An SCTP-based Mobility Management Framework for Smartphones and Tablets

The current wireless network landscape comprises a plethora of technologies including WLAN, WiMAX and 3G, and not much speaks for a radical change of the state of affairs in the near future. In light of this, it becomes pivotal to facilitate vertical handover between different types of wireless networks. Although, a large number of vertical handover schemes have been proposed in the past several years, the majority of the proposed solutions reside in the network and/or link layer -- e.g., Mobile IP and various IEEE 802.21 schemes - and relatively few are transport-layer solutions. However, we think transport-layer solutions many times are attractive, particularly in cases where there are no economic incentives to upgrade the existing network infrastructure. To this end, we have designed a lightweight, transport-level mobility framework based on the Stream Control Transmission Protocol (SCTP) and its extension for dynamic address reconfiguration. The framework API has been kept very small and closely aligned with the SCTP sockets extensions, which makes porting of existing applications fairly straightforward. To demonstrate its usefulness for low-power tablets and smart phones, we have implemented our framework on a Motorola Xoom tablet running the Android OS. Our initial proof-of-concept experiment gave satisfactory results with a handover performance on par with that of other vertical handover solutions.