Asus is releasing yet another model in the PadFone series—its unique phone-plus-tablet-dock product. If you've never heard of the PadFone, it's a phone and a tablet. The tablet has no processor, ram, storage, or modem; it's just a battery, display, speakers, and a few ports. The phone docks into the back of the tablet like a backpack and seamlessly displays all your apps and data on the larger device. The tablet battery charges the phone when docked.
The new version is an AT&T exclusive (in the US, at least) called the "PadFone X." Details on the specs are pretty slim at the moment, but we know the phone has a five-inch "HD" screen and runs Android 4.4. The tablet has a nine-inch (also "HD") screen, with a brushed metal front, soft touch back, and dual front-facing speakers. We don't have exact numbers for the battery in the tablet, but Asus says it should provide "two times longer" battery life for the smartphone.
The really interesting part of the Padfone is its advanced connectivity features, like Carrier Aggregation, Voice over LTE (VoLTE), and HD Voice. Carrier Aggregation allows the device to use multiple LTE bands from the same carrier at once. AT&T owns LTE bands 2, 4, 17, 29, and 30 in the US, and, while they are not all yet developed in all areas, being able to use spectrum from multiple bands should provide a huge boost to bandwidth. Voice over LTE is exactly what it sounds like: it uses a data connection to make a phone call instead of the legacy GSM voice network. This allows for things like HD Voice—sending your voice over the network at a higher bitrate—and is a big step in sunsetting the GSM network and going all-LTE. While the PadFone X will presumably have a GSM modem, VoLTE will eventually leave devices with just an LTE modem, leading to smaller, simpler internals and lower power requirements.