VPN capable nodes

Media independent handover is an IEEE 802.21standards-based solution that defines access technologyagnostic interworking procedures. The IEEE 802.21working group, initially chaired by Ajay Rajkumarfrom Bell Labs, began work in 2004, resulting in astandard being approved in January 2009.The goal of MIH is to facilitate handovers betweenheterogeneous access networks through the definitionof a core set of services and components that wouldexist within both UE and throughout the network.MIH partitioned the services into three general categories: command, event, and information. Additionally,MIH defines a protocol for communication betweenMIH-capable nodes (e.g., mobile node [MN] to network, or network to network) that allows for coordinated efforts before, during, and after a handover.An MIH-capable node contains an MIH function(MIHF) that provides one or more of the core servicesto the upper layers (MIH users), and expects a minimum set of functions from the lower (link) layers. As shown in Figure 2, MIH users gain access to MIHservices through an MIH service access point(MIH_SAP), whereas MIHF gains access to lower layer