Cellular backup connections

Hi All, I finally got around to setting up a cellular backup device in our new POP. I am currently testing with T-Mobile where the cell signal strength is at 80%. The connection is 4G. When SSH'ing in remotely the connection seems rather slow. Ping times seem to be all over the place (for instance now I am seeing: rtt min/avg/max/mdev = 174.142/336.792/555.574/99.599 ms) . Is that just cellular or is that more related to the provider and the location where I am? I could in theory test with VZ and ATT as well. With Verizon they charge $500.00 just to get a public IP and I want to avoid that if possible. Thanks and sorry in advance if this is off topic.