more on re: Beceem kicking butt in Mobile WiMax

Begin forwarded message:

From: Dewayne Hendricks <[email protected]>
Date: October 6, 2006 3:26:03 PM EDT
To: Dewayne-Net Technology List <[email protected]>
Subject: [Dewayne-Net] re: Beceem kicking butt in Mobile WiMax
Reply-To: [email protected]

[Note:  This comment comes from reader Robert Berger.  DLH]

> From: "Robert J. Berger" <[email protected]>
> Date: October 6, 2006 9:33:45 AM PDT
> To: [email protected]
> Subject: Re: [Dewayne-Net] Beceem kicking butt in Mobile WiMax
>
> Well that article was full of misconceptions!
>
>> WiMax ranges much as 10 miles, while the WiFi we know today  
>> reaches only a few hundred feet. Intel wants to use WiMax to allow  
>> someone to get wireless access on a laptop anywhere.
>
> We all should know by now that the answer to all questions of RF  
> coverage and capacity is "it depends".
>
> WiMax has no magic over WiFi, just additional cost and extra  
> applications of hype. The modulations are basically the same. The  
> WiMax MAC has no more than a 4 dB advantage over WiFi when you  
> compare them at the same power levels and antenna gain. That is  
> dwarfed by all other considerations such as the fact that multi- 
> GigaHertz frequencies barely propagate thru any physical object  
> including trees, especially wet trees. Trees are about 15 - 20 dB  
> of attenuation most household walls are 10 - 15 dB.
>
> Licensed WiMax is allowed to have more power than WiFi. Current  
> WiMax base stations operate at around 34 dBm of output power,  
> Commercial muni-wireless WiFi APs operate at around 24 - 26 dBm. So  
> the difference between Licensed WiMax and unlicensed WiFi transmit  
> power is about the same as one tree of  obstruction attenuation.
>
> To get to a "laptop anywhere" the laptop has to have a transmit  
> power that is at least in the same ball park as the transmitter.  
> Otherwise the laptop can hear the AP, but the AP can't hear the  
> laptop.
>
> A laptop has severe power constraints, so today most laptop Wifi  
> transmit power is around 13dB - 18 dB. Its a low probability that  
> laptop vendors are going to be putting 24dBm radios into laptops.
>
> WiMax CPE (subscriber units) that are being sold in a fixed  
> configuation have 20 dBm to 26 dBm of transmit power. As does WiFi  
> CPE that are being sold for muni-wireless (http://www.peplink.com/ 
> productsLoader.php?productName=surf) and are also less expensive  
> than the WiMax CPE.
>
> This asymmetrical transmit power issue is currently a problem for  
> muni-wifi deployments as is building and tree obstructions. It will  
> be no different for WiMax. But WiFi APs are so dramatically less  
> expensive than WiMax that you can afford to have many more of WiFi  
> APs thus creating more coverage at a similar cost.
>
> And as I have been saying all along, WiFi is recapitulating the  
> evolution of Ethernet while WiMax is following in the footsteps of  
> all the failed competitors of Ethernet.
>
> That does not mean that there will not be business successes in  
> WiMax just as there were some VERY successful ATM and Token Ring  
> companies (for a while) .  Intel and others are pouring capital  
> down the WiMax drain so it will be good for those companies that  
> can pick off that capital while its flowing. Maybe Beceem is one of  
> those.
>
> I thought that this line was interesting:
>
>> Turns out, Intel is having to resell Beceem’s chip for Intel’s  
>> WiMax efforts — even though Intel is spending $1 billion on  
>> distributing WiMax. You’d think Intel, the chip giant, would want  
>> to sell its own chips. You look behind the curtains, and there’s  
>> only this tiny start-up Beceem doing it all. Intel recently sold  
>> off a mobile handset chip unit too, so it doesn’t have too much  
>> momentum in the mobile space.
>
> I wonder how much longer Intel will continue to pour the $billions  
> into WiMax after they have divested themselves of it.

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