do i need to have a phone to get the watch. can i just activate the watch standalone?

[AC Question]

i want to get the watch with my number attached to it. i use an iPhone now but want to just use the watch as my phone for calls and texts and not use a phone.
if i buy an att watch s2 can i just activate it or do i need a samsung phone to set it up. i know i can use number sync but do i need a samsung phone to setup the number sync?
can i also have the option of having att transfer my cell number from my iPhone to the watch?