This week in my graduate class on networking algorithms, I asked my class to focus on the question of whether network coding will become a part of "the network" (whatever you choose that to mean). Given the wealth of papers that have appeared its clear the academic community has embraced the notion of network coding, and there's certainly lots of interesting theory. But I don't know of what I would call a significant real-world deployment -- will we see one in the next decade or so? This is, to me, an important question -- certainly I'd be more inclined to work on network coding problems if I think there's a potential for real-world impact. The class has read a few current papers, and I wondered what they would think.
Interestingly, the class pretty much split down the middle, with perhaps a slight bias toward no. The main reasons cited against the development of practical network coding was that there didn't seem to be an immediate killer applications, and the gains, while non-trivial, weren't enough to cover many of the inherent problems (network support, backward compatibility, etc.) in deploying network coding. A common example given was that there were many challenges in mesh/ad hoc networks, and network coding (while useful) wasn't solving the really important ones. On the more optimistic side, several students saw situations (wireless mesh network, "closed" networks where complete control is centralized so network coding can be set up easily) and possible important issues (can network coding improve energy usage?) that would lead to more widespread network coding use in the years to come.
The discussion reminded me of short survey I once wrote up on "Digital Fountains" (and hey, when Googling I see the powers-that-be even posted my slides) where besides discussing their applications I asked why they weren't now in widespread use. The issues sound familiar.
I'd be happy to have others offer their opinions to my class on this issue. Feel free to comment on whether you think we'll see real-world deployments of network coding systems in the future (or let me know of any in existence now!), and what you see the challenges being for network coding going from an interesting idea to a deployed solution.