text: The Medium Access Control protocol of Power Line Communication networks (defined in Homeplug and IEEE 1901 standards) has received relatively modest attention from the research community. As a consequence, there is only one analytical model that complies with the standardised MAC procedures and considers unsaturated conditions. We identify two important limitations of the existing analytical model: high computational expense and predicted results just prior to the predicted saturation point do not correspond to long-term network performance. In this work, we present a simplification of the previously defined analytical model of Homeplug MAC able to substantially reduce its complexity and demonstrate that the previous performance results just before predicted saturation correspond to a transitory phase. We determine that the causes of previous misprediction are common analytical assumptions and the potential occurrence of a transitory phase, that we show to be of extremely long duration under certain circumstances. We also provide techniques, both analytical and experimental, to correctly predict long-term behaviour and analyse the effect of specific Homeplug IEEE 1901 features on the magnitude of misprediction errors. Our simplified analysis is then used to model the priority resolution scheme defined in Homeplug IEEE 1901. We show that previous tendencies found in simulations and in an off-the-shelf testbed are correctly captured in our framework. We also show that resorting to the traffic differentiation provided by the different contention parameters alone solves the starvation faced by lower-access category traffic.
  @cite_14: There are a lot of MAC approaches in the power line communication. This paper is focused on the most widespread broadband power line communication, HomePlug system. The paper deals with the medium access control function of the HomePlug system. The various probabilistic distributions were tested for random values generating. We show, that it is important to choose the suitable rounding function for a random integer number getting.
  @cite_22: Channel response and noise in the in-home power-line channel are time varying, and show periodic patterns since electric devices, which are major noise sources, synchronously run with the ac-line cycle. Using the relatively stable channel characteristic of the power line, orthogonal frequency-division multiple access (OFDMA) schemes in power-line communications (PLCs) can achieve multiuser diversity gain even in random access. In this paper, we propose a carrier-sense multiple access with a collision-avoidance (CSMA CA) protocol for OFDMA-based broadband PLC. To achieve the maximum diversity gain, we formulate a utility maximization problem for our considered framework. Then, we solve this problem by dividing it into two subproblems. The first one divides the whole bandwidth into a certain number of subchannels appropriately, and then the second one allocates a subchannel to each node according to the channel condition. To solve each subproblem, we first consider optimal algorithms and then heuristic algorithms to overcome the complexity. Through extensive simulations, we show that our proposal greatly improves the overall system utility compared to the single-channel CSMA CA scheme. The performance improvement of our proposal over the single channel scheme is mainly achieved by lowering collision probability and exploiting multiuser diversity.
  @cite_21: As demands for data communications among home personal devices in home environments increase, various types of home-networking technologies have appeared. Among them, power line communication is one of the most promising wired home-networking technologies, because the existing power line facilities can be utilized for data transmission without deploying any new physical links. HomePlug 1.0 is the most popular power line communication technology, which has been standardized by the HomePlug power line alliance, and attempts to mitigate the effect of time- and frequency-varying channels by enhanced modulation and channel coding. Although HomePlug 1.0 has undergone field trials and simulations, its analytic model and performance was only conducted for throughput under saturation conditions. We propose a new analytic model to evaluate MAC throughput and delay of HomePlug 1.0 both under saturation and under normal traffic conditions. We verify our proposed model via simulations and evaluate the performance of HomePlug 1.0.
  @cite_1: The back off algorithms are significant time consumptions function in the transmitting. This paper introduces a simulation of parameters of CSMA CA and simulation of back off function of CSMA CA used in power line technologies. The paper also describes the basic approaches for modeling of back off function and introduces simulation of this function with significant parameter. As will be seen, a few significant parameters for simulation of CSMA CA with obtaining acceptable results could be used.
  @cite_3: HomePlug AV (HPAV) is the standard for distribution of Audio Video content as well as data within the home by using the power line. It uses a hybrid access mechanism that combines TDMA with CSMA CA for MAC technology. The CSMA CA protocol in HPAV has two main control knobs that can be used for access control: contention window (CW) size and deferral counter (DC). In this paper, we extensively investigate the impacts of CW and DC on performance through simulations, and propose an adaptive mechanism that adjusts the CW size to enhance the throughput in HPAV MAC. We find that the CW size is more influential on performance compared to the DC. Therefore, to make the network control easier, our proposal uses a default value of DC and adjusts the CW size. Our scheme simply increases the CW size if the network is too busy and decreases it if too idle. We compare the performance of our proposal with those of the standard and other competitive schemes in terms of throughput and fairness. Our simulation and analysis results show that our adaptive CW mechanism performs very well under various scenarios.
  @cite_19: 
  @cite_5: In this work, a network simulator for power line communications based in the Homeplug-AV technology is presented. The simulator implements both the physical and the MAC layers, along with an in-home power line channel generator, which makes it very useful in a wide variety of network optimization procedures. To the authors' knowledge, performance evaluation of the MAC layer of Homeplug-AV by means of simulations has been always accomplished assuming excessively simplistic channel conditions. Therefore, this simulator represents an important contribution, as it includes a realistic physical model along with the CSMA CA protocol described in the standard. In this paper, the proposed simulator is employed to evaluate the performance of the Homeplug-AV standard in an in-home network. The obtained results are then applied to video services planning in networks based in this standard.
  @cite_16: This letter proposes an extension of the HomePlug-AV CSMA CA mathematical model. The existing models do not take into account the existence of different transmission rates between each transmitter-receiver pair. These differences are due to the modulation and coding used by the transmitter to overcome the channel limitations. The proposed model is evaluated by means of simulation in an in-building scenario.
summary: Consequently, the analytic model in @cite_21 has been widely used both to derive performance metrics and as a basis for extension @cite_3 @cite_14 @cite_16 @cite_1 @cite_5 @cite_22 as it strictly follows the procedure defined in the standard and it considers saturated as well as unsaturated conditions. This widespread use motivates our improvements in terms of reducing complexity while maintaining the accuracy and retaining all features defined in the standard @cite_19 and understanding the transitory nature of the results predicted before saturation in @cite_21 .