LTE Advanced Pro

6Wi-Fi Integration – Network Discovery and Selection

6.1. Mechanisms defined by 3GPP organization

6.1.1. ANDSF function

The selection of the access network and the management of the traffic between LTE (Long-Term Evolution) access and Wi-Fi (Wireless Fidelity) access are supported by the ANDSF (Access Network Discovery and Selection Function) server.

The configuration data are provided by the ANDSF server and are organized in a hierarchical structure called the device management tree. The exchange of the management object (MO) between the ANDSF server and the mobile is based on extensible markup language (XML).

The mobile can reach the ANDSF server via Wi-Fi access to the Internet or via Wi-Fi access or LTE access to the 4G mobile network.

The ANDSF server can push the information to the mobile (push mode) or the mobile can interrogate the ANDSF server and receive the corresponding information (pull mode). If the mobile submits a request, then it may also include other information in its request, such as its location and the list of discovered radio access networks.

The mobile can discover the ANDSF server in one of the following configurations:

• – static configuration;
• – DNS (Domain Name System) resolution for which a specific full qualified domain name (FQDN) is used

andsf.mnc <MNC> .mcc <MCC> .pub.3gppnetwork.org

• – dynamic configuration by a DHCP (Dynamic Host Configuration Protocol) server.

The ANDSF server determines the access on which the mobile must transfer the ...