Application-Level Middleware to Proactively Manage Handoff in Wireless Internet Multimedia

Abstract

Abstract. New deployment scenarios tend to consider the requirement of session continuity for service provisioning, especially multimedia streaming, to limited heterogeneous portable devices roaming among wireless localities. In particular, multimedia streaming should not experience any interruption while clients roam in wired-wireless integrated networks based on the standard besteffort Internet. The paper proposes an application-level middleware approach to proactively overcome Wi-Fi handoff and maintain multimedia session continuity in the wireless Internet by exploiting mobile proxies running on the wired network. Mobile middleware proxies locally support resource-limited clients, avoid packet losses during handoffs, pre-fetch local buffers with multimedia contents before handoff occurrence, and possibly reconfigure/renegotiate ongoing sessions after handoffs. Experimental results show that, notwithstanding the application-level implementation, mobile proxies can avoid streaming discontinuities with good efficiency in wireless-wired integrated networks even if their pro-activity is based on simple and lightweight handoff prediction techniques.

Dynamic and context-aware streaming adaptation to smooth quality degradation due to IEEE 802.11 performance anomaly

“…In general, we claim the need for application-level middlewares to ease the design and implementation of multimedia streaming services by providing flexible solutions to crucial mobility issues, such as application-specific caching and filtering, interoperable session control, and QoS management [4]. By focusing on performance anomaly, the long-term optimal solution will probably be to modify the 802.11a/b/g standard specifications.…”

“…By following the above design guidelines, we have developed an innovative anomaly-aware facility for multimedia services and integrated it with our Mobile agent-based Ubiquitous multimedia Middleware (MUM), 1 an application-level middleware for streaming adaptation and service continuity in mobile environments [4]. In the following, we rapidly overview the overall MUM design and specifically present the anomaly facility architecture.…”

“…The application-level approach permits to perform management operations selectively, e.g., only for multimedia services: such management differentiation is usually not allowed by lower-layer anomaly management solutions. Moreover, application-level infrastructures can more easily and appropriately exploit applicative protocols such as RealTime Protocol (RTP) and scalable encoding techniques (e.g., MPEG4) to adjust provisioning by acting as mediators between clients and servers [4].…”

“…Traditional (fixed) multimedia systems adopt a reservation-based approach and consider QoS adaptation as an infrequent management action to perform only during overload/congestion situations. Wireless multimedia systems instead should consider QoS adaptation as a usual management action to counteract (even proactively) frequent and abrupt QoS variations in the wireless medium [3,4].…”

Meeting Interactivity Requirements in Mobile E-Witness: An Experimental Study

“…In fact, there exist very few works, available in the literature, that focus on session layer handover and resource and mobility management mechanisms. These works, which include [1] and [3], propose middleware solutions based on the use of proxies to support handoff.…”