We have had a Verizon wifi modem for years without issue until the device died a month ago and we had to buy a replacement. Of course Verizon doesnt stock them and it would be 2 months until they had one. So I bought one on Amazon. But now my daughter cant connect from upstairs and has to bring her laptop downstairs to connect to the router. I noticed the new modem does not have the 2 antennas on the back like the old one but it has a place for them. the manual says they are optional but I cant find a place to buy them. How do I boost the signal strength so it internet works upstairs again?