The quality of VoIP services, in terms of both audio reception and service reliability, has long been a sticking point for the industry.

Among wired networks, the problem is bad enough. But for wireless providers looking to deliver IP services, not to mention their enterprise customers, there is an even greater hesitancy to jump into a technology that may suffer from quality degradation along with potential security flaws.

But some vendors are looking to overcome those doubts through the use of the new Evolution-Data Optimized (EV-DO) wireless networking technology. It is a wireless standard used by many CDMA providers, particularly in Asia and Eastern Europe, that is just starting to makes it way to the United States.

Among the first North American providers to deliver a commercial EV-DO network is Sprint, which recently launched service in San Diego using the Revision A framework of the standard. The company plans to launch in 20 additional markets by the end of 2006, which gives some indication of the confidence Sprint (News - Alert) has that the technology will gain rapid market acceptance.

Sprint reports that its network delivers upload speeds in the 300-400 kbps range, with downloads topping 800 kbps.

That offers a lot of bandwidth for IP voice communications, along with a lot of other applications, but there is still a lack of accountability when it comes to delivering the quality of service (QoS) levels available in many other services.

Within the past week, however, a company called Airvana Inc., based in Chelmsford, Mass., demonstrated a QoS-enabled mobile-to-mobile VoIP system carried across an EV-DO Rev. A network.

The system utilized a pair of handsets based on QualComm’s MSM6800 baseband ASIC, plus related software. The goal was to establish a QoS-based call over delay-sensitive and low latency data flows in a commercial-grade Rev.A environment.

“VoIP is a highly delay-sensitive application, and delivering VoIP over an IP-based wireless infrastructure requires sophisticated QoS techniques,” said Vedat Eyuboglu, Airvana’s CTO, in a press release. “Our demonstration of VoIP on Airvana’s QoS-enabled commercial EV-DO Rev.A network infrastructure is a significant step towards commercial VoIP services over EV-DO Rev. A.”

Airvana has been developing products for the EV-DO market for a number of years. The company gained notice a while back by combining CDMA2000 1xEV-DO technology with an IP-Radio Access Network architecture to deliver a carrier-class service for a wide range of mobile broadband applications.

In targeting VoIP services, the company established a Multimedia/VoIP laboratory to test commercial IP-based mobile broadband technologies, focusing primarily on fixed mobile and 1xEV-DO Rev. A applications. A key hurdle to overcome is maintaining QoS levels to individual call performance, particularly when voice and data packets converge into a single network.

The lab is currently evaluating live VoIP calls in mixed-load networks, methods to boost symmetry and latency reduction, and simultaneous voice/video/data triple play technologies.

“Rev. A promises to deliver a new breed of performance on CDMA2000 networks,” said Roberto Padovani, CTO for QualComm in a press release. “The VoIP Lab serves as a viable proving ground for operators preparing Rev. A upgrades.”

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Arthur Cole is a freelance journalist specializing in the high-tech communications and information field.

VoIP Quality of Service