Multicast Mobility in Mobile IP Version 6 (MIPv6) : Problem Statement and Brief Survey

Publisher PD

CASPR: Judiciously Using the Cloud for Wide-Area Packet Recovery

We revisit a classic networking problem -- how to recover from lost packets in the best-effort Internet. We propose CASPR, a system that judiciously leverages the cloud to recover from lost or delayed packets. CASPR supplements and protects best-effort connections by sending a small number of coded packets along the highly reliable but expensive cloud paths. When receivers detect packet loss, they recover packets with the help of the nearby data center, not the sender, thus providing quick and reliable packet recovery for latency-sensitive applications. Using a prototype implementation and its deployment on the public cloud and the PlanetLab testbed, we quantify the benefits of CASPR in providing fast, cost effective packet recovery. Using controlled experiments, we also explore how these benefits translate into improvements up and down the network stack

On predictive routing of security contexts in an all-IP network

While mobile nodes (MNs) undergo handovers across inter-wireless access networks, their security contexts must be propagated for secure re-establishment of on-going application sessions, such as those in secure mobile internet protocol (IP), authentication, authorization, and accounting (AAA) services. Routing security contexts via an IP network either on-demand or based on MNs' mobility prediction, imposes new challenging requirements of secure cross-handover services and security context management. In this paper, we present a context router (CXR) that manages security contexts in an all-IP network, providing seamless and secure handover services for the mobile users that carry multimedia-access devices. A CXR is responsible for (1) monitoring of MNs' cross-handover, (2) analysis of MNs' movement patterns, and (3) routing of security contexts ahead of MNs' arrival at relevant access points. The predictive routing reduces the delay in the underlying security association that would otherwise fetch an involved security context from a remote server. The predictive routing of security contexts is performed based on statistical learning of MNs' movement pattern, gauging (dis)similarities between the patterns obtained via distance measurements. The CXR has been evaluated with a prototypical implementation based on an MN mobility model on a grid. Our evaluation results support the predictive routing mechanism's improvement in seamless and secure cross-handover services by a factor of 2.5. Also, the prediction mechanism is shown to outperform the Kalman filter-based method [13] as a Kalman Fiter-based mechanism up to 1.5 and 3.6 times regarding prediction accuracy and computation performance, respectively. Copyright © 2009 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65037/1/135_ftp.pd

Network layer access control for context-aware IPv6 applications

As part of the Lancaster GUIDE II project, we have developed a novel wireless access point protocol designed to support the development of next generation mobile context-aware applications in our local environs. Once deployed, this architecture will allow ordinary citizens secure, accountable and convenient access to a set of tailored applications including location, multimedia and context based services, and the public Internet. Our architecture utilises packet marking and network level packet filtering techniques within a modified Mobile IPv6 protocol stack to perform access control over a range of wireless network technologies. In this paper, we describe the rationale for, and components of, our architecture and contrast our approach with other state-of-the- art systems. The paper also contains details of our current implementation work, including preliminary performance measurements

Planning Support Systems: Progress, Predictions, and Speculations on the Shape of Things to Come

In this paper, we review the brief history of planning support systems, sketching the way both the fields of planning and the software that supports and informs various planning tasks have fragmented and diversified. This is due to many forces which range from changing conceptions of what planning is for and who should be involved, to the rapid dissemination of computers and their software, set against the general quest to build ever more generalized software products applicable to as many activities as possible. We identify two main drivers – the move to visualization which dominates our very interaction with the computer and the move to disseminate and share software data and ideas across the web. We attempt a brief and somewhat unsatisfactory classification of tools for PSS in terms of the planning process and the software that has evolved, but this does serve to point up the state-ofthe- art and to focus our attention on the near and medium term future. We illustrate many of these issues with three exemplars: first a land usetransportation model (LUTM) as part of a concern for climate change, second a visualization of cities in their third dimension which is driving an interest in what places look like and in London, a concern for high buildings, and finally various web-based services we are developing to share spatial data which in turn suggests ways in which stakeholders can begin to define urban issues collaboratively. All these are elements in the larger scheme of things – in the development of online collaboratories for planning support. Our review far from comprehensive and our examples are simply indicative, not definitive. We conclude with some brief suggestions for the future