The new modem pushes LTE device speeds to 1.2Gbps, bridging the gap with future 5G networks.
We haven’t even seen the first gigabit LTE phones yet, but Qualcomm is already working on the second generation. With its X20 modem, announced today, the dominant mobile chip maker says it can push speeds of up to 1.2Gbps on the spectrum that every US carrier has.
“With X20, we are really expanding the addressable market for this capability,” said Serge Willenegger, Qualcomm SVP for product management. “You only need 10MHz of licensed spectrum, plus LAA, to get gigabit speeds on the new modem. That was really the purpose, to really propagate gigabit as far as possible.”
Fast networks require lots of airwaves. Until now, carriers have been broadening their highways by knitting together different lanes of licensed spectrum. The X20’s trickiest trick is to heavily incorporate LAA (Licensed Assisted Access), which uses Wi-Fi airwaves to supplement carriers’ licensed spectrum. T-Mobile, Verizon, and AT&T have all said they’re working on LAA. Sprint, meanwhile, has so much spectrum in its 2.5GHz band that it may be able to do the 5x carrier aggregation necessary for 1.2Gbps without dipping into the Wi-Fi pool.
The X20 allows carriers to cast off older networks by enabling dual-SIM, dual-VoLTE. That means carriers in countries where two-SIM phones are popular don’t have to lay down or keep maintaining their 2G networks for voice. That encourages new carriers like Jio, an LTE-only carrier in India.
It also supports several new frequency bands that are coming online in the US in the next few years: the 600MHz band, which is being auctioned right now, and the 3.5GHz CBRS band, which is currently being negotiated.
What Does Gigabit LTE Mean?
Qualcomm is pushing hard towards gigabit LTE to bridge the gap between today’s LTE networks and upcoming, multi-gigabit 5G NR (New Radio) networks. 5G NR is designed to operate best on higher frequencies than existing LTE networks, so LTE is going to be around for quite a while. With gigabit speeds on LTE, a fallback from 5G to LTE—especially in the early days of 5G rollouts, which may extend through 2021—feels like a gentle decline and not a precipitous drop.
That means application developers can start working on some 5G-type applications, like VR education and gaming, before the full 5G rollouts happen. The real break will come in latency. LTE networks have much more latency than 5G NR will, so LTE won’t be able to replace NR for applications like autonomous cars.
Also, the X20 and X16 advertise themselves as gigabit LTE, but you shouldn’t expect 1Gbps LTE speeds to every phone—or to any phones, for that matter. The 1.2Gbps speed is a theoretical maximum, and it gets dragged down by network conditions and by older devices on the network. Still, though, Qualcomm has shown that consistent 100Mbps speeds can be possible, which begins to enable new uses like entirely cloud-based applications that are just as responsive as local ones.
The X20 will appear in “commercial products” in the first half of 2018. That may include phones, as it’s almost certain to be part of Qualcomm’s 2018 Snapdragon phone chipset, the successor to this year’s Snapdragon 835.
“Historically, we’ve announced a discrete modem and then we announce the new Snapdragon at some point. Unless something wrong happens, we integrate the new modem into the new Snapdragon,” Willenegger said.
Qualcomm needs to announce these things far in advance to prevent a chicken-and-egg problem from developing with carriers. Now that carriers know what Qualcomm’s modems will support and when, they can spend the big bucks to build their networks with confidence.