Qing Wei

Context-aware handover using active network technology

Context-aware computing can play a major role to improve the services of mobile networking systems. In this paper, we focus on optimizing handover decisions in heterogeneous environments, where the user has a choice among different mobile networks and access points. In our approach, the decision is not only based on the signal quality, but also on the knowledge about the context of mobile devices and networks. Since context information and context processing evolves fast, we propose a flexible, integrated approach for context management, which can adapt in several ways. Our architecture encompasses programmable platforms and distributed context management components in network nodes and mobile devices, as well as a service deployment scheme for network services. This flexible architecture is able to actively deploy different handover services. It manages dynamic context information and allows mobile devices to be always connected to the most suitable access network. Our architecture is validated in a prototype implementation and performance results are discussed.

A framework for context-aware handover decisions

Traditionally, handover decisions are made mainly based on the signal strength. However, with the evolution of mobile networks moving toward a heterogeneous solution, this simple decision mechanism is not enough any more. To choose the optimal access router among the multitude points of attachment available to the network, there is a need for a more intelligent handover decision mechanism. In this paper we provide a general framework for handover decisions which take into account the context of both the mobile network and the user. Our solution shows how to collect the context, to compile information, and to propagate it proactively. Due to the fast evolving nature of context information, our flexible framework allows one to update the decision algorithm and the context data. We present the architecture and the main components of our proposed implementation based on active networks.

Active Networks for 4G Mobile Communication: Motivation, Architecture, and Application Scenarios

In this paper, we examine the application of active networking technology to future mobile networks. We first introduce an architecture for programmable 4th generation (4G) mobile networking, including all system layers on the network and terminal side. Based on this architecture, we discuss programmability in future mobile networks. We investigate the main driving forces and obstacles for the application of active networks. In particular, we show that flexible component installation and cross-layer interfaces are a main motivation for programmable mobile networks. This is illustrated by a number of applications for future mobile networks, including context-aware mobility management and paging, where flexibility is a key requirement for future mobile services.

Context-Aware Handover Based on Active Network Technology

Context-aware computing can play a major role to improve the services of mobile networking systems. In this paper, we focus on optimizing handover decisions based not only on the signal quality, but also on the knowledge about the context of mobile devices and networks. Since context information and context processing evolves fast, we propose a flexible, integrated approach for context management, which can adapt in several ways. Our architecture encompasses active platforms in network nodes and mobile devices, distributed context management components on these platforms, and service deployment for network services. This flexible architecture is able to actively deploy different handover services. It can manage different kinds of context information and allow mobile devices to be always connected to the most suitable access network. Our architecture is validated in a prototype implementation.

Challenges and new approaches for efficient data gathering and dissemination in pervasive wireless networks

Motivated by the current trends in wireless technologies, we present challenging scenarios consisting of moving and uncoordinated wireless objects as well as algorithms that are likely to perform well in such environments. Our primary interest is to design network protocols to efficiently build and maintain distributed communication systems based on opportunistic design principles. Such systems should continue to operate well even if communication is sporadic, no end-to-end routes are available, and sources and consumers of information are not known in advance. Also the environment poses many challenges, that are typical for wireless mobile devices, such as wireless channel impairments, the impossibility of having up-to-date and accurate views of the network topology at every device, and limited energy resources. In the second part of the paper, we discuss and propose solutions for data dissemination in such an environment by exploiting network coding techniques. Furthermore, we report first results which reveal that network coding largely outperforms standard solutions which are based on the classical store and forward paradigm.

Context management with programmable mobile networks

We show that the use of context information can significantly improve the services of mobile networking systems. We present an architecture for context management which addresses the specific requirements of mobile networks. Context information is collected at different locations in the network, and then preprocessed before transmitting to the mobile device. Our context management framework clearly separates application independent and application specific context exchange. For the on-demand deployment of application specific modules, our architecture encompasses a service deployment infrastructure and programmable platforms in network nodes and mobile devices. As an example, we discuss optimizing handover decisions based on the knowledge about the context of mobile devices and networks. This is validated in a prototype implementation, which shows the deployment of different context-aware handover services.