Abdulaziz M. Ghaleb

Energy efficiency of LTE macro base station

The growing energy consumption in wireless networks driven by dramatic increases in mobile users and network traffic, are putting mobile operators under immense challenges towards meeting the demands of both cost reduction and environment conservation. The network Energy Efficiency (EE) considers not only energy consumed by the base station (BS), but also the capacity and coverage of the network. In this paper we study the impact of modulation and coding schemes (MCS), bandwidth (BW) size and transmitted power on the energy efficiency of a LTE macro base station. Although it is very much expected that higher transmission power results in lower EE, the difference actually diminishes when cell size increases. At around 1200m it is found that the EE are almost equal for all transmission power considered. On the other hand, EE increases significantly as the BW increases. Similar effect on EE is observed when MCS changes from lower order to higher order scheme. In fact EE becomes more sensitive to MCS change at higher bandwidth.

Energy-aware load adaptive framework for LTE heterogeneous network

One of the main approaches for improving the network energy efficiency EE is through the introduction of load adaptive techniques, where the networks components/subsystems are switched off when the network is lightly loaded. Optimising such a dynamic operation in a heterogeneous network HetNet remains an active topic of research. In this paper, a traffic load-adaptive model that aims to evaluate the EE of base stations in Long Term Evolution LTE HetNet is presented. First, a model that simulates the load-adaptive power consumption behaviour of LTE HetNet is developed. In this regard, a load adaptation factor is introduced to assess the networks EE performance. The model also adapts and predicts the achievable data rate of each base station with respect to the traffic load. Our study shows that the fully load-adaptive LTE HetNet can significantly improve networks EE up to 10%, 40%, and 80% for high, medium, and low loads, respectively, as compared to the conventional non load-adaptive HetNet. In addition, we show that the full adaptive network operation can achieve significant EE gains under a realistic daily traffic profile up to 86%. The proposed evaluation model is essential to assess the network EE and can be used in future studies that focus on improving the adaptation level of the already installed network equipments. Copyright ©2014 John Wiley & Sons, Ltd.

QoS-aware joint uplink-downlink scheduling in FDD LTE-Advanced with carrier aggregation

Efficient resource utilization is of a high importance for LTE/LTE-A network performance and provisioning of user quality of experience. The eNodeB (LTE base station) is responsible for controlling the radio resources between the user and LTE /LTE-A network. The resources can be scheduled in two schemes; either independently or jointly by considering both uplink (UL) and downlink (DL) together. Joint scheduling is an attractive approach for resource utilization and for providing better Quality of Service (QoS), but it adds some computational complexity to the system. This paper aims to provide QoS-aware joint UL-DL scheduling for LTE-A utilizing the functionality of carrier aggregation. The scheme presented enforces the fair sharing of the resources between the UL and DL channels while maintaining good QoS. The work is based on simulation using the MATLAB-based IS-Wireless system level simulator. The key contributions of this work lie in addressing both the joint scheduling and the carrier aggregations while considering the QoS and traffic conditions of the users.

On the extension of traditional resource allocation algorithms in LTE-A to joint UL-DL scheduling with FDD carrier aggregation

Through and spectral efficiency maximization are two of the most challenging issues to be addressed by current and future cellular networks. To achieve these goals however, radio resources need to be utilized in a coordinated manner to provide better network performance and ensure adequate user quality of service (QoS). The radio resources are controlled by LTE base station (eNodeB) and can be scheduled either independently or jointly by considering both uplink (UL) and downlink (DL). This paper addresses the joint UL-DL scheduling in a carrier aggregation (CA) supportive LTE-advanced networks. This work provides good insights of the implementation of the traditional scheduling algorithms for joint UL-DL scheduling for LTE-A utilizing the functionality of CA. We present preliminary results from a MATLAB-based IS-Wireless system level simulator that confirm the importance of the fair sharing of the resources between the UL and DL channels while maintaining a good QoS. Furthermore, simulation results show that the resource utilization and spectral efficiency can be significantly improved by dynamically changing the bandwidth portion between the UL and DL. Finally, we also show that there is a significant improvement in both UL and DL data rates using the proposed CA and joint scheduling schemes.