Wireless/Mobile Voice Quality

Who owns your customer experience?

And who is your customer going to blame when things go wrong?

The world of voice communication is becoming more complex. Despite consolidation in the industry, device and IP telephony proliferation are making it more difficult to engineer for high voice quality. These two trends introduce impairments that are beyond the physical boundaries of your network - but direct impact your customers’ experience.

Ditech Networkshas created unique tools that provide wireless carriers the capability to both improve and monitor the voice quality of your customer’s experience.

Voice Quality Assurance (VQA™)

Unmatched suite of voice improvement capabilities

Experience Intelligence™ (EXi)

Customer experience metrics to improve network performance management

The Advantage of Excellent Voice Quality in Wireless Networks

In the increasingly competitive voice services market, wireless operators must explore new ways to increase profits while reducing costs. Alongside capital and operating expense concerns, there are issues of customer retention and pressures to improve network capacity and service quality as ways to increase revenue from existing users, as well as attract new ones.

Investing in better voice quality for mobile calls is a cost-effective way of improving customer satisfaction, increasing network capacity with minimal capital investment, and gaining competitive advantage by presenting subscribers with a powerful service differentiator.

Ditech Networks’ Voice Quality Assurance (VQA™) solutions improve the voice quality of communications networks for service providers who want to boost customer retention, increase revenue per user, and grow their business. Our full line of voice quality enhancement and echo cancellation solutions leverage our technical expertise with industry-leading service and support to enable operators to improve voice quality, reduce costs, and realize greater profits.

Ditech’s VQA technology includes algorithms of specific benefit to mobile networks. Acoustic Echo Control (AEC) eliminates even the most severe non-linear, non-stationary echoes that may be present in mobile networks. For mobile calling environments, which typically have high background noise, Ditech’s Adaptive Noise Cancellation (ANC) technology features a high-precision noise reduction algorithm that removes unwanted noise components by up to 21 dB, dramatically improving voice quality. VQA technology also provides Enhanced Voice Intelligibility (EVI), which compensates for high levels of ambient noise in the listener’s environment by dynamically tuning the incoming speech’s spectral characteristics, thereby improving the listening experience and conversational quality.

Ditech has a range of complete voice quality solutions specifically designed to improve the quality and capacity of mobile communications in all networks, including CDMA, GSM, 3G, and iDEN.

GSM Association AwardProduct of the Year

Experience Intelligence™ (EXi) Technology

Ditech's EXi solution introduces the ability to measure a comprehensive range of voice quality impairments including echo, background noise, and speech level on every call in the network. EXi on Ditech's mobile voice processing platforms provides perceptual quality scores for each call using Telchemy's VQmon™ technology, an extended form of the ITU-T G.107 E-model. Overall, EXi provides operators with a concise and trusted metric that makes it possible to consistently manage the customer experience across the entire network.

Ditech has worked with wireless carriers to perform network quality audits that help identify the level of impairments that exist in their networks. Using VQA technology, Ditech can then remove the identified impairments.

CDMA Networks

Code Division Multiple Access (CDMA), one of the major wireless standards available today, has opened the door to a new generation of mobile communications products and services. Using digital encoding "spread spectrum" Radio Frequency (RF) techniques, CDMA breaks up speech into small, digitized segments and then encodes them to identify individual calls. CDMA allows wireless service providers to pack more digital signals into a particular slice of the radio network, enabling a large number of users to share the same band of spectrum, which greatly increases system capacity.

At the same time, CDMA networks face a number of impairments that require voice quality improvement. For example, connectivity to the Public Switched Telephone Network (PSTN) and the use of inexpensive handsets makes hybrid and acoustic echoes prevalent, causing degraded service quality. In addition, CDMA networks are subject to the ambient noise present in mobile environments. Amplification from a user’s handset microphone can intensify background noise, exacerbating the noise problem on a call and further degrading the voice quality for the talker and the listener. Another voice quality problem faced by CDMA and other wireless networks is the transfer that occurs when signals travel between different networks, making voice levels too high or too low for optimal listening comfort.

