An application-driven mobility management scheme for hierarchical mobile IPv6 networks

Mobile users are expected to be highly dynamic in next generation mobile networks. Additionally they will be served a wide variety of services with different transmission rates and expect high Quality of Service (QoS). Since the number of mobile subscribers is rapidly increasing and given the limited resources of any robust network, guarantee of high QoS is possible only by the deployment of network elements that optimally allocate network resources and instantly adapt to network conditions. In attempt to support mobility in IP networks, the Hierarchical Mobile IPv6 (HMIPv6) has been proposed. An important issue that has been highly overlooked in the design of HMIPv6 consists in its lack of a mechanism that can efficiently control and distribute traffic among multiple Mobility Anchor Points (MAPs). In the absence of such mechanism, some MAPs may get congested while others remain underutilized. In such scenario, mobile users connecting to congested MAPs may experience significant packet drops and excessive queuing delays. This ultimately affects QoS. In this vein, this paper proposes an application-driven mechanism for selection of MAPs. The key idea behind the proposed scheme consists in the reference of access points to the transmission rate of the users' applications to decide which MAP visiting users should be registering with. The decision of MAPs is performed in a way that the load variance of all MAPs, serving the access point in question, is minimized. Issues related to the frequency of binding update messages are also considered in the selection of MAPs. The performance of the proposed scheme is evaluated via computer simulations. In terms of QoS, encouraging results are obtained: better traffic distribution among MAPs and lower handoff delays.