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Today, nearly every smartphone can connect to both cellular and Wi-Fi networks.  These smart devices are now designed to optimize connections, with automated features to connect to the best connection in a given environment.

So what does this mean when you’re actually using your device?

Generally, voice traffic is carried on the cellular network, and if a Wi-Fi network is available, data traffic is carried over Wi-Fi.  However, smartphones can’t or don’t connect to the cellular network in many business environments and are strictly limited to Wi-Fi connectivity.

This is partly due to the expense of cellular subscription plans for large businesses, poor cellular coverage within the four walls, or the wish to use existing Wi-Fi infrastructure that was not optimally designed.In these situations, smartphones are dependent on the Wi-Fi network not only for data, but also for voice.  Voice over Wireless LAN (VoWLAN) is the term used to describe voice traffic carried over a Wi-Fi network.

When designed and implemented correctly, a VoWLAN solution can deliver high voice quality to mobile users who are solely dependent on a Wi-Fi network for connectivity.  The latest and greatest consumer smartphones you see on TV can be alluring for many who seek voice quality over VoWLAN. But service on these types of devices can often fall well short of the mark for the demands of business.

Instead, businesses should opt for a mobile communications device that is purpose-built and optimized to deliver excellent VoWLAN for enterprise settings.

When talking to a friend or colleague on a typical mobile phone, it’s generally considered acceptable if you have to occasionally ask them to repeat themselves or even if the call drops.  But for on-site professionals, the expectation and need is for a reliable, clear call every time.  The risk of inaccurate patient information or losing a sale is too great.  As such, businesses often look to VoWLAN rather than mobile networks to ensure call quality for their mobile workers.

Why Voice Transmission is Unique in Wi-Fi Settings

When information is delivered over a Wi-Fi network, sometimes data packets (a unit of data or communication sent over a digital network) can get delayed or lost in transmission.  When this happens, these packets are corrected or re-sent.  This process typically takes just a few milliseconds and has no discernible impact on regular applications such as web browsing or transferring files – in other words, any data functionality on your mobile device like sending an email or accessing a webpage is not severely impacted.

However, VoWLAN treats voice traffic as data over the Wi-Fi network, which makes voice traffic vulnerable to the same issues as any other data transmission.  When data loss, delays, or corruption happen to a VoWLAN call, the effect can be much more dramatic, resulting in poor call clarity as well as popping and crackling sounds, or even causing the call to drop.

In order to avoid this problem, the entire VoWLAN ecosystem needs to be implemented and configured in such a way that calls are of the highest quality, handovers between access points are seamless, and that any individual point in the system does not get overloaded.  This results in voice transmissions taking priority over any other network traffic, leading to uninterrupted calls.

To achieve this requires a combination of specialized hardware and software built into the handsets and network access points that only enterprise-grade devices like Spectralink’s Versity have been able to achieve.  Two main factors contributing to the leading voice quality of Versity are QoS with voice prioritization, and AP placement optimized by device hardware engineering.

QoS and Voice Prioritization

Unlike data traffic, voice traffic cannot tolerate unpredictable delays.  In a work environment that relies on high-quality mobile calls, the mobile devices used need to incorporate specialized components to optimize all aspects of the call.

Unfortunately, one of the greatest challenges for smartphones in an in-building work environment is delivering acceptable voice communication leveraging Quality of Service (QoS) when using an organization’s in-building Wi-Fi network.

So, what’s QoS (Quality of Service), and why is it important?  According to TechTarget, QoS refers to “technology that manages data traffic to reduce packet loss, latency, and jitter on a network.  QoS controls and manages network resources by setting priorities for specific types of data on the network… QoS [is used] to meet the traffic requirements of sensitive applications, such as real-time voice and video, and to prevent the degradation of quality caused by packet loss, delay, and jitter.”

Most smartphones do support Wi-Fi functionality, but are typically missing QoS support for prioritizing voice packets; Spectralink enterprise smartphones, however, enables QoS through our proprietary Voice Quality Optimization (VQO) application for voice prioritization.

Seamless Roaming and Hand-offs

Purpose-built enterprise mobile devices are engineered to deliver a continuous, reliable voice connection as a user moves throughout the building or campus.  Users move from hallway to patient room to meeting room while using their devices, roaming from one access point to another during the transition, and need to do so with no loss of packets or degradation of audio quality while on a call.

Here’s where the locations of access points become important.

According to, an access point (AP) is “a device that creates a wireless local area network, or WLAN, usually in an office or large building.  An access point connects to a wired router, switch, or hub via an Ethernet cable, and projects a Wi-Fi signal to a designated area.” To provide seamless connectivity for VoWLAN applications, the access points must be positioned with sufficient overlapping coverage to ensure there are no gaps – or dead spots – between them.

As wireless voice users move throughout the workplace, the device will seek out other APs to roam to in order to maintain the most reliable network connection.  Most consumer smartphones will wait until the signal from the AP they are attached to is very weak before seeking a new one to connect to, which can lead to a dropped call.

A dedicated, voice-optimized enterprise device, however, will constantly seek and roam to the strongest connection available on the network in order to ensure that the device can always be reached and that voice quality remains high.  These phones, like the so that the hand-off – switching from one AP to another – is always seamless, even mid-call.

So what does this mean when it comes down to ensuring excellent voice quality in a Wi-Fi business environment?  Choosing the right enterprise device, like a Spectralink Versity instead of a consumer smartphone, that achieves industry-leading voice quality through engineering-optimized devices, strategically placed APs, and employing QoS technology like our proprietary VQO, ensures crystal clear voice communications for every deskless worker on the move.