Enhancing Voice Quality in CDMA Networks

Ditech’s Voice Quality Assurance solutions resolve these issues. In the CDMA network, Ditech’s voice processor platforms can be deployed between the Mobile Switching Center (MSC) and the PSTN. In this configuration, both hybrid and acoustic echoes can be cancelled, and high background noise and level controls can be adjusted. Ditech’s VQA technology solves CDMA networks’ unique challenges and improves the way voice calls sound with the following features:

For CDMA networks, Ditech also offers a CDMA Capacity solution, an Echo Cancellation solution, and an Advanced Echo Cancellation solution. Please contact us for more information.

GSM Networks

Global System for Mobile communication (GSM) is the major digital mobile telephone system covering nearly every nation in the world. As GSM networks continue to evolve, many carriers face the challenge of providing additional network capacity to accommodate rapid subscriber growth and demands for new services. In addition, capacity issues worsen during peak hours, especially in densely populated metropolitan centers.

One method of cost-effectively increasing capacity on GSM networks is the utilization of Half-Rate (HR). HR vocoders provide an economical channel capacity solution, but they have not been widely deployed because they are associated with degraded voice quality. HR creates additional voice channels but is more susceptible to noise impairments, degrading the quality of voice services. Signal strength, ambient noise, and the effects of tandem speech transcoding also reduce the sound quality of voice calls.

Full-Rate Voice Quality for GSM Half-Rate

Ditech Networks’ voice quality products address these impairments and assure optimal voice quality performance in GSM networks. Ditech’s GSM solutions are specifically designed to enable the deployment of Half-Rate vocoders in GSM networks while improving voice quality of all codecs. In live network subscriber tests, VQA technology has shown significant improvement in voice quality scores for wireless networks, especially in the HR mode, which is more susceptible to ambient degradations.

Ditech’s voice processing platforms are compatible with GSM A-Interface-specific features such as TFO (Tandem Free Operation) and HSCSD (High Speed Circuit Switched Data). Ditech’s Voice Quality Assurance solutions solve key quality challenges for GSM operators, including the following voice quality features that enable GSM operators to improve and manage the quality of calls made on their networks:

For GSM networks, Ditech also offers a GSM Capacity solution, an Echo Cancellation solution, and an Advanced Echo Cancellation solution. Please contact us for more information.

3G Networks

The evolution of third-generation (3G) technology heralds a new era for mobile communications, signaling a shift in focus from voice-only communications services to the delivery of a wide range of multimedia, content-rich information applications. When fully evolved, 3G wireless capabilities promise to increase efficiency and improve the performance of mobile wireless networks by enabling service subscribers to make a phone call, shop on the Internet or watch a video clip, all at the same time from one portable multimedia device.

Widespread deployment of 3G networks may not be realized for several years, and voice service continues to be the major use of this forward-looking technology. Service providers, however, need to be ready to take advantage of the unrestricted communications opportunities offered by this advanced technology while continuing to address the voice quality needs of current service customers. Ditech Networks’ voice quality enhancement and echo cancellation products enable service providers to provide superior voice quality for current subscribers while preparing for the future demands of the 3G revolution.

Similar to any wireless network, 3G network users encounter echo, noise, and voice intelligibility impairments that affect the perceived quality of the call. 3G networks are plagued with acoustic or non-linear echo paths. Because the echo return paths are non-stationary, it is more difficult to locate and fix the problem. The high levels of background noise common in all wireless calls are also a problem in 3G networks, as they significantly reduce the sound quality of calls for the end-users.

Superior Voice Performance for 3G Networks

Ditech’s voice processing platforms provide voice quality improvement and fit into the network at the point where voice traffic is converted from packet to PCM at the Media Gateway (MG). Ditech’s Voice Quality Assurance solution for GSM is compatible with 3G-specific features such as TFO (Tandem Free Operation) and 3G Streaming Video Transparency (ITU H.324). Ditech’s VQA solution includes the following voice quality features that enable 3G operators to improve, measure, and manage the quality of calls made on their networks:

All voice improvement features are automatically disabled in the presence of high-speed data applications such as 3G circuit-switched video, allowing the delivery of advanced 3G services without the need to configure special bypass circuits for these calls.

For 3G networks, Ditech also offers Echo Cancellation and Advanced Echo Cancellation solutions. Please contact us for more information.