Carriers around the country use different frequencies.  It depends upon which licenses they own or with whom they have roaming agreements.  In one area they may use 800MHz and in another area they may use 1900MHz.  How can you determine which frequency of cell signal booster to purchase?  There is a website called www.WirelessAdvisor.com that can give you some guidelines.  Remember, things change and sometimes websites like this may not be up-to-date.

The decision is easy when purchasing a vehicle cell phone booster.  You should always use a dual-band system in a vehicle.  When driving, you will most likely be switched between several towers as you travel through the countryside.  One tower may be 800MHz the other 1900MHz.  Let’s take an Sprint carrier example.  Sprint is a 1900MHz carrier, but if you are a Sprint customer you might find yourself roaming on a 800MHz regional carrier tower.  Bottom line, in a vehicle you should always go dual-band.

Building systems have a different set of variables when selecting a cell signal booster system.  Your system is stationary, not mobile like a vehicle system.  Some carriers favor certain frequencies.  For example Sprint and T-Mobile primarily use 1900MHz.  Alltel used to primarily be a 800MHz carrier, but then it was purchased by Verizon who uses both 800Mhz and 1900MHz. 

The safe bet for any building cell signal booster system is dual-band.  Today you have a Sprint cell phone using 1900MHz.  Next year you switch to Verizon or someone else and you may find your system does not help you any more.  A dual-band system protects your equipment investment.  You might switch carriers or your carrier might switch frequencies.  Either way, you might get stuck if you purchase a single-band system.