Integration of unidirectional technologies into wireless back-haul architecture

This thesis was submitted for the degree of Docter of Philosophy and awarded by Brunel University.Back-haul infrastructures of today's wireless operators must support the triple-play services demanded by the market or regulatory bodies. To cope with increasing capacity demand, the EU FP7 project CARMEN has developed a cost-effective heterogeneous multi-radio wireless back-haul architecture, which may also leverage the native multicast capabilities of broadcast technologies such as DVB-T to off-load high-bandwidth broadcast content delivery. However, the integration of such unidirectional technologies into a packet-switched architecture requires careful considerations. The contribution of this thesis is the investigation, design and evaluation of protocols and mechanisms facilitating the integration of such unidirectional technologies into the wireless back-haul architecture so that they can be configured and utilized by the spectrum and capacity optimization modules. This integration mainly concerns the control plane and, in particular, the aspects related to resource and capability descriptions, neighborhood, link and Multi Protocol Label Switching (MPLS) Label-Switched Path (LSP) monitoring, unicast and multicast LSP signalling as well as topology forming and maintenance. During the course of this study we have analyzed the problem space, proposed solutions to the resulting research questions and evaluated our approach. Our results show that the now Unidirectional Technology (UDT)-aware architecture can readily consider Unidirectional Technologies (UDTs) to distribute, for example, broadcast content

Seamless integration of unidirectional broadcast links into QoS-constrained broadband wireless mesh access networks

Proceeding of: International Conference for Internet Technology and Secured Transactions ICITST 2009, London, U.K., 9-12 Nov. 2009Wireless Mesh Networks (WMNs) have matured in recent years. They allow two nodes to communicate via multiple hops when no direct connectivity exists. This allows community networks such as Freifunk [3] to provide affordable Internet access to their communities by sharing a few gateway nodes. Increasing demand for multi-media content poses a challenge for the typical WMN routing protocols such a Optimised Link State Routing (OLSR) which lack Quality of Service (QoS) support. Although, numerous solutions have been proposed to introduce QoS awareness such as [4], those WMNs fail to meet commercial operator requirements in term of reliability and QoS guarantees. In this paper we propose the seamless integration of Broadcast technologies such as Digital Video Broadcast (DVB) to introduce support for high-bandwidth multi-media services.European Community's Seventh Framework ProgramPublicad

QoS-aware flow monitoring and event creation in heterogeneous MPLS-based Wireless Mesh Networks supporting unidirectional links

Proceedings of: IEEE 9th Malaysia International Conference on Communications (MICC 2009), 15-17 December 2009, Kuala Lumpur, MalaysiaMonitoring is a crucial task in QoS-aware networks since it provides statistics to verify that the network performs within the committed QoS parameters. It is especially important in a resource-constrained Carriergrade Wireless Mesh Access Network (CG-WMAN) in order to monitor a node’s neighborhood, established links as well as MPLS QoS-traffic flows, so-called Label-Switched Paths (LSPs). In this paper, we present a monitoring architecture for LSPs in a heterogeneous CG-WMAN, where configurable Rating Agents perform adaptive per-LSP event creation based on monitoring statistics, QoS-requirements and overall network state. Keeping the footprint of the monitoring mechanism at a minimum, our approach is based on quasipassive monitoring minimizing the transmission of extra frames. To support unidirectional links as well as 1-to-N multicast trees, a receiving side feedback-free mechanism is proposed which can be extended with transmitting side functionality. Initial results obtained in our testbed show that we can reliably detect under-performing links according to the QoS requirements of the payload.European Community's Seventh Framework ProgramPublicad

Measurements and evaluations for an IEEE 802.11a based carrier-grade multi-radio wireless mesh network deployment

