Showing papers by "Antonio Iera published in 2009"

Integration of Ad-hoc Networks with infrastructured systems for multicast services provisioning

Abstract: Focus of this paper is on an integration framework between UMTS (Universal Mobile Telecommunications System) and Mobile Ad-hoc NETworks (MANET), specifically designed to increase the effectiveness of cellular systems in supporting multicast transmissions. The aim is to overcome the scalability constrains of cellular network by enriching it through multi-hop communications. To the purpose of reducing the adverse impact of multicast transmission in the wireless cellular environment and to improve the system scalability, in this paper we propose a Radio Resource Management (RRM) policy based on a MBMS/MANET integrated architecture. The proposed solution has been successfully tested through a comprehensive simulation campaign. Obtained results make us confident that a well-designed integration is a promising approach to overcome the UMTS (and beyond UMTS networks, as well) inadequacy in supporting multicast services efficiently.

Cooperative terminals for Incident Area Networks

Abstract: Past crises all over the world (09/11, tsunami, etc.) have highlighted the importance of the availability of critical up-to-date information in real-time at the place where required. The key need is, consequently, for reliable communication systems to coordinate emergency operations even when existing infrastructures are damaged. In this case, rapidly deploying ad-hoc networks in the disaster area is a feasible solution. Incident Area Network (IAN), are self-forming temporary network infrastructures brought to the scene of an incident to support personal and local communications among different public safety end-users. This paper aims at defining the system architecture of IANs where the cooperation among terminals is foreseen. Furthermore, several open issues are identified and possible solutions are proposed.

SINR-Based Transport Channel Selection for MBMS Applications

Abstract: Multimedia broadcast multicast services (MBMS), introduced by Third Generation Partnership Project (3GPP) in universal mobile telecommunications system (UMTS) release 6 specification, have the aim to support downlink streaming and game services to groups of users. MBMS can supply users with resources in two different modalities: point-to-point (PtP) and point-to-multipoint (PtM). The power consumed by the network is an important topic to discuss when considering the presence of MBMS services. The UMTS system is, in fact, interference- limited; thus, the power available to Node B is limited and it must be enough to serve any user under its coverage. Therefore, the choice of the most efficient transport channel in terms of power consumption is a key aspect for the MBMS, since a wrong transport channel selection for the transmission of the MBMS data could adversely affect the overall capacity of the system. In this paper we search for the most efficient transport channel to convey MBMS data, by comparing the performance of the high speed downlink shared channel (HS-DSCH), the dedicated channel (DCH), and the forward access channel (FACH), for given transmission power levels and cell coverage size.

On the Performance of "Compensation-Based" and "Greedy" Scheduling Policies in IEEE 802.16 Networks

Abstract: The provision of Quality of Service (QoS) is one of the primary requirements for IEEE 802.16/WiMAX to become a reference technology for multimedia service delivery. This paper reports on the design and analysis of some channel-aware scheduling algorithms for downlink traffic delivery in a fixed point-to-multipoint WiMAX network. In particular, compensation-based and greedy approaches are compared according to their ability to provide QoS and fairness to traffic flows when not working in ideal channel conditions. Simulations highlight that the greedy philosophy fails to provide service differentiation, especially when users perceive heterogeneous channel conditions.

Channel-aware class-based scheduling for QoS support in IEEE 802.16/WiMAX networks

Abstract: One of the fundamental requirements for IEEE 802.16/WiMAX to become a key technology for high-speed multimedia service delivery is QoS differentiation. Although the IEEE 802.16 standard gives some guidelines to design a QoS architecture to support multimedia services, implementation details are left to manufacturers. This paper reports on the design and analysis of a channel-aware Deficit Round Robin (DRR) based scheduling algorithm for downlink traffic delivery in a point-to-multipoint WiMAX network. A technique for compensation of channel errors is proposed to preserve QoS differentiation and fairness under non-ideal channel conditions. Simulations confirm effectiveness of the compensation techniqueunder different channel conditions and network loads.

High Altitude Platforms: Radio Resource Management Policy for MBMS Applications

Abstract: In this work we are interested in investigating how the High Altitude Platform (HAP) can efficiently support Multimedia Broadcast/Multicast Service (MBMS) in a scenarios wherein the terrestrial network is not available To this aim, we propose to implement an efficient policy of Radio Resources Management (RRM) into the HAP Radio Network Controller (H-RNC) The proposed technique allows to improve the overall system capacity by selecting the most efficient multicast transport channel in terms of power consumption and by defining the switching thresholds between point-to-point and point-to-multipoint connections

Radio resource management policy for multicast transmissions in high altitude platforms

Abstract: In this research work we aim at investigating how efficient high altitude platforms (HAPs) can be in supporting multimedia broadcast/multicast service (MBMS) in scenarios in which the terrestrial coverage is not available. In particular, we propose to implement an efficient policy of radio resources management (RRM) into the HAP radio network controller (H-RNC). The proposed technique allows to increase the overall system capacity by selecting the most efficient multicast transport channel in terms of power consumption, amongst dedicated channel (DCH), forward access channel (FACH), and high speed downlink shared channel (HS-DSCH). (7 pages)

On the impact of the user terminal velocity on HSPA performance in MBMS multicast mode

Abstract: Multimedia Broadcast/Multicast Services (MBMS), introduced in Universal Mobile Telecommunication System (UMTS), have the aim to allow transmissions from a single source entity to multiple destinations. From the radio perspective, MBMS foresees both point-to-point (PtP) and point-to-multipoint (PtM) transmission mode, supported by Dedicated, Common, and Shared channels. The High Speed Downlink Packet Access (HSDPA), analyzed in this paper, can guarantee a higher data rate through the introduction of High Speed Downlink Shared Channel (HS-DSCH), thus improving the performance of MBMS transmissions. The aim of this paper is to investigate the impact of the User Equipment (UE) speed on the maximum number of users that the HS-DSCH can support for MBMS applications. In particular, two different mobility profiles are taken into account (Pedestrian and Vehicular) and the obtained results are validated by considering different transmission power levels, cell coverage sizes and bit rates.

Evolutionary theory for cluster head election in cooperative clusters implementing network coding

Abstract: In this paper a cluster head election problem is studied for a cooperative wireless network. The nodes in the cluster use random linear network coding to enhance the throughput performance in spreading the data for a file download service. Some of the nodes in the cluster will access through their cellular link parts of a file to be exchanged among all the cooperative nodes. In such a wireless environment, network coding enhances significantly the throughput performance. A good choice of the nodes acting as information sources for the cluster depends on their position and cellular link throughput and turns to be of utmost importance for the achievement of high performance levels. Therefore, a cluster head election algorithm is needed, which shall be fast in converging to either the optimal or, alternatively, a satisfactory sub-optimal solution. We propose to use the evolutionary theory. Results of our investigations are introduced with reference to a high performing implementation of a genetic algorithm under different network conditions both in static and in mobile environments.