Solutions for IPv6-based mobility in the EU project MobyDick

Proceedings of the WTC 2002, 18th World Telecommunications Congress, Paris, France, 22 -27 September, 2002.Mobile Internet technology is moving towards a packet-based or, more precisely, IPv6-based network. Current solutions on Mobile IPv6 and other related QoS and AAA matters do not offer the security and quality users have come to take for granted. The EU IST project Moby Dick has taken on the challenge of providing a solution that integrates QoS, mobility and AAA in a heterogeneous access environment. This paper focuses on the mobility part of the project, describes and justifies the handover approach taken, shows how QoS-aware and secure handover is achieved, and introduces the project's paging concept. It shows that a transition to a fully integrated IP-RAN and IP-Backbone has become a distinct option for the future.Publicad

Radio network management in cognitive LTE-Femtocell Systems

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London.There is a strong uptake of femtocell deployment as small cell application platforms in the upcoming LTE networks. In such two-tier networks of LTEfemtocell base stations, a large portion of the assigned spectrum is used sporadically leading to underutilisation of valuable frequency resources. Novel spectrum access techniques are necessary to solve these current spectrum inefficiency problems. Therefore, spectrum management solutions should have the features to improve spectrum access in both temporal and spatial manner. Cognitive Radio (CR) with the Dynamic Spectrum Access (DSA) is considered to be the key technology in this research in order to increase the spectrum efficiency. This is an effective solution to allow a group of Secondary Users (SUs) to share the radio spectrum initially allocated to the Primary User (PUs) at no interference. The core aim of this thesis is to develop new cognitive LTE-femtocell systems that offer a 4G vision, to facilitate the radio network management in order to increase the network capacity and further improve spectrum access probabilities. In this thesis, a new spectrum management model for cognitive radio networks is considered to enable a seamless integration of multi-access technology with existing networks. This involves the design of efficient resource allocation algorithms that are able to respond to the rapid changes in the dynamic wireless environment and primary users activities. Throughout this thesis a variety of network upgraded functions are developed using application simulation scenarios. Therefore, the proposed algorithms, mechanisms, methods, and system models are not restricted in the considered networks, but rather have a wider applicability to be used in other technologies. This thesis mainly investigates three aspects of research issues relating to the efficient management of cognitive networks: First, novel spectrum resource management modules are proposed to maximise the spectrum access by rapidly detecting the available transmission opportunities. Secondly, a developed pilot power controlling algorithm is introduced to minimise the power consumption by considering mobile position and application requirements. Also, there is investigation on the impact of deploying different numbers of femtocell base stations in LTE domain to identify the optimum cell size for future networks. Finally, a novel call admission control mechanism for mobility management is proposed to support seamless handover between LTE and femtocell domains. This is performed by assigning high speed mobile users to the LTE system to avoid unnecessary handovers. The proposed solutions were examined by simulation and numerical analysis to show the strength of cognitive femtocell deployment for the required applications. The results show that the new system design based on cognitive radio configuration enable an efficient resource management in terms of spectrum allocation, adaptive pilot power control, and mobile handover. The proposed framework and algorithms offer a novel spectrum management for self organised LTE-femtocell architecture. Eventually, this research shows that certain architectures fulfilling spectrum management requirements are implementable in practice and display good performance in dynamic wireless environments which recommends the consideration of CR systems in LTE and femtocell networks

Smart PIN: performance and cost-oriented context-aware personal information network

The next generation of networks will involve interconnection of heterogeneous individual networks such as WPAN, WLAN, WMAN and Cellular network, adopting the IP as common infrastructural protocol and providing virtually always-connected network. Furthermore, there are many devices which enable easy acquisition and storage of information as pictures, movies, emails, etc. Therefore, the information overload and divergent content’s characteristics make it difficult for users to handle their data in manual way. Consequently, there is a need for personalised automatic services which would enable data exchange across heterogeneous network and devices. To support these personalised services, user centric approaches for data delivery across the heterogeneous network are also required. In this context, this thesis proposes Smart PIN - a novel performance and cost-oriented context-aware Personal Information Network. Smart PIN's architecture is detailed including its network, service and management components. Within the service component, two novel schemes for efficient delivery of context and content data are proposed: Multimedia Data Replication Scheme (MDRS) and Quality-oriented Algorithm for Multiple-source Multimedia Delivery (QAMMD). MDRS supports efficient data accessibility among distributed devices using data replication which is based on a utility function and a minimum data set. QAMMD employs a buffer underflow avoidance scheme for streaming, which achieves high multimedia quality without content adaptation to network conditions. Simulation models for MDRS and QAMMD were built which are based on various heterogeneous network scenarios. Additionally a multiple-source streaming based on QAMMS was implemented as a prototype and tested in an emulated network environment. Comparative tests show that MDRS and QAMMD perform significantly better than other approaches

