MBR1515 External Antennas

Help, I am moving to a remote area, my Verizon' phone works good there ,However my MBR1515 Mobile Broadband does not, can i connect a external antenna,s up to this unit , i see there are two antenna,s on the back are they both for broadband tx/rx?? or is one for wi/fi ? if anyone knows what type of antenna and connector i need?I will order one or two as required?, I am not planning to use my wi/fi portion of this netgear device only the internet ,connected to wired PC,s any ideas or help would be such a welcome every one i have asked suggested everything but the correct out side antenna , HELP ,Thank you in advance,Eagerbecky