[OLPC-AU] SDIO on external SD slot
quozl at laptop.org
Mon Mar 7 16:51:24 EST 2011
On Mon, Mar 07, 2011 at 09:54:07AM -0500, Martin Langhoff wrote:
> On Mon, Mar 7, 2011 at 1:12 AM, Sridhar Dhanapalan
> <sridhar at laptop.org.au> wrote:
> > Thanks Wad, Peter and Martin. We are currently trialling the use of 3G
> > Wifi access points, with government-approved content filtering
> > supplied by the telco. Just to be thorough, I am also investigating
> > what our other options may be.
> Interesting. For anything larger than ~ 20 users, I definitely
> recommend an XS. The XS can then be your bridge between 3G and Wifi
The data rate and latency of the Australian "Telstra Next G" 3G service
are quite reasonable ... for the regional areas it is a dual-cell HSPA
with 14.4 Mbit/s deployed nationwide. Timing radius out to about 120km
from a high enough tower operating on 850 MHz band. Modems typically
obtain 3 Mbit/s or 7.2 Mbit/s of the available 14.4 Mbit/s. The uplink
and peering are excellent, with latencies of the order of 50ms to 100ms
even in the outback.
Therefore I'd put the threshold for proxy advantage closer to ~ 40
The capital city towers are configured differently, something around 42
Mbit/sec. I've heard there is more contention and packet loss in these
areas, but haven't measured them personally.
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