Robert Brännström

M-MIP: extended mobile IP to maintain multiple connections to overlapping wireless access networks

In future wireless access networks, connectivity to wired infrastructure will be provided through multiple access points with possibly different capabilities and utilization. The demand for increased network performance requires the ability to predict the best overall performance of those access points and to switch access point when the performance changes. Then there is the demand for mobility between networks with maintained connectivity which requires the ability to switch the point of attachment. We propose Multihomed Mobile IP, enabling performance discovery at the networks layer and the capability to decide what AP to use. Mobile IP support is needed to allow mobile hosts to move between networks with maintained connectivity. Multihomed Mobile IP enables mobile hosts to register multiple care-of addresses at the home agent, to enhance the performance of wireless network connectivity. This article describes a simulator evaluation of multihomed Mobile IP.

Mobility management for multiple diverse applications in heterogeneous wireless networks

This paper presents a mobility management solution to support both applications who are mobility-aware and those who are not. Mobility management in heterogeneous network environments needs to address the double meaning of the IP address as an endpoint identifier and a location identifier. Application-layer mobility use a non-IP endpoint identifier (e.g. user@realm) while network-layer mobility uses a fixed home IP- address as endpoint identifier. The resolving of the endpoint identifier to a temporary unicast IP address as location identifier needs support from a mobility management system. This paper proposes a mobility support system that integrates the benefits of application-layer SIP mobility with network-layer MIP mobility. A cross-layer information system provides context for mobility adaptation. Context awareness enhances handover decisions, transport performance and media adoption. The network-layer mobility supports the application to locate the destination on- demand for the initial setup of the sessions. The paper includes an initial evaluation of the network-layer mobility part of the solution.

Traffic load metrics for multihomed mobile IP and global connectivity

Support for host mobility an essential and necessary feature for roaming users who connect to wireless networks via access points. Access points may have different capabilities, be connected to different networks and be installed by different providers. A mobile host will discover multiple access points in this environment. In such an environment, a mobile host should be able to use the best available connection to communicate with a correspondent host and perhaps use multiple connections for different hosts. In areas with wireless local area network access, pockets with limited or no coverage could exist. Such restricted connectivity could be compensated by neighbor hosts who form an ad hoc network and relay packets until they reach an access point. This paper describes and discusses a proposed solution towards enabling and supporting connectivity in wireless networks. In the proposed solution the network layer software will evaluate and decide which wireless network connections to use. A Running Variance Metric (RVM) and a Relative Network Load(RNL) are used to measure the traffic load of access points in wireless access networks. RVM and RNL can be efficiently used for both infrastructure networks and ad hoc networks. Multihomed Mobile IP (M-MIP) is an extension of Mobile IP that enables mobile hosts to use multiple care-of addresses simultaneously. The extension enhances network connectivity by enabling the mobile host, the home agent and correspondent hosts to evaluate and select the best connection. A proposed gateway architecture using M-MIP that integrates wired IP networks with ad hoc networks is described. The M-MIP and gateway architecture using the RVM and RNL metrics have been validated with simulation studies and results are presented.

Maintaining Gateway Connectivity in Multi-hop Ad hoc Networks

The need for maintaining gateway connectivity in an ad hoc access network is vital considering the 80/20 ratio of Internet traffic. There are several proposals of how to integrate gateway forwarding strategies but they all rely on the route discovery procedure of reactive routing protocols. We propose a proactive approach to avoid the delay of the route discovery process. Mobile IP is often suggested to handle macro mobility and we use the advertisements periodically sent by the gateway to update routing tables in the ad hoc network. Since advertisements may arrive to a mobile host through multiple paths, it is important to keep track of the best path to each gateway. We demonstrate the use of a proposed dynamic metric and how to handle location of correspondent hosts. A simulation study demonstrates the usefulness and efficiency of our approach

Port-based Multihomed Mobile IPv6: Load-balancing in Mobile Ad hoc Networks

With todays heterogeneous access to the Internet, users will move between wired and wireless environments and between infrastructure mode and ad hoc mode of wireless communication. When a mobile node moves from an infrastructure connection and connects multihop to an Internet gateway, the performance will degrade and it may not be able to send all of its traffic via a single gateway. This highlights the need of load-balancing between Internet gateways, especially since the behavior of users today involves a multitude of parallel activities generating multiple flows. This paper proposes a solution that enables distribution of individual traffic flows via different Internet gateways instead of using one single gateway. The proposal includes extensions to mobile IP in order to handle flow mobility bindings. The performance of the solution is verified by simulation studies.

Port-based Multihomed Mobile IPv6 for Heterogeneous Networks

Future wireless networks are expected to be based on coexistence of multiple different access network technologies. Mobile devices will then be equipped with multiple wireless interfaces enabling connectivity via multiple architectures. Different wireless technologies differ widely considering their capabilities and coverage. This requires a mobile node to maintain multiple active connections depending on the applications used and available access networks. To enable this, a mobile node needs to be multihomed and able to direct traffic flows via different interfaces. This paper describes a proposal extending mobile IPv6 with multihoming functionality. Multihoming is managed using IP address, protocol and port number

Running variance metric for evaluating performance of wireless IP networks in the MobileCty testbed

This paper proposes and analyzes a Running Variance Metric performance measurement of wireless local area networks and its formal aspects. Our approach evaluates the performance of wireless local area networks in infrastructure mode as well as in ad hoc mode. The Running Variance Metric is used to discover relative traffic loads of available access-points/gateways at the network layer in order to provide connectivity to the wired network. The paper discusses a simulation study. The simulation results demonstrate the usefulness and efficiency of the Running Variance Metric to evaluate the utilization of available access-points/gateways. It is also shown that this metric can be used for hop-analysis in multihop ad hoc wireless networks.

A Case Study of Application Development for Mobile and Location-Based Services

In this paper we present a case study of a location-dependent service, aimed for tourists. Two applications are developed, one based on native technologies, the other on HTML5 and related frameworks. We provide implementation details and compare the different solutions in terms of location support, compliance with required features, and cross-platform functionality. Our experiments show that web-based approaches may lead to significant benefits over using native technologies; both versions of the application displayed comparable location support and compliance with required features, while the web version superseded its native counterpart in cross-platform functionality.

Smart City: The smart sewerage

This paper describes a sensor-based system for monitoring of sewer flooding. A global trend in Smart Cities is the installation of sensors for surveillance of the city infrastructure. The presented system is mounted in a number of strategic sewers for initial evaluation. In order to monitor the natural variations of the sewer (including daily variations) the system should be able to integrate into normal monitoring/alarm systems. The communication channel and mounting position (sewer well in the ground) put limitations on the system.

Agent Selection Strategies in Wireless Networks with Multihomed Mobile IP

Mobile IP is a proposed standard for mobility management in IP networks. With today’s emerging possibilities within wireless broadband communication, mobility within networks will increase. New applications and protocols will be created and Mobile IP is important to this development, since Mobile IP support is needed to allow mobile hosts to move between networks with maintained connectivity. This article describes multihomed Mobile IP enabling mobile hosts to register multiple care-of addresses at the home agent, to enhance the performance of wireless network connectivity. A prototype is described and a simulator evaluation shows the performance of our approach.