Voice on the Internet
In-Stat has just published a report called “Wi-Fi for Voice: Consumer Research Around Wi-Fi Phones.”
The report finds that consumers are unenthused about Wi-Fi-only phones, which is not exactly news. This is of course not a strike against VoWLAN, since everybody will be using VoWLAN on their cell phones in just a few years.
Reuters picked up on one little sentence buried in a Nokia press release entitled “Nokia Demonstrates Leadership in Technologies for Internet on Mobile Devices at Web 2.0 Expo.” The relevant paragraph, in its entirety, reads:
“Nokia Shows Commitment to WiMAX as Web 2.0 Enabler
“Nokia is dedicating significant research, development and intellectual property to WiMAX and supports efforts in making it a global broadband standard. The combination of WiMAX broadband technology and Web 2.0 services offers people an enriched high-speed Internet experience free from the desktop PC. Nokia plans to bring its first WiMAX enabled mobile device to market in early 2008.”
With no apparent evidence, the headline of the Reuter’s story mentioned the word “phone,” and the Internet echo chamber commenced to spawn dozens of stories saying that Nokia is going to release a WiMAX phone in 2008. Actually it looks more as though they are talking about an Internet Tablet like their N800, which is much less exciting.
A Nokia phone based on WiMAX would either have to have a regular cellular radio for the voice channel, or it would use WiMAX for voice. A phone that uses WiMAX for voice would most likely be aimed at a wireless Internet provider that doesn’t have a cellular network, for example ClearWire in the USA. This would put a date on their anticipated entry into mobile voice over WiMAX to compete with the incumbent cellular operators.
But that’s not what the press release says.
In-Stat recently published a report on FMC. It shows most people still relatively uninterested in running voice on increasingly pervasive Wi-Fi networks, though PBX users are intrigued by the potential of dual-mode phones.
Potentially VoIP calls can sound radically better than what we are used to even on landline phones. So why don’t they? It may be lack of will. Some say the success of the mobile phone industry proves that people don’t care about sound quality on their calls. I don’t think this is a valid inference. All it proves is that people value mobility higher than sound quality.
The telephonic journey from mouth to ear, often thousands of miles in tens of milliseconds, traverses a chain of many weak links, each compounding the impairment of the sound. First, the phone. Whether it’s a headset, a desk phone or a PC, the microphone and speakers have to be capable of transmitting the full frequency spectrum of the human voice without loss, distortion or echo. Second the digital encoding of the call; it has to be done with a wideband codec. Third, the codec has to be end-to-end, so no hops through the circuit switched phone network. Finally the network must convey the media packets swiftly and reliably, since delayed packets are effectively lost, and lost packets reduce sound quality.
Discussions of VoIP QoS normally dwell mainly on the last of these factors, but the others are at least as important. The exciting thing about dual-mode cell phones is that they provide a means to cut through them. Because they must handle polyphonic ring tones and iPod-type capabilities, the speakers on most cell phones can easily carry the full frequency range of the human voice. Cell phone microphones can also pick up the required range, and DSP techniques can mitigate the physical acoustic design challenges of the cell phone form factor. Smart phone processors have the oomph to run modern wideband codecs. This leaves the issue of staying on the IP network from end-to-end. The great thing about dual-mode phones is that they can connect directly to the Internet in the two places where most people spend most of their time: at work and at home.
So if you and the person you are talking to are both in a Wi-Fi enabled location, and you both have a dual mode cell phone, your calls should not only be free, but the sound should be way better than toll quality.
Check out the V2oIP website for an industry initiative on this topic.