title: How do clients on wireless networks decide who can transmit at any given time?
body: <p>I've been thinking about wireless networking a little bit recently, and I came upon a realization last night that I can't find an answer to: how do clients know when they can transmit and <em>not</em> stomp over another clients' transmission?</p>
  
  <p>I assume there is documentation for this sort of thing available, but I've been unable to find anything useful over a half hour of casual Google queries, probably because I don't know the right terms. Apologies in advance if this is a silly question . . .</p>
  
  <p>Here's why I'm confused: based on my understanding of how RF hardware works, we can model the transmission medium as a <em>safe</em> shared register between different RF clients (because what one client broadcasts can be overwritten by other clients and get a muddle between the two). But safe registers only have consensus number 1, so how can we establish who can transmit at any given point? I'm assuming that only one client can transmit at once -- perhaps this is my fundamental misunderstanding?</p>
  
  <p>Even the use of a randomized consensus protocol seems unwieldy, because the only ones I know of use atomic registers, not safe registers, and also have no upper bound, so two identical devices with the same random seed would proceed for a <em>very</em> long time.</p>
  
  <p>Thanks!</p>