CSN – Core Service Network.
Definition
  • It is a combination of a set of network functions and provides IPconnections for the WiMAX subscribers. The CSN consists of the router,AAA agent or server, subscriber database, and Internet gateway equipment. The CSN can a new network entity in a new WiMAX system or can realize the functions of CSN through some existing network equipment.
Main functions of the CSN: 
  • Establish the connections between subscribers and assign IP addresses for the 
  • Perform the Internet access. 
  • Use the AAA agent or server. 
  • Control the user system parameters-based QoS and license. 
  • Establish and manage tunnels between the ASN and the CSN. 
  • Perform the subscriber accounting and settlement. 
  • Perform the inter-ASN mobility management. 
  • Realize WiMAX services, such as location based service, point-to-point service,  multicast service, IMS, and emergency call.