Khedr M.E.,Arab Academy for Science and Technology |
Hassan R.,National Telecom Regulatory Authority |
Digham F.F.,National Telecom Regulatory Authority
European Journal of Scientific Research | Year: 2012
A problem in modern wireless communications is the scarcity of electromagnetic radio spectrum. The traditional fixed spectrum assignment strategy results in spectrum crowding on most frequency bands. Due to limited availability of radio spectrum and high inefficiency in its usage, cognitive radio networks have been seen as a promising solution to reducing current spectrum under-utilization while accommodating for the increasing amount of services demands and applications in wireless networks. Compared with the traditional networks, cognitive radio networks exhibit some distinct features, which result in necessity of further research in the resource allocation and scheduling that have been solved for the traditional networks. In this paper, we focus on the packet scheduling in a single cell cognitive radio system, an adaptive downlink scheduling for real time and nonreal time applications with the consideration of the primary user activity is proposed. The proposed algorithm satisfies different traffic models based on the QoS level of each traffic type and the spectrum availability. The performance of the proposed algorithm has been evaluated in terms of throughput and delay. This algorithm provides better QoS guarantee for real time traffic and more efficient spectrum utilization for cognitive radio systems. © EuroJournals Publishing, Inc. 2012.
Gad A.A.E.,National Telecom Regulatory Authority |
Digham F.,National Telecom Regulatory Authority
2010 IEEE Symposium on New Frontiers in Dynamic Spectrum, DySPAN 2010 | Year: 2010
The concept of dynamic spectrum access (DSA) promoting "just-in- time" access to the spectrum, moving the cost of a spectrum license from a fixed up-front cost to a variable ongoing cost, based on the customers demand for the service not for the access. Such a new concept, while holds a great potential success, causes dramatic changes to the business model behind the provision of wireless services as well as the way policies are formed. What is missing then is to develop a reasonable scenario that can compile the whole technological progress that has already been done in this area in order to develop a right novel that can guarantee the continuation of the socio-economic growth of the mobile industry and the wireless access. In this paper, we analyze the key strengths, weaknesses, opportunities, and threats pertinent to the DSA concept in order to provide a compiled set of prioritized strategies that can pave the path forward for a successful DSA story. Our analysis and recommended strategies account for individual technical, business, and policy perspectives. ©2010 IEEE.
Baraka H.A.,National Telecom Regulatory Authority |
Elwany M.H.,Alexandria University |
El-Gamily I.H.,National Telecom Regulatory Authority |
El-Gamily H.I.,National Authority for Remote Sensing and Space science |
El-Gamily H.I.,Kuwait Institute for Scientific Research
Egyptian Journal of Remote Sensing and Space Science | Year: 2013
TeleDensity is a very important tool to show the trend of economic development at the country level. There is a big gap in the value of TeleDensity between the Least Developed Countries and developed countries. In general, TeleDensity is usually measured at the National level. The calculated TeleDensity value of Egypt in 2010 is more than the world average value and less than the average value of Europe. This study aims at introducing a new approach to breakdown TeleDensity from the National to Sector level, and estimates the occupied fixed lines (OFL) at both Sector and Shiyakha levels. Alexandria Governorate that is located at the northern coast of Egypt was selected as a case study in this research. Detailed analysis was applied at the Shiyakha level inside the El-Montazah sector. The proposed GIS-based approach is used to project the Exchanges and their spatial coverage extent at the Shiyakha level. TeleDensity was calculated at the Governorate and Sector levels. The resultant TeleDensity was used to estimate the OFL at the Sector and Shiyakha levels. The results indicated that the TeleDensity of Alexandria Governorate (24.1%) is considered among the highest values, whereas El-Fayoum Governorate is considered as having the lowest TeleDensity value in Egypt. In general, the lowest TeleDensity values were observed at the Governorates of Upper Egypt. It is noticed that the highest OFL values were concentrated on the northern sectors of the Alexandria Governorate study area. It is concluded that the GIS plays an important role in visualizing and analyzing the telecom infrastructure. © 2012 National Authority for Remote Sensing and Space Sciences. Production and hosting by Elsevier B.V. All rights reserved. 12.
Soliman M.A.,National Telecom Regulatory Authority |
Taha T.E.,Menoufia University |
Swelam W.,University of Waterloo |
Gomaa A.,Benha University
Progress In Electromagnetics Research C | Year: 2012
In this paper, 4G smart planar dual-band phased array antenna suitable for fourth generation (4G) Long Term Evolution (LTE) at 3.5 GHz and also Wireless Local Area Network (WLAN) at 5 GHz systems is developed. The proposed planar array antenna is built using a microstrip rectangular U-slotted patch antenna element. Single element and linear sub-arrays with 1 × 2 and 1 × 4 dimensions of this element are designed, fabricated, and measured by the same authors. Separate feeding technique is used for each element of the smart planar array antenna; such that full beam-shaping can be achieved by steering the pattern main-loop to different angles in both azimuth and elevation directions with different amplitudes. Beam steering up to ±22 degrees can be achieved in both azimuth and elevation direction at 60 degree phase shift without the presence of any grating lobes. At this value of phase shift, the gain is 22.62 dBi without changing in the mutual coupling. This is also suitable for 4G Multiple-Input Multiple-Output (MIMO) wireless mobile applications with reduced power consumption. Design simulation and optimization processes are carried out with the aid of the Agilent Advanced Design System (ADS) electromagnetic simulator that uses the full- wave Method of Moment (MoM) numerical technique.