Multiplayer gaming on a wireless connection is a serious no-no. A wireless connection instantly increases ping right off the bat - which is an important metric in determining connection quality for gaming. Then, you get signal interference which is dynamic. Meaning; someone turns on the microwave - boom, interference. Neighbour using the same wireless channel as you? Boom, interference. Heck, even a solar storm can interfere. These things don't normally bother people using wireless for general browsing or even streaming videos. But when using something like NHL - you'll notice every single packet that isn't delivered 100%.
It can get you through in a pinch (travelling) but if your xbox is in a permanent spot - I implore you to run a hardwire connection and your experience will be much more consistent.