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Über dieses Buch

This book constitutes the proceedings of the 7th International Conference on Wireless and Satellite Services, WiSATS 2015, held in Bradford, UK, in July 2015. The conference was formerly known as the International Conference on Personal Satellite Services (PSATS) mainly covering topics in the satellite domain. As the scope of the conference widened to include wireless systems, the conference was renamed WiSATS.
The 29 revised papers were presented at the conference in three technical sessions and one special session on “Network Coding for Satellites”. WiSATS 2015 also hosted two workshops along with the main conference: The first workshop, Communication Applications in Smart Grid (CASG 2015), focused on the merging area of using communication technology within the electricity power grid for smart monitoring and control. The second workshop, Advanced Next-Generation Broadband Satellite Systems (BSS 2015), focused on the use of satellite systems for providing next-generation broadband services.

Inhaltsverzeichnis

Frontmatter

Workshop on Communication Applications in Smart Grid (CASG) 1

Frontmatter

Residential Energy Consumption Scheduling Techniques Under Smart Grid Environment

Abstract
In recent years the load demand by residential consumers are rapidly increasing due to the usage of many electric appliances in daily needs. Load demand during peak hours is becoming increasingly larger than off-peak hours, which is the major reason for inefficiency in generation capacity. Introduction of smart grid technology in Demand Side Management programs provides an alternative to installation of new generation units. Consumers can play a major role in reducing their energy consumption by communicating with utilities so that they can minimize their energy costs and get incentives, which also helps utilities in many ways. Smart grid technologies provide opportunities to employ different pricing schemes which also help in increasing the efficiency of appliance scheduling techniques. Optimal energy consumption scheduling reduces the peak load demand in peak hour. Peak average ratio (PAR) also minimizes the energy consumption cost. In this paper, we observes different energy consumption scheduling techniques that schedule the house hold appliances in real-time to achieve minimum energy consumption cost and to reduce peak load demand in peak hours to shape the peak load demand. Formulation and Solution methodology of residential energy consumption scheduling is presented with simulation results illustrating the working of the model.
J. Santosh Kumar, K. Shanti Swarup

Residential Demand Response Algorithms: State-of-the-Art, Key Issues and Challenges

Abstract
Demand Response (DR) in residential sector is considered to play a key role in the smart grid framework because of its disproportionate amount of peak energy use and massive integration of distributed local renewable energy generation in conjunction with battery storage devices. In this paper, first a quick overview about residential demand response and its optimization model at single home and multi-home level is presented. Then a description of state-of-the-art optimization methods addressing different aspects of residential DR algorithms such as optimization of schedules for local RE based generation dispatch, battery storage utilization and appliances consumption by considering both cost and comfort, parameters uncertainty modeling, physical based dynamic consumption modeling of various appliances power consumption at single home and aggregated homes/community level are presented. The key issues along with their challenges and opportunities for residential demand response implementation and further research directions are highlighted.
Rajasekhar Batchu, Naran M. Pindoriya

A Roadmap for Domestic Load Modelling for Large- Scale Demand Management within Smart Grids

Abstract
This paper discusses the potential of the domestic sector to provide Demand Side Management (DSM) services. The inherent drawback of the domestic sector is its structure, consisting of numerous small loads, the high variety of sub-types, the deviation of consumption profiles between households but also the daily variation of each household’s demand. In order for DSM to be coordinated and controlled effectively there is a need to create appropraite load clusters and categories. Moreover, there is a variety of domestic loads which can be considered controllable or ‘smart’. These smart loads have different characteristics, constraints and thus suitability for DSM services. Hence, typical clustering of load profiles is not optimal and the problem needs to solved on a lower level. A promising method is proposed, some initial results are shown, and finally future work and possible imporvements are discussed.
Alexandros Kleidaras, Aristides Kiprakis

Agent-Based Models for Electricity Markets Accounting for Smart Grid Participation

