[Olsr-users] Using multiple radio cards

Derek C (spam-protected)
Fri Aug 8 17:31:49 CEST 2008


Hi Victor,

Funny actually - I have quite a few antennas which are very close to each
other (generally a few planar or sectors and perhaps an omni on top) - as
close as I can get them when room gets tight and I haven't noticed any
problems with throughput due to proximity.  But then again thats not then
same thing perhaps as two omnis "looking" at each other directly.

I wonder if multiple (directional) on the same frequency could have an
advantage over single radio omnis in terms of distance even if
interference is being introduced on the single channel?  My big problem
with omnis is very distance (even on 2.4 where once I managed to get
around 3 KM between two 10dBm omnis with 60mWatt Merakis but it was woeful
and a very unacceptable throughput but I'd say there would be a severe
distance limitation with 5Ghz & omnis).

Derek


On Fri, August 8, 2008 4:22 pm, Victor wrote:
> Hi Derek,
>
>
> Yeh it does. There are some commercial companies that have released
> products that are self contained and in the same frequency band but I'm
> not sure how they did it.
>
> In my setup was completely different. I was using Linksys routers with a
> modified version of Freifunk/Openwrt so it was just a matter of using
> Ethernet cable to separate the two routers.
>
>
> Using a PC, I would just suggest using USB wireless devices and have a
> long USB cable. But the problem of cards in the same frequency band is
> well known and researched.
>
> Victor
>
>
> -----Original Message-----
> From: Derek C [mailto:(spam-protected)]
> Sent: Friday, August 08, 2008 11:57 PM
> To: Victor
> Cc: (spam-protected)
> Subject: Re: [Olsr-users] Using multiple radio cards
>
>
> Hi Victor,
>
>
> Thats very interesting - it does make it awkard to build simple mesh
> nodes too as they can't be self-contained.
>
> Did you only use multiple antennas to seperate back-haul and customer
> connections or did you use multiple cards to improve back-haul performance?
>
>
> thanks,
>
> Derek
>
>
>
> On Fri, August 8, 2008 11:21 am, Victor wrote:
>
>> Hi Derek,
>>
>>
>>
>> Just note that when using multiple radio cards you will still need
>> physical separation (antenna) separation between the radio cards
>> otherwise they will still be interfering with each other no matter what
>> channel you set them to. Mixing a and g band radios is okay and you wont
>> need the physical separation because the frequencies are far enough
>> apart. When I was working on this for an honours thesis I found that I
>> needed a minimum of 1 meter separation between the antennas otherwise
>> you get worse performance than just a single card.
>>
>>
>>
>> Victor
>>
>>
>>
>> -----Original Message-----
>> From: (spam-protected)
>> [mailto:(spam-protected)] On Behalf Of
>> (spam-protected) Sent: Friday, August 08, 2008 8:00 PM
>> To: (spam-protected)
>> Subject: Olsr-users Digest, Vol 15, Issue 6
>>
>>
>>
>> Send Olsr-users mailing list submissions to
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>> Today's Topics:
>>
>>
>>
>> 1. Yippie - routing now working (due to LinkQualityLevel
>> setting) (Derek C) 2. Using multiple radio cards (Derek C) 3. Re: Using
>> multiple radio cards (Benjamin Henrion) 4. Re: Using multiple radio
>> cards (Derek C) 5. Re: Using multiple radio cards (aaron)
>> 6. Re: Using multiple radio cards (Derek C)
>>
>>
>>
>>
>> ----------------------------------------------------------------------
>>
>>
>>
>> Message: 1
>> Date: Thu, 7 Aug 2008 17:12:02 +0100 (IST)
>> From: "Derek C" <(spam-protected)>
>> Subject: [Olsr-users] Yippie - routing now working (due to
>> LinkQualityLevel	setting)
>> To: (spam-protected)
>> Message-ID:
>> <(spam-protected)>
>> Content-Type: text/plain;charset=iso-8859-1
>>
>>
>>
>> NOTE: SORRY - somehow I posted my message to the olsr dev mailing list
>> rather than the users one (and I'm not on the dev mailing list either).
>>
>>
>> Hi again,
>>
>>
>>
>> To let you know - quite blindly I started modifying olsrd.conf settings
>>  to see if the routing would start working - and it paid off.
>>
>> I switched "UseHysteresis" to "no" and then I changed
>> "LinkQualityLevel"
>> from "0" (default) to "1" - after this, and a olsrd restart of course,
>> routing came up!
>>
>> Actually I had avoided the LinkQualityLevel setting because I thought
>> it really was "Hysteresis" OR "LinkQualityLevel" and Hysteresis sounded
