Escalonamento de recursos em redes LTE utilizando processo envelope de tráfego multifractal e curva de serviço mínima

Abstract

In this work, a variation of the MWM (Multifractal Wavelet Model) model is proposed for network traffic flows, in such a way that its parameters are estimated adaptively. Next, it proposes an envelope process of network traffic based on the parameters' adaptive estimation of this model, whose final objective is to provide quality of service (QoS) in real time. The proposed envelope is compared to the main envelopes processes known in the literature, that are based on traffic models, such as: Brownian Motion (Bm), Fractional Brownian Motion (fBm) and Multifractal Brownian Motion (mBm). This work investigates the use of F-OFDM multi-carrier modulation, which is one of the candidates for 5G networks. It is known that the LTE / LTE-A (Long-Term Evolution) network uses Adaptive Modulation and Coding (AMC) technique that have the function of adjusting the modulation order and code rate based on the user's channel state information, in order to achieve a Block Error Rate (BLER) lesser than 10%. In this work, simulations of the LTE downlink are carried out using OFDM and F-OFDM multicarrier modulation, with the objective of mapping the BLER as a function of SNR (Signal-to-Noise Ratio). This mapping is necessary for the network to adjust the modulation and code scheme appropriate to each user. It's also proposed an adaptive algorithm for resource allocation in the LTE/LTE-A downlink, with admission control of the users. This algorithm aims to improve the performance of some network parameters and to guarantee maximum delay, through of following information: backlog, channel condition and user’s traffic behavior. In order to control the admission of users and to estimate the maximum delay of the network, a minimum adaptive service curve of the LTE / LTE-A network is proposed. The proposed algorithm for resource allocation is compared with several scheduling schemes known in the literature through computational simulations of different LTE network scenarios using OFDM and F-OFDM multi-carrier modulation.