Abstract
A better understanding of the process of setting wholesale electricity prices does benet not only the generating companies but also the end users as it forces them to be responsible with their energy use in the time of peak electricity demand leading to smaller fluctuations in demand. Determining when a generator could maximise the prot based on demand fluctuations reduces risk and potential losses that could occur for generating companies. Based on this premise, this paper will outline the use of agent-based models (ABM) in future wholesale energy markets. By comparing agent-based modelling with methods currently employed by economists, this paper will show the impact ABM can have on developing a safer market structure. The results will propagate the idea of agent-based models influence on managing risks, controlling demand, and maximising prot in a time of smart grid technology. This paper is a proposal for work on smart grids in union with agent-based modelling being done in the future if suitable and useful.
Sara Lupo, Aristides Kiprakis

Workshop on Communication Applications in Smart Grid (CASG) 2

Frontmatter

Securing the Information Infrastructure for EV Charging

Abstract
We consider the functional and security requirements for the information exchanges in the infrastructure for EV charging being trialled in the Netherlands, which includes support for congestion management using the smart charging protocol OSCP. We note that current solutions do not provide true end-to-end security, even if all communication links are secured (for instance with TLS), as some data is forwarded between multiple parties. We argue that securing the data itself rather than just securing the communication links is the best way to address security needs and provide end-to-end security.
Moreover, because of the number of parties involved and the fact that the precise roles of these parties are still evolving, we argue that more data-centric communication solutions, using pub/sub (publish/subscribe) middleware, may be better suited than using point-to-point communication links between all parties, given the flexibility and scalability provided by pub/sub middleware.
Fabian van den Broek, Erik Poll, Bárbara Vieira

Workshop on Advanced Next Generation Broadband Satellite Systems (BSS) 1

Frontmatter

Capacity Enhancing Techniques for High Throughput Satellite Communications

Abstract
In this paper, we present physical layer and system level techniques that can increase the capacity of a multi-beam high throughput satellite (HTS) communication system. These include advanced predistortion and equalization techniques for the forward link, synchronization and non-linear distortion minimization techniques for the return link waveforms. Interference management techniques such as precoding, multi-user detection (MUD), interference cancellation and coordination are evaluated under realistic co-channel interference (CCI) conditions. Interference-aware radio resource management (RRM) algorithms are presented for the forward and return links with full frequency reuse. These include satellite-switched smart gateway diversity, interference-aware scheduling (IAS) for the forward link and scheduling based on multi-partite graph matching for the return link. The capacity enhancing techniques are evaluated in the Broadband Access via Integrated Terrestrial and Satellite Systems (BATS) framework.
Svilen Dimitrov, Stefan Erl, Benjamin Barth, Rosalba Suffritti, Niccoló Privitera, Gabriele Boccolini, Adegbenga B. Awoseyila, Argyrios Kyrgiazos, Barry G. Evans, Stephan Jaeckel, Belén Sánchez, Ana Yun Garcia, Oriol Vidal

Intelligent Gateways Enabling Broadband Access via Integrated Terrestrial and Satellite Systems

Abstract
Satellite broadband systems will play a key role in reducing the Digital Divide by complementing terrestrial networks in the delivery of next generation broadband to users in remote and rural locations. We describe an integrated broadband delivery system to fixed users that makes simultaneous use of heterogeneous access networks in order to optimize the end-user QoE. The design of the overall network architecture and the key building blocks of the routing entities at both ends of the integrated system are presented. The paper argues that MPTCP is an appropriate mechanism to offer hybrid communications over heterogeneous links and details a specific implementation of the intelligent routing gateways. Results from in-factory validation tests of the prototyped platforms are presented and discussed.
Luc Ottavj, Emmanuel Duros, Jacques Webert, Fabrice Gamberini, Christian Niephaus, Javier Perez-Trufero, Simon Watts