>> like
> a
>> better system to opt for...
>>
>> thanks,
>>
>> Derek
>>
>>
>>
>> --
>> --
>> Derek C
>> In Ireland
>>
>>
>>
>>
>>
>>
>>
>> ------------------------------
>>
>>
>>
>> Message: 2
>> Date: Thu, 7 Aug 2008 17:40:15 +0100 (IST)
>> From: "Derek C" <(spam-protected)>
>> Subject: [Olsr-users] Using multiple radio cards
>> To: (spam-protected)
>> Message-ID:
>> <(spam-protected)>
>> Content-Type: text/plain;charset=iso-8859-1
>>
>>
>>
>> Hi again,
>>
>>
>>
>> On multiple radio cards:  I'm new to AdHoc networking but I know that
>> AdHoc networks don't hunt for APs over different frequencies like the
>> typical AP->STA type setup.
>>
>> I was hoping to have a dual [backbone] radio setup with one omni
>> antenna and one directional antenna per node to try to allow for links
>> with increased range over omni -> omni arrangements.
>>
>> It does seem counter-productive to me to use the same frequency for two
>>  individual radio cards - surely the interference would cause major
>> slow-downs in communications?  (even more so than in a repeating single
>>  radio card setup due to re-transmissions?).  Funny though because I
>> think I've read over people's setup with two radio cards set to the same
>>  frequency.
>>
>> Does anyone have any experience or opinions on dual radio setups?
>>
>>
>>
>> thanks,
>>
>> Derek
>>
>>
>>
>>
>>
>> --
>> --
>> Derek C
>> In Ireland
>>
>>
>>
>>
>>
>>
>>
>> ------------------------------
>>
>>
>>
>> Message: 3
>> Date: Thu, 7 Aug 2008 18:57:43 +0200
>> From: "Benjamin Henrion" <(spam-protected)>
>> Subject: Re: [Olsr-users] Using multiple radio cards
>> To: "Derek C" <(spam-protected)>
>> Cc: (spam-protected)
>> Message-ID:
>> <(spam-protected)>
>> Content-Type: text/plain; charset=ISO-8859-1
>>
>>
>>
>> On Thu, Aug 7, 2008 at 6:40 PM, Derek C <(spam-protected)> wrote:
>>
>>
>>> Hi again,
>>>
>>>
>>>
>>> On multiple radio cards:  I'm new to AdHoc networking but I know that
>>>  AdHoc networks don't hunt for APs over different frequencies like
>>> the typical AP->STA type setup.
>>>
>>> I was hoping to have a dual [backbone] radio setup with one omni
>>> antenna and one directional antenna per node to try to allow for links
>>>  with increased range over omni -> omni arrangements.
>>>
>>> It does seem counter-productive to me to use the same frequency for
>>> two individual radio cards - surely the interference would cause major
>>>  slow-downs in communications?  (even more so than in a repeating
>>> single radio card setup due to re-transmissions?).  Funny though
>>> because I think I've read over people's setup with two radio cards set
>>> to the same frequency.
>>>
>>> Does anyone have any experience or opinions on dual radio setups?
>>>
>>>
>>
>> I should publish soon my findings about multiple radio.
>>
>>
>>
>> Basically the more seperation in frequencies the better.
>>
>>
>>
>> If you want to use 2 different channels in the 2.4 band, try to use
>> ch1 and ch13 or example, or at least non-overlapping channels (ex:
> 1-6-11).
>
>>
>>
>> If you are using omnis, try also to have Hpol and Vpol for better
>> seperation.
>>
>> In the 5gh band, use 5.2 and 5.8 in order to maximise the seperation.
>>
>>
>>
>> --
>> Benjamin Henrion <bhenrion at ffii.org>
>> FFII Brussels - +32-484-566109 - +32-2-4148403
>>
>>
>>
>>
>>
>> ------------------------------
>>
>>
>>
>> Message: 4
>> Date: Thu, 7 Aug 2008 18:55:45 +0100 (IST)
>> From: "Derek C" <(spam-protected)>
>> Subject: Re: [Olsr-users] Using multiple radio cards
>> To: "Benjamin Henrion" <(spam-protected)>
>> Cc: (spam-protected)
>> Message-ID:
>> <(spam-protected)>
>> Content-Type: text/plain;charset=iso-8859-1
>>
>>
>>
>> Hi Benjamin,
>>
>>
>>
>> I'm going to be using 802.11a 5Ghz (one planer & one omni).  I have a
>> separate 2.4 Ghz card & omni for bandwidth supply to customer notebooks
> (so
>
>> three cards total per node).
>>
>> The problem with any separate frequencies at all is that, as far as I
>> can see, it hobbles adhoc mesh networking altogether in that one node
>> won't see any neighbors that are not on its assigned frequency.
>>
>> How did you approach this with multiple radio cards and frequencies?
>>
>>
>>
>> thanks for any information
>>
>> Derek
>>
>>
>>
>>
>> On Thu, August 7, 2008 5:57 pm, Benjamin Henrion wrote:
>>
>>
>>> On Thu, Aug 7, 2008 at 6:40 PM, Derek C <(spam-protected)> wrote:
>>>
>>>
>>>
>>>> Hi again,
>>>>
>>>>
>>>>
>>>>
>>>> On multiple radio cards:  I'm new to AdHoc networking but I know
