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We propose an energy-efficient resource allocation framework suitable for multicast service delivery over 3GPP's Long Term Evolution Advanced Single Frequency Network evolved Multimedia Broadcast and Multicast Service networks. A key aspect of the considered system model is that multicast communications are delivered according to the Random Linear Network Coding (RLNC) principle. The proposed optimization framework aims at minimizing the transmission energy associated with the delivery of a set of multicast flows. The goal is achieved by jointly optimizing the transmission power and the RLNC scheme of each flow. Furthermore, we present a heuristic strategy that can efficiently find a good-quality feasible solution of the presented resource allocation model.

This paper deals with the modeling and analysis of the resequencing delay in time-division duplexing communication systems that adopt the Selective Repeat Automatic Repeat-reQuest error control strategy. Under the assumption that packet misordering at the receiving end is induced by channel errors, this paper proposes an analytical approach based on the absorbing Markov chain theory to accurately predict the impact of the resequencing delay on the quality of the provided services. Numerical results, which are derived by means of computer simulations, are also given to validate the proposed analytical model.

Fountain codes are gradually being incorporated into broadcast technologies, such as multimedia streaming for 4G mobile communications. In this paper, we investigate the capability of existing fountain-coded schemes to recover a fraction of the source data at an early stage and progressively retrieve the remaining source packets as additional coded packets arrive. To this end, we propose a practical Gaussian elimination decoder, which can recover source packets "on-the-fly". Furthermore, we introduce a framework for the assessment of progressive packet recovery, we carry out a performance comparison of the investigated schemes and we discuss the advantages and drawbacks of each scheme.

In this paper, we propose a novel advanced multirate design for evolved Multimedia Multicast/Broadcast Service (eMBMS) in fourth generation (4G) Long-Term Evolution (LTE)/LTE-Advanced (LTE-A) networks. The proposed design provides: i) reliability, based on random network coded (RNC) transmission, and ii) efficiency, obtained by optimized rate allocation across multi-rate RNC streams. The paper provides an in-depth description of the system realization and demonstrates the feasibility of the proposed eMBMS design using both analytical and simulation results. The system performance is compared with popular multi-rate multicast approaches in a realistic simulated LTE/LTE-A environment.

This paper deals with the issue of reliably transmission of short messages through satellite. The problem is of paramount importance for emergency and alerting scenarios. In particular, we propose a novel efficient Network Coding (NC) communication scheme aiming to improve the delivery probability of the transmitted information messages. A suitable analytical approach has been developed in order to highlight the performance of the proposed NC scheme and to allow its optimization. The accuracy of the proposed approach has been validated by resorting to computer simulations. Performance comparisons with the classical NC scheme are also presented here to highlight the advantages of the proposed NC scheme in the case of AWGN and Rician communication channels.

The last years have been characterized by an increasing interest in the grid and cloud computing that allow the implementation of high performance computing structures in a distributed way by exploiting multiple processing resources. The presence of mobile terminals has extended the paradigm to the so called pervasive grid networks, where multiple heterogeneous devices are interconnected to form a distributed computing resource. In such a scenario, there is the need of efficient techniques for providing reliable wireless connections among network nodes. This paper deals with the proposal of a suitable resource management scheme relying on a routing algorithm able to perform jointly the resource discovery and task scheduling for implementing an efficient pervasive grid infrastructure in a wireless ad hoc scenario. The proposed solutions have been considered within two different parallelization processing schemes, and their effectiveness has been verified by resorting to computer simulations. Copyright (c) 2011 John Wiley & Sons, Ltd.

In this paper, we investigate the performance advantages achieved by using a symbol combining (SC) approach in a random linear network coding (RLNC) scheme for broadcast communications over lossy channels. In particular, the focus is on a modified RLNC scheme that makes use of the repeated transmissions of each data symbol belonging to the same coded packet to implement the SC approach at the receiving ends. By considering the mean number of transmissions and energy consumption for each coded packet as objective metrics, two optimization procedures are proposed and compared in this paper. We consider a broadcast network model where an access point (AP) has to broadcast coded packets to a set of receiving nodes. In addition, the analysis presented in this paper is extended to broadcast communications in butterfly topology networks. For all the considered scenarios, the better behavior of the SC RLNC scheme results is clearly evident in comparison with the basic RLNC, without requiring additional implementation complexity at each receiving end.