Comunicações veiculares híbridas

Vehicle Communications is a promising research field, with a great potential for the development of new applications capable of improving road safety, traffic efficiency, as well as passenger comfort and infotainment. Vehicle communication technologies can be short-range, such as ETSI ITS-G5 or the 5G PC5 sidelink channel, or long-range, using the cellular network (LTE or 5G). However, none of the technologies alone can support the expected variety of applications for a large number of vehicles, nor all the temporal and spatial requirements of connected and autonomous vehicles. Thus, it is proposed the collaborative or hybrid use of short-range communications, with lower latency, and of long-range technologies, potentially with higher latency, but integrating aggregated data of wider geographic scope. In this context, this work presents a hybrid vehicle communications model, capable of providing connectivity through two Radio Access Technologies (RAT), namely, ETSI ITS-G5 and LTE, to increase the probability of message delivery and, consequently, achieving a more robust, efficient and secure vehicle communication system. The implementation of short-range communication channels is done using Raw Packet Sockets, while the cellular connection is established using the Advanced Messaging Queuing Protocol (AMQP) protocol. The main contribution of this dissertation focuses on the design, implementation and evaluation of a Hybrid Routing Sublayer, capable of isolating messages that are formed/decoded from transmission/reception processes. This layer is, therefore, capable of managing traffic coming/destined to the application layer of intelligent transport systems (ITS), adapting and passing ITS messages between the highest layers of the protocol stack and the available radio access technologies. The Hybrid Routing Sublayer also reduces the financial costs due to the use of cellular communications and increases the efficiency of the use of the available electromagnetic spectrum, by introducing a cellular link controller using a Beacon Detector, which takes informed decisions related to the need to connect to a cellular network, according to different scenarios. The experimental results prove that hybrid vehicular communications meet the requirements of cooperative intelligent transport systems, by taking advantage of the benefits of both communication technologies. When evaluated independently, the ITS-G5 technology has obvious advantages in terms of latency over the LTE technology, while the LTE technology performs better than ITS-G5, in terms of throughput and reliability.As Comunicações Veiculares são um campo de pesquisa promissor, com um grande potencial de desenvolvimento de novas aplicações capazes de melhorar a segurança nas estradas, a eficiência do tráfego, bem com o conforto e entretenimento dos passageiros. As tecnologias de comunicação veícular podem ser de curto alcance, como por exemplo ETSI ITS-G5 ou o canal PC5 do 5G, ou de longo alcance, recorrendo à rede celular (LTE ou 5G). No entanto, nenhuma das tecnologias por si só, consegue suportar a variedade expectável de aplicações para um número de veículos elevado nem tampouco todos os requisitos temporais e espaciais dos veículos conectados e autónomos. Assim, é proposto o uso colaborativo ou híbrido de comunicações de curto alcance, com latências menores, e de tecnologias de longo alcance, potencialmente com maiores latências, mas integrando dados agregados de maior abrangência geográfica. Neste contexto, este trabalho apresenta um modelo de comunicações veiculares híbrido, capaz de fornecer conectividade por meio de duas Tecnologias de Acesso por Rádio (RAT), a saber, ETSI ITS-G5 e LTE, para aumentar a probabilidade de entrega de mensagens e, consequentemente, alcançar um sistema de comunicação veicular mais robusto, eficiente e seguro. A implementação de canais de comunicação de curto alcance é feita usando Raw Packet Sockets, enquanto que a ligação celular é estabelecida usando o protocolo Advanced Messaging Queuing Protocol (AMQP). A contribuição principal desta dissertação foca-se no projeto, implementação e avaliação de uma sub camada hibrída de encaminhamento, capaz de isolar mensagens que se formam/descodificam a partir de processos de transmissão/receção. Esta camadada é, portanto, capaz de gerir o tráfego proveniente/destinado à camada de aplicação de sistemas inteligentes de transportes (ITS) adaptando e passando mensagens ITS entre as camadas mais altas da pilha protocolar e as tecnologias de acesso rádio disponíveis. A sub camada hibrída de encaminhamento também potencia uma redução dos custos financeiros devidos ao uso de comunicações celulares e aumenta a eficiência do uso do espectro electromagnético disponível, ao introduzir um múdulo controlador da ligação celular, utilizando um Beacon Detector, que toma decisões informadas relacionadas com a necessidade de uma conexão a uma rede celular, de acordo com diferentes cenários. Os resultados experimentais comprovam que as comunicações veículares híbridas cumprem os requisitos dos sistemas cooperativos de transporte inteligentes, ao tirarem partido das vantagens de ambas tecnologias de comunicação. Quando avaliadas de forma independente, constata-se que que a tecnologia ITS-G5 tem vantagens evidentes em termos de latência sobre a tecnologia LTE, enquanto que a tecnologia LTE tem melhor desempenho que a LTE, ai nível de débito e fiabilidade.Mestrado em Engenharia Eletrónica e Telecomunicaçõe

