well, as an Intern at a Telecom company, these are terms that frequently come up, and the actual mechanism of say a simple task like sending an SMS, to a more complicated one like Voice calls etc etc... me's not a pro as yet (ob!) not being from Communication background... but reading those e-books is awesome!
for, very few ppl wud know that GSM = Global System for Mobile, and CDMA = Code Division Multiple Access.. and that 3G (The iPhone 3G, remember?!) = 3rd Generation mobiles etc etc.. that there have been 2G phones (the ones which we used a few yrs ago, and now we're using 2.5G ones, to facilitate the transition between 2G and 3G) :O
well.. more when i know more... just read the basic concepts.. :P lolz..