Modeling the Lifecycle Greenhouse Gas Emissions of a Hybrid Satellite System

Abstract
The aim of this paper is to present the approach used to model the greenhouse gas emissions of a hybrid broadband terrestrial/satellite system over its lifecycle. The lifecycle analysis showed that the electricity used by the customer premises equipment was responsible for the majority of the GHG emissions, assuming that the power plants continue to use fossil fuels. Emissions from manufacture, transport and waste treatment represented only 0.00453 % of the total emissions. Under a 1 % cut-off rule only the in-use emissions from on grid electricity would need to be considered. Manufacture, transport, and waste treatment can be safely ignored. This includes emissions from the manufacture of the satellite launch vehicle and the transport of the satellite into geostationary orbit.
David Faulkner, Keith Dickerson, Nigel Wall, Simon Watts

Workshop on Advanced Next Generation Broadband Satellite Systems (BSS) 2

Frontmatter

Extending the Usable Ka Band Spectrum for Satellite Communications: The CoRaSat Project

Abstract
Broadband access by satellite in Ka band will become constrained by spectrum availability. In this context, the EU FP7 project CoRaSat is examining the possible spectrum extension opportunities that could be exploited by a database or sensing approach in Ka band via the use of cognitive mechanisms. The database/sensing approach utilises spectrum sharing scenarios between Fixed Satellite Services (FSS), Fixed Services (FS) and Broadcast Satellite Service (BSS) feeder links are considered. Data bases and spectrum sensing have been evaluated to determine white spaces across the shared spectrum for several EU countries. Resource allocation schemes are investigated to place the carriers in the white spaces so as to maximize the throughput of the system. A multibeam satellite system model has been used to demonstrate the capacity gains that can be achieved by using the cognitive schemes. The overall system is being demonstrated in a laboratory trial.
Barry Evans, Paul Thompson, Eva Lagunas, Shree Krishna Sharma, Daniele Tarchi, Vincenzo Riccardo Icolari

On the Feasibility of Interference Estimation Techniques in Cognitive Satellite Environments with Impairments

Abstract
The increasing demand of wider frequency bands in wireless communications has lead in the last years to the introduction of novel techniques allowing to exploit more efficiently the radio spectrum. In particular, spectrum sharing is considered one of the key technologies for future wireless systems. Cognitive radio is considered the most important technique for efficiently allowing the spectrum sharing among heterogeneous systems. If on one hand the cognitive radio techniques have been extensively assessed in terrestrial communications, they remain quite an unexplored area in Satellite Communications (SatComs). In this paper an Interference Estimation technique for SatComs aiming to reuse the spectrum resources primarily allocated to terrestrial communications is discussed. In particular, its assessment in a realistic scenario, where multiple impairments are considered, is discussed.
Daniele Tarchi, Vincenzo Riccardo Icolari, Joel Grotz, Alessandro Vanelli-Coralli, Alessandro Guidotti

Technology Trends for Ka-Band Broadcasting Satellite Systems

Abstract
This paper provides an overview of the technology trends pertinent to Ka-band broadcasting satellite systems. Starting from the state-of-the-art digital broadcasting systems, we present technology trends that can further expand the use of Ka-band satellite broadcasting and improve the performance and efficiency. In particular, it is shown that the combination of DVB-S2X features offer significant advances and opportunities to service providers. This is true particularly in geographical areas that are subject to severe atmospheric attenuation.
Nader S. Alagha, Pantelis-Daniel Arapoglou

WiSATS Session 1

Frontmatter

Evaluating the Performance of Next Generation Web Access via Satellite

Abstract
Responsiveness is a critical metric for web performance. Update to the web protocols to reduce web page latency have been introduced by joint work between the Internet Engineering Task Force (IETF) and the World Wide Web Consortium (W3C). This has resulted in new protocols, including HTTP/2 and TCP modifications, offering an alternative to the hypertext transfer protocol (HTTP/1.1). This paper evaluates the performance of the new web architecture over an operational satellite network. It presents the main features of the new protocols and discusses their impact when using a satellite network. Our tests comparing the performance of web-based applications over the satellite network with HTTP/2 confirm important reductions of page load times with respect to HTTP/1.1. However, it was also shown that performance could be significantly improved by changing the default server/client HTTP/2 configuration to best suit the satellite network.
Raffaello Secchi, Althaff Mohideen, Gorry Fairhurst

Multimodality in the Rainfall Drop Size Distribution in Southern England

Abstract
Mutimodality appears in the modelling of rainfall drop size distributions (DSDs), and the understanding of the distribution in general is important as it helps in the predicting and mitigation of attenuation due to rain of satellite signals in frequencies above 10 GHz. This work looks at the occurrence of multimodality in the rainfall DSDs in southern England, with data captured at the Chilbolton Observatory for a seven year period (2003 to 2009). The investigation looks at the variation in the number of modes against different rain rates and seasons. It shows that multimodality is a relatively common occurrence, and hence there is a need to model this phenomenon when attempting to predict rain attenuation of satellite signals.
K’ufre-Mfon E. Ekerete, Francis H. Hunt, Ifiok E. Otung, Judith L. Jeffery

Wireless Sensor Networks and Satellite Simulation

Abstract
Connecting wireless sensor networks (WSN) by the air becomes attractive due to advances in Satellites and Unmanned aerial vehicle (UAV). This work focus on specification and simulation of situations where several distant WSN have gateways visited periodically by a mobile on a static path. To develop and evaluate collection and control services, it is first needed to run system level simulation. This paper reports on producing automatically representations of complex topology where mobile cooperate with sensor fields with respect to timing constraints from both sides. Simulation programs are produced for graphic accelerators (GPU), and concurrent process architectures.
P.-Y. Lucas, Nguyen Huu Van Long, Tuyen Phong Truong, B. Pottier

Mission Analysis for the Optimization of the GPS Coverage for an Earth Observation Satellite

Abstract
The goal of this work is to present an advanced study of the GPS coverage capability of a Low Earth Orbit (LEO) satellite. The motivation for this arises in the satellite control environment, during the operations preparation phase, by the need of predicting the time necessary to the on-board GPS receiver to fix the first orbital position, after the on-orbit injection at LEOP (Launch and Early Operational Phase). Once the first acquisition is performed, the satellite will be ready to enter the normal mode. The availability of a proper GPS coverage at LEO altitudes should be evaluated not only during the LEOP - clearly more critical - but also in the entire routine life of the satellite. Different approaches to optimize the GPS coverage, proposed by manufacturers and satellite operators, are considered, showing key strengths and weak points of the selected strategies. Operational and structural constraints must be taken into account when aiming at the proposal of different approaches to the GPS coverage issue, such as occultation of the on-board star trackers and the GPS antennas.
Roberta Falone, Pietro Ivan Chichiarelli, Ennio Gambi, Susanna Spinsante

WiSATS Session 2

Frontmatter

Proposal of Time Domain Channel Estimation Method for MIMO-OFDM Systems

Abstract
This paper proposes a time domain channel estimation (TD-CE) method for Multi Input Multi Output-Orthogonal Frequency Division Multiplexing (MIMO-OFDM) systems. The feature of proposed TD-CE method is to estimate channel frequency responses for all links between transmit and receive antennas in MIMO-OFDM systems by using one scattered pilot preamble symbol in the time domain. The proposed method can achieve higher channel estimation accuracy even when the number of transmission antennas is larger and the transmission signal is sampled by a non-Nyquist rate in which the number of IFFT points is different from the number of data subcarriers due to the insertion of null subcarriers (zero padding) at the both ends of data subcarriers. This paper shows various computer simulation results in the time-varying fading channels to demonstrate the effectiveness of the proposed channel estimation method as comparing with the conventional channel estimation methods.
Tanairat Mata, Pisit Boonsrimuang, Kazuo Mori, Hideo Kobayashi

An OFDM Timing Synchronization Method Based on Averaging the Correlations of Preamble Symbol

Abstract
In this paper, we propose a novel timing synchronization method for orthogonal frequency division multiplexing (OFDM) systems with a single-symbol preamble. The proposed method has an impulsive timing metric and outperforms the conventional methods in multipath fading channels by averaging M 0 differential correlations of the preamble. Using this method, the system will achieve accurate timing synchronization and keep low out-of-band radiation. Performances of the proposed estimator with different M 0 values are evaluated in terms of bias and mean square error (MSE). Simulation results validate the effectiveness of the proposed timing synchronization method.
Yunsi Ma, Chaoxing Yan, Sanwen Zhou, Tongling Liu, Lingang Fu

A Printed Wideband MIMO Antenna for Mobile and Portable Communication Devices

Abstract
A printed crescent-shaped monopole MIMO antenna is presented for handheld wireless communication devices. The mutual coupling between the two antenna elements can be minimised by implementing a I-shaped common radiator. Both the simulated and measured results agree that the antenna covers the operating frequency band from 1.6 to 2.8 GHz with the return loss and isolation better than 10 dB and 14 dB respectively. To further verifying the MIMO characteristic including far-field, gain, radiation efficiency, channel capacity loss and envelope correlation, the results confirm that the antenna can operate effectively in a rich multipath environment.
Chan H. See, Elmahdi Elkazmi, Khalid G. Samarah, Majid Al Khambashi, Ammar Ali, Raed A. Abd-Alhameed, Neil J. McEwan, Peter S. Excell

A New Approach for Implementing QO-STBC Over OFDM

Abstract
A new approach for implementing QO-STBC and DHSTBC over OFDM for four, eight and sixteen transmitter antennas is presented, which eliminates interference from the detection matrix and improves performance by increasing the diversity order on the transmitter side. The proposed code promotes diversity gain in comparison with the STBC scheme, and also reduces Inter Symbol Interference.
Yousef A. S. Dama, Hassan Migdadi, Wafa Shuaieb, Elmahdi Elkazmi, Eshtiwi A. Abdulmula, Raed A. Abd-Alhameed, Walaa Hammoudeh, Ahmed Masri

Special Session on Network Coding for Satellite Communication Systems

Frontmatter

Network Coding for Multicast Communications over Satellite Networks

Abstract
Random packet errors and erasures are common in satellite communications. These types of packet losses could become significant in mobile satellite scenarios like satellite-based aeronautical communications where mobility at very high speeds is a routine. The current adaptive coding and modulation (ACM) schemes used in new satellite systems like the DVB-RCS2 might offer some solutions to the problems posed by random packet errors but very little or no solution to the problems of packet erasures where packets are completely lost in transmission. The use of the current ACM schemes to combat packet losses in a high random packet errors and erasures environment like the satellite-based aeronautical communications will result in very low throughput. Network coding (NC) has proved to significantly improve throughput and thus saves bandwidth resources in such an environment. This paper focuses on establishing how in random linear network coding (RLNC) the satellite bandwidth utilization is affected by changing values of the generation size, rate of packet loss and number of receivers in a satellite-based aeronautical reliable IP multicast communication. From the simulation results, it shows that the bandwidth utilization generally increases with increasing generation size, rate of packet loss and number of receivers.
Esua Kinyuy Jaff, Misfa Susanto, Muhammadu Ali, Prashant Pillai, Yim Fun Hu

Network Coding over SATCOM: Lessons Learned

Abstract
Satellite networks provide unique challenges that can restrict users’ quality of service. For example, high packet erasure rates and large latencies can cause significant disruptions to applications such as video streaming or voice-over-IP. Network coding is one promising technique that has been shown to help improve performance, especially in these environments. However, implementing any form of network code can be challenging. This paper will use an example of a generation-based network code and a sliding-window network code to help highlight the benefits and drawbacks of using one over the other. In-order packet delivery delay, as well as network efficiency, will be used as metrics to help differentiate between the two approaches. Furthermore, lessoned learned during the course of our research will be provided in an attempt to help the reader understand when and where network coding provides its benefits.
Jason Cloud, Muriel Médard

Network Coding Applications to High Bit-Rate Satellite Networks

Abstract
Satellite networks are expected to support multimedia traffic flows, offering high capacity with QoS guarantees. However, system efficiency is often impaired by packet losses due to erasure channel effects. Reconfigurable and adaptive air interfaces are possible solutions to alleviate some of these issues. On the other hand, network coding is a promising technique to improve satellite network performance. This position paper reports on potential applications of network coding to satellite networks. Surveys and preliminary numerical results are provided on network coding applications to different exemplary satellite scenarios. Specifically, the adoption of Random Linear Network Coding (RLNC) is considered in three cases, namely, multicast transmissions, handover for multihomed aircraft mobile terminals, and multipath TCP-based applications. OSI layers on which the implementation of networking coding would potentially yield benefits are also recommended.
Giovanni Giambene, Muhammad Muhammad, Doanh Kim Luong, Manlio Bacco, Alberto Gotta, Nedo Celandroni, Esua Kinyuy Jaff, Misfa Susanto, Yim Fun Hu, Prashant Pillai, Muhammad Ali, Tomaso de Cola

Can Network Coding Mitigate TCP-induced Queue Oscillation on Narrowband Satellite Links?

Abstract
Satellite-based Internet links often feature link bandwidths significantly below those of the ground networks on either side. This represents a considerable bottleneck for traffic between those networks. Excess traffic banks up at IP queues at the satellite gateways, which can prevent conventional TCP connections from reaching a transmission rate equilibrium. This well-known effect, known as queue oscillation can leave the satellite link severely underutilised, with a corresponding impact on the goodput of TCP connections across the link. Key to queue oscillation are sustained packet losses from queue overflow at the satellite gateway that the TCP senders cannot detect quickly due to the long satellite latency. Network-coded TCP (TCP/NC) can hide packet loss from TCP senders in such cases, allowing them to reach equilibrium. This paper reports on three scenarios in the Pacific with two geostationary and one medium earth orbit connection. We show by simulation and circumstantial evidence that queue oscillation is common, and demonstrate that tunneling TCP over network coding allows higher link utilisation.
Ulrich Speidel, Lei Qian, ’Etuate Cocker, Péter Vingelmann, Janus Heide, Muriel Médard

Network Coding over Satellite: From Theory to Design and Performance

Abstract
The concept of network coding has greatly evolved since its inception. Theoretical and achievable performance have been obtained for a wide variety of networking assumptions and performance objectives. Even if powerful, such a broad applicability poses a challenge to a unified design approach over different communication networks and systems.
In this work, we propose a (non-reductionist) unified network coding design architectural framework where an ontology of abstraction domains is introduced rather than layer/system/network-specific assumptions and designs. The framework brings together network and system design and seems compatible with upcoming (more general) design frameworks such as software-defined networking, cognitive networking or network virtualization. We illustrate its applicability showing the case of network coding design over DVB-S2X/RCS.
M. A. Vazquez-Castro, Paresh Saxena

WiSATS Session 3

Frontmatter

Gateway Selection Optimization in Hybrid MANET-Satellite Network

Abstract
In this paper, we study the problem of gateway placement in an hybrid mobile ad hoc – satellite network. We propose a genetic algorithm based approach to solve this multi-criteria optimization problem. The analysis of the proposed algorithm is made by means of simulations. Topology dynamics are also taken into account since the node mobility will impact the gateway placement decisions. Our solution shows promising results and displays unmatched flexibility with respect to the optimization criteria.
Riadh Dhaou, Laurent Franck, Alexandra Halchin, Emmanuel Dubois, Patrick Gelard

A Pragmatic Evaluation of Distance Vector Proactive Routing in MANETs via Open Space Real-World Experiments

Abstract
Mobile Ad hoc Networks constitute a promising and fast developing technology that could significantly enhance user freedom. The flexibility provided by such networks is accompanied by unreliability due to notably dynamic conditions that render routing quite problematic. For that reason, the research community has proposed multiple protocols claimed to address this issue, however, only few have been tested via real experiments, while even fewer have reached maturity to become readily available to end users. The main purpose of this paper is to pragmatically evaluate a promising, complete, and finalized MANET protocol via real-world experimentation in open space environment. The considered protocol, with the acronym B.A.T.M.A.N, which is based on distance vector proactive routing, was tested in different networking scenarios that revealed its ability to satisfactorily handle traffic under different conditions.
Thomas D. Lagkas, Arbnor Imeri, George Eleftherakis

Elastic Call Admission Control Using Fuzzy Logic in Virtualized Cloud Radio Base Stations

Abstract
Conventional Call Admission Control (CAC) schemes are based on stand-alone Radio Access Networks (RAN) Base Station (BS) architectures which have their independent and fixed spectral and computing resources, which are not shared with other BSs to address their varied traffic needs, causing poor resource utilization, and high call blocking and dropping probabilities. It is envisaged that in future communication systems like 5G, Cloud RAN (C-RAN) will be adopted in order to share this spectrum and computing resources between BSs in order to further improve the Quality of Service (QoS) and network utilization. In this paper, an intelligent Elastic CAC scheme using Fuzzy Logic in C-RAN is proposed. In the proposed scheme, the BS resources are consolidated to the cloud using virtualization technology and dynamically provisioned using the elasticity concept of cloud computing in accordance to traffic demands. Simulations shows that the proposed CAC algorithm has high call acceptance rate compared to conventional CAC.
Tshiamo Sigwele, Prashant Pillai, Yim Fun Hu

Implementation of DVB-S2X Super-Frame Format 4 for Wideband Transmission

Abstract
Recently the extension of the digital video broadcasting second generation standard for transmission over satellite (DVB-S2) has been finalized in order to achieve a higher spectral efficiency without introducing fundamental changes to the complexity and structure of the common DVB-S2 standard [1]. Therefore, this extension is termed DVB-S2X. In this paper, we focus on a more powerful physical layer frame structure, known as Super-Frame (SF), which has been adopted as optional waveform container in Annex E of the DVB-S2X specification [2]. The paper provides insights to capabilities of the SF structure in support of emerging system applications. Analytical results of the SF performance are complemented by the performance results obtained from an end-to-end testbed implementing SF format 4, which is optimized for wideband transmission and very low SNR reception conditions. The testbed includes prototype design of modulator and demodulator featuring the SF generation and detection capability. The prototype devices are able to operate at a wide range of signal-to-noise ratios and at high symbol rates. This design represents the basis for planned over-the-air tests using a single wideband satellite transponder to demonstrate the feasibility of transmitting and receiving 1 Gbit/s.
Christian Rohde, Holger Stadali, Javier Perez-Trufero, Simon Watts, Nader Alagha, Riccardo De Gaudenzi

Technology Impact on Agricultural Productivity: A Review of Precision Agriculture Using Unmanned Aerial Vehicles

Abstract
Technology application to agricultural productivity is thought to be the solution to meet food demand of the growing population. In a rapidly changing world, with the prospect of decreasing arable land due to urbanization and industrialization, agricultural output requires a 70 % increase in production levels and efficient growth in the harvesting, distribution and consumption of the resources, to meet demand. There are innovations in Information and Communications Technology that can be applied to the agricultural sector in areas of precision farming, use of farm management software, wireless sensors, and use of agricultural machinery. Remote sensing technology is playing a key role through precision agriculture. This paper highlights ways in which precision agriculture is impacting on agriculture with the use of unmanned aerial vehicles for image capturing, processing and analysis.
H. S. Abdullahi, F. Mahieddine, R. E. Sheriff

Backmatter

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