Accelerating Mobile IP hand-offs through Link-layer Information, An Experimental Investigation with 802.11b and Internet Audio

In this study the Fast Hinted Cell Switching movement detection method for Mobile IP is introduced. This method assumes that the Link-Layer is capable of delivering information to Mobile IP regarding the identity of the local mobility agent. This tends to negate the need for Mobile IP movement detection as well as agent discovery and leads to accelerated Mobile IP hand-offs. Moreover, the existence of Link-Layer information renders the presence of periodic mobility agent broadcast advertisements as unnecessary which enables a more efficient utilisation of the network capacity. The performance of the proposed solution is experimentally compared against that of Eager Cell Switching that is considered the fastest of traditional Mobile IP movement detection methods. The scenarios investigated involve straight line movement patterns and Mobile IP hand-offs between Foreign Agents that provide wireless network connectivity through IEEE 802.11b Wireless LAN standard, compliant hardware. The IEEE 802.11 SSID field was utilised to contain information important to Mobile IP such as the identity of the local mobility agent. The overlying communication involves a unidirectional GSM audio stream directed to the mobile node. Through the experimental investigation it is determined that the proposed solution outperforms its Eager Cell Switching counterpart by managing faster Mobile IP hand-offs and minimum packet loss of the active audio stream.