Proceeding of: The Fifth International Conference on Wireless and Mobile Communications, (ICWMC 2009), 23-29 August 2009, Cannes/La Bocca (France)Although there currently exists a number of Wireless Local Area Network based mesh network deployments most have been deployed to provide best effort broadband Internet access. Consequently, they cannot meet the requirements of network operators in order to utilise these networks to offer carrier grade services. The goal of providing carrier grade services over a wireless mesh infrastructure requires high performance in terms of throughput and reliability. One way of achieving this increase in performance is to utilise multi-radio Mesh Nodes, however, due to the Physical Layer layer limitations of 802.11a this can have significant problems. This paper analyses these issues and investigates what performance can be expected when frequency multiplexing is considered. The results presented in this paper are based on real measurements taken from multi-radio Mesh Nodes and are evaluated using statistical algorithms. The main contribution of this paper is an analysis of the impact of the Adjacent Channel Interference effect in 802.11a based multi-radio Mesh Nodes.European Community's Seventh Framework ProgramThis work was partially funded by the European Commission within the 7th Framework Program in the context of the ICT project Carrier-Grade Mesh Networks (CARMEN) (Grant Agreement No. 214994).Publicad

Open RAN: A Concise Overview

Open RAN has emerged as a transformative approach in the evolution of cellular networks, addressing challenges posed by modern applications and high network density. By leveraging disaggregated, virtualized, and software-based elements interconnected through open standardized interfaces, Open RAN introduces agility, cost-effectiveness, and enhanced competition in the Radio Access Network (RAN) domain. The Open RAN paradigm, driven by the O-RAN Alliance specifications, is set to transform the telecom ecosystem. Despite extensive technical literature, there is a lack of succinct summaries for industry professionals, researchers, and policymakers. This paper addresses this gap by providing a concise, yet comprehensive overview of Open RAN. Compared to previous work, our approach introduces Open RAN by gradually splitting up different components known from previous RAN architectures. We believe that this approach leads to a better understanding for people already familiar with the general concept of mobile communication networks. Building upon this general understanding of Open RAN, we introduce key architectural principles, interfaces, components and use-cases. Moreover, this work investigates potential security implications associated with adopting Open RAN architecture, emphasizing the necessity of robust network protection measures

Outcome after PSMA-PET/CT-based salvage radiotherapy for nodal recurrence after radical prostatectomy

PURPOSE Nodal recurrent prostate cancer (PCa) represents a common state of disease, amenable to local therapy. PSMA-PET/CT detects PCa recurrence at low PSA levels. The aim of this study was to evaluate the outcome of PSMA-PET/CT-based salvage radiotherapy (sRT) for lymph node (LN) recurrence. METHODS A total of 100 consecutive patients treated with PSMA-PET/CT-based salvage elective nodal radiotherapy (sENRT) for LN recurrence were retrospectively examined. Patients underwent PSMA-PET/CT scan due to biochemical persistence (bcP, 76%) or biochemical recurrence (bcR, 24%) after radical prostatectomy (RP). Biochemical recurrence-free survival (BRFS) defined as PSA 1~ng/ml) with improved DMFS, respectively. No such association was seen for the number of affected lymph nodes. CONCLUSIONS Overall, the present analysis shows that the so far, unmatched sensitivity and specificity of PSMA-PET/CT translates in comparably high BRFS and DMFS after PSMA-PET/CT-based sENRT for patients with PCa LN recurrence. Concomitant ADT, duration of ADT, PSA value before sRT, and localization of LN metastases were significant factors for improved outcome

Feasibility of Different Tumor Delineation Approaches for 18F-PSMA-1007 PET/CT Imaging in Prostate Cancer Patients

