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[aprssig] Andorid APRS

Jeffrey Johnson ortelius at gmail.com
Thu Dec 24 00:38:54 UTC 2009


Wow! Let me quickly correct some serious mis-information here.

> a phone.]  The real question now is which (if any) carriers will allow a
> non-proprietary non-crippled version of a "generic" phone operate on their
> networks.

I have various unlocked phones including Nokias and the Google Dev
Phone. Unlocked means just that. I can put in a SIM from any (GSM)
carrier I like and it 'just works'. There is the issue of incompatible
3G frequencies between the carriers. If you have ever travelled in
Europe or anywhere else in the world that uses GSM (pretty much
everywhere), the paradigm of unlocked phones predominates. Its only in
the US that we have the paradigm of phones locked to a specific
carrier.

> 2)     Most cell phone GPS's are relatively dumb devices (just the RF front
> end) and depend on cell network access to function. As a result, your APRS
> GPS functionality would disappear when you leave the coverage footprint of
> your chosen cell carrier, if you try to use the phone's GPS with your radio.

You are talking about Assisted GPS here. Yes this is very true of lots
of what I would call 'low-end' smartphones (blackberry, windows mobile
etc). This is simply NOT the case with Android devices or iPhone. The
GPS in my G1 and my iPhone works just fine if I turn off ALL of the
radios.

> 3)     Android mapping apps are most likely to use Google Maps downloaded
> from the Internet via the cell phone's data access, meaning:

Google Maps is one of many options available to android developers. I
have developed android apps based on OpenStreetMap, maps I have
created myself with open source tools using the Nutiteq library among
others.

> a)   You are potentially going to run up huge airtime charges for data
> acccess.  Most so-called unlimited data plans have monthly bandwidth caps;
> i.e. download quotas of "x" megabytes.  [Currently the iPhone users tethered
> to ATT's network are screaming and howling about ATT's plan to do away with
> unlimited data access and start charging by the amount of monthly bandwidth
> used. ]

Monthly bandwidth caps on Verizon and other carriers are measured in
the Gigabytes of data which constrains usage like video and audio
streaming. AT&T currently does not have bandwidth caps, but is
considering going to tiered pricing. In any case, maps are actually
quite small in size. unless you want to cache a huge chunk of maps
down to your phone in which case, you could use an android based
device like the Archos 5 Internet tablet
http://www.archos.com/products/imt/archos_5it/index.html?country=ru&lang=en
which is WiFi only and doesnt even work on the cell phone networks.

> b)     Once again, if you are out of the cell carrier's coverage foot print
> -- NO MAPS!!

There are a plethora of apps for the iPhone that allow you to download
maps to your phone while on a WiFi connection and then use them out in
the field without an internet connection. Many/Most of these are based
on the Route-Me library which can be used with various map tile
sources including OpenStreetMap, Bing (Microsoft Maps), Yahoo Maps and
even google maps if you don't mind violating the Terms of Service. I
have also developed several apps based on this library and have been
able to use my phone with GPS AND Maps in the absence of cell coverage
or WiFi.

So, wrong, wrong, wrong and wrong. Please check your facts before
posting mis-information.

Jeff
KJ6CKB



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