XLTE is the name given to Verizon's AWS spectrum, which the company initially purchased back in 2012. Akin to opening another lane on a congested freeway, XLTE will open up new bandwidth for those using an AWS-compatible device, which includes the iPhone 5s and the 5c, ultimately resulting in faster LTE speeds. XLTE simply refers to LTE on the AWS spectrum, with Verizon's described speed increases resulting from more available bandwidth.
While not directly beneficial to users of older iPhones, XLTE does have the potential to result in increased bandwidth on the standard 700MHz spectrum used by those devices, as newer devices will automatically take advantage of the AWS spectrum.
XLTE delivers faster peak data speeds and a minimum of double the bandwidth to 4G LTE customers in high traffic areas in markets nationwide where AWS spectrum has been activated.XLTE is currently available in multiple cities across 44 different states, which can be found on Verizon's website [PDF]. According to Verizon's estimates, the newly available AWS spectrum will improve LTE speeds for approximately 35 percent of the active devices on its network.
While XLTE network enhancements are invisible to the customer, the mobile experience is not. XLTE Ready devices automatically access both 700 MHz spectrum and the AWS spectrum in XLTE cities. Customers with 4G LTE devices operating solely on the 700 MHz spectrum in XLTE markets also benefit from the extra capacity created by XLTE Ready device traffic moving to the AWS spectrum.
It is important to note that XLTE is simply a marketing term for LTE on Verizon's AWS spectrum rather than a new wireless standard. It is similar to AT&T's move to call HSPA+ 4G back in 2012 in order to distinguish it from standard HSPA 3G speeds.
Verizon has also announced VoLTE -- or Voice over LTE -- which is set to roll out to its network later this year. VoLTE, much like AT&T's HD Voice, will improve voice quality by allowing users to make calls over LTE.