[BC] Questions about streaming and my router for Netflicks smartphones ...

Have a situation that garners a good forum post here .. I have a Blue Ray Player thast receives my wifi from my router which is a dual band DIR850L D-link model.. not a cheap one, but not the very best either.. but it does have a dual networking of 2.4mhz and 5 ghz bands .. Until I received my recent New Modem from Shaw recently( august 2015) .. Netflicks endured a lot of 'buffering' lost signal from the other room in my apartment .. I know that I could sting 50 feet of cat5 wire and directly hotwire the two units together for Netflicks to work better . .but the latest modem from shaw fixed this ! . .I now have an 80 % success rate of streaming - compared to about 30 / 40 % before ., BUT a new problem has popped up now . .the bandwidth from my dlink router to my Netflicks streaming seems to 'suck the air dry' when I want to use my smart phone in the same room ., what happens is- web site will appear (probably cashed)., but can't pursue any links within that web site ' it just hangs' . .so changed my smartphone settings to 'forget' about this current network ( my own) . and just use the default cell phone coverage for its own network ( telus) and therefore am using data I have to pay for on account of my cell phone monthly package .. When Netflicks gets turned off for the night the smart phones work properly again .. I have the router network channels set up for channel 11 for 2.4 network and 161 for the 5 ghz .. Initially I had presumed that by using 2.4 ghz for netflicks.. and using 5ghz for my smart phone would fix this but it still didn't work .. My Dlinkstaff support has set up my router the way they feel should be set up , but have not spoken to a Shaw rep about this for fear 1. of the long wait on the help line ..2. the failure to understand what it is I am looking for .., and 3. the rep possibly suggesting that either the router or the LG blue ray player are at fault and not their own Shaw equipment . .My Shaw account is set for the 30MB download package .. not the expensive 100 , bu5t not the cheap 10-15 MB service either .. Ideas?? except for the cat5 wire would be appreciated .. Thanks !!