On Providing Energy-efficient Data Transmission to Mobile Devices

The transformation from telephony to mobile Internet has fundamentally changed the way we interact with the world by delivering ubiquitous Internet access and reasonable cost of connectivity. The mobile networks and Internet services are supportive of each other and together drive a fast development of new services and the whole ecosystem. As a result, the number of mobile subscribers has skyrocketed to a magnitude of billions, and the volume of mobile traffic has boomed up to a scale no-one has seen before with exponential growth predictions. However, the opportunities and problems are both rising. Therefore, to enable sustainable growth of the mobile Internet and continued mobile service adaption, this thesis proposes solutions to ensure that the reduction of overall environmental presence and the level of QoE are mutually addressed by providing energy-efficient data transmission to mobile devices. It is important to understand the characteristics of power consumption of mobile data transmission to find opportunities to balance the energy consumption and the growth of mobile services and the data volumes. This research started with power consumption measurements of various radio interfaces and investigations of the trade-off between computation and communication of modern mobile devices. Power consumption models, state machines and the conditions for energy-efficient mobile data transmission were proposed to guide the development of energy-saving solutions. This research has then employed the defined guideline to optimise data transmission for energy-efficient mobile web access. Proxy-based solutions are presented in this thesis, utilising several strategies: bundling-enabled traffic shaping to optimise TCP behaviour over congested wireless links and keep the radio interface in low power consumption states as much as possible, offloading HTTP-object fetching to shorten the time of DNS lookups and web content downloading, and applying selective compression on HTTP payload to further reduce energy consumption of mobile data transmission. As a result, the solutions dramatically reduce the energy consumption of mobile web access and download time, yet maintain or even increase user experience

Provisioning Quality of Service of Wireless Telemedicine for E-Health Services: A Review

In general, on-line medical consultation reduces time required for medical consultation and induces improvement in the quality and efficiency of healthcare services. The scope of study includes several key features of present day e-health applications such as X-ray, ECG, video, diagnosis images and other common applications. Moreover, the provision of Quality of Service (QoS) in terms of specific medical care services in e-health, the priority set for e-health services and the support of QoS in wireless networks and techniques or methods aimed at IEEE 802.11 to secure the provision of QoS has been assessed as well. In e-health, medical services in remote places which include rustic healthcare centres, ships, ambulances and home healthcare services can be supported through the applications of e-health services such as medical databases, electronic health data and the transferring of text, video, sound and images. Given this, a proposal has been made for a multiple service wireless networking with multiple sets of priorities. In relation to the terms of an acceptable QoS level by the customers of e-health services, prioritization is an important criterion in a multi-traffic network. The requirement for QoS in medical networking of wireless broadband has paved the way for bandwidth prerequisites and the live transmission or real-time medical applications. The proposed wireless network is capable of handling medical applications for both normal and life-threatening conditions as characterized by the level of emergencies. In addition, the allocation of bandwidth and the system that controls admittance designed based on IEEE 802.16 especially for e-health services or wireless telemedicine will be discussed in this study. It has been concluded that under busy traffic conditions, the proposed architecture can used as a feasible and reliable infrastructure network for telemedicine