>>>> that AdHoc networks don't hunt for APs over different frequencies
>>>> like the typical AP->STA type setup.
>>>>
>>>> I was hoping to have a dual [backbone] radio setup with one omni
>>>> antenna and one directional antenna per node to try to allow for
>>>> links with increased range over omni -> omni arrangements.
>>>>
>>>> It does seem counter-productive to me to use the same frequency for
>>>>  two individual radio cards - surely the interference would cause
>>>> major slow-downs in communications?  (even more so than in a
>>>> repeating single radio card setup due to re-transmissions?).  Funny
>>>> though because I think I've read over people's setup with two radio
>>>> cards set to the same frequency.
>>>>
>>>> Does anyone have any experience or opinions on dual radio setups?
>>>>
>>>>
>>>>
>>>
>>> I should publish soon my findings about multiple radio.
>>>
>>>
>>>
>>>
>>> Basically the more seperation in frequencies the better.
>>>
>>>
>>>
>>>
>>> If you want to use 2 different channels in the 2.4 band, try to use
>>> ch1 and ch13 or example, or at least non-overlapping channels (ex:
>> 1-6-11).
>>
>>
>>>
>>>
>>> If you are using omnis, try also to have Hpol and Vpol for better
>>> seperation.
>>>
>>> In the 5gh band, use 5.2 and 5.8 in order to maximise the seperation.
>>>
>>>
>>>
>>>
>>> --
>>> Benjamin Henrion <bhenrion at ffii.org>
>>> FFII Brussels - +32-484-566109 - +32-2-4148403
>>>
>>>
>>>
>>>
>>
>>
>> --
>> --
>> Derek C
>> In Ireland
>>
>>
>>
>>
>>
>>
>>
>> ------------------------------
>>
>>
>>
>> Message: 5
>> Date: Thu, 07 Aug 2008 20:36:24 +0200
>> From: aaron <(spam-protected)>
>> Subject: Re: [Olsr-users] Using multiple radio cards
>> To: Derek C <(spam-protected)>
>> Cc: (spam-protected)
>> Message-ID: <(spam-protected)>
>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>
>>
>>
>>
>>> How did you approach this with multiple radio cards and frequencies?
>>>
>>>
>>>
>>
>> I would just use multiple cards / radios in that case.
>>
>>
>>
>> a.
>>
>>
>>
>>
>> ------------------------------
>>
>>
>>
>> Message: 6
>> Date: Thu, 7 Aug 2008 20:42:16 +0100 (IST)
>> From: "Derek C" <(spam-protected)>
>> Subject: Re: [Olsr-users] Using multiple radio cards
>> To: "aaron" <(spam-protected)>
>> Cc: (spam-protected)
>> Message-ID:
>> <(spam-protected)>
>> Content-Type: text/plain;charset=iso-8859-1
>>
>>
>>
>> Hi again Aaaron,
>>
>>
>>
>> On single radio [backbone] mesh systems - part of the advantage to the
>> adhoc / olsrd network is that the nodes "see" all nearby neighboring
>> nodes so can route via them as necessary.  This must be necessary
>> (important
>> anyway) for routing via new (better signal / less hops) nodes as they
>> appear and for resilient links.
>>
>> If two radio cards are used and two channels are used then nodes would
>> have to be programmed with the channel to use (per radio card, etc) as
> they
>> are going out for installation but without any automated channel
>> selection it would be just like having separate olsrd networks wouldn't
>> it?
>>
>> Before dabbling olsr I was trying out my own perl based scripts to find
>>  neighbors - I was using AP and STA cards (not adhoc networking) but
>> this was flawed because I couldn't work out safe routes to gateway nodes
>> (only
>> routes to nearby strong signal neighbors) but in a way it was good
>> because I always had unique frequencies.
>>
>>
>> If you are using separate radio cards and separate channels would you
>> just manually structure your "hybrid" network or is there any other
>> intelligent options?
>>
>> thanks for any information
>>
>> Derek
>>
>>
>>
>>
>>
>>
>> On Thu, August 7, 2008 7:36 pm, aaron wrote:
>>
>>
>>>
>>
>>>> How did you approach this with multiple radio cards and
>>>> frequencies?
>>>>
>>>>
>>>>
>>>
>>> I would just use multiple cards / radios in that case.
>>>
>>>
>>>
>>>
>>> a.
>>>
>>>
>>
>>
>> --
>> --
>> Derek C
>> In Ireland
>>
>>
>>
>>
>>
>>
>>
>> ------------------------------
>>
>>
>>
>> --
>> Olsr-users mailing list
>> (spam-protected)
>> http://lists.olsr.org/mailman/listinfo/olsr-users
>>
>>
>>
>> End of Olsr-users Digest, Vol 15, Issue 6
>> *****************************************
>>
>>
>>
>>
>> --
>> Olsr-users mailing list
>> (spam-protected)
>> http://lists.olsr.org/mailman/listinfo/olsr-users
>>
>>
>>
>
>
> --
> --
> Derek C
> In Ireland
>
>
>
>
>


-- 
--
Derek C
In Ireland






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