Is "Basic" Wi-Fi Offload Good Enough?

The latest Cisco Visual Networking Index (VNI) forecasts a 13-fold increase of mobile data traffic between 2012 and 2017. The report also predicts a significant increase in data offload to Wi-Fi as operators deal with the network stress associated with this traffic.

wi fi quality of experience blog article

Offload Challenge: Data and Subscribers Are One

While data offload has become a priority for mobile operators around the world, many are discovering a wide variety of approaches, with pros and cons to each. When it comes to developing a traffic management strategy, it’s important to balance capacity gains with overall quality of experience (QoE). Operators aren’t just moving data, they’re moving subscribers; if network performance is poor or connections are clumsy over Wi-Fi, customer satisfaction declines.

Data Offload: You Get What You Pay For

Basic Wi-Fi offload models use simplistic algorithms, such as a received signal strength indicator (RSSI), to make data offload decisions, but they do little to ensure quality of service. For example, a Wi-Fi access point may beacon a strong radio signal, indicating that it’s a good candidate for data offload; however, there may be internal network problems, like faulty switches or broken backhaul links, which prevent users from accessing the operator’s core network. With basic Wi-Fi offload, operators have no visibility into these QoE-affecting conditions. In this scenario, subscribers may be frustrated by the fact that they can connect to a Wi-Fi access point, but can’t access any data.

More advanced data offload models assess and enforce quality of service (QoS) policies. They can automatically detect problems with access equipment or the core network, making them temporarily unavailable to subscribers, to ensure customers are connected to a good data connection. This “blacklisting” of Wi-Fi access points, based on dynamic conditions, is an example of how an intuitive data offload approach can prevent a poor user experience.

Traffic Management: Problems You Don't Know You Have

As operators look to Wi-Fi as an integral part of their network strategies, they must remain acutely aware of the significant differences between simply offloading data and intelligently managing traffic. What seems like a cost-effective approach today may result in a much higher cost down the road, as network demands and user expectations increase.

A good analogy is a limo driver equipping his Town Car with four mini-sized spare tires. The mini spares are cheap and easy to install, but after about 100 miles, they’ll be trashed and need replacing. Even worse, the passengers who rode in the limo would have a horribly bumpy ride, and avoid that limo service in the future. The driver would be much better off taking a longer term view and investing in the steel-belted radials that ensure a safe, smooth ride from the get-go.

What to Consider in a Data Offload Approach:

  • Will the strategy ensure the same QoE over all networks (3G, 4G, and Wi-Fi)?
  • Will it support offloading to home and office Wi-Fi networks, where most Wi-Fi connections occur?
  • Will it address signaling traffic and support application-based network policies?
  • Will it provide closed-loop reporting to continuously monitor and improve QoE, even off the operator network?

These are just some of the factors to be considered in developing a traffic management strategy that includes offloading data to Wi-Fi. Do you have others? Please share them on the message board below.