Next generation mobile wireless hybrid network interworking architecture

It is a universally stated design requirement that next generation mobile systems will be compatible and interoperable with IPv6 and with various access technologies such as IEEE 802.11x. Discussion in the literature is currently as to whether the recently developed High Speed Packet Access (HSPA) or the developing Long Term Evaluation (LTE) technology is appropriate for the next generation mobile wireless system. However, the HSPA and the LTE technologies are not sufficient in their current form to provide ubiquitous data services. The third–generation mobile wireless network (3G) provides a highly developed global service to customers through either circuit switched or packet switched networks; new mobile multimedia services (e.g. streaming/mobile TV, location base services, downloads, multiuser games and other applications) that provide greater flexibility for the operator to introduce new services to its portfolio and from the user point of view, more services to select and a variety of higher, on-demand data rates compared with 2.5-2.75G mobile wireless system. However cellular networks suffer from a limited data rate and expensive deployment. In contrast, wireless local area networks (WLAN) are deployed widely in small areas or hotspots, because of their cost-effectiveness, ease of deployment and high data rates in an unlicensed frequency band. On the other hand, WLAN (IEEE 802.11x) cannot provide wide coverage cost-efficiently and is therefore at a disadvantage to 3G in the provision of wide coverage. In order to provide more services at high data rates in the hotspots and campus-wide areas, 3G service providers regard WLAN as a technology that compliments the 3G mobile wireless system. The recent evolution and successful deployment of WLANs worldwide has yielded demand to integrate WLANs with 3G mobile wireless technologies seamlessly. The key goal of this integration is to develop heterogeneous mobile data networks, capable of supporting ubiquitous data services with high data rates in hotspots. The effort to develop heterogeneous networks – also referred to fourth-generation (4G) mobile wireless data networks – is linked with many technical challenges including seamless vertical handovers across WLAN and 3G radio technologies, security, common authentication, unified accounting & billing, WLAN sharing (by several mobile wireless networks – different operators), consistent QoS and service provisioning, etc. This research included modelling a hybrid UMTS/WLAN network with two competent couplings: Tight Coupling and Loose Coupling. The coupling techniques were used in conjunction with EAP-AKA for authentication and Mobile IP for mobility management. The research provides an analysis of the coupling techniques and highlights the advantages and disadvantages of the coupling techniques. A large matrix of performance figures were generated for each of the coupling techniques using Opnet Modeller, a network simulation tool

IEEE 802.11 Wireless LAN Security Performance Using Multiple Clients

IEEE 802.11 Wireless Networks have gained popularity, providing users mobility and flexibility in accessing information. Existing solutions for wireless LAN networks have been exposed to security vulnerabilities. Previous study has evaluated the security performance of IEEE 802.11 wireless networks using single server-client architecture. This research investigated the effect of multiple security mechanisms on the performance of multi-client congested and un-congested networks. The effect of different TCP and UDP packet sizes on performance of secure networks was also studied. The results showed that WEP encryption significantly degrades the performance of congested wireless networks. Network performance degradation increased as the number of clients was increased under all security mechanisms

Cognitive radio systems in LTE networks

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London.The most important fact in the mobile industry at the moment is that demand for wireless services will continue to expand in the coming years. Therefore, it is vital to find more spectrums through cognitive radios for the growing numbers of services and users. However, the spectrum reallocations, enhanced receivers, shared use, or secondary markets-will not likely, by themselves or in combination, meet the real exponential increases in demand for wireless resources. Network operators will also need to re-examine network architecture, and consider integrating the fibre and wireless networks to address this issue. This thesis involves driving fibre deeper into cognitive networks, deploying microcells connected through fibre infrastructure to the backbone LTE networks, and developing the algorithms for diverting calls between the wireless and fibre systems, introducing new coexistence models, and mobility management. This research addresses the network deployment scenarios to a microcell-aided cognitive network, specifically slicing the spectrum spatially and providing reliable coverage at either tier. The goal of this research is to propose new method of decentralized-to-distributed management techniques that overcomes the spectrum unavailability barrier overhead in ongoing and future deployments of multi-tiered cognitive network architectures. Such adjustments will propose new opportunities in cognitive radio-to-fibre systematic investment strategies. Specific contributions include: 1) Identifying the radio access technologies and radio over fibre solution for cognitive network infrastructure to increase the uplink capacity analysis in two-tier networks. 2) Coexistence of macro and microcells are studied to propose a roadmap for optimising the deployment of cognitive microcells inside LTE macrocells in the case of considering radio over fibre access systems. 3) New method for roaming mobiles moving between microcells and macrocell coverage areas is proposed for managing spectrum handover, operator database, authentication and accounting by introducing the channel assigning agent entity. The ultimate goal is to reduce unnecessary channel adaptation