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Header compression techniques theoretically can improve the speech quality of multimedia applications. However it introduces a new impairment directly related to the loss of packets, that can impact negatively on the quality. Its deployment over wireless mesh networks needs special treatment due to the usually high loss rates of such a network. This work(More)
In Cognitive Radio Ad Hoc Networks (CRAHNs), malicious Secondary Users can exploit CR (Cognitive Radio) capabilities to perform Primary User Emulation Attacks (PUEA). These attacks pretend the transmission of a Primary User (PU), giving to malicious users the priority of using licensed frequencies over well-behaved unlicensed Secondary Users (SU). Since(More)
The possible existence of self-organized criticality in Barkhausen noise is investigated theoretically through a single interface model, and experimentally from measurements in amorphous magnetostrictive ribbon Met-glas 2605TCA under stress. Contrary to previous interpretations in the literature, both simulation and experiment indicate that the presence of(More)
In this paper we present PbP-EDCA, a Full Duplex (FD) MAC protocol that operates according to the high-priority access rules of the standard IEEE 802.11 EDCA. With PbP-EDCA, nodes that win a contention perform a sequence of narrow-band orthogonal transmissions rather than one single wide-band. PbP-EDCA employs the Carrier Sense Multiple Access/Collision(More)
We address the question of weak versus strong universality scenarios for the random-bond Ising model in two dimensions. A finite-size scaling theory is proposed, which explicitly incorporates ln L corrections (L is the linear finite size of the system͒ to the temperature derivative of the correlation length. The predictions are tested by considering long,(More)
We study the probability distributions of interface roughness, sampled among successive equilibrium configurations of a single-interface model used for the description of Barkhausen noise in disordered magnets, in space dimensionalities d = 2 and 3. The influence of a self-regulating (demagnetization) mechanism is investigated, and evidence is given to show(More)
We use transfer-matrix and finite-size scaling methods to investigate the location and properties of the multicritical point of two-dimensional Ising spin glasses on square, triangular, and honeycomb lattices with both binary and Gaussian disorder distributions. For square and triangular lattices with binary disorder, the estimated position of the(More)
We consider long, finite-width strips of Ising spins with randomly distributed couplings. Frustration is introduced by allowing both ferromagnetic and antiferromagnetic interactions. Free energy and spin-spin correlation functions are calculated by transfer-matrix methods. Numerical derivatives and finite-size scaling concepts allow estimates of the usual(More)