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Wireless Networks With Power Efficiency

      -Pari.S, Senior Consultant Delivery, In2IT Technologies Pvt Ltd, South Africa

The mode of communication and the effectiveness on their usage with respect to telecommunication industry has grown enormously in the past decade and will continue to grow in the future for both the developed and the developing countries in the world. It is now that the world is addressing the significant environmental impact telecommunications is creating as well as the incredible cost on power usage of the network elements in the ever growing industry. This realization has led to a push towards Green Communications that strives for improving energy efficiency as well as energy independence of telecommunications and the ICT sector. This paper reviews recent energy efficient advances made at specific point within the communications cycle such as components, network operation and topology, and incorporating renewable and alternative energy in wireless communication environment.

I. Introduction
The cellular network is the largest factor contributing to the mobile industry’s environmental impact with the emission of 2% on the entire world’s carbon footprint of greenhouse gas emission. The seriousness of the issue is apparent from the perspective of energy costs and sustainability. In some telecommunications markets, energy-related costs account for as much as half of a mobile operator’s operating expense. The expectation that energy costs may rise three fold over the next decade it will be a great cause for concern which should be addressed primarily.

II. Next Generation Wireless
The next generation wireless networks are fully engaged with high speed Internet access every place and every time. The smart phones creates new traffic demand applications, such as mobile video, gaming, M-commerce. Such applications cause unlimited data traffic. It requires more resource utilization and increasing energy consumption in the network. By default, the more energy consumption leads to the greenhouse gas emission. This is also a major threat for sustainability and environmental protection. In wireless communication networks, all the mobile nodes and sensor devices has limited power capabilities. Within a time stamp the reliable communication must be performed in the network, if the communication is not completed within the allocated time stamp, automatically they required more energy from the network resources and reduce the power capabilities of the nodes in the network. Due to this problem, the wireless network can get service interruption.

III. Impact
The typical power consumption of today’s telecommunication industry falls as retail 2 %, datacenter 8%, core transmission 15%, mobile switching 20% and lastly the major consumer is the base stations which is of 58% of the total power consumption. The subject of energy consumption is more closely related to the part of carbon emission which is also determined as the foot prints of carbon emission when discussing this we need to take in consideration of the GHG (Green House Gases) which contributes more on the global warming issue relevantly. Based on global electricity production statistics, an average of 500 g CO2e/kWh is emitted. However, in reality the CO2e emissions per kWh vary depending on the country or region where the electricity is produced. For example, in Australia the emissions are approximately 875 g CO2e/kWh while in Iceland the emissions are virtually zero. This is due to the technologies used for energy production. Coal and gas installations emit typically between 800 and 950 g CO2e/kWh. The greenhouse gas emissions for nuclear power are also very low, but this energy source has other environmental issues related to it such as the treatment of nuclear waste.

IV. Developing Efficient Systems & Processes
The base stations are the most accounted for a significant proportion of the total power consumption of a wireless network so in this article the processing of base stations are considered mainly for effective and efficient way of reducing the power consumption in base stations with LTE (Long Term Evolution) capability. Industry concept of the energy consumption rating (ECR) is typically defined as a ratio of peak power divided by the maximum data throughput for a base station transmitter.

Alternative energy source of energy harvesting techniques such as solar and kinetic energy can replace or complement batteries in base stations. Cross layer design for resource allocation for information exchange across protocol layers shows better performance especially with heterogeneous data and video services. By imposing this tighter delay constraint, power savings can be achieved through cross- layer design and source-channel coding as opposed to the typical power control methodology.

QoS and capacity are evaluated outside the protocol stack, while energy efficiency is measured within the PHY layer. The self- organizing networks can automatically optimize wireless network operation mostly of reducing power consumption on QoS requirements and channel conditions. Coordinated management and load balancing among nodes underneath an overall smart grid has positive impact on energy consumption without adversely affecting QoS and capacity.

A group of collaborating radios offer several benefits over a lone radio, such as enabling lower power consumption per node and, under certain conditions, lower power consumption for the whole network. Allowing matching between power demand and supply. Meeting high computing and latency requirements by leveraging the computing resources in the network and simplifying small form factor node designs with lower computing and power resources per node.

Base stations should include schedulers which operate to the traffic load that can be turned on and off accordingly. Cache servers will improves system performance, especially with heavy generated traffic. A caching proxy server causes the response time of the requested services of stored contents on users request. This server saves a copy of the repeated requested data and transmits those upon requesting those data which causes a cost, bandwidth and energy saving. Besides, it causes that the whole of the contents is transferred to the mobile / wireless clients in a short time.

V. Conclusion
There is no doubt that the explosive growth in voice and data usage and the rising energy costs are leading to significant impact in the carbon emission and the operation expense. The capability of integrating new technologies into an existing system becomes crucial in developing a future-proof communication solution.