Pepwave MAX-BR1-AE-T cellular high ping

I have a high ping on cellular 3g,I have a server on the cellular company and all of my SIM cards are locked on that server so when I connect to that server I get high ping and lag of service some times I get 2500ms ping how could I get a lower ping.

P.S: I can’t change the location of my pepwave MAX-BR1-AE-T my signal strength -79 dbm .