Gábor Jeney

Design and Evaluation of a Novel HIP-Based Network Mobility Protocol

The rapid growth of IP-based mobile telecommunication technologies in the past few years has revealed situations where not only a single node but an entire network moves and changes its point of attachment to the Internet. The main goal of any protocol supporting network mobility is to provide continuous, optimal and secure Internet access to all nodes and even recursively nested mobile subnetworks inside a moving network. For this purpose, the IETF (Internet Engineering Task Force) has developed the NEtwork MObility Basic Support (NEMO BS) protocol which extends the operation of Mobile IPv6 (MIPv6). In order to bypass the same problems suffered by MIPv6 and NEMO BS, a novel Host Identity Protocol (HIP) extension called HIP-NEMO is introduced, proposed and evaluated in this paper. Our proposal is based on hierarchical topology of mobile RVSs (mRVS), signaling delegation and inter-mRVS communication to enable secure and efficient network mobility support in the HIP layer. The method provides secure connectivity and reachability for every node and nested subnet in the moving network and supports multihomed scenarios as well. Moreover, HIPNEMO reduces signaling and packet overhead during network mobility management by achieving route optimization inside any moving network even in nested scenarios. To evaluate the proposed scheme we present a simulation model implemented in OMNeT++ and discuss the results of our simulation based analysis to show the efficiency of the approach compared to the NEMO BS protocol formulated by the IETF.

Design and evaluation of host identity protocol (HIP) simulation framework for INET/OMNeT++

Host Identity Protocol (HIP) decouples IP addresses from higher layer Internet applications by proposing a new, cryptographic namespace for host identities. HIP has great potential in means of mobility and multihoming support, security, and performance, such making it quite a promising candidate as the basic architecture of the Future Internet. However, HIP is still in development and very early standardization phase: the protocol is continuously evolving due to its adaptivity to functional changes and extensions. Aiming to completely understand the protocols behavior, its applicability to wide-scale usage and to analyze current and future improvements and enhancements, it is crucial to develop a proper, RFC-compliant, extensible simulation model for Host Identity Protocol. In this paper we present the structural design and the functional details of our HIP simulation framework (called HIPSim++) integrated into the INET/OMNeT++ discrete event simulation environment. In order to evaluate the accuracy and preciseness of HIPSim++, we designed a real-life HIP testbed and compared the simulation outcomes with the reference results obtained from this HIP testing architecture. Our analysis show excellent accuracy and consistent operation of the simulation framework in terms of handover metrics (latency, packet loss, throughput) and behavior when compared to the real-life experiences of the HIP testbed.

GPS aided predictive handover management for multihomed NEMO configurations

In this document we propose a new handover management solution which can be used to provide ubiquitous connections and seamless Internet access. The new solution is based on GPS position information and previous records of network parameters and exploits the benefits of multihomed mobility configurations. Based on actual GPS coordinates and previously recorded data, the system is able to predict handovers and to prepare itself for the appearance of networks. With the proposed solution, handover latency could almost be totally eliminated in multihomed networking environments.

Practical Limits of Femtocells in a Realistic Environment

This article deals with the interference limitations of introducing femtocells in existing mobile networks. Femtocells are cheap alternatives for mobile operators to extend their network and to provide better coverage. However, having more femtocells increases the interference in existing components. Finally, the whole system could lock up itself, if the interference exceeds the maximum acceptable level. The question is the maximum number of femtocells per macrocell. In this article, it will be shown how this limit can be computed analytically -- without simulations.

On SCTP multihoming performance in native IPv6 UMTS-WLAN environments

Multihoming is one of the most attractive features of SCTP (Stream Control Transmission Protocol) aiming to make this prosperous transport scheme competitive in mobile environments when the mobile hosts are equipped with multiple interfaces. The complementary characteristic of the 3G UMTS (Universal Mobile Telecommunications System) and WLAN (Wireless Local Area Network) architectures motivates operators to integrate these two successful technologies. Recently spreading wireless devices are increasingly provided with multiple networking interfaces such enabling end-users to access Internet services using e.g. the WLANs higher bandwidth wherever available, and connecting to the UMTS network in other cases. This paper investigates the performance of multihomed SCTP hosts through extensive experimental studies in such an integrated heterogeneous environment. In order to do this we designed and implemented a real native IPv6 UMTS-LAN testbed equipped with novel IPv6-based mobile technologies, such providing ideal conditions for SCTP multihoming performance analysis. In this testbed architecture we analyzed numerous settings to measure the handover behavior of the protocol in terms of handover effectiveness, link changeover characteristics, throughput and transmission delay. As our results show, accurate SCTP parameter setup can significantly decrease the handover delay and eliminate the data transmission interrupts.

