I have read the Wiki articles on each, and can’t for the life of me figure the difference, except I am guessing 3G is faster, or superior in some way.
My Kindle1 still uses the former if I am not mistaken, on the Sprint network. Or, has that changed too?
My Verison cell phones are 3 G.
In simple terms, what is the difference between these two services?.
EVDO is a CDMA-based subset of the category loosely nicknamed “3G” or 3rd generation: International Mobile Telecommunications-2000 (IMT-2000)…
OK, of what? 
Do they use the same cell towers?
Is it just an upgrade in the software, or any hardware (other than the phones) changes involved?
I’m not sure what you mean by “the same cell towers” since a given tower can contain different equipment. Certainly not all towers are upgraded simultaneously. I often get 1xRTT instead of EVDO when I am using my Sprint card.
EVDO is an improvement of the original CDMA2000 standard. Code Division Multiplexing is one of the ways to deliver mobile radio signals. I am not an expert but as far as I know both software and hardware are required on the cell tower sides as well as EVDO-capable devices on the mobile side.
3G is an industry marketing classification more than any a technical measure. It includes a few different technologies like the ones listed on this page:
EVDO is usually classified as 2.5G because its much, much faster than typical 2G but not as quick as the technologies classified as 3G, although there’s a lot of debate here. Personally, my old CDMA phone got better throughput in low reception conditions than my AT&T 3G (which falls back to EDGE more often than I care to admit.)
Verizon 3G is CDMA. Its the same as Sprint’s. Each company uses its own towers, but obviously they have data and voice roaming deals with each other.
A less technical/accurate (but more honest) explanation is that “3G” is just short for “third-generation”, which is about as meaningful as “NEXT GENERATION!” or “REVOLUTIONARY!” or “HIGH-TECH!”.
All “3G” tells the average user is that a phone can download data faster than a carrier’s 2G service and slower than the same carrier’s 4G service.
It’s not as useful for comparing across carriers because coverage, reception, and congestion would likely impact your real-world experience more than a theoretical top speed would. See something like this Wireless Broadband Service Comparison Chart for a more useful comparison, though nothing beats real-life testing in your exact area (i.e., by trying out competing carriers and utilizing their trial periods before sticking with one contract).
EV-DO is the cellular technology (and popular name) that both Verizon and Sprint use for their 3G services. With the Kindle, your main speed bottleneck is the processor and the e-Ink display, not its cellular technology. A good smartphone on the same 3G network can display things much quicker, though it won’t have the screen size and battery life of the Kindle.
Verizon 3G is EVDO.
2.5 G is CDMA2000 1X on Verizon and Edge on AT&T
Yes. “3G” is more a marketing term. It stands for “third-generation digital cellular standard,” denoting, very roughly, a certain speed of wireless data connection.
EVDO, however, is one side of a format war, like Blu-Ray vs. HD-DVD or DVD+R vs. DVD-R or Beta vs. VHS. It is one member of the “CDMA” grouping.
The other side of the format war is the “GSM” grouping.
The CDMA camp was promoted by the US company Qualcomm, and is used primarlly in the Americas. It accounts for around 20% of cellular customers.
The GSM camp was invented in Europe by the Groupe Spéciale Mobile (hence the initials). It is used worldwide, and accounts for around 80% of cellular customers.
GSM was designed with roaming and interoperability in mind; these had to be retrofitted into CDMA. GSM phones carry their numbers in a SIM card which can be transferred from phone to phone. This makes swapping phones easy. In the original CDMA phones, the phone number is programmed into the phone, and swapping phones required a visit to the supplier’s store, though I believe that some CDMA phones have SIMs now.
New phones are developed first for GSM, and are often never available for CDMA systems (iPhone, I’m looking at you!).
Some companies are transitioning away from CDMA towards GSM: Bell and Telus, the two big CDMA carriers in Canada, last year activated HSPA networks, which is the third-generation member of the GSM family.
Eventually, all carriers are supposed to be adoping the same fourth-generation standard, known as “LTE”. But that’s going to take a while.
EVDO is 3G, so they are the “same”.
The responses you will get will get will talk alot about GSM vs CDMA … just take a look at wikki’s G3 page. G3 can be TDMA or CDMA. CDMA vs GSM is like a “diesel vs ford argument”. Even if you research technologys to death you wont be able to answer the question you actualy want to know the answer to. Just today on the way to lunch two brand new android phone users on different networks did download tests. 800kbs vs 19kbs. The 19K was AT&T in the bright spot on the verison comercials maps for AT&T. If you move away from that part of town AT&T gets much faster.
Meflin