Security for network services delivery of 5G enabled device-to-device communications mobile network

The increase in mobile traffic led to the development of Fifth Generation (5G) mobile network. 5G will provide Ultra Reliable Low Latency Communication (URLLC), Massive Machine Type Communication (mMTC), enhanced Mobile Broadband (eMBB). Device-to-Device (D2D) communications will be used as the underlaying technology to offload traffic from 5G Core Network (5GC) and push content closer to User Equipment (UE). It will be supported by a variety of Network Service (NS) such as Content-Centric Networking (CCN) that will provide access to other services and deliver content-based services. However, this raises new security and delivery challenges. Therefore, research was conducted to address the security issues in delivering NS in 5G enabled D2D communications network. To support D2D communications in 5G, this thesis introduces a Network Services Delivery (NSD) framework defining an integrated system model. It incorporates Cloud Radio Access Network (C-RAN) architecture, D2D communications, and CCN to support 5G’s objectives in Home Network (HN), roaming, and proximity scenarios. The research explores the security of 5G enabled D2D communications by conducting a comprehensive investigation on security threats. It analyses threats using Dolev Yao (DY) threat model and evaluates security requirements using a systematic approach based on X.805 security framework. Which aligns security requirements with network connectivity, service delivery, and sharing between entities. This analysis highlights the need for security mechanisms to provide security to NSD in an integrated system, to specify these security mechanisms, a security framework to address the security challenges at different levels of the system model is introduced. To align suitable security mechanisms, the research defines underlying security protocols to provide security at the network, service, and D2D levels. This research also explores 5G authentication protocols specified by the Third Generation Partnership Project (3GPP) for securing communication between UE and HN, checks the security guarantees of two 3GPP specified protocols, 5G-Authentication and Key Agreement (AKA) and 5G Extensive Authentication Protocol (EAP)-AKA’ that provide primary authentication at Network Access Security (NAC). The research addresses Service Level Security (SLS) by proposing Federated Identity Management (FIdM) model to integrate federated security in 5G, it also proposes three security protocols to provide secondary authentication and authorization of UE to Service Provider (SP). It also addresses D2D Service Security (DDS) by proposing two security protocols that secure the caching and sharing of services between two UEs in different D2D communications scenarios. All protocols in this research are verified for functional correctness and security guarantees using a formal method approach and semi-automated protocol verifier. The research conducts security properties and performance evaluation of the protocols for their effectiveness. It also presents how each proposed protocol provides an interface for an integrated, comprehensive security solution to secure communications for NSD in a 5G enabled D2D communications network. The main contributions of this research are the design and formal verification of security protocols. Performance evaluation is supplementary

Promoting quality of life through participation in Healthy Cities programme: sharing the experiences of Kuching city

We live in an era where the issue of 'quality of life' is of prime concern with special reference to urban areas in the face of environmental and social deterioration, growing human insecurity and exposure to infectious and high risk diseases; not surprisingly, cities are blamed for the declining quality of life. The declining social and environmental conditions in urban areas warrant the need for swift solutions to be found and concrete measures/actions to be taken to arrest the further worsening of urban conditions. The Healthy Cities Movement was conceived as a result of the growing realization of the gravity of human-induced crisis that has besieged urban dwellers. It is in line with the spirit of Healthy Cities Movement that Kuching agreed to participate in the Healthy City Programme which began in 1995 and ended in 2000. The purpose to be served by this paper is to share the experiences of Kuching city in implementing the programme with a focus on how coordinated local action is achieved through multisectoral approach or 'smart partnership' which in turn engenders collaboration through community participation and inter-agency linkages. The information collated for the purpose of this paper is mostly derived from secondary sources

Advance control of multilevel converters for integration of distributed generation resources into ac grid

