Mobile data traffic offloading is a key strategy for mobile operators seeking to reduce infrastructure costs and to manage the heavy demands placed on network capacity. Access Network Discovery and Selection Function (ANDSF) is a key technology for enabling carriers to offload data traffic from the mobile network.
ANDSF is an element of the 3GPP standard that is designed to assist mobile devices in discovering offload destinations, including Wi-Fi, WiMAX, and CDMA2000 networks. The feature was designed to provide mobile devices with information about available alternative wireless networks and to enforce policies for selecting and using those networks. The standard is location- and device-specific, but it is not intended to be responsive to real-time network conditions. A mobile network cell can be tagged to a defined list of Wi-Fi hotspots or WiMAX base stations in the same geographical area, designating those alternative sources of connectivity as possible offload destinations.
ANDSF can implement policies using either a pull model or a push model, depending upon carrier preference. In the pull model, the mobile device contacts the ANSDF server to request policy information. Once the requested information is provided, the device interprets and acts on the policy, identifying local offload destinations and connecting to them if appropriate. The push model has two variations. The ANDSF server may push the entire set of offload polices to the device. Alternatively, the server may instruct the device to contact it for more information, in which case the push function is effectively initiating a pull action on the part of device.
ANDSF requires Open Mobile Alliance Device Management (OMA-DM) support on the device. OMA-DM is a device management protocol that was created by the Open Mobile Alliance. Its scope includes such functions as provisioning and configuring devices, as well as performing software upgrades.
SEVEN Networks is committed to supporting ANDSF with our Wi-Fi QoE offload management software product, because we recognize that carriers are interested in open technologies that provide them with maximum flexibility.