Sprint have a network quality reputation. The carrier is seen as traditionally lagging behind AT&T and Verizon Wireless, in a similar way to T-Mobile US, when it comes to providing cellular coverage. This has resulted in slower data transfer rates and more areas of no coverage – unless you live in Denver, that is, where the carrier has successfully trialled its aggregated spectrum networking plan, which combines some of Sprint's existing spectrum with the 2.5 GHz spectrum is acquired from the Clearwire deal back in 2013. Carrier aggregation combines two or more bands of spectrum operating at different frequencies in order to improve data performance. We can liken it to using a garden hose to fill a bucket: if we combine two or three garden hoses of different diameters, we may almost double or triple the flow rate. In order to use carrier aggregation, your device needs to support all of the necessary frequency bands that your carrier is operating on plus you'll need the right software.
There are other benefits to customer beyond those compatible devices benefitting from a performance boost. Another improvement is that those devices not supporting carrier aggregation can potentially benefit from faster network transfer speeds if the carrier is able to better utilize the different frequencies. Essentially, Sprint's network can offload some network traffic onto their newly deployed 2.5 GHz frequency and away from their traditional LTE frequencies. This effect works very well in areas of network congestion, where installing a 2.5 GHz network can release a bottleneck and improve network performance for all customers.
Another benefit is that because Sprint already has a cache of 2.5 GHz spectrum, it is not participating in the up-and-coming 600 MHz frequency auction that the FCC is launching in the New Year. There are some very important differences between the 600 MHz and 2.5 GHz (2,500 MHz) frequencies: chiefly, the higher the frequencies, the higher the potential network performance but the poorer the signal propagation. In other words, Sprint's new 2.5 GHz network will require more masts for the same population coverage as the signal is easily blocked by walls and solid objects. We have already written about Sprint's network densification plan: that is, saturate the ground with masts so as to provide the best possible network experience for customers. Sprint's Chief Executive Officer, Marcelo Clare, spoke about the Denver network improvements earlier in the month: "Denver is a microcosm of what we want the rest of the country to be.Denver was already pretty dense and we decided the sites the way I want to see the rest of the country… if you combine spectrum, large blocks of spectrum, you combine that with a densification of the network, and you combine that with carrier aggregation, to basically 2CA, then we have the ability to have the best network in those specific markets. And the new iPhone that's launching in 7 days is going to have two carrier aggregation, which is something so important to Sprint." Sprint's aim is to be the first or second network, as judged by network quality, in 80% of American cities by the end of 2017. This will require an aggressive network optimization strategy but the early Denver results are impressive (and in the most recent RootMetrics survey, Sprint scored the highest). We will have to see how quickly the other carriers are able to buy and deploy their 600 MHz spectrum.