11,962 research outputs found
Integrated Support for Handoff Management and Context-Awareness in Heterogeneous Wireless Networks
The overwhelming success of mobile devices and wireless
communications is stressing the need for the development of
mobility-aware services. Device mobility requires services
adapting their behavior to sudden context changes and being
aware of handoffs, which introduce unpredictable delays and
intermittent discontinuities. Heterogeneity of wireless
technologies (Wi-Fi, Bluetooth, 3G) complicates the situation,
since a different treatment of context-awareness and handoffs is
required for each solution. This paper presents a middleware
architecture designed to ease mobility-aware service
development. The architecture hides technology-specific
mechanisms and offers a set of facilities for context awareness
and handoff management. The architecture prototype works with
Bluetooth and Wi-Fi, which today represent two of the most
widespread wireless technologies. In addition, the paper discusses
motivations and design details in the challenging context of
mobile multimedia streaming applications
Delay Tolerant Networking over the Metropolitan Public Transportation
We discuss MDTN: a delay tolerant application platform built on top of the Public Transportation System (PTS) and able to provide service access while exploiting opportunistic connectivity. Our solution adopts a carrier-based approach where buses act as data collectors for user requests requiring Internet access. Simulations based on real maps and PTS routes with state-of-the-art routing protocols demonstrate that MDTN represents a viable solution for elastic nonreal-time service delivery. Nevertheless, performance indexes of the considered routing policies show that there is no golden rule for optimal performance and a tailored routing strategy is required for each specific case
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