This paper focuses on the QoS-constrained jointly optimal adaptive distributed source coding, channel coding, network coding and power control for Co-Channel Interference (CCI)-limited wireless multiple class multicast networks, such as, for example, Wireless Sensor Networks (WSNs). The goal is to allocate the available system-wide resources by jointly performing Loss-Less Distributed Source Coding (LLDSC) and Intra-Session Network Coding (ISNC), while leveraging channel coding and power control for CCI-mitigation. Due to the presence of CCI, the resulting cross-layer optimization problem is inherently nonconvex. Hence, we develop a distributed, iterative and asynchronous algorithm for the optimal adaptive QoS management of the available bandwidth/power/flow resources. Actual performance and adaptive capability of the proposed resource management algorithm in the presence of: i) abrupt changes of the statistics of the source flows; ii) failures of the interior network nodes; and, iii) fast fading, are numerically tested.

In this paper, we focus on the quality-of-service (QoS)-constrained jointly optimal congestion control, network coding, and adaptive distributed power control for connectionless wireless networks affected by multiple access interference (MAI). The goal is to manage the available network resources, so as to support multiple multicast sessions with QoS requirements when intrasession network coding (NC) is allowed. To cope with the nonconvex nature of the resulting cross-layer optimization problem, we propose a two-level decomposition that provides the means to attain the optimal solution through suitable relaxed convex versions of its comprising subproblems. Sufficient conditions for the equivalence of the primary nonconvex problem and its related convex version are derived, occurrence of such conditions investigated, and performance with respect to conventional routing-based layered solutions analyzed. Moreover, we develop a distributed algorithm to compute the actual solution of the resource allocation problem that quickly adapts to network time-evolutions. Performance of this algorithm and its adaptivity are evaluated in the presence of varying network/fading conditions and noisy measurements.

Traffic Engineering application to the cross-layer design of Multiple Access Interference (MAI)-affected powerlimited wireless networks, when Quality of Service constraints are also present, leads to deal with nonconvex resource allocation problems. Although several manageable-complexity solutions have been proposed, they are based on specific capacity functions and, generally, fail to provide reliable results in low-SINR (Signal to Interference plus Noise Ratio) scenarios. We develop a two-level decomposition that is able to find the optimal solution of a wide nonconvex cross-layer problem, which combines user utility, flow control, QoS multipath routing,Medium Access Control (MAC) design and power control, by means of a suitable relaxed convex version of its comprising flow control and power-allocation sub-problems. Sufficient conditions for the equivalence of the primary (nonconvex) problem and its related (convex) version are provided. Moreover, we develop a distributed, iterative, asynchronous algorithm for computing the solution of the overall nonconvex resource allocation problem, that is able to (quickly) self-adapt to possible network time evolutions (as, for example, node failure events) and, most importantly, that may be implemented on top of connectionless networking platforms. Actual performance of the overall proposed solution and its robustness against node-failure events are numerically tested and compared with the corresponding ones of Destination Sequenced Distance Vector-based single-path routing algorithms.

Ultra Wide Band (UWB) communication systems operate in the frequency range between 0 and 10.6 GHz so they induce the Scientific Community to solve the problem of coexistence with concurrent telecommunication services. This is the leading reason why both the Federal Communications Commission (FCC) and the European Telecommunications Standards Institute (ETSI) gave strict indications about the spectral limits to be respected and require the transmitter and receiver to be compliant with these spectral masks. To this end, it is mandatory to carefully shape the UWB pulse, for this can be accurately designed so as to avoid severe performance reduction while guarding inter-systems coexistence. The UWB technology and, more, the pulse shaping allow to apply the cognitive paradigm where the transmitter and receiver are the actors of this functionality since the performance are tied to channel features and interference presence. The widespread choice of Gaussian-like pulses has proven, however, largely suboptimal from a power emission point of view since they fail to optimize performance. Goal of this contribution is to show how to achieve a good compromise between spectral emission, rate and synchronization errors robustness, via a modified version of the Parks-McClellan method, considering channel impairments due to its frequency-selective nature and to the inter-pulse interference.

Power Line Communication (PLC) systems are currently envisioned as a possible solution for distributing multimedia contents and allowing Internet access with a capillary (already built) network without demanding further infrastructure. The real challenge for PLCs consists in providing connectivity where Public Switch Telephone Network (PSTN)-based Internet Access and/or Wi-Fi/WiMAX seem to be unable to solve the problem of Digital Divide. In this paper we introduce a new metric, i.e. the goodput, to balance transmission rate and bit error rate (BER) in resource allocation issues for Power Line Communication systems. In detail, we state the well-known integer bit-loading problem as a goodput maximization with constraints on the power consumption and the maximum decoding time. The use of Trellis Coded Modulation (TCM) allows to pursue the goodput maximization weighing error probability and transmission rate which would have otherwise been in trade-off. Numerical results are presented to stress how our solution improves system performances, both in ideal conditions and with additional impairments such as crosstalk and impulsive noise, with respect to the conventional Maximum Rate (MR) and Minimum BER (MB) approaches and to validate the suitability of TCMs in comparison with higher complexity codes.

The interference induced by UWB communication on systems operating in the frequency range between 0 and 10.6 GHz is the main reason why the essential role in these systems' design is played by the pulse shape selection. That's why an accurate shaping choice can lead to avoid severe performance reduction and to guard systems coexistence. To this end, FCC (and ETSI in the near future) gave strict indications about the spectral limits to be respected, so as to define, as the purpose of UWB systems realization, the compliance with this spectral mask. The, widely used, choice of Gaussian-like pulses is, however, largely suboptimal from a power emission point of view since they are unable to maximize the signal-to-noise ratio (SNR). Goal of this contribution is to achieve a good compromise, in a cognitive way, between spectral emission, rate and synchronization errors robustness, via a modified version of the Parks-McClellan method, considering channel impairments due to its frequency-selective nature, to the inter-pulse interference and in-band interference.