Protocol design and analysis of a HIP-based per-application mobility management platform

Rapid evolution of wireless networking has provided wide-scale of different wireless access technologies like Bluetooth, ZigBee, 802.11a/b/g, DSRC, 3G UMTS, LTE, WiMAX, etc. The complementary characteristic of the above architectures motivates next generation network operators to integrate them in a supplementary and overlapping manner. Recent wireless devices are equipped with multiple interfaces, thus enabling concurrent communication sessions. With the advance of such heterogeneous structures - and considering that users are often running applications simultaneously - the traditional per-host mobility management approach cannot be the optimal solution for handling connection changes. Instead, the concept of per-application mobility management is to be introduced, where a dedicated interface (i.e. access network) is selected by each application according to its QoS prerequisites and the actual networking conditions. Aiming to benefit from this novel concept in practice, in this paper we designed and evaluated a HIP-based per-application mobility management platform founded on the promising Host Identity Protocol (HIP) and the cross-layer building blocks closely incorporating with it.

Novel results on SCTP multihoming performance in native IPv6 UMTS-WLAN environments

Multihoming is one of the most attractive features of stream control transmission protocol (SCTP) aiming to make this prosperous transport scheme competitive in mobile environments when the mobile hosts are equipped with multiple interfaces. The complementary characteristic of the 3G universal mobile telecommunications system (UMTS) and wireless local area network (WLAN) architectures motivates operators to integrate these two successful technologies. Recently spreading wireless devices are increasingly provided with multiple networking interfaces such enabling end-users to access internet services using e.g., the WLANs higher bandwidth wherever available, and connecting to the UMTS network in other cases. This paper investigates the performance of multihomed SCTP hosts through extensive experimental studies in such an integrated heterogeneous environment. In order to do this, we designed and implemented a real native IPv6 UMTS-WLAN testbed equipped with novel IPv6-based mobile technologies, such providing ideal conditions for SCTP multihoming performance analysis. In this testbed architecture we analysed numerous settings to measure the handover behaviour of the protocol in terms of handover effectiveness, link changeover characteristics, throughput and transmission delay. As our results show, accurate SCTP parameter setup can significantly decrease the handover delay and eliminate the data transmission interrupts.

Performance Evaluation of Key IMS Operations over IPv6-Capable 3G UMTS Networks

Due to the rapid development of high bit-rate IP-based mobile networking architectures, the increasing number of end-user terminals, and the emerging convergence of different communication services with the IP world, the IPv6 protocol and the IP Multimedia Subsystem (IMS) are considered to be the key technologies towards the realization of next generation mobile and wireless telecommunications. Both IPv6 and IMS are widely covered in the literature as self-possessed researches and studies. However, the challenge of provisioning IPv6-based IMS services over 3rd Generation (3G) Universal Mobile Telecommunication System (UMTS) networks as well as related problems and performance issues were not considered so far. In this work, we try to fill this gap and raise attention on some potentially significant aspects of the integration of 3G UMTS, IMS and IPv6. Our research in this context mainly concerns the questions and challenges of the transition from IPv4 to IPv6 in all-IP 3G and beyond multimedia systems and their impacts on the performance of IMS services and applications. Different methods providing IPv6 support in existing mobile telecommunication architectures and the co-existence of IPv4/v6 during the first phases of the integration of the new Internet Protocol have substantial impact on the network and service/application performance. In order to quantify these effects, we designed and implemented a 3G UMTS testbed (including the IMS core) and compared the performance characteristics of three selected transition techniques with native IPv4 and IPv6 scenarios. Our results expose the main benefits and drawbacks of the five technologies and their actually available implementations.

Communications challenges in the Celtic-BOSS project

The BOSS project [1] aims at developing an innovative and bandwidth efficient communication system to transmit large data rate communications between public transport vehicles and the wayside to answer to the increasing need from Public Transport operators for new and/ or enhanced on-board functionality and services, such as passenger security and exploitation such as remote diagnostic or predictive maintenance. As a matter of fact, security issues, traditionally covered in stations by means of video-surveillance are clearly lacking on-board trains, due to the absence of efficient transmission means from the train to a supervising control centre. Similarly, diagnostic or maintenance issues are generally handled when the train arrives in stations or during maintenance stops, which prevents proactive actions to be carried out. The aim of the project is to circumvent these limitations and offer a system level solution. This article focuses on the communication system challenges.

Examining anycast address supported mobility management using mobile IPv6 testbed

This paper introduces a new method how mobile IPv6 protocol can be extended easily to work efficiently in the case of micromobility environment. The proposed method reduces the volume of control messages during the mobile operation and results more seamless handover helping real-time applications.