[1st-mile-nm] Information request on wireless reliability and frequency conflicts

[Bob Knight]

Another note - polarization may be your friend in crowded spectrum.

Bob


Bob Knight wrote:
> You need to look at the WISPA archives relative to Motorola Canopy. 
> While it is the largest deployed base in that community, it also is 
> considered to be the largest problem interference-wise, at least in the 
> 2.4 (not 2.6) Ghz band. In our area, though, they're using 900 Mhz.
>
> In 2.4, there are 11 channels (in the US, at least). Ideally (and 
> nowadays, this is far from ideal given the spectrum pollution), one 
> wants things 5 channels apart, especially when hidden node problems are 
> anticipated. The problem is that hidden node is going to be a problem 
> pretty much no matter what measures you take.
>
> WiMax can be used in various bands from 2-66 Ghz. 2.5 and 3.5 are 
> licensed spectrum and it can be used in 5.8. It seems to be suited to 
> 700  Mhz as well.
>
> Our experience on 5.8 is very positive. We use it for our backhauls. One 
> nice thing about this spectrum allocation is that the channels are 
> non-overlapping. Our backhaul sink for the DS-3 has 5 different links 
> coming in with no interference.
>
> Admittedly, we are rural. But I guarantee that if the Santa Fe spectrum 
> in 5.8 (or Eldo for that matter) were crowded, we'd see it. And we don't.
>
> So where are you seeing problems?
>
> Bob
>
> peter wrote:
>   
>> We are involved in several projects investigating wireless conflict 
>> signals within corporations and hospitals and are finding some strange 
>> results which could impact Wi-Fi and Wi - Max usage and indeed the 
>> whole paradigm first mile wireless use.
>>
>> Basically this is what we are seeing
>>
>> Open wireless frequencies that have been typical used are 900 - 2.6 
>> and now 5.8ghtz.
>>
>> 802.11 of various types operates in both the 2.6 and 5.8 sectors ( 5.8 
>> is 802.11n and 802.16 wi max )  the 900 htz range is packed and so is 
>> the 2.8 ghtz
>>
>> Inside of a hospital for instance multiple monitoring equipment types 
>> and portable phone systems operate on the same frequencies and so does 
>> a huge amount of SCADA operations.
>>
>> Although channel switching is supposed to prevent signal conflict 
>> wi-fi  signal boosters and all wimax whether static or mobile is 
>> continually channel hunting and knocking everything else of of the 
>> channel making many types of systems non usable
>>
>> It would seem that a major problem is manufacturers testing their 
>> equipment in a silo arena and this would also be relevant to the white 
>> space transmission requests before the FCC at present
>>
>> This looks like a huge problem and if anyone is experiencing the same 
>> issues please contact us
>>
>> Apparently Motorola with their Canopy system and Intel ( wi-fi and max 
>> ) did a large amount of research  but when the conflict issues arose 
>> chose to ignore the results or assumed that channel frequency switch 
>> would fix the problem but its not
>>
>> ( : ( : pete
>> -- 
>>
>> Peter Baston
>>
>> *IDEAS*
>>
>> /www.ideapete.com/ <http://www.ideapete.com/>
>>
>> 3210 La Paz Lane
>>
>> Santa Fe, NM 87507
>>
>> /Albuquerque// Office: 505-890-9649/
>>
>> /Santa Fe// Office: 505-629-4227/
>>
>> /Cell: 505-690-3627/
>>
>> /Fax: 866-642-8918/
>>
>> /_Mailto:pete at ideapete.com <mailto:pete at ideapete.com>_/
>>
>>  
>>
>>  
>>
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