Sprint has long held a significant amount of spectrum; it has 204MHz of holdings, including 160MHz of 2500MHz spectrum in the top 100 markets. It has a large amount of high-band (2500MHz) spectrum and smaller amounts of low-band (800MHz) and medium-band (1900MHz) spectrum, providing a good balance between capacity and coverage, but it has so far failed to leverage the full value of its spectrum assets. This looks to be changing: Sprint has finally been making investments that take advantage of its strong spectrum portfolio.
Improving network capacity and coverage with a variety of innovations
At Sprint’s 2017 Analyst Day, John Saw, Sprint’s chief technology officer, mapped out several forthcoming network plans that will take advantage of Sprint’s vast spectrum holdings, specifically its 2500MHz spectrum.
While 2500MHz spectrum is great for capacity, it doesn’t propagate far. Later this year Sprint plans to introduce an innovative solution, which it helped develop, to extend the range of this spectrum. High-performance user equipment (HPUE) will extend 2500MHz spectrum coverage by 30%, to nearly match (within 99%) Sprint’s midband 1900MHz coverage range. In Sprint’s outdoor coverage drive tests, 2500MHz HPUE matched the performance of 1900MHz LTE. While HPUE isn’t set to arrive until later this year, some HPUE-capable devices are already available to Sprint customers, including the LG G6, Samsung Galaxy S8, and ZTE Max XL phones.
Sprint also plans to implement massive MIMO, a wireless transmission technique that uses a massive number of antennas to improve cell capacity, by end-2018. This is something that can only be done with high-band spectrum, making Sprint’s 2500MHz spectrum a perfect candidate. Massive MIMO will offer a significant capacity boost to Sprint’s macronetwork. At Mobile World Congress in February 2017, Sprint and Nokia demonstrated the ability of massive MIMO to boost cell capacity by up to eight times that of LTE, using 2500MHz spectrum with 128 antennas, 64 transmit and 64 receive (referred to as 64T64R). Massive MIMO can also improve antenna beamforming performance and reduce the costs of network build. Sprint says that massive MIMO offers a competitive advantage and that it will be a key to 5G, since those networks will need to handle much more traffic at higher speeds.
Gigabit Class LTE
Sprint plans to offer Gigabit Class LTE, a service that uses three-channel carrier aggregation and 60 MHz of Sprint’s 2500 MHz spectrum in combination with 4X4 MIMO and 256-QAM higher order modulation to achieve Category 16 LTE download data speeds, enabling a 5G-like throughput experience. Sprint plans to offer gigabit-class LTE service in high-traffic locations across the country, which will help Sprint meet future demand for mobile broadband. This is part of Sprint’s strategy to build a strong foundation for 5G by increasing the density of its network with the addition of small cells and smart antennas.
Sprint, Qualcomm, and Motorola Mobility demonstrated gigabit-class LTE at the Smoothie King Center in New Orleans in March 2017. The demonstration used a Motorola device with Qualcomm’s Snapdragon X16 LTE modem, the first commercially announced modem to support gigabit-class LTE speeds. This Motorola device is set to become a flagship phone for Sprint in the future.
5G in 2500MHz
Sprint is planning to launch 5G using 2500MHz spectrum. Sprint, Softbank, and Qualcomm are working together to develop technologies for 5G, including the 3GPP New Radio standard in Band 41 (2500MHz) for accelerated wide-scale 5G deployments. The companies plan to provide commercial 5G services and devices in late 2019.
Ahead of these network innovations and plans, Sprint is working on increasing the density of its network, which will help it prepare for 5G as well. Because Sprint has such a large amount of 2500MHz spectrum, the company was able to dedicate 20MHz of its 2500MHz spectrum to small cells. Sprint’s technologies for small-cell coverage encompass mini macro, air pole, femtocells, strand mounts, and its Magic Box.
Sprint’s Magic Box is a small cell with an indoor sector and an outdoor sector, which uses LTE UE relay for backhaul. The Sprint customer places the Magic Box near a window, where it improves the customer’s coverage and speeds, as well as that of their neighbors. The Magic Box also has a use case for an urban commercial setting.
Finally reaping the benefits of network advantages
Sprint has been talking about its spectrum advantage for years, specifically that linked to its vast 2500MHz holdings. But it hasn’t done much to capitalize on it, having so far failed to leverage its spectrum holdings to attain a better position than its rivals.
But now Sprint seems to be making moves to harness its high-band spectrum for both capacity and coverage, while also preparing for the forthcoming 5G era. And the timing might be just right, with the raging unlimited data wars highlighting the vital importance of capacity. Sprint is improving speeds with carrier aggregation and improving coverage with innovations such as the forthcoming HPUE.
Now we must wait and see whether Sprint executes its plans in a way that finally enables it to reap the benefits of its spectrum position.
Sprint Update, October 2016, TE0001-001059 (November 2016)
US Update, April 2017, TE0001-001082 (May 2017)
Kristin Paulin, Senior Analyst, North & South America