Public sector ICT management strategy and its impact on e-government: a case study

This paper explores the relationship between public sector information and communications technology (ICT) management strategies and electronic government (e-Gov) initiatives. We use an adaptation of the technology enactment framework to explore various technological, organisational, and institutional factors that play a role in the development of ICT management strategies in a public agency. Using the case study of a city (anonymised and referred to in this paper as the ‘City’) in the U.S. state of Connecticut, we examine how these factors in turn help determine the city’s e-Gov initiatives. Our findings show that the bureaucratic structure and culture of the public agency play a key role in the type of ICT strategy adopted in the city and that this has important repercussions for the outcome of its e-Gov programme

A scalable data-plane architecture for one-to-one device-to-device communications in LTE-Advanced

One-to-one device-to-device (D2D) communications are expected to play a major role in future releases of LTE-A, as well as in future 5G networks. Despite the abundance of works on resource allocation for D2D communications, few works, if any, discuss how D2D should be realized within the LTE-A protocol stack. While it is generally understood that D2D endpoints should be able to communicate both on the direct path or sidelink (SL) and on the relayed path (RP) through the eNB, little has been said on how this can be achieved in practice. In this paper we present a comprehensive proposal for a data-plane architecture for D2D communication: we define how communications should occur on the SL and the RP, and propose a solution for the challenges associated with mode switching between the SL and the RP. In particular, we argue that two different communication modes on the RP are required to allow D2D connections to be kept alive across cell borders in a multicell environment. Our proposal is scalable, since it does not require any signaling, and is guaranteed to not introduce losses. We evaluate our proposal through detailed system-level simulations, also focusing on its interplay with transport-layer protocols

Optimal joint routing and link scheduling for real-time traffic in TDMA Wireless Mesh Networks

We investigate the problem of joint routing and link scheduling in Time-Division Multiple Access (TDMA) Wireless Mesh Networks (WMNs) carrying real-time traffic. We propose a framework that always computes a feasible solution (i.e. a set of paths and link activations) if there exists one, by optimally solving a mixed integer-non linear problem. Such solution can be computed in minutes or tens thereof for e.g. grids of up to 4x4 nodes. We also propose heuristics based on Lagrangian decomposition to compute suboptimal solutions considerably faster and/or for larger WMNs, up to about 50 nodes. We show that the heuristic solutions are near-optimal, and we exploit them to investigate the optimal placement of one or more gateways from a delay bound perspective

Ecological Sanitation: Technical Issues on the Adequacy of On-Site Storage and Treatment of Human Waste

A recent development in the water and sanitation sector is the concept of ecological sanitation (Eco-sanitation, or "Eco-San"); that is, the on-site storage and treatment of human fecal waste. The goal of this type of sanitation is to provide the user with a hygienic means of waste disposal, as well as a safe, stable, and useful end product. This paper examines the efficacy of such systems; namely, the type of treatment provided and the extent of pathogen destruction. Mathematical models of pathogen die-off data from experimental studies are used to estimate the hygienic quality of human fecal material under conditions normally found in Eco-San systems. A review of the literature shows major gaps in the data available to model the Eco-San systems. Lack of field data on the Eco-San process results in an incomplete description of the operating conditions. The scarcity of data on the kinetics of pathogen destruction at low temperatures also adds uncertainty to the assessment. Also, much of the available kinetic data is from studies that are carried out under conditions not necessarily encountered in Eco-San. Extrapolation of pathogen destruction from the kinetic models developed under different test conditions show inconsistent results. The use of the EPA Part503 Biosolids Rule pathogen reduction model also is not appropriate as a guide to determining treatment efficiency. More research and data on the survival of pathogens at lower temperature ranges is needed to determine the exact nature of Eco-San process efficiency. Existing data is used to develop a simplified model for the prediction of pathogen destruction. Recommendations are made to develop indicators of the efficacy of Eco-San treatment. The conclusions include a discussion on the way to operate double-vault latrines in dual phase manner that will result in a safe, hygienic end product.Master of Public Healt

D2D Communications for Large-Scale Fog Platforms: Enabling Direct M2M Interactions

To many, fog computing is considered the next step beyond the current centralized cloud that will support the forthcoming Internet of Things (IoT) revolution. While IoT devices will still communicate with applications running in the cloud, localized fog clusters will appear with IoT devices communicating with application logic running on a proximate fog node. This will add proximity-based machine-to-machine (M2M) communications to standard cloud-computing traffic, and it calls for efficient mobility management for entire fog clusters and energy-efficient communication within them. In this context, long-term evolution-advanced (LTE-A) technology is expected to play a major role as a communication infrastructure that guarantees low deployment costs, native mobility support, and plug-and-play seamless configuration. We investigate the role of LTE-A in future large-scale IoT systems. In particular, we analyze how the recently standardized device-to-device (D2D) communication mode can be exploited to effectively enable direct M2M interactions within fog clusters, and we assess the expected benefits in terms of network resources and energy consumption. Moreover, we show how the fog-cluster architecture, and its localized-communication paradigm, can be leveraged to devise enhanced mobility management, building on what LTE-A already has to offer

Throughput-optimal Resource Allocation in LTE-Advanced with Distributed Antennas

Distributed antennas are envisaged for LTE-Advanced deployments in order to improve the coverage and increase the cell throughput. The latter in turn depends on how resources are allocated to the User Equipments (UEs) at the MAC layer. In this paper we discuss how to allocate resources to UEs so as to maximize the cell throughput, given that UEs may re-ceive from several antennas simultaneously. We first show that the problem is both NP-hard and APX-hard, i.e. no polynomial-time algorithm exists that approximates the opti-mum within a constant factor. Hence, we pro-pose and evaluate two polynomial-time heuristics whose complexity is feasible for practical purposes. Our simulative analysis shows that, in practical scenarios, the two heuristics are highly accurate

Minimizing power consumption in virtualized cellular networks

Cellular network nodes should be dynamically switched on/off based on the load requirements of the network, to save power and minimize inter-cell interference. This should be done keeping into account global interference effects, which requires a centralized approach. In this paper, we present an architecture, realized within the Flex5GWare EU project, that manages a large-scale cellular network, switching on and off nodes based on load requirements and context data. We describe the architectural framework and the optimization model that is used to decide the activity state of the nodes. We present simulation results showing that the framework adapts to the minimum power level based on the cell loads

Practical feasibility, scalability and effectiveness of coordinated scheduling algorithms in cellular networks towards 5G

Coordinated Scheduling (CS) is used to mitigate inter-cell interference in present (4G) and future (5G) cellular networks. We show that coordination of a cluster of nodes can be formulated as an optimization problem, i.e., placing the Resource Blocks (RB) in each node’s subframe with the least possible over-lapping with neighboring nodes. We provide a clever formulation, which allows optimal solutions to be computed in clusters of ten nodes, and algorithms that compute good suboptimal solutions for clusters of tens of nodes, fast enough for a network to respond to traffic changes in real time. This allows us to assess the relationship between the scale at which CS is performed and its benefits in terms of network energy efficiency and cell-edge user rate. Our results, obtained using realistic power, radiation and Signal-to-Interference-and-Noise-Ratio (SINR) models, show that optimal CS allows a significant protection of cell-edge users. Moreover, this goes hand-in-hand with a reduction in the num-ber of allocated RBs, which in turn allows an operator to reduce its energy consumption. Both benefits actually increase with the size of the clusters. The evaluation is carried out in both a 4G and a foreseen 5G setting, using different power models, system bandwidths and SINR-to-datarate mappings