Keywords

1 Introduction

In the recent years, WSN have got consideration from many research communities. A great number of applications, such as medical care, military target tracking, disaster relief, etc., are using this technology. Limited power supply is one of the major concerns as sensor nodes are generally battery-powered devices [1]. The main challenge is to how to decrease the energy utilization of nodes, so that the network life span could be extended. Energy utilization is also a key issue in the designing and implementing algorithms and protocols for WSN. Hence, most research is happening in WSN area which is related to energy optimization. Many routing algorithms are specifically designed for the optimization of energy in WSN and have been proposed. Some algorithms like ant colony optimