Volume 20, Issue 1, May 2013

Radio Wave Propagation Path Loss Modelling in Mobile Communications Environment: a Case Study of Ogun-state in Nigeria [Full Text]

Ibikunle Frank and Somoye Abiodun

Abstract — Propagation models are used extensively in network planning, particularly for conducting feasibility studies and during initial deployment. This research work sets out to determine the propagation model that is best suitable for Ogun-State in Nigeria. Accurate characterization of radio propagation channel through important parameters and a mathematical model is important for predicting signal coverage, achievable data rates, specific performance attributes of signalling and reception schemes. This can be achieved by modifying the Okumura-Hatamodel which has wide acceptability and is currently in use for mobile radio propagation to suit the terrain of the investigated regions in Nigeria. The Okumura-Hata’s equation for predicting signal path loss was simulated.From the results, necessary adjustments to the model were done for use in mobile communications system designto improve Quality of Service (QoS) of networks. The proposed Simulation method employed in this research proved to be more efficient, faster and accurate than the other two existing methods (i.e., Physical and Empirical methods) that are mostly used. Also, the average propagation path loss in this work is lower than that of Okumura-Hata’s average propagation path loss for urban and suburban areas. This implies that the method proposed in this our present work leads to improvement in Qos of the investigated regions. 

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Optimal Access Guarantee in Hybrid Access 
Femtocells Using Fuzzy Logic System [Full Text]

Waheed Moses Audu, E. N. Onwuka, O. Ugweje and M. A. Aibinu

Abstract — Determining the optimal access guarantee level for hybrid access Femto cells remains an unsolved component of Femto cell development. In this paper, we present a hybrid access scheme that uses Signal-to-interference plus noise ratio (SINR) and channel (time) availability for determining the appropriate access guarantee level. These parameters can be easily obtained by the Femto device’s self-configuration and initialization capability. Fuzzy logic scheme employing the Mamdani system was used for processing due to its simplicity and manageable trade off in accuracy. A Sugeno system was then included in the two stage Fuzzy Inference System to achieve the desired result. In our results, we present an Access Guarantee metric that was used to determine the optimal access region. An Access Guarantee value of about 45.6% was obtained in our simulation specific environment. 

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Healthcare Monitoring based on Wireless 
Sensor Network with New Features 
[Full Text]

Mahmoud Shaker, Samir Jasim and Akram Jaddoa Khalaf

Abstract — Development of healthcare monitoring systems based on wireless sensor network (WSN) has seen a great increase ex- tensively in previous years and so far. These systems are more prevalent because of the importance of human life and the provision of appropriate techniques to be applied. So they should be suitable for healthcare requirements.In the presented paper we designed a re- al-time healthcare monitoring system based on WSN. The system senses and displays ECG, Heart Rate, and temperature of a patient. The ECG is the main sensor in this system and the heart rate is calculated programmatically from ECG signal. The temperature of the human body is measured using thermistor. The system is characterized by its friendly GUI, easy to use, and very simple to manage by the doctor in charge. In addition that the system has the ability to detect and put in work any new node (patient node) automatically also when any node fails in operation for any cause, the system detects it and put it out of service automatically. Also in the designed system we add the doctor node; this node is movable (doctor accompined when he is out of Intensive Care Unit, ICU) wich gives him an alarm signal for any ubnormal case. In relation to the network used in this work is star topology and the wireless protocol is ZigBee. The soft- ware used is LabVIEW as a processing, graphical user interface (GUI), and an auto alarm. This system operates in hospital healthcare and it can be operates in home healthcare.The presented system is installed in Merjan Hospital – Babylon city and tested by the hospi- tal doctors for many cases; the obtained results are approved and very satisfactory.