HOLLYWOOD BEACH, Fla.--Sprint (NYSE:S) CTO Stephen Bye said there is no "silver bullet" in terms of what the carrier and its peers are doing to architect their networks to handle increased mobile data.
"We're going to have to push the envelope in every direction," he said during a keynote appearance here during the PCIA wireless infrastructure conference. He said that as Sprint continues to deploy its LTE network, it will turn to a variety of techniques to help it manage increasing data traffic. The comments are notable considering Sprint continues to offer unlimited data services, while its main rivals have switched to metered data pricing structures.
Specifically, Bye said Sprint will use bandwidth aggregation (which could be carrier aggregation via LTE Advanced standards), higher-order MIMO antenna technology, and also coordinated multi-point (CoMP) transmission, which improves spectral efficiency and cell-edge user performance in LTE Advanced.
Bye also said that no matter what, Sprint and other carriers need to "make sure the marginal cost per gigabyte is coming down as we deploy these technologies." He said that as Sprint deploys LTE and makes its network more advanced, "we need to make sure there is a return on that invested capital."
By the end of the year, Sprint aims to cover 200 million POPs with its 1900 MHz LTE network. The carrier is also working to launch LTE on the 800 MHz spectrum freed by the shuttering of its iDEN network. Sprint also plans to launch a nationwide TD-LTE network on the 2.5 GHz spectrum it now owns through its purchase of Clearwire earlier this year, and is currently evaluating vendors for that effort. Sprint expects to launch TD-LTE on 5,000 Clearwire sites by the end of this year, and expand that to all of its 38,000 Network Vision cell sites starting next year. Sprint has said its TD-LTE network will eventually require more sites beyond that 38,000 figure since 2.5 GHz signals don't travel as far as lower-band signals.
The Sprint CTO noted that Sprint is using FDD-LTE on its 800 MHz and 1900 MHz spectrum and TD-LTE for its 2.5 GHz spectrum." It really gives us the best of both," he said. Bye noted that given the asymmetry of traffic flows, with more people still downloading content than uploading it, "obviously TDD has tremendous opportunity to be able to absorb that traffic as well."
"All three bands are much greater than the sum of the parts," Bye said.
Bye also said that Sprint thinks small cells will continue to be a key part of its network. Further, he said Sprint's parent company SoftBank is helping it explore the benefits of cloud RAN architectures, which he said can inexpensively deliver dynamic management of inter-cell interference, better cell-edge performance and improved spectral efficiency.
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