An integrated priority-based cell attenuation model for dynamic cell sizing

A new, robust integrated priority-based cell attenuation model for dynamic cell sizing is proposed and simulated using real mobile traffic data.The proposed model is an integration of two main components; the modified virtual community – parallel genetic algorithm (VC-PGA) cell priority selection module and the evolving fuzzy neural network (EFuNN) mobile traffic prediction module.The VC-PGA module controls the number of cell attenuations by ordering the priority for the attenuation of all cells based on the level of mobile level of mobile traffic within each cell.The EFuNN module predicts the traffic volume of a particular cell by extracting and inserting meaningful rules through incremental, supervised real-time learning.The EFuNN module is placed in each cell and the output, the predicted mobile traffic volume of the particular cell, is sent to local and virtual community servers in the VC-PGA module.The VC-PGA module then assigns priorities for the size attenuation of all cells within the network, based on the predicted mobile traffic levels from the EFuNN module at each cell.The performance of the proposed module was evaluated on five adjacent cells in Selangor, Malaysia. Real-time predicted mobile traffic from the EFuNN structure was used to control the size of all the cells.Results obtained demonstrate the robustness of the integrated module in recognizing the temporal pattern of the mobile traffic and dynamically controlling the cell size in order to reduce the number of calls dropped

Dynamic evolving neural fuzzy inference system equalization scheme in mode division multiplexer for optical fiber transmission

The performance of optical mode division multiplexer (MDM) is affected by inter-symbol interference (ISI), which arises from higher-order mode coupling and modal dispersion in multimode fiber (MMF). Existing equalization algorithms in MDM can mitigate linear channel impairments, but cannot tackle nonlinear channel impairments accurately. Therefore, mitigating the noise in the received signal of MDM in the presence of ISI to recover the transmitted signal is important issue. This paper aims at controlling the broadening of the signal from MDM and minimizing the undesirable noise among channels. A dynamic evolving neural fuzzy inference system (DENFIS) equalization scheme has been used to achieve this objective. Results illustrate that nonlinear DENFIS equalization scheme can improve the received distorted signal from an MDM with better accuracy than previous linear equalization schemes such as recursive‐least‐square (RLS) algorithm. Desirably, this effect allows faster data transmission rate in MDM. Additionally, the successful offline implementation of DENFIS equalization in MDM encourages future online implementation of DENFIS equalization in embedded optical systems

Comparison of Different Wavelength Propagations over Few-Mode Fiber based on Space Division Multiplexing in Conjunction with Electrical Equalization

Abstract—Nonlinearities in optical fibers deteriorate system performances and become a major performance-limiting issue. This article aims to investigate the compensation of nonlinear distortions in optical communication systems based on different wavelength propagations over few-mode fiber (FMF). The study adopted Space Division Multiplexing (SDM) based on decision feedback equalizer (DFE). Various transmission wavelength of the FMF system is applied to mitigate the attenuation effect on the system. In this paper, different wavelengths (780, 850 and 1550 nm) are used in SDM. Extensive simulation is performed to assess the attenuation and Bit Error Rate (BER) in each case. The results show that the wavelength of 1550 nm produces higher power and less attenuation in the transmission. Furthermore, this wavelength produces the best distance with less BER compared to 780 nm and 850 nm wavelengths. Moreover, the validations show improvement in BER and eye diagram

Selective mode excitation in SCM-OCDMA

A six-channel 2.4GHz subcarrier multiplexing - optical code division multiple access (SCM-OCDMA) system in conjunction with the selective excitation of LP01 and LP02 modes is presented for a multimode fiber Local Area Network. Simulation results demonstrate that mode selectivity increases the bandwidth-distance product and improves the BER performance of the channel

Enhanced probability density function using APD in SAC-OCDMA systems based SPD technique

This paper examines the avalanche photodiode (APD) gain impact on spectral-amplitude coding optical code-division multiple-access (SAC-OCDMA) systems based single photodiode detection (SPD) technique. Numerical results are used for inspecting the APD gain influence upon the probability density function (PDF) and signal-to-noise ratio (SNR) performance. The usage of APD over positive-intrinsic-negative (PIN) photodiode accommodates more users with improved PDF and higher SNR

Triple-play services using different detection techniques for SAC-OCDMA systems

The development of many high bit-rate multimedia applications has emphasized the demand for service differentiation or prioritization techniques to ensure end-user quality-of-service (QoS) necessities. This paper focuses on utilizing different detection schemes in spectral-amplitude coding optical code-division multiple-access (SAC-OCDMA) systems to support 'triple-play' services (voice, video, and data) with diverse QoS requirements. The used subtraction detection techniques are complementary, AND, as well as modified-AND.Modified double-weight (MDW) codes are used as the signature codes for SAC-OCDMA systems.The simulation results show that modified-AND subtraction detection demonstrates better performance over other detection approaches

APD Gain Effect on SAC-OCDMA System using Modified-AND Detection Technique

This paper investigates the avalanche photodiode (APD) gain effect on spectral-amplitude coding optical code-division multiple-access (SAC-OCDMA) system using a modified-AND subtraction detection in comparison to the conventional AND detection scheme. Analytical results are presented to investigate the APD gain impact on the bit-error rate (BER) performance. In addition, we confirm the influence of the APD over the positive-intrinsic-negative (PIN) photodiode on the system performance using data transmission simulations

Reducing BER of spectral-amplitude coding optical code-division multiple-access systems by single photodiode detection technique

In this paper, we present a single photodiode detection (SPD) technique for spectral-amplitude coding optical code-division multiple-access (SAC-OCDMA) systems. The proposed technique eliminates both phase-induced intensity noise (PIIN) and multiple-access interference (MAI) in the optical domain. Analytical results show that for 35 simultaneous users transmitting at data rate of 622 Mbps, the bit-error rate (BER) = 1.4x10^-28 for SPD technique is much better compared to 9.3x10^-6 and 9.6x10^-3 for the modified-AND as well as the AND detection techniques, respectively. Moreover, we verified the improved performance afforded by the proposed technique using data transmission simulations

Reducing BER of spectral-amplitude coding optical code-division multiple-access systems by single photodiode detection technique

In this paper, we present a single photodiode detection (SPD) technique for spectral-amplitude coding optical code-division multiple-access (SAC-OCDMA) systems. The proposed technique eliminates both phase-induced intensity noise (PIIN) and multiple-access interference (MAI) in the optical domain. Analytical results show that for 35 simultaneous users transmitting at data rate of 622 Mbps, the bit-error rate (BER) = 1.4x10^-28 for SPD technique is much better compared to 9.3x10^-6 and 9.6x10^-3 for the modified-AND as well as the AND detection techniques, respectively. Moreover, we verified the improved performance afforded by the proposed technique using data transmission simulation