In this letter, we propose two optimized multicast communication strategies based on the Network Coding principle which aim to significantly improve the performance in terms of the power cost and delivery delay associated to the transmission of the whole data flow. The proposed strategies are of special interest for service delivered in an unreliable mode. The reported numerical results clearly show that both the strategies achieve the aforementioned goals in comparison with the Random Linear Network Coding alternative.

This paper presents a novel energy-aware communication scheme based on random network coding that is suitable for multicast and broadcast data delivery over Long Term Evolution (LTE) and LTE-Advanced networks. The proposed energy-aware transmission scheme minimises the average energy consumption of the macro base station that is required to deliver a message to all users in a multicast group in an LTE-A network. The energy saving gains and improved performance of the proposed scheme are compared to classical error control strategies. The reported analytical results clearly show a performance improvement of almost two-fold compared to the considered alternative.

Network coding (NC) is a promising technique recently proposed to improve network performance in terms of maximum throughput, minimum delivery delay, and energy consumption. The original proposal highlighted the advantages of NC for multicast communications in wire-line networks. Recently, network coding has been considered as an efficient approach to improve performance in wireless networks, mainly in terms of data reliability and lower energy consumption, especially for broadcast communications. The basic idea of NC is to remove the typical requirement that different information flows have to be processed and transmitted independently through the network. When NC is applied, intermediate nodes in the network do not simply relay the received packets, but they combine several received packets before transmission. As a consequence, the output flow at a given node is obtained as a linear combination of its input flows. This chapter deals with the application of network coding principle at different communications layers of the protocol stack, specifically, the Medium Access Control (MAC) and physical (PHY) Layers for wireless communication networks.

3GPP's Long Term Evolution (LTE) represents the one of the most valuable alternatives to offer a wireless broadband access in fully mobile network context. In particular LTE is able to manage several communication flows characterized by different QoS constrains. This paper deals with a network topology where the mobile users are clustered in Multicast Groups and the base station broadcasts a different traffic flow to each cluster. In order to improve the network throughput on a per-user basis, all communications rely on a Random Linear Network Coding (RLNC) scheme. A key aspect in the QoS management is represented by the power adaptation strategy in use. This paper proposes a novel convex formulation to the power adaptation problem for the downlink phase taking into account the specific RLNC scheme adopted by each communication flow. By the proposed convex formalization, an optimal solution of the problem can be early found in real time. Moreover, the proposed power adaptation strategy shows good performance for what concern throughput and fairness among the users when compared with other alternatives.

Long Term Evolution (LTE) is considered one of the main candidate to provide wireless broadband access to mobile users. Among main LTE characteristics, flexibility and efficiency can be guaranteed by resorting to suitable resource allocation schemes, in particular by adopting adaptive OFDM schemes. This paper proposes a novel solution to the sub-carrier allocation problem for the LTE downlink that takes into account the queues length, the QoS constraints and the channel conditions. Each user has different queues, one for each QoS class, and can transmit with a different data rate depending on the propagation conditions. The proposed algorithm defines a value of each possible sub-carrier assignment as a linear combination of all the inputs following a cross-layer approach. The problem is formulated as a Multidimensional Multiple-choice Knapsack Problem (MMKP) whose optimal solution is not feasible for our purposes due to the too long computing time required to find it. Hence, a novel efficient heuristic has been proposed to solve the problem. Results shows good performance of the proposed resource allocation scheme both in terms of throughput and delay while guarantees fairness among the users. Performance has been compared also with fixed allocation scheme and round robin.

The interest towards real-time computing has lead an even more interest in grid computing. While in the past the implementation of grid computing has been done on high performance computers, in the recent years there is an increasing interest in the pervasive grid scenarios, where multiple devices can be used for a distributed computing. The most challenging idea is to use mobile devices connected among them with wireless connections for setting up pervasive grid environments. In this context, it is a crucial problem the optimization of the routing algorithms among the processing nodes, in order to satisfy the performance requirements of a distributed computing. Aim of this paper is the design of specific routing algorithms for different pervasive grid applications with a particular attention to time sensitive scenarios.

In the last years an even more attention has been focused on emergency and crisis management systems. Both communication and computing aspects are of primary importance for a fast and reliable response in these particular scenarios. Differently from other approaches, in this paper we consider an integrated communication and computing solution, by proposing a joint approach, where a distributed computing platform and a heterogeneous meshed communication system interoperate in order to enhance the system reliability and readiness.