[Canberrauav] bandwidth at CMAC

Andrew Tridgell tridge at samba.org
Sat Nov 24 16:31:04 EST 2012

Hi again,

Jack and I did some testing at CMAC of the little WiFi gateway that I've
put in as part of the weather station:


it gives us a wireless access point out at CMAC, going out via the 3G
modem on the RaspberryPi.

We found that the download speed was surprisingly good - with the new
dongle I bought:


and the antenna on the table in the clubhouse we got a great link - good
enough for us to watch a youtube video with no problems, and good for
accessing complex websites like diydrones.com. It had clearly negotiated
a HSDPA link.

So we discussed a bit what plan we should get with TPG. I had initially
proposed a $5/mon plan, which would give us 500MB/month. 


I think given the speed we get that we should get a larger plan, which
will make internet access at CMAC much more practical. I'd propose we
either get the $10/mon plan, which gives 1G/mon, or the $15.99/mon plan,
which gives 2G/mon.

The weather station plus camera will use about 250MB/month if we take
photos every 15minutes on average, so Jack has proposed that CMAC pay
$5/mon and CanberraUAV pay the rest, as we are likely to be the largest
data users.

I may also put in some shaping/throttling rules on the link if we find
people start downloading too much. It is setup now to send me a SMS when
we approach the monthly limit, so I'll know if we are using too
much. The wireless network is password protected, with the password
available to club members. 

Currently the sim in the weather station is a $1/mon plan, which gives
50MB/mon. If everyone is OK with it I'll change it over to a $10 or
$15.99 plan. Note that we can change plans if we find our usage isn't
what we expect - the plan change takes effect the next month.

Excess data costs 2.7c/MB. We have also setup the RaspberryPi as a SMS
gateway (for alerts and possible alarm usage, plus for remote
reboot). Each SMS sent costs 25c. Received SMS is free.

I'll just do it on my credit card to keep it simple, and get reimbursed
by CanberraUAV/CMAC depending on how we decide to split it.

Cheers, Tridge

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