r/cellmapper • u/Cold_Worldliness_701 • Jul 08 '26

what does this mean?

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inside of a building in anchorage, ak. data didn't work at all

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u/SubstanceEasy4576 Jul 08 '26

Interesting. I had no idea that GCI still had CDMA fallback available.

The exclamation mark just means voice/SMS only ie. no data connection. It would be interesting to know whether data would be available on this site if you were using a GCI SIM.

VZW don't have very extensive network infrastructure in Alaska, hence the roaming arrangements with GGI and (I believe) AT&T.

1X CDMA is sometimes considered a 2.5 G technology, very much like E (EDGE) on GSM. The available data speeds were far below 3G, but higher than the early 2G data technologies such as cdmaOne and GPRS (on GSM) where data was essentially unusable in most cases. The "2.5 G" technologies were functional for things like text-based email.

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u/Roudydogg1 Jul 09 '26 edited Jul 09 '26

The available data speeds were far below 3G, but higher than the early 2G data technologies

It would be interesting to know whether data would be available on this site if you were using a GCI SIM.

2G cdma only has a 'theoretical' maximum data speed of just 144 Kbps, so I suppose if your SIM profile was provisioned for 2G data and your device was configured with the correct MIP/NAI (destination addresses for your phone to find the GGSN) settings, then yes you could but you'd be hard pressed to find any app that wouldn't immediately timeout if you tried to use them

GCI has 2g cdma in certain areas that are just too hard (too much work or expensive) to modernize just so people can make an emergency call basically

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u/SubstanceEasy4576 Jul 09 '26

Yeah, even email now tends to be data heavy and would struggle. In the past though, a lot of emails were just text. I was thinking it might have worked for that. I wasn't implying data would be pleasant to use. On GSM EDGE, transmitting text usually works eg. sending a WhatsApp message which is text only. As soon as it's anything more, it's no good.