Background: Delineation of PSMA-positive tumor volume on PET using PSMA-ligands is of highest clinical interest as changes of PSMA-PET/CT-derived whole tumor volume (WTV) have shown to correlate with treatment response in metastatic prostate cancer patients. So far, WTV estimation was performed on PET using 68Ga-labeled ligands; nonetheless, 18F-labeled PET ligands are gaining increasing importance due to advantages over 68Ga-labeled compounds. However, standardized tumor delineation methods for 18F-labeled PET ligands have not been established so far. As correlation of PET-based information and morphological extent in osseous and visceral metastases is hampered by morphological delineation, low contrast in liver tissue and movement artefacts, we correlated CT-based volume of lymph node metastases (LNM) and different PET-based delineation approaches for thresholding on 18F-PSMA-1007 PET. Methods: Fifty patients with metastatic prostate cancer, 18F-PSMA-1007 PET/CT and non-bulky LNM (short-axis diameter ≥10mm) were included. Fifty LNM were volumetrically assessed on contrast-enhanced CT (volumetric reference standard). Different approaches for tumor volume delineation were applied and correlated with the reference standard: I) fixed SUV threshold, II) isocontour thresholding relative to SUVmax (SUV%), and thresholds relative to III) liver (SUVliver), IV) parotis (SUVparotis) and V) spleen (SUVspleen). Results: A fixed SUV of 4.0 (r=0.807, r2 = 0.651, p0.05 each). Recently reported cut-offs for intraprostatic tumor delineation (isocontour 44% SUVmax, 42% SUVmax and 20% SUVmax) revealed inferior association for LNM delineation. Conclusions: A threshold of SUV 4.0 for tumor delineation showed highest association with volumetric reference standard irrespective of potential changes in PSMA-avidity of background tissues (e. g. parotis). This approach is easily applicable in clinical routine without specific software requirements. Further studies applying this approach for total tumor volume delineation are initiated

Genome analysis of the necrotrophic fungal pathogens Sclerotinia sclerotiorum and Botrytis cinerea

Sclerotinia sclerotiorum and Botrytis cinerea are closely related necrotrophic plant pathogenic fungi notable for their wide host ranges and environmental persistence. These attributes have made these species models for understanding the complexity of necrotrophic, broad host-range pathogenicity. Despite their similarities, the two species differ in mating behaviour and the ability to produce asexual spores. We have sequenced the genomes of one strain of S. sclerotiorum and two strains of B. cinerea. The comparative analysis of these genomes relative to one another and to other sequenced fungal genomes is provided here. Their 38–39 Mb genomes include 11,860–14,270 predicted genes, which share 83% amino acid identity on average between the two species. We have mapped the S. sclerotiorum assembly to 16 chromosomes and found large-scale co-linearity with the B. cinerea genomes. Seven percent of the S. sclerotiorum genome comprises transposable elements compared t

Genomic Analysis of the Necrotrophic Fungal Pathogens Sclerotinia sclerotiorum and Botrytis cinerea

Sclerotinia sclerotiorum and Botrytis cinerea are closely related necrotrophic plant pathogenic fungi notable for their wide host ranges and environmental persistence. These attributes have made these species models for understanding the complexity of necrotrophic, broad host-range pathogenicity. Despite their similarities, the two species differ in mating behaviour and the ability to produce asexual spores. We have sequenced the genomes of one strain of S. sclerotiorum and two strains of B. cinerea. The comparative analysis of these genomes relative to one another and to other sequenced fungal genomes is provided here. Their 38–39 Mb genomes include 11,860–14,270 predicted genes, which share 83% amino acid identity on average between the two species. We have mapped the S. sclerotiorum assembly to 16 chromosomes and found large-scale co-linearity with the B. cinerea genomes. Seven percent of the S. sclerotiorum genome comprises transposable elements compared to <1% of B. cinerea. The arsenal of genes associated with necrotrophic processes is similar between the species, including genes involved in plant cell wall degradation and oxalic acid production. Analysis of secondary metabolism gene clusters revealed an expansion in number and diversity of B. cinerea–specific secondary metabolites relative to S. sclerotiorum. The potential diversity in secondary metabolism might be involved in adaptation to specific ecological niches. Comparative genome analysis revealed the basis of differing sexual mating compatibility systems between S. sclerotiorum and B. cinerea. The organization of the mating-type loci differs, and their structures provide evidence for the evolution of heterothallism from homothallism. These data shed light on the evolutionary and mechanistic bases of the genetically complex traits of necrotrophic pathogenicity and sexual mating. This resource should facilitate the functional studies designed to better understand what makes these fungi such successful and persistent pathogens of agronomic crops