Nextel I580, do I need to be subscribed to Nextel for my carrier?

I posted here a couple years ago regarding my new LG phone. I can't stand it and I want to go back to Motorola. I'm up in Canada and my cell phone provider is Telus and they have an assortment of phones that, with renewing my contract, are offered quite a bit cheaper than the regular price. However, I don't want to be a clone with another RAZR or subpar LG....so I have been browsing other phones. The Nextel (Motorola) I580 really caught my eye from the article in PC Magazine...due to its rugged design (I work in a trade) and its great reviews and most importantly the ability to actually capture and hold a signal (which my LG just cannot do very well).

So, can I buy this phone and use it with my carrier or will it not work due to technical issues?

Thanks in advance

If you want to use the Motorola i580, You need to be a Customer of the Telus MiKE network.