Conan Kudo

shared drive

git blame

Name Game

It originally meant "Telefon" (the German word for telephone), as Deutsche Telekom was the telephone company, but it later became "Telekom" (the German word for telecom) as DT branched out into more things (T-Mobile, T-Home, T-Com, T-Online, T-Ventures, etc.).

Blind man

You're referring to GSM1x. It could work, but then Sprint would have to turn off all EvDO, since it wouldn't be supported by it. Handover between the GSM1x system to the CDMA core to enable EvDO would create the same problems. It also would force Sprint to move to SIM based authentication for its CDMA handsets, and older handsets would break, since the GSM1x system uses 3GPP authentication schemes.

I meant 8 bit+8 kHz. I simply forgot that it wasn't also 8 Kbps. Still pretty crappy audio, though.

It's not just Tier 1 U.S. operators. It's everyone who is deploying VoLTE. That includes SoftBank, DoCoMo, KDDI, SK Telecom, LG U+, KT, Hutchison Telecom (d/b/a "3"), T-Mobile International, Vodafone, O2, and others. They are also all preparing for EVS. It'll be easy for them to support the codec, but that won't matter if handsets don't quickly adopt it. It does help that EVS will work on GSM, WCDMA, and LTE, though. PCM sucks compared to members of the AMR and EVRC codec families used over a decade ago. PCM is only just better than the first-generation codecs used in the earliest digital network systems. It is an awful codec to fall down to. And actually, 70% is worse than 0%, because it reinforces an expectation that it should work. If it was 0%, then no one expects it to work, and thus, Sprint's churn rates can't get even worse from voice related problems.

Verizon Wireless, AT&T, T-Mobile US, and all other VoLTE network operators (like VTel, et al) are using the AMR-WB codec now, so anyone who wants to connect to those systems will need to have the codec anyway. So the AMR codec family absolutely will be supported. PCM at 8kbps is pretty horrible. Too many artifacts to make sense of it, most of the time. Regardless of that, the success rate is too low relative to SRVCC between GSM/WCDMA and LTE and call continuity expectations by mobile voice users. A 70% success rate is terrible, given that the current standard of success is well over 98%. Even a 85-90% success rate is considered unacceptable, and that's what we have now with CSFB from LTE to CDMA. The only reason it's even being done is because Sprint can't afford SV-LTE for Spark devices (because that makes them blatantly extremely custom devices).

EVRC-NW is not going to be supported for VoLTE ever. The 3GPP has indicated it has no intent to add support for the EVRC family, and 3GPP2 has fallen apart over the last 18 months (useful activity has dropped to nearly nothing these days). The only codecs supported for VoLTE at this time are EVS (in draft process now), the AMR codec family, the GSM codec family, and PCM. Potentially, Opus will be added in order to support interworking with WebRTC, which declares Opus as a "mandatory-to-implement" codec for the technology. If Sprint was to do VoLTE now, it'd have to use the AMR codec family to provide a high-quality voice service.

Ah, you're right. VoiceStream acquired CIVS I to bring that network into the fold for Seattle-Tacoma.

At this time, that's not possible. I also find it extremely hard to believe that Sprint will be able to do it, especially when no one else has been able to get it to work (or wants to anymore). SRVCC does not support continuous transcoding, which is required for compatibility with EVRC codec family. The roaming mechanism could support it, but it would be EVRC encoding PCM, which doesn't afford any benefits except compressed bandwidth. If it could be done without unacceptably high failure rates, I think Verizon, KDDI, and others would do it. Since it isn't, they don't want to touch it. It would degrade the quality of the network experience for customers, which they definitely don't want. It's already hard enough to keep customers from leaving to GSM/UMTS operators, they don't want to make it worse by impairing the quality of their voice systems even more.

Not without some really messy breakages. Essentially, because the two systems use totally different core network platforms (as opposed to GSM/UMTS+LTE systems), making the two systems establish seamless voice handover is so technically challenging that it is not practical to make it work. That said, some work was done two years ago to establish a prototype mechanism for it. It works by treating the CDMA network as an visitor network and using the roaming handover mechanism to transfer the call. By doing so, however, the call drops to the lowest common codec: PCM. So HD Voice and all the other stuff is gone. What's worse is that the prototype didn't work very well in testing, with extraordinarily high failure rates (>20-30% of all calls failed to transfer). In the end, the CDMA operators who were driving the development of the idea killed it because of the unacceptable quality. Verizon and KDDI went on to just roll out VoLTE without any form of interconnection with the CDMA network layer.

T-Mobile's network in the NY-NJ-CT area was constructed by its predecessor: Omnipoint Corporation. John W. Stanton's VoiceStream Wireless acquired Omnipoint in 1999 and later executed an agreement to take full ownership of American Personal Communications' (marketed under the Sprint Spectrum brand) GSM facilities and spectrum for Washington-Baltimore and Seattle-Tacoma from Sprint PCS, which completed in January 2000. Edit: Seattle-Tacoma came from CIVS I (Cook Inlet/VoiceStream PCS JV), not Omnipoint

T-Mobile affiliate iWireless is a member of the CCA. Its coverage is represented in the CCA coverage map.

Most likely not, since it was developed before February 11.

What liquidity? Sprint has been negative FCF every quarter for some time now. And the operating cash reserves dipped into the red late last year.

Nexus devices are special in that they are intended for developers, and thus are not considered "iconic" devices. Thusly, that very scenario is quite likely.

Probably not, as it's all still dependent on that whitelisting system.