Wi-Fi can be a welcome relief for networks that are overwhelmed by mobile data traffic, and some mobile network operators are exploring carrier-driven Wi-Fi offload. Moving a user off the network may seem counterintuitive, but in today’s pricing environment it often makes sense. Most customers buy their data in “buckets” rather than by the gigabyte, so moving them to Wi-Fi may not cost the carrier anything. But keeping the user on an overloaded 3G network may result in a bad experience, and could eventually cost the carrier a customer.
To make the most of Wi-Fi offload, carriers need to know which users are moving to Wi-Fi, what their quality of experience is, and what applications they are using. If Wi-Fi is a “black hole,” operators will not know whether users are having consistent experiences, and they will not know whether the Wi-Fi network is supporting the high-bandwidth activities that users expect from Wi-Fi, like streaming video and sharing large files. According to Cisco, the world’s leading vendor of Wi-Fi network equipment, visibility is increasingly important as Wi-Fi supports multiple devices and activities simultaneously.
“It also allows the enterprise or the service provider to apply a policy so latency-sensitive applications like voice or video get a higher priority … over something like Web browsing,” said Rad Sethuraman, senior director of product management at Cisco. These are similar to the policies that mobile network operators may use in their cellular networks, but they are not integrated.
“Today, from a policy standpoint, the Wi-Fi is handled separately from the mobile core,” said Sethuraman. But integration could be around the corner. Sethuraman said that Cisco is adding a small cell module to its Wi-Fi access points. The company has recently partnered with small cell maker SpiderCloud Wireless, and is offering SpiderCloud’s solutions to its customers.
Knowing when to offload traffic
Wi-Fi networks may be a relief valve, but they can also become overloaded. Access points will “listen” before they “talk” so they may not connect to a device if other access points are using the available spectrum. Equipment vendors like to point out that Wi-Fi operates in spectrum that is unlicensed but not unlimited.
Service providers can use real-time network intelligence to know whether or not devices should try to connect to the network. Smith Micro Software’s cloud-controlled software dynamically pushes policy to devices, based on input from other devices on the network. For example, if one subscriber tries to connect to Wi-Fi and has a bad experience, the next subscriber to approach that hot spot will stay on the LTE network.
“It eliminates that manual step of the operator needing to look at analytics, evaluate analytics, understand what’s happening and then manually push policy,” said Carla Fitzgerald, CMO at Smith Micro Software. “My device’s experience can update the service and it can dynamically push a new policy out to any devices in the geofence.”
Understanding the quality of available Wi-Fi is key to network operators, but as offload becomes more common they will want to integrate this knowledge with intelligence about the cellular network. Some operators will want to give users the best possible connection in every situation, and in order to do this they will need clear visibility into both networks. Eventually, some operators will want to integrate Wi-Fi with the mobile core.
For more on voice over Wi-Fi and Wi-Fi offloading, read the complimentary RCR Wireless feature report and watch the on-demand webinar featuring Republic Wireless, InterDigital Communications, Ixia and Senza Fili Consulting.
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