Today, most smartphones can connect to mobile (cellular) or wireless networks for both data and voice communications. In many environments where smartphones are unable to connect to the mobile network, the smartphone relies on Voice over Wireless LAN (VoWLAN) for voice communications. Seems simple enough, but many consumer-grade smartphones are not able to deliver the voice quality required of in enterprise environments, especially in industries like healthcare, retail, manufacturing and hospitality.

Challenges with Consumer Smartphones and Voice Over Wireless LAN

Voice communication over Wireless LAN is dependent on the Wi-Fi network and the mobile device, so both need to be implemented and configured to optimize the quality of voice calls. From the mobile device perspective, here are the main considerations:

  • Seamless hand overs between access points
  • Prioritization of voice transmissions over any other network traffic
  • Network load and Call Admission Control (CAC)
  • Optimization for third-party voice/Unified Communications (UC) apps

Consumer-grade smartphones are primarily designed for mobile voice calls and data, and do not have the capability to maintain a continuous Wi-Fi voice call while a user is mobile.

Even within environments that implement best practices in Wi-Fi networks for VoWLAN, most consumer smartphones do not have the intelligent Wi-Fi network scanning capability to look for available access points to keep the audio from dropping during a voice call versus enterprise-grade wireless smartphones.

That’s why consumer smartphones often have large gaps in audio. In this example, the mobile user is counting 1, 2, 3, 4, 5 but the numbers 2, 3 dropped. What if in a hospital a doctor and nurse are having this conversation and the doctor is prescribing 250 mg of antimicrobial medication and the nurse only hears 50 mg? Patients could be at risk, but not only that, audio gaps are frustrating for both employees and customers. Most smartphones support Wi-Fi functionality, but this support is optimized for data - not voice - and is typically missing key features such as Quality of Service (QoS) support for prioritizing voice packets.

To manage network load, Call Admission Control (CAC) allows access points to manage its network load based on traffic requirements submitted by requesting devices and rejects if there are insufficient resources. Mobile devices provide the expected traffic data to help voice transmissions be admitted onto the Wi-Fi network. The growth in UC by enterprises adds a layer of complexity to VoWLAN quality for mobile devices. The study by 451 Research showed the benefits and productivity gains for companies deploying UC capabilities to their mobile workforces. To leverage UC capabilities, smartphones must run the UC call platform mobile apps such as Microsoft Skype for Business, Cisco Spark, Avaya One-X Mobile or Broadsoft UC-One. These UC apps give smartphone users an integrated collaboration experience with presence, IM, voice and video capabilities. Note that even with the growth of UC capabilities, voice quality is still the most important reason enterprise customers select a mobile device vendor*.

Most consumer smartphones are not equipped for voice optimization for third-party UC voice apps that run on their devices. This impacts mobile users’ ability to have quality voice over WLAN. Spectralink Voice Quality Optimization (VQO) for Third-Party Voice/Video UC apps For enterprise use, Spectralink Voice Quality Optimization (VQO) is an engineered system that enables voice prioritization and seamless handoffs to access points while the user roams delivering superior voice quality over in-building, enterprise Wi-Fi networks. It is a key component of every Spectralink mobile device.

With the newest software release of Spectralink PIVOT smartphones, VQO has been extended to optimize third-party UC voice/video apps. Spectralink VQO software has the additional technology to automatically detect that third-party application is placing a voice or video call and will automatically apply its roaming algorithms, to enable roaming and voice prioritization for those third-party voice/video/UC applications. This is especially great news for enterprise wireless mobile users that are leveraging vertical applications and UC applications in their workplace.

Announcing Spectralink Voice Quality Optimization (VQO) 2.5 for PIVOT Smartphones – for more information click here (link to

*Walker Consultant Study 2015

Spectralink VQO White Paper

By Linda Zwicki

Sr. Product Marketing Manager


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