With a shiny new network and state-of-the-art equipment in place, Sprint shifts its focus to local market optimization
By Dr. John Saw, Chief Network Officer, Sprint
July 14, 2014
As we finish the rip and replace of our 3G network, as well as reach 471 4G LTE markets, we now have a completely new platform in place. This is where the fun begins as we shift much of our focus and resources on local market optimization. By optimization, we simply mean the implementation of various technologies and techniques to make our network more efficient and deliver improved performance and faster data speeds. Each cell site within our network is like a single puzzle piece that when first deployed is roughly cut. Our job with optimization is to take a surgical approach to every site and make sure each one fits perfectly into the overall network puzzle.
We’re focused on three areas for network optimization – coverage, interference, and capacity – to achieve the best call quality and data speeds we can deliver. We address all of these areas by making sure each cell site has the correct set of network parameters. Every base station has hundreds of configuration parameters that affect a customer’s voice and data experience, and each of these can be altered to change the behavior of the network. The key thing here is to manage the network locally by having engineers on the ground looking at performance and tending to every site.
On the coverage front, we’re leveraging our tri-band spectrum position to use 1.9GHz FDD-LTE for broad market coverage, 800MHz FDD-LTE for in-building coverage, and 2.5GHz TDD- LTE for coverage in dense urban markets. With market-level optimization, the goal is to make sure we’re applying exactly the right mix of our three spectrum bands to best serve the unique coverage demands of each locale.
In addition to prescribing the right spectrum mix within a market for coverage, our local engineering teams work to minimize interference, one of the primary inhibitors of wireless performance. Many things can cause interference such as the physical landscape (buildings, trees etc.) or too much distance between a cell site and the transmitting device (aka customer). One of the best ways to address interference is to adjust antenna orientations and tilts to ensure strong coverage between cell sites.
Lastly, when optimizing our network we evaluate capacity – the amount of spectrum available to a market – and if needed, we apply capacity to increase data performance. Capacity is added in a number of ways – through a software update, addition of more carriers, aggregation of carriers, and the addition of radios and small cells. This summer we’re excited to begin the installation of 8T8R radios within our 2.5GHz footprint allowing our cell sites to send multiple data streams and achieve better signal strength. Our deployment of 4x2 MIMO at 2.5GHz is also expected to increase data throughput and coverage without requiring additional bandwidth. Even more exciting though is the potential for higher levels of MIMO such as 8x8 which is only possible with the use of 8T8R equipment. While we don’t have plans today for 8x8 MIMO, this is a significant competitive advantage that we could potentially utilize at some point in the future. Lastly, by the end of the year we expect to begin 2X20 (40MHz) carrier aggregation in the 2.5GHz spectrum band, giving us added capacity and faster data speeds.
One example of a market where we’re applying these techniques is Chicago. Last month Macquarie Capital analyst Kevin Smithen spent the day performing speed tests on our new 2.5GHz service in the Chicago area. His conclusion? Sprint consistently had the highest average LTE downstream and upstream speeds among the four major wireless carriers tested, and that Sprint will be in a position to offer a vastly-superior 3 channel 2.5GHz experience in most major downtown areas by mid-2015. Similarly, analyst Jeff Kagan also recently had positive things to say about the improvements we’re making to our network.
Building an entirely new network from the ground up has been a difficult endeavor, but a time in the not-so-distant future is coming when customer demands for bandwidth, and technology changes with 4G and beyond, will require the kind of platform we now have in place. A network is never done and we’re excited about the improved performance our customers are experiencing as we shift our attention to market-level optimization.
The 50-60Mbps peak speeds customers are seeing in Sprint Spark markets are indicative of where our network is headed, and we’re working hard to quickly bring that kind of outstanding performance to customers all across the country.