Tommaso Pecorella

Predictive bandwidth control for GEO satellite networks

The paper presents a novel approach for dynamic bandwidth allocation (DBA) in GEO satellite networks based on adaptive predictive control. In the proposed DBA scheme each satellite gateway (SG) uses an adaptive predictor to forecast the future input traffic flow along with a predictive bandwidth controller to generate a bandwidth request to the network control center (NCC) according to a receding-horizon policy, via solution of an optimal control problem. A multi-service traffic scenario is considered with a careful eye to guarantee differentiated quality of service requirements. Simulation experiments demonstrate that the DBA technique proposed in this work outperforms fixed allocation as well as existing DBA methods.

A network architecture solution for efficient IOT WSN backhauling: challenges and opportunities

At present, Sensor Networks and the emerging Internet of Things paradigm are playing a key role in the industry and in academic research. In this article we outline a common scenario, currently arising standards, and other emerging technologies having a direct impact on network architecture. In particular we introduce a novel network architecture based on an M2M Gateway and discuss it in relation to smart building applications. The proposed network architecture will improve services for users and will offer new opportunities for both service providers and network operators.

Proposal and performance evaluation of an efficient multiple-access protocol for LEO satellite packet networks

This paper deals with a modified version of the packet reservation multiple-access (PRMA) protocol suitable for integration of real-time (voice) and best effort (data) traffic in low Earth orbit (LEO) satellite communication systems. The proposed scheme differs from previous alternatives on the method adopted to handle access requests for voice and data terminals, and to transmit data messages. An analytical approach is proposed and validated in the case of voice and classical (i.e., geometric distributed) data traffic in order to derive system performance in terms of mean data message delay and voice packet dropping probability. However, in order to better highlight the advantages of the proposed approach typical interactive and background traffics types have been also considered. Performance comparisons with previous proposed PRMA protocols for voice and data transmission in LEO satellite communication systems are also shown in order to highlight the better behavior of the proposed scheme. Finally, a brief discussion concerning the extension of the proposed S-PRMA protocol to the case of different satellite communication systems is also provided.

A gateway architecture for IP satellite networks with dynamic resource management and DiffServ QoS provision

IP satellite networks are gaining a considerable interest mainly due to their ability to deliver high bandwidth services to nation-wide areas. However some difficulties still exist to implement IP-based transport mechanisms on geostationary satellite networks (i.e. TCP-based protocols are affected by the large delay-bandwidth product). The satellite network architecture presented in this paper is designed to provide a complete QoS support for IP traffic based on the DS paradigm, while minimizing the waste of the valuable satellite resource. The proposed technique operates on two time scales: a short-term reaction compensates fast traffic variations by an appropriate scheduling while a medium term resource allocation mechanism reduces the wasted bandwidth. Copyright

Short paper: Overcoming IoT fragmentation through standard gateway architecture

Vertical approach still largely dominates smart devices systems. Even in IoT, proprietary protocols and backend systems are still common. The presented solution aims at harmonizing different standards and architectures, improving sustainability and security. It also allows to use a IaaS approach to further enhance the sensor networks business model.

Analysis of secure handover for IEEE 802.1x-based wireless ad hoc networks

The handover procedure in secure communication wireless networks is an extremely time-consuming phase, and it represents a critical issue in relation to the time constraints required by certain real-time traffic applications. In particular, in the case of the IEEE 802.1X model, most of the time required for a handover is used for packet exchanges that are required for authentication protocols, such as Extensible Authentication Protocol Transport Layer Security (EAP-TLS), that require an eight-way handshake. Designing secure re-authentication protocols to reduce the number of packets required during a handover is an open issue that is gaining interest with the advent of a pervasive model of networking that requires realtime traffic and mobility. This article presents the 802.1X model and evaluates its application to ad hoc networks based on IEEE 802.11 i or IEEE 802.1 be standards, focusing on the problems that must be evaluated when designing handover procedures, and suggesting guidelines for securing handover procedures. It also presents a novel protocol to perform secure handovers that is respectful of the previous analysis and that has been implemented in a mesh environment.

Secure, fast handhoff techniques for 802.1X based wireless network

Wireless networks that support client mobility have to face the challenge of providing a secure, performant handoff between different access points. IEEE 802.1X [1] model provides a secure mechanism used by many standard protocols to securely generate keying material between two peer hosts when one of the two is accessing the network for first time, but that is hardly usable for reauthentication during handoff procedures without loss of performance. This paper deals with the proposal of a novel scheme to transport authentication credentials during handoff that uses a two-way only exchange with the backend authentication server maintaining the security of the system. As a high-level method it can be applied to different types of network, such as IEEE 802.11i [2] infrastructure or ad-hoc mode networks in a mesh environment.

QoS provisioning in GEO satellite with onboard processing using predictor algorithms

Recently, IP satellite networks have attracted considerable interest as a technology to deliver high-bandwidth IP-based multimedia services to nationwide areas. In particular, IP satellite networks seem to be one of the most promising technologies for connecting users in rural areas, where a wired high-speed network (e.g., xDSL) is not foreseen to be used. However, one of the main problems arising here is to guarantee specific quality of service constraints in order to have good performance for each traffic class. Among various QoS approaches used in the Internet, recently the DiffServ technique has become the most promising solution, mainly for its scalability with respect to the IntServ approach. Moreover, in satellite communication systems, DiffServ computational capabilities are placed at the edge points, reducing the implementation complexity of the satellite onboard equipment. This article deals with the problem of QoS provisioning for packet traffic by considering some resource allocation schemes, including bandwidth allocation techniques and priority-driven onboard switching algorithms. As to the first aim, the proposed technique takes advantage of proper statistical traffic modeling to predict future bandwidth requests. This approach takes into consideration DiffServ-based traffic management to guarantee QoS priority among different users. Moreover, the satellite onboard switching problem has been addressed by considering a suitable implementation of the DiffServ policy based on a cellular neural network.

Emergency satellite communications: research and standardization activities

Space communications is an ideal candidate to handle critical and emergency situations arising on a regional to global scale, provided there is effective integration among them. The article presents a review of solutions offered by space communication systems for early warning and emergency communication services. It includes an up-to-date review of public research and standardization activity in the field, with a specific focus on mass alert. The main technical issues and challenges are also discussed along with the cutting-edge research from the scientific community.

Multi-terminal dynamic bandwidth allocation in GEO satellite networks

The paper presents a novel approach for dynamic bandwidth allocation in geostationary satellite networks. Each satellite gateway (SG) uses a local adaptive predictor to forecast the future input traffic flow along with a local predictive (receding-horizon) controller to generate a bandwidth request to the network control center (NCC). In turn, the NCC globally shares out the available bandwidth among the requesting SGs according to a suitable fair resource allocation policy. Simulation experiments demonstrate the effectiveness of the proposed approach in terms of efficient bandwidth usage and low packet delivery delays under different traffic load conditions.