Premi extraordinari doctorat curs 2011-2012, àmbit d’Enginyeria IndustrialDistributed generation (DG) with a converter interface to the power grid is found in many of the green power resources applications. This dissertation describes a multi-objective control technique of voltage source converter (VSC) based on multilevel converter topologies, for integration of DG resources based on renewable energy (and non-renewable energy)to the power grid. The aims have been set to maintain a stable operation of the power grid, in case of di erent types of grid-connected loads. The proposed method provides compensation for active, reactive, and harmonic load current components. A proportional-integral (PI) control law is derived through linearization of the inherently non-linear DG system model, so that the tasks of current control dynamics and dc capacitor voltage dynamics become decoupled. This decoupling allows us to control the DG output currents and the dc bus voltage independently of each other, thereby providing either one of these decoupled subsystems a dynamic response that signi cantly slower than that of the other. To overcome the drawbacks of the conventional method, a computational control delay compensation method, which delaylessly and accurately generates the DG reference currents, is proposed. The rst step is to extract the DG reference currents from the sensed load currents by applying the stationary reference frame and then transferred into synchronous reference frame method, and then, the reference currents are modi ed, so that the delay will be compensated. The transformed variables are used in control of the multilevel voltage source converter as the heart of the interfacing system between DG resources and power grid. By setting appropriate compensation current references from the sensed load currents in control circuit loop of DG link, the active, reactive, and harmonic load current components will be compensated with fast dynamic response, thereby achieving sinusoidal grid currents in phase with load voltages while required power of loads is more than the maximum injected power of the DG resources. The converter, which is controlled by the described control strategy, guarantees maximum injection of active power to the grid continuously, unity displacement power factor of power grid, and reduced harmonic load currents in the common coupling point. In addition, high current overshoot does not exist during connection of DG link to the power grid, and the proposed integration strategy is insensitive to grid overload.La Generació Distribuïda (DG) injectada a la xarxa amb un convertidor estàtic és una solució molt freqüent en l'ús de molts dels recursos renovables. Aquesta tesis descriu una técnica de control multi-objectiu del convertidor en font de tensió (VSC), basat en les topologies de convertidor multinivell, per a la integració de les fonts distribuïdes basades en energies renovables i també de no renovables.Els objectius fixats van encaminats a mantenir un funcionament estable de la xarxa elèctrica en el cas de la connexió de diferents tipus de càrregues. El mètode de control proposat ofereix la possibilitat de compensació de les components actives i reactives de la potencia, i les components harmòniques del corrent consumit per les càrregues.La llei de control proporcional-Integral (PI) s’obté de la linearització del model inherentment no lineal del sistema, de forma que el problema de control del corrent injectat i de la tensió d’entrada del convertidor queden desacoblats. Aquest desacoblament permet el control dels corrents de sortida i la tensió del bus de forma independent, però amb un d’ells amb una dinàmica inferior.Per superar els inconvenients del mètode convencional, s’usa un retard computacional, que genera les senyals de referència de forma acurada i sense retard. El primer pas es calcular els corrents de referència a partir de les mesures de corrent. Aquest càlcul es fa primer transformant les mesures a la referència estacionaria per després transformar aquests valors a la referència síncrona. En aquest punt es on es poden compensar els retards.Les variables transformades son usades en els llaços de control del convertidor multinivell. Mitjançant aquests llaços de control i les referències adequades, el convertidor és capaç de compensar la potencia activa, reactiva i els corrents harmònics de la càrrega amb una elevada resposta dinàmica, obtenint uns corrents de la xarxa de forma completament sinusoïdal, i en fase amb les tensions.El convertidor, controlat amb el mètode descrit, garanteix la màxima injecció de la potencia activa, la injecció de la potencia reactiva per compensar el factor de potencia de la càrrega, i la reducció de les components harmòniques dels corrents consumits per la càrrega. A més, garanteix una connexió suau entre la font d’energia i la xarxa. El sistema proposat es insensible en front de la sobrecarrega de la xarxaAward-winningPostprint (published version

REGULATION OF CELL-MEDIATED CYTOTOXICITY : I. AUGMENTATION OF CELL-MEDIATED CYTOTOXICITY INDUCED BY RADIATION

Mice were treated with sublethal and midlethal doses of irradiation (500–700 rads) and injected intravenously with allogeneic or semiallogeneic F1 hybrid spleen cells. The cytotoxicity developed by their spleen cells was measured with the lysis of 51Cr-labeled target cells and was found to be stronger (although delayed in time) than the cytotoxic activity of spleen cells from nonirradiated mice. The injection of syngeneic thymus or spleen cells in the irradiated mice after their treatment with allogeneic spleen cells exerted a suppressor activity, i.e., reduced the level of cell-mediated cytotoxicity (CMC). The majority of effector cells involved in the modified CMC response of irradiated mice was shown to be of host origin and lysed specifically target cells of the same genotype as the donor. A small percentage of the cells obtained from the spleens of irradiated recipients of allogeneic spleen cells was composed of donor cells which lysed specifically target cells of the same genotype as the host. These results demonstrate that the precursors of the cytotoxic cells responsible for target cell lysis are relatively radioresistant and suggest that their response is regulated by radiosensitive thymus-dependent cells