Re: [Paparazzi-devel] XBee 868 MHz Issues with Paparazzi

[Chris Wozny]

After digging some more I found the sub band you were talking about.
It's the 869.7-870.0 MHz G4 band. The only thing that worries me is
that it can only transmit at 5 mW.

- Chris

On Tue, Apr 10, 2012 at 9:30 AM, Chris Wozny <address@hidden> wrote:
> Christophe,
>
> Do you know which sub bands can transmit 100% of the time? We really only
> need a couple kilometers which is probably an overestimate. Also, are
> modules that work on this band drop in replacements? The XBee 868LP can
> handle 865-870 MHz which makes me think it should be able to get on this
> less restrictive band via configuring the device.
>
> Best,
> Chris
>
> On Apr 10, 2012, at 4:53 AM, Christophe De Wagter <address@hidden>
> wrote:
>
> The XBee 868 with their theoretical 40km range are not unusable. You just
> need to consider the consequences of it being really a long range modem.
>
> There are some options to use them:
>
> 1) legal option: do not sent too much data, so others within the 40km radius
> can also use the frequency.
>     1a) transmit less than 0.4 seconds every 4 seconds.
>     1b) fly less than 6 minutes when sending 100% of time
>     1c) in between: e.g. fly less than 12 minutes when sending 50% of the
> time.
>
> 2) illegal option: reset your modem every 5min with a xbee-reset module and
> you can send 9600 kilobits non-stop both ways.
>
> Note 1: when the modem in your airplane stops sending because it sent too
> much already, then it still works and can receive commands for instance. It
> will just wait until the hour passes until sending again as the duty cycle
> rule applies to full hours.
> Note 2: also consider you can pick up data from others from quite far away.
> So make sure you program your unique ID's and safety codes for instance.
> Note 3: for shorter range there are also different sub-bands on 868 that can
> send 100% of time.
>
> On Tuesday, April 10, 2012, Chris Wozny wrote:
>>
>> All,
>>
>> Due to EU regulations, we must use either 433 MHz, 868 MHz, 2.4 GHz
>> for IMAV2012. I was wondering if there have been any developments with
>> the 868 MHz band issues with Paparazzi or if it's still fairly
>> unusable. Also, does anyone know of any 433 MHz transmitters tailored
>> for AUTO2 outdoor flight? I'm curious as to why XBee doesn't make any
>> 433 MHz modems...
>>
>> - Chris
>> _______________________________________________
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> --
> -Christophe