At an analyst event in San Jose CA hosted by T-Mobile and Qualcomm, T-Mobile US (NASDAQ TMUS) officially launched its nationwide Gigabit Class LTE, demonstrating the speed and network capacity improvements possible using flagship smartphones equipped with gigabit LTE modems.  Currently 17 devices on the market support gigabit LTE, all but one using Qualcomm's X16 modems.

Gigabit LTE, or Gigabit Class LTE as T-Mobile calls it, has three requirements necessary for downlink peak data rates at or near 1 Gbps:

1. Downlink carrier aggregation (CA); three or more bands or component carriers at 20 MHz each (60 MHz or more) are needed to get all the way to 1 Gbps, although less aggregate bandwidth can get your device close.
2. Downlink 4 x 4 MIMO, which means four transmit antennas in a base station sector transmitting to four independent receive antennas in the user equipment.
3. 256QAM modulation in the downlink.

Devices capable of all three requirements, backed by a capable network, can reach downlink speeds up to 1 Gbps (peak), or what is termed LTE Cat. 16 performance.  T-Mobile now offers five such devices, the Moto Z2 Force, Samsung Galaxy S8, Samsung Galaxy Note 8, Samsung Galaxy S8 Active, and LG V30/V30+.  These devices use Qualcomm’s Snapdragon 835 processor with X16 modem. 

• One feature unique to Qualcomm’s X16 modems is that they support licensed assisted access (LAA), which uses LTE over unlicensed 5 GHz spectrum in addition to LTE over licensed spectrum.
• With LAA, Qualcomm says that 90 percent of operators will be able to launch gigabit LTE, even those short of spectrum, as LAA provides additional component carriers for carrier aggregation.

At the event, T-Mobile explained that it now offers LTE-A in more than 920 regional US markets, with Gigabit Class LTE live in 430 of these markets, double the company’s previous gigabit LTE coverage.  In addition, with its latest AWS-3 extension and 600 MHz spectrum additions, the company has expanded its LTE coverage to 321 million POPs.  Gigabit Class LTE from T-Mobile uses carrier aggregation combining the company’s 600 MHz or 700 MHz spectrum with mid-band spectrum (1.7 – 2.2 GHz).

Capacity demonstration, Gigabit Class LTE versus older devices

Backed by Qualcomm, T-Mobile stressed that upgrading the network to gigabit LTE has had two benefits, speed and capacity:

Speed.  Users of LTE Cat. 16 devices experience faster, smoother downloads of videos and photos, and lower wait times for cloud access:

• On average, downloading a movie while boarding an aircraft, for example, takes less than half the time compared to using an LTE Cat. 12 device.
• In one demo, a Cat. 12 phone downloaded three photos.Meanwhile, a Cat. 16 phone next to it downloaded 14 photos in the same amount of time.
• Gigabit LTE can support more than double the simultaneous users of virtual reality without video glitches and lags.
• Even users farthest from a base station tower at the edge of a cell experience higher data rates with a gigabit LTE device, typically 70 percent of what they can experience close in.

Capacity.  Gigabit LTE improves network capacity, improving speeds even for users of older, less-capable LTE Cat. 9 and Cat. 12 devices:

• As shown in the photo, six LTE Cat. 9 devices had an average data rate of 44.3 Mbps in an impressive live demo.The total speed for the six devices, or the sector capacity, in this case was 266 Mbps.
• Switching three of the devices out and replacing them with gigabit LTE devices provided faster data rates for the faster devices, but also freed up network resources and increased the data rates for the three, older LTE Cat. 9 devices. In this case, the aggregate speed increased 54 percent to 409 Mbps.
• Finally, replacing all six devices with gigabit LTE devices upped the average data rate to 112 Mbps, and the total aggregate speed to 675 Mbps.This was an increase of 154 percent compared to using six LTE Cat. 9 devices.

The demos showed that users with gigabit LTE devices can experience more than double the data rates of older devices, and that even users of older phones benefit.  With gigabit LTE, the operator gets increased capacity, better spectral efficiency, less congestion, and ultimately this delivers better real-world speed and service for all users.

At the end of the session, an analyst pointed out one interpretation of all this by stating, “Do the morally right thing, don’t buy an iPhone!”

In response, a T-Mobile official was quick to point out that while they would like to see as many gigabit LTE phones on their network as possible, what features Apple wishes to put into its phones and on what development schedule is up to Apple.  A Qualcomm manager noted that a version of the iPhone X available in Australia on Telstra’s network supports gigabit LTE using a Qualcomm X16 modem, so Apple has not ignored gigabit LTE.

T-Mobile’s announcement makes it clear that gigabit LTE has arrived here in the US, with support by three of the four major operators.  According to the GSA in an October 2017 report, 43 operators around the world now offer gigabit LTE, and 275 have invested in the upgrades needed for it. 

The approach of 5G in 2019 has apparently accelerated the push for LTE-A and gigabit LTE.  Operators eager to embrace 5G will need gigabit LTE as a foundation when users are out of 5G coverage areas, and operators in less of a hurry to deploy 5G will need gigabit LTE to avoid losing subscribers to the competition.

For more about T-Mobile’s spectrum holdings and plans for LTE and 5G, see T-Mobile Adopts 600 MHz for 4G and Nationwide 5G.