Communication is a fundamental human need and mankind has developed tons of methods of communication over the course of history. Communication technology of a time is a lot dependent upon science and technology of that time and currently we are on the peak of science & technology and so are our communication systems of modern time. Today the challenge is to make a communication system faster & greener.

Today wireless communication has major share in overall communication systems. Wireless Communication has revolutionised the life of people and has evolved big time. Mobile Communication, Satellite Communication, Space Communication, WLAN, Backhaul Networks are few of the well known terms that are associated with wireless communication. We know wireless technology is now finding applications in several other areas such as in wireless energy harvesting, factory automation, vehicular communication, health service networks and personal area networks etc. Due to the huge data demand and increasing number of users, the network capacity of current wireless communication systems is strained and thus arise a need for next generation wireless communication.

• CHALLENGES FACED BY NEXT GENERATION COMMUNICATION SYSTEMS

  A. Limited Radio Resources

  The next generation wireless systems aim to achieve features like high data rate, data reliability, high throughput and high spectral efficiency. Achieving these features with limited radio resources is a huge challenge for next generation wireless systems.

  B. Increasing Energy Consumption

  The transition from current technology to next generation wireless technology is not as simple due to the increase demand for energy/power in next generation systems. To transmit data bits the requirements are (a) bandwidth - to send/receive bits (b) power/energy - to power up & cool down the base station amplifiers thereby adding to environmental hazards and cost. In Information and Communication Technologies (ICT), mobile communication contributes to around 15-20% of the total energy consumption. Around 3% of the world's electricity consumption is attributed to ICT contributing to about 2% of worldwide CO2 emission.

• SOLUTIONS FOR THE NEXT GENERATION COMMUNICATION SYSTEMS

  A. Efficient Communication systems

  The need of the hour is to have efficient communication systems; efficient in terms of power/energy and bandwidth (spectrum). Energy/power efficient system will reduce the increasing energy/power consumption, thereby reducing the carbon footprint and cutting down environmental hazards. Spectral efficient system will support maximum number of users in a given bandwidth thereby utilising the limited radio resources efficiently.
  Energy Efficiency and spectral efficiency are the key parameters to rate the performance of communication systems. Energy efficiency of wireless communication system is given by the ratio of average sum throughput to the total average power consumption.
  

  Thus to increase the energy efficiency, one has to either increase the throughput or to decrease the total power consumption.
  Throughput = Cell density (cell/area) * Available Spectral(Hz)*Spectrum efficiency (bits/s/Hz/cell)

  B. Optimal Resource Allocation

  To design a sustainable cellular wireless communication system, optimal utilization of resources is utmost important. Optimal allocation of resources such as time, space, frequency, energy/power is done to achieve the ultimate goal of maximizing long term system properties such as ergodic capacities and average power consumption. Effective resource allocation methods need to be designed to improve the efficiency of these systems. For example, an optimal resource allocation scheme in which by optimally allocating transmit pilot power, transmit data power and training duration while keeping the total energy fixed, the spectral efficiency is maximized. In another scheme, the transmit power and rate are adapted according to the channel conditions such that the energy per bit consumption is minimized.
  Thus we all agree that there is a requirement of higher and higher speed going forward but at the same time the energy and power consumption of wireless networks need to come down else it will have two fold impacts - increase in cost and environment degradation. To counter these problems there is a requirement of green communication system designed along the lines of solutions described above and utilizing number of paradigm-shifting technical approaches that could tackle the problems discussed in this article.

By - Ashu Taneja - Asst. Prof., ECE, Chitkara University H.P.