Arquivo:CMO - GPRS-EDGE.pdf Pags 1 a 6
Tutorial GPRS:
http://www.ossidian.com/demo/gprs-eng-china/tut/tut06.swf
http://books.google.com.br/books?id=Q-C4o-HBBaIC&pg=PA102&lpg=PA102&dq=%22packet+control+unit%22&source=bl&ots=Pf6HSf4_2T&sig=Vg0JvPaGjXnJcu7ghldWOOAO0p0&hl=pt-BR&ei=ClO_TZCDLsjAgQfXvtHdBg&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCwQ6AEwAjgo#v=onepage&q=%22packet%20control%20unit%22&f=false