Clearwire?

I have a few question and I was curious if anyone had the answers? 1) does clearwire network support mobile or only fixed wimax? aka. is it possible to do voip while mobile using clearwire's network? What happens when moving from one antenna to another. Is the network 802.16e ? 2) What is the network coverage and what is the importance of rural areas with regards to business strategy. What regions are Clearwire servicing? 3) What kind of encryption algorithm is used? TDES, AES? If AES, what is the key size? 128, 192 or 256? 4) Are there limits on bandwidth and are limits different for upload and download. 5) What about Sprint? Is Sprint competing now, if not when? Just thought this would be a fun topic. I use Vonage and comcast right now but I'm thinking of switching to Clearwire and even possiable buying stock... I've heard that sprint is also using wimax... And it up and coming Write back let me know your thoughts. Cheers