Wireless Broadband Router MN-500

I have been using the wireless broadband router MN-500,
with the wireless notebook adapter MN-510 for almost two
years. As of today, I cannot get any signal strength
anywhere in my house except right next to the router.
Even that signal strength is only good. Just ten or
twenty feet away, no connection at all. I have been using
it two floors away for almost two years, without trouble.
We have added no new electronic devices, phones, etc. in
the last day. I also tried changing the channel on the
router and then the laptop, but that didn't help either.
Is this likely a hardware failure issue?

Thanks