Category 2018

Its Simple

GSM works far better than CDMA for one simple reason — the broadcast band it uses is more reliable. Nonetheless, among those that tout they use GSM, AT&T (prepaid counterpart Cricket) and T-Mobile (prepaid counterpart MetroPCS), T-Mobile/MetroPCS dropped service repeatedly in recent tests.   MetroPCS uses IP6 addressing over T-Mobile’s network. Nonetheless, Verizon, despite their use of CDMA,  works well in most East Texas areas.

It would be hard to generalize, but in actual tests around the East Texas Lake Areas, MetroPCS phones dropped everything from cell service, to texts, to data during cloudy days.  Sprint phones and its counterpart Boost Mobile are expected to perform equally poorly in outlying East Texas areas.  While AT&T and Cricket might be better alternatives in some cases, there is always an expense trade-off.  Data plans vary between these companies but the main advantage any company will have over another is, up-time percentage:  Weather sometimes interrupts service–but a few clouds should not drop service entirely for any noticeable length of time.

A Little More

A feature of some cellular services is the routing of calls and texts over the same bandwidth as its data stream.  This means very annoyingly–no data access also means no texting.   GSM uses two different bandwidths, one for calls and texts, and the other for data.  This means you might temporarily hit a spot where you are without data (maps, music, web browsing), but your phone and texts will still generally work.  Photos sent via text do not actually go via text–because by definition texting is, well, text.  Thus, pictures always use data as multimedia or email messages, and may not go out at all in areas with poor service.

Here is a table extracted from https://techspirited.com/gsm-vs-cdma comparing GSM and CDMA technology. I have added a column to weight for usefulness in sparsely populated Rains County and adjacent rural areas.

Topic	GSM	CDMA	Rains County
Companies	ATT, Cricket, T-Mobile,Boost, Europe	Sprint,Verizon,US Cellular	GSM more available in rural areas, however carriers are recently abandoning 3G networks, and now support only 4G and 5G phones.
% Use	50%, 3.7 billion	5%, 350 million	Roughly as of 2016; others LTE 12%, HSPA 29%
Call Quality	Good	Better	Insignificant difference overall
Carriers	Flexible	Hardwired	GSM users may switch SIM cards to compatible networks CDMA users must switch phones to use a different network
US Coverage	Good	Good	GSM slightly more available in rural areas
Emergency	112	Varies	112 is recognized as emergency help number worldwide on GSM networks only
Battery	Better	Good	CDMA uses more energy
Speed	Varies	Varies	Both technologies run neck and neck as far as real-user experience is concerned. Speed is not a significant factor for calls and texts. It only affects data such as downloads and sending pictures.
Roaming	Free	$$$	GSM is more widely used, and usually free roaming
Inside Buildings	Good	Good	Metallic buildings interrupt all sorts of wireless communications. 5G networks are notably less accessible than 3G and 4G phone networks

MetroPCS, AT&T, Cricket, Verizon, T-Mobile, Boost, and Sprint are trademarks of their respective companies.

The cellular carriers are competing by using different technologies to market their version of the cellular services.  For example, AT&T  uses a protocol called GSM, while Sprint uses CDMA.  Technology is quickly changing, but for the most part, CDMA phones are permanently tied to the carrier from which they were purchased.  GSM phones however, are the type that have a removable card that can be swapped out to switch carriers to another GSM compatible carrier.  A few carriers are crossover carriers, meaning they support to some extent both GSM and CDMA phones.

The reason a company is offering you a free phone to switch from your existing carrier is that they know that the phone you have is likely not compatible with their network, and that the free phone you are about to receive from them is not compatible with your current carrier either.  Thus the free phone will be permanently tied to their service, a strong incentive for you to remain loyal to them.  This may not however be a big issue for a prepaid service. The phone was free and thus effectively dispensable. The data on the phone can be backed up (synced) to an Internet-based email account before you disconnect it, and when you get a new phone on a new carrier, you simply reconnect to that same email account and presto, all your apps and contacts are back.

Another common error in shopping for a phone, is that the marketeers are not just trying to sell you a phone, they are pushing camera sales.  A smart phone is not in the same paradigm as a traditional landline phone, which only permitted talking to people.  Smart phones are camera-video_recorder-stereo-phone-and-more all built into one small device.  Some of the features are incidental to the device (a speaker phone for example), while many features being pushed are non-essential (a camera isn’t needed to talk on a phone).  Thus the difference in price is all about the non-essential features you may or may not need.  If it is a phone at all, it will do the basic–it will allow you to make and receive calls.

So the next time you buy a phone with a carrier, just remember, you are effectively buying a disposable device that is locked to that carrier.  If you buy a more expensive smart phone with spicy features, realize you bought a camera more than you bought a phone and someday you may want to switch phone carriers and find out that your smart camera is not compatible with the phone carrier you want.  And yes, you can continue to use your smart camera without phone service, if that is what you want to do, but you willneed to periodically connect your device to a computer to extract the images since it will no longer be automatically backing all that stuff up to the Internet via a cellular connection.