BOSTON -- Oracle Industry Connect -- Sprint CEO Dan Hesse revealed in his keynote here Tuesday that the operator is ready to launch its HD Voice service across the US in July.
HD Voice increases the clarity of a voice call across seven octaves, as opposed to the four octaves that many current smartphones support. Sprint seen some delays to the service, which it first expected to have available in 2013, it is so far only deployed in a few markets like Kansas City. (See Sprint Commits to Tri-Band, HD Voice Phones, Sprint Bringing Spark to Kansas City, and Sprint Delays HD Voice Launch to Q2.)
"Voice is still the killer app," Hesse told the crowd.
"Some of you may have experienced [HD Voice], we've launched in a few markets," he said. "We'll launch the entire country around the first of July."
Hesse also took the time to try and explain Sprint's "Spark" 4G update plans. "I'm told this is a technical crowd," he said.
As the image above shows, Sprint is using its Clearwire-derived 2.5GHz spectrum for LTE speed and capacity. The 1900MHz 4G portion gets more coverage and capacity, while the 800MHz LTE signals go a long way for better coverage. (See Stephen Bye: Sprint's Network Visionary and Igniting the Future: Sprint Spark.)
Hesse says that Sprint can also eek more range out of 2.5GHz LTE TDD spectrum with "8 transmitters and 8 receivers in one box" (8T8R) at the cellsite and MIMO (multiple antenna arrays) on the device.
Combining this with carrier aggregation -- bonding unrelated radio channels for a fatter pipe -- could give Sprint 120MHz of spectrum to play with in the second half of 2015, Hesse said.
"That's two big channels of 60MHz," he adds. "We're talking 18 months away."
The company expects that this update could lead to device download speeds of 150 Mbit/s to 180 Mbit/s.
Hesse told them that this is what justified the company's buyout of long-time partner Clearwire, access to 90MHz of 2.5GHz spectrum across the US. "You need these super big highways and that's why we spent all the money for Clearwire," he said. John Saw, former CTO of Clearwire, and the man behind the company's LTE strategy, has just taken over as chief networks officer at Sprint. (See John Saw to Become Sprint Network Boss.)
— Dan Jones, Mobile Editor, Light Reading
The difference between narrowband (G.711/G.729/AMR) and wideband (G.722/AMR-WB) is substantial, definitely worth the effort.
The difference between wideband and "super-wideband" (G.719, SILK, some modes of Opus or AMR-WB+) may not be a dramatic for the purpose of voice.
Some time ago I was asked to give a presentation at Astricon about the implementation of Polycom's Siren codes in Asterisk. That presentation included some recorded comparisons between narrowband, wideband and super-wideband in several languages. They can be found online here:
http://www.mgraves.org/2009/10/asterisk-hdvoice-hearing-the-siren%E2%80%99s-song-part-2/2/