Context-aware handoff middleware for transparent service continuity in wireless networks

Advances in wireless networking and content delivery are enabling new challenging provisioning scenarios where a growing number of users access continuous services, e.g., audio/video streaming, while moving among different points of attachment to the Internet, possibly with different connectivity technologies, e.g., Wi-Fi, Bluetooth, and cellular 3G. That calls for novel middlewares capable of dynamically personalizing service provisioning to the characteristics of client environments, in particular to discontinuities in wireless resource availability due to handoffs. The paper proposes a novel middleware solution, called Mobile agent-based Ubiquitous multimedia Middleware (MUM), that performs effective and context-aware handoff management to transparently avoid service interruptions during both horizontal and vertical handoffs. MUM exploits the full visibility of wireless connections available and their handoff implementations (handoff awareness), of service quality requirements and handoff-related quality degradations (QoS awareness), and of network topology and local resource availability (location awareness); that visibility enables MUM to provide original solutions for handoff prediction, multimedia continuity via adaptive data buffering/pre-fetching, and proactive re-addressing/rebinding. (C) 2007 Elsevier B.V. All rights reserved.