To evaluate the performance of distributed medium access control (MAC) layer of emerging ultra wideband (UWB) and 60-GHz millimeter wave (mmWave) wireless personal area networks (WPANs) based on distributed reservation protocol (DRP) of ECMA-368 and ECMA-387 standards, we provide an analytical model for the probability distribution of steady state throughput as a function of the network dimensions size, number of devices, antenna beamwidth, transmission range, bit error rate (BER), antenna disturbance rate (ADR), aggregation length, payload size, and incoming frame rate. Using this model, the optimal payload size is computed as an example of optimization problem. We also propose a formula forthe starvation and fairness and using them, we found a major flaw in DRP, i.e., its poor fairness. We develop a fair DRP (FDRP) protocol and modify our model to cover it. The models are evaluated by simulation of ad-hoc network scenarios and results show that the average error is less than 2 percent.

To evaluate the performance of the distributed medium access control layer of the emerging ultrawideband and 60-GHz millimeter wave (mmWave) wireless personal area networks based on ECMA-368 and ECMA-387 standards, the first step is to determine the beacon period length (BPL) of the superframe in a given network. In this paper, we provide an analytical model for the probability mass function (PMF) of the BPL as a function of the network dimensions, number of beaconing devices, antenna beamwidth, and the transmission range of the devices. To enable devices with steerable directional antennas in the ECMA-387 standard to have simultaneous communications with neighbors in their different antenna sectors, we propose an improvement to the standard for which we computed the PMF of the BPL in its worst case. The effect of beacon period (BP) contraction on the PMF is also considered and modeled. The proposed model for all cases is evaluated by simulating different scenarios in the network and the results show that on average, the model for the average BPL has an error of 1.2 and 2.5 percent in the current definition of the standard and in the proposed modification, respectively, without BP contraction and 0.9 and 1.5 percent, respectively, with BP contraction.

In the Internet telephony, loss of IP packets causes instantaneous discontinuities in the received speech. In this paper, we have focused on finding an error resilient method for this problem. Our proposed method creates artificial correlation between speech samples that pre-distorts the speech signal. The receiver uses this correlation to reconstruct the lost speech packets. An appropriate speech enhancement technique is designed for the reduction of the processing error in the recovered speech caused by the speech codecs. The SegSNR results show the superiority of our proposed speech enhancement method over a recently proposed one.