The VoIP industry is expanding at a rapid pace. VoIP is continuing to garner attention from major carriers and service providers who offer audio conferencing services but want to improve audio quality while decreasing the costs associated with the service.

Delivering a high level of voice quality is an important requirement in any VoIP conferencing system, as poor voice quality can cause customers to look at their other communication options. A low level of voice quality can also negatively impact the rate of growth.

Voice Quality Enhancement (VQE) encompasses an integrated set of features designed to improve VoIP quality and formulate the statistics needed for constant performance monitoring. According to a whitepaper from Radisys, titled “Improving Audio Quality in

VoIP Conferencing Services,” this requires sophisticated digital signal processing algorithms that perform rapid real-time IP packet processing, a key component in next-generation VoIP audio conferencing architecture.

The three most common sources of audio quality problems in a network are audio noise, packet loss and echo.

Audio noise is essentially any type of background noise. This can be anything ranging from your pesky neighbor’s dog to people laughing nearby. This factor is enhanced as people conduct conversations anywhere they can get service; including airports, malls, and cars—all locations that are full of have constant interruptions.

Packet loss is dropped or delayed signals, due to high traffic IP networks. Without special technology that is designed to work specifically with dropped packets, the audio signal will sound extremely ‘choppy’.

Acoustic echo occurs when the sound from the receiver’s speaker does not have the correct echo isolation feature and is transmitted back by the receiver’s microphone, which causes a highly annoying vibration sound, with an echo of their own voice after a delay.

Technology to remove audio quality impairments in a VoIP network is an important part of any solution. But along with the functions to improve VoIP quality, service providers also need a standard, objective way to measure voice quality in order to accurately monitor performance. Voice quality metrics provides objective measurements for administering service level agreements (SLAs) and help when trying to discover audio quality issues in a network.

There are two different architectural approaches designed to integrate VQE into the network and a RadiSys (News - Alert) case study entitled “Improving VoIP Conference Quality,” outlines the implications of both. The first approach consists of a dedicated, single-purpose network element located between the subscriber and the network core. The disadvantages to this approach are two-fold. Not only is the price per line extremely high leading to increased service costs, but by requiring a new, dedicated network element, both CAPEX/OPEX (News - Alert) and network complexity are increased.

The second solution outlined in the case study is to integrate RadiSys VQE capabilities into an IP media server, already included in the provider’s network. Integrated into a previously existing network, this conference quality solution requires no new network elements and better addresses the voice quality issues of the IP server. As opposed to the single-purpose network element solution, the RadiSys solution provides a greater level of voice quality at about one-fifth the cost of the alternative.

VoIP in conjunction with VQE can overcome multiple obstacles that come with IP packet networks. RadiSys media servers can work in a single network element and be integrated with VQE, thus elevating the level of end-user satisfaction in next-generation networks and accelerating the growth of VoIP and IMS services. By performing VQE in the same network element, CSPs and their application developers can quickly see many benefits in both economic and technical segments.