle." When we get too many devices trying to work in the same space, it's like putting a bunch of people on opposite sides of the room and asking them to shout across the room to speak to each other. This works fine when one or two conversations are going, but it doesn't scale very well.

Mesh networks offer the possability of having each node pass a note to the node closest to them in the direction of the node they are trying to reach. They only have to speak loud enough for that closest node to hear, making meshes a lot more scalable. Like passing notes in high school rather than shouting across the room and getting the teacher pissed off at you. :) I suspect that as wireless devices become more popular we'll need something like mesh networks to make more efficient use of the spectrum. In fact, in a manner similar to Bittorrent and Freenet, the more people that participate in a mesh network, the more resiliant and speedy the whole network is.

sb