GIOVANNI GIAMBENE - Academia.edu (original) (raw)

Papers by GIOVANNI GIAMBENE

Space Communications, 2007

Satellite systems are a valid alternative to cover wide areas on the earth and to provide broadba... more Satellite systems are a valid alternative to cover wide areas on the earth and to provide broadband communications to mobile and fixed users. Satellite systems should be able to provide to mobile users the same access characteristics of the terrestrial counterparts. This paper investigates packet scheduling aspects for Satellite Universal Mobile Telecommunication System (S-UMTS) transmissions based on Satellite-High Speed Downlink Packet Access (S-HSDPA). A geostationary bent-pipe satellite has been considered. The performance of different scheduling schemes has been compared in the envisaged S-HSDPA scenario, considering video streaming and Web traffic flows. We have obtained that the Proportional Fairness scheduler with Exponential Rule (PF-ER) permits to achieve the best performance for video traffic. Moreover, video traffic traces have been used to evaluate the objective video quality achieved at the application layer, considering the

2003 IEEE 58th Vehicular Technology Conference. VTC 2003-Fall (IEEE Cat. No.03CH37484), 2003

UTRA-TDD is one of the adopted air interfaces for third-generation (3G) mobile communication syst... more UTRA-TDD is one of the adopted air interfaces for third-generation (3G) mobile communication systems. In UTRA-TDD, packets with different quality of service (QoS) requirements need to be managed. We formulate the downlink packet scheduling problem in terms of dynamic programming by taking into account all the allocation constraints. Hence, we define a frame-by-frame exact downlink scheduling algorithm to support Web

Lecture Notes in Electrical Engineering, 2009

IEEE Transactions on Vehicular Technology, 1998

The universal mobile telecommunications system (UMTS) will consist of space UMTS (S-UMTS) and ter... more The universal mobile telecommunications system (UMTS) will consist of space UMTS (S-UMTS) and terrestrial UMTS (T-UMTS) components. An algorithm for predicting the traffic capacity in terms of the number of subscribers for the satellite component of UMTS is presented. The algorithm takes into account the takeup characteristics of new products, the growth of gross domestic product (GDP), the projection of population, the tariff of the service, and price fall over the forecast period. The predicted traffic is used to generate a traffic grid in terms of Erlang of dimension 36 2 72 in steps of 5 in both the latitude and longitude directions. The traffic grid is used to evaluate the performance of a dynamic channel allocation (DCA) technique as well as a fixed channel allocation (FCA) technique. Both channel allocation techniques have been considered with the queuing of handover (QH) requests. In order to compare the respective techniques' performance, a low-earth orbit mobile satellite system (LEO-MSS) mobility model is developed to take into account the effect of satellites' motion during interbeam handovers. A theoretical model for obtaining the values of blocking probabilities for low-traffic loads is presented. Finally, the performance of the DCA-QH technique is compared with the FCA-QH technique under suitably defined traffic and mobility conditions.

IEEE Network, 2018

Future 5G mobile communication systems are expected to integrate different radio access technolog... more Future 5G mobile communication systems are expected to integrate different radio access technologies including the satellite component. Within the 5G framework, the terrestrial services can be augmented with the development of High Throughput Satellite (HTS) systems and new mega constellations meeting 5G requirements, such as high bandwidth, low latency, increased coverage, including rural areas, air, and seas. This paper provides an overview of the current 5G initiatives and projects followed by a proposed architecture for 5G satellite networks where the SDN/NFV approach facilitates the integration with the 5G terrestrial system. In addition, a novel technique based on network coding is analyzed for the joint exploitation of multiple paths in such integrated satelliteterrestrial system. For TCP-based applications, an analytical model is presented to achieve an optimal traffic split between terrestrial and satellite paths and optimal redundancy levels.

Foundations and Trends® in Networking, 2017

Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 2009

The aim of this paper is to consider the problems of TCP performance in broadband GEO satellite n... more The aim of this paper is to consider the problems of TCP performance in broadband GEO satellite networks and to propose a crosslayer approach for a transport-layer PEP that makes spoofing actions on ACKs to modify them in case the satellite network is congested. This approach is investigated here from the signaling standpoint with a special attention to the BSM reference model and considering a specific GEO satellite network architecture based on the DVB-S2/-RCS standards. The proposed PEP can prevent congestion in the satellite network, thus allowing a better TCP performance. This work has been carried out within the framework of the EU SatNEx II FP6 Network of Excellence.

Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 2011

Satellite communications have a significant potentiality in the railway scenario, but suffer from... more Satellite communications have a significant potentiality in the railway scenario, but suffer from strong variations in the received signal power and need suitable solutions to deal with long channel disruptions due to tunnels. The approach envisaged in this paper is based on the adoption of a hybrid network (satellite and terrestrial WiFi coverage) and a Vertical Handover (VHO) scheme to switch seamlessly from one segment to another whenever link quality degrades and a new segment is available. Details are provided for the adoption of MIH and MIPv6 in such a context, referring to the BSM standard. Transport layer performance is evaluated considering different TCP versions (e.g., NewReno, BIC, and CUBIC) as well as possible cross-layer approaches to improve the performance in the presence of VHOs. Design criteria are provided taking into account train speed and overlap area size. Finally, interesting TCP performance results are achieved by updating the ssthresh value and limiting the cwnd value after VHOs by means of cross-layer approaches. This work has been carried out within the framework of the ESA SatNEx III project.

31st AIAA International Communications Satellite Systems Conference, 2013

This paper proposes the use of network coding in handover strategies applied in Smart Gateway Div... more This paper proposes the use of network coding in handover strategies applied in Smart Gateway Diversity (SGD) architectures, in order to mitigate information losses usually experienced by traditional handover techniques. The focus is actually about the benefit resulting from network coding application in terms of improved transmission robustness at the cost of reasonable satellite capacity waste.

2013 IEEE International Conference on Communications (ICC), 2013

This work aims at introducing two novel packet retransmission techniques for reliable multicast i... more This work aims at introducing two novel packet retransmission techniques for reliable multicast in the framework of Instantly Decodable Network Coding (IDNC). These methods are suitable for order-and delay-sensitive applications, where some information is of high importance for an earlier gain at the receiver's side. We introduce hence an Unequal Error Protection (UEP) scheme, showing by simulations that the Quality of Experience (QoE) for the end-users is improved even without complex encoding and decoding.

2008 IEEE International Workshop on Satellite and Space Communications, 2008

DVB-S2 is a second-generation standard for satellite transmissions, developed to improve the perf... more DVB-S2 is a second-generation standard for satellite transmissions, developed to improve the performance of DVB-S. Recently, research efforts have been devoted to extend this standard for mobile usage. In this paper we consider a scenario composed of a Ku-band GEO bent-pipe satellite, a gateway and some mobile users. The interest is here in investigating the performance of a scheduling scheme to manage DVB-S2 resources on the forward channel for the delivery of video CBR and FTP traffic flows to mobile users. A novel scheduler scheme, called UBMT, has been proposed that aims to manage CBR packet transmission deadlines while maximizing the aggregated goodput. Simulation runs have permitted to validate the optimal performance achieved by UBMT in comparison with other schemes. The impact of different TCP versions has been investigated as well showing the good results obtained with the SACK option.

In this paper, real-time channel prediction (RTChP) technique is implemented with channel-aware s... more In this paper, real-time channel prediction (RTChP) technique is implemented with channel-aware scheduling algorithms to increase decision accuracy at the scheduler. The channel-aware scheduler receives feedback messages in the form of channel state information (CSI) from the terminals via reservation slots in the return link. In the face of reliable multicast transmission, the channel-aware scheduler aims to reduce the number of packets received in error at the terminals. As a consequence, additional retransmission passes can be decreased, resulting in higher resource utilization in the forward link and reduced session delay. Simulation results are presented with considerations of a channel-aware scheduling (CAS) algorithm. From simulation results, RTChP increases performance gain when a lower number of terminals are considered. However, when the scenario involves more terminals, the prediction technique is ineffective and its performance deteriorates. Essentially, the RTChP implem...

IET Communications, 2010

The Broadband Satellite Multimedia (BSM) architecture standardised by ETSI defines a Satellite In... more The Broadband Satellite Multimedia (BSM) architecture standardised by ETSI defines a Satellite Independent Service Access Point (SI-SAP) interface layer that separates the satellite independent features of the upper layers from the satellite dependant features of the lower layers, and provides a mechanism to carry IP based protocols over these satellite dependent lower layers. This enables interoperability at the IP layer between satellite systems of different physical and link layers technologies that fully comply with the SI-SAP concept. This paper reviews past and current standardisation activities including the BSM QoS architecture, security architecture, network management that have been carried out by the ETSI TC-SES/BSM working group and looking into the future to extend current SI-SAP functions that can enhance existing QoS provision and security management capabilities as well as proposing a mobility management architecture that complies with the IEEE 802.21 MIH framework to support BSM mobility and to allow integration of satellite networks with fixed and mobile network infrastructures. A service-based network management architecture is also proposed to allow management flexibility and integration of business and operation support functions, paving the way for satellite integration into the Internet of the Future.

Cross-layering T The layered OSI approach for air interface design is based on the separate optim... more Cross-layering T The layered OSI approach for air interface design is based on the separate optimization of distinct protocols, thus reducing the complexity and allowing the interoperability among equipments of different manufacturers through the use of standardized interfaces.

Sensors, 2021

Forests play a fundamental role in preserving the environment and fighting global warming. Unfort... more Forests play a fundamental role in preserving the environment and fighting global warming. Unfortunately, they are continuously reduced by human interventions such as deforestation, fires, etc. This paper proposes and evaluates a framework for automatically detecting illegal tree-cutting activity in forests through audio event classification. We envisage ultra-low-power tiny devices, embedding edge-computing microcontrollers and long-range wireless communication to cover vast areas in the forest. To reduce the energy footprint and resource consumption for effective and pervasive detection of illegal tree cutting, an efficient and accurate audio classification solution based on convolutional neural networks is proposed, designed specifically for resource-constrained wireless edge devices. With respect to previous works, the proposed system allows for recognizing a wider range of threats related to deforestation through a distributed and pervasive edge-computing technique. Different p...

IEEE Transactions on Aerospace and Electronic Systems, 2019

Machine-to-machine services are witnessing an unprecedented diffusion, which is expected to resul... more Machine-to-machine services are witnessing an unprecedented diffusion, which is expected to result in an everincreasing data traffic load. In this context, satellite technology is playing a pivotal role, since it enables a widespread provisioning of machine-to-machine services. In particular, oil industry, maritime communications, as well as remote monitoring are sectors where the use of satellite communications is expected to dramatically explode within the next few years. In the light of this sudden increase of machine-to-machine data transported over satellite, a more thorough understanding of machine-tomachine service implementation over satellite is required, especially focusing on the interaction between transport and MAC layers of the protocol stack. Starting from these observations, this paper thoroughly analyses the interaction between TCP and the Contention Resolution Diversity Slotted Aloha access scheme defined in the DVB-RCS2 standard, assuming the use of an MQTT-like protocol to distribute machine-to-machine services. A novel TCP model is developed and validated through extensive simulation campaigns, which also shed important lights on the design choices enabling the efficient transport of machine-tomachine data via satellite.

Sensors

This paper deals with IoT devices deployed in remote areas without terrestrial Internet connectiv... more This paper deals with IoT devices deployed in remote areas without terrestrial Internet connectivity. We consider connecting IoT devices on the ground to the Internet through an aerial system based on an Unmanned Aerial Vehicle (UAV) for smart agriculture and environmental monitoring. The UAV flying over the remote area receives data from distributed IoT devices. The transmissions between the ground sensors and the UAV are carried out via LoRa. We have proposed a synchronization protocol for the opportunistic communication of LoRa IoT devices with a gateway onboard the UAV to save node battery life. Class A LoRa nodes on the ground transmit only when the UAV is expected to pass close to them; otherwise, they stay in the sleeping state most of the time. This paper provides a detailed description of the formulation of the synchronization protocol. The UAV’s flying dynamics have been considered for characterizing its speed and the time of visibility of each IoT sensor. Our model has al...

One of the key drivers for next-generation mobile communications, 5G, is the support of the Inter... more One of the key drivers for next-generation mobile communications, 5G, is the support of the Internet of Things (IoT) with billions of objects being connected to the Internet with low latency. The 5G technology will support the realization of smart cities, smart environments, and big data applications. Within the 5G framework, the terrestrial services can be augmented with the recent development of High Throughput Satellite (HTS) systems and mega-Low Earth Orbit (LEO) satellite constellations. In this paper, we investigate the integration of 5G technology and IoT by means of an aerial component composed of drones and satellites for a rural scenario. The prospected system can provide enhanced services, e.g., fire alarm detection, smart agriculture, animal tracking, and plant disease control. A use case of an agriculture application consisting of a number of areas whose sensor data are collected via drones is described. The proposed architecture consists of the drones connected to a sa...

2019 IEEE 2nd 5G World Forum (5GWF), 2019

IEEE Wireless Communications Letters

Non-Terrestrial Networks (NTNs) are expected to be a key component of 6th generation (6G) network... more Non-Terrestrial Networks (NTNs) are expected to be a key component of 6th generation (6G) networks to support broadband seamless Internet connectivity and expand the coverage even in rural and remote areas. In this context, High Altitude Platforms (HAPs) can act as edge servers to process computational tasks offloaded by energy-constrained terrestrial devices such as Internet of Things (IoT) sensors and ground vehicles (GVs). In this letter, we analyze the opportunity to support Vehicular Edge Computing (VEC) via HAP in a rural scenario where GVs can decide whether to process data onboard or offload them to a HAP. We characterize the system as a set of queues in which computational tasks arrive according to a Poisson arrival process. Then, we assess the optimal VEC offloading factor to maximize the probability of real-time service, given latency and computational capacity constraints.