In order to address the challenges that have come with the exploding demand for higher speed, traffic growth and mobile wireless devices, Mobile network operators have decided to move to the notion of small cells based on cloud radio access network. The merits of cloud based RAN includes the ease of infrastructure deployment and network management as well as the fact that its performance are optimized and it is cost effective the merits of cloud based RAN includes the ease of infrastructure deployment and network management as well as the fact that its performance are optimized and it is cost effective. Notwithstanding, cloud radio access network comes with so many strict requirements to be fulfilled for its fronthaul network. In this paper, we have presented these requirements for a 5G fronthaul network. Particular interest on the time division multiplex passive optical network’s challenge of latency was treated by proposing an optimized version of the round robin dynamic bandwidth allocation algorithm. Results obtained show an improvement in the latency of the original algorithm which meets the fronthaul requirement. Other test parameters like jitter and BER were also improved by our proposed optimized algorithm.

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This research work conducted a design and simulation of an ultra-low power all-optically tuned nonlinear ring resonator-based add-drop filter. The purpose of this study is to investigate a CMOS-compatible nonlinear material system for an optical filter with temperature resilience, polarization insensitivity, and fast and energy-efficient tunability. The all-optical tunability was achieved using an optical pump that photo-excites the high nonlinear Kerr effect in the device material system. A three-dimensional multiphysics approach was used, combining the electromagnetics and thermo-structural effects in the filter. Hybrid graphene on an ultra-rich silicon nitride ring resonator-based filter enabled the realization of an ultra-high tuning efficiency (0.275 nm/mW for TE mode and 0.253 nm/mW for TM mode) on a range of 1.55 nm and thermal stability of 0.11 pm/K. This work contributed to the existing literature by proposing (1) the integration of a high Kerr effect layer on a low loss, high index contrast, and two-photon absorption-free core material with an athermal cladding material system and (2) the use of a cross-section shape insensitive to polarization. Moreover, the tuning mechanism contributed to the realization of an all-optical on-chip integrable filter for Dense Wavelength Division Multiplexing systems in the less occupied L band.

This paper has analyzed the performance a Wireless Division Multiple Access (WCDMA) system model at a data rate of 384kbps and 2Mbps over an Additive White Gaussian Noise (AWGN) channel. The signal was modulated by Quadrature Phase Shift Keying (QPSK) and Quadrature Amplitude Modulation (QAM) with modulation order, M=16. The performance of the system was enhanced by implementing convolution coding scheme. This study was important as it formed a basis through which the performance analysis can be extended to Long Term Evolution (LTE) networks which have data rates starting from 1Mbps to as high as 100Mbps.The performance of the WCDMA at these data rates was seen to improve when convolutional coding scheme was implemented. Since the Shannon capacity formula depends on the BER of a system then this improvement means an additional capacity in the channel and this can accommodate more users in the channel. The results have further shown that the choice of a modulation technique depending on the throughput required affects the BER performance of the system. Therefore, there must be a trade-off between the throughput required, the modulation format to be used and the pulse shaping filter parameters.

Fourth generation cellular networks provide ubiquitous broadband access to a growing number of mobile users worldwide. In this context, resource allocation in orthogonal frequency division multiple access femtocell network systems presents an important milestone towards realization of high-speed services. In this paper, we focus on impact of mobility dynamics on time/frequency allocation in femtocell network. We considered users' mobility dynamics taking into account the variation of their positions with time. We propose a scalable mobility-aware femtocell cluster-based resource allocation (M-FCRA) scheme based on cluster formation, clusterhead resource allocation with user mobility awareness, and resource contention resolution. M-FCRA formulates the frequency/time resources allocation mathematically as a min-max optimization problem and generates synchronized resource reservation requests that maximize bandwidth utilization and quality of service. The results show that M-FCRA performs better than femtocell clusterbased resource allocation (FCRA) algorithm at various signal to interference and noise ratio levels in terms of throughput satisfaction rate and spectrum spatial reuse.