Asia's Source for Enterprise Network Knowledge

Monday, January 23rd, 2017

Wireless Mobility

The essential components for Wi-Fi calling

The essential components for Wi-Fi calling

As the number of smartphones increases exponentially, people are coming to expect ‘always-on’ services. This is particularly true in Asia Pacific, which contains the largest proportion of smartphone users in the world. Smartphone penetration in countries such as Australia and Singapore is now over 80 percent, and Asian millennials are spending an average of 2.8 hours per day (or 42.5 days per year) on their smartphones.

The scale and speed of this growth is creating added pressures on mobile networks. Mobile network operators (MNO) need to do more to ensure customers are constantly receiving a reliable and robust service that meets their demands.

While mobile operators might take comfort as the market looks towards projected growth, there are other areas of the world that are developing. They are finding new ways to become more resourceful, but this is actually hindering the service provided by MNOs. New buildings are being designed and built in more environmentally friendly ways, and the ‘green’ materials – such as the metal-oxide coating on glass windows – are in fact impeding mobile signals to users inside. This makes it harder for MNOs to deliver the service their customers want (and pay for) which results in a dissatisfied customer base. This is a problem no network operator can afford to have in such a fiercely competitive environment. 

It has quickly become apparent that Wi-Fi can be utilised to solve this issue, and many MNOs have realised that by leveraging existing Wi-Fi networks – which have become ubiquitous already – consumers can still benefit from all of their subscription packages through services like Wi-Fi calling. While voice over Wi-Fi isn’t a new technology, providing carrier-class native Wi-Fi calling is a lucrative option for MNOs. Unlike over-the-top (OTT) services like Skype and WhatsApp, Wi-Fi calling is integrated into the phone rather than via a third party app. However, it does mean that the MNO needs to hand over critical information and deliver services on an infrastructure that isn’t their own. This is a complete change in mindset for operators, as suddenly it means quality of service (QoS) is out of their hands, they have to relinquish control to a wireless infrastructure they can’t guarantee, and effectively, put their reputation on the line.

In order to make sure this doesn’t create a problem, it’s crucial that MNOs invest in a wireless infrastructure that is ready to support a carrier-class service. This is also true for enterprises wishing to build their own, wholly-owned networks. Superior, enterprise-grade wireless networks can be defined by their ability to deliver the following:

High-density, high-performance

There shouldn’t be a dip in coverage or call quality because more clients want to use the network. A strong radio frequency (RF) signal from a smart antenna will help to mitigate interference by continuously optimizing the RF path to the client in real time. The smart antenna ensures the client maintains the highest possible data rates even in poor RF conditions, this helps reduce the negative effects of dropped packets and jitter on real time data traffic.

In high density environments, such as a school, or an office building, directed roaming will help ensure the overall quality of user experience for the entire wireless LAN (WLAN) network. Clients should be directed towards another Wi-Fi access point (AP) that can provide a better user experience. If a signal falls below user-definable signal strength (RSSI) or throughput thresholds, the AP can automatically provide a list of alternatives and request the client to move to an AP with a stronger signal. This solves the problem of clients that stay connected or ‘sticky’ with a given AP, even if it no longer provides the best connection.

Intelligent data prioritisation

However, getting a strong signal is only the first step. Wireless networks need to be able to prioritise data packets to ensure those which require the highest QoS are at the front of the queue. Many data flows are encrypted, especially when it comes to messaging services, so the network can’t identify them correctly. However, smart wireless technologies allow even these encrypted packets to be recognised based on behaviour and classified into one of four queues: voice, video, best effort and background. This is done by looking at the type-of-service (ToS) bits set by the smartphone in the IP header, or by using automatic packet flow heuristics that constantly examine the size and frequency of packets in any flow, encrypted or not.

Smart access control

To some people, being able to connect to the Wi-Fi is enough to convince them that they have a decent signal; however, unless there’s enough bandwidth available or network capacity to support all of the users they may as well not be connected to the network at all. If too many new devices attempt to connect to a given Wi-Fi access point (AP), clients who are connected already may experience service degradation. APs can now implement a capacity-based client access control algorithm to decline connection requests from new clients if the service doesn’t meet their requirements. This allows organisations to protect the user experience during periods of heavy load.

The key to enabling a true carrier-class service is to make use of a carrier class Wi-Fi network infrastructure. This requires smart antenna technology to guarantee the user’s device gets the strongest possible signal, mechanisms to prioritise voice traffic even when it’s encrypted, and call admission control to limit the load. Once all of these components have been addressed, MNOs have the ability to provide superior voice over Wi-Fi services to customers, keeping them happy and ultimately retaining a loyal customer base.

Michael Lok is Managing Director, ASEAN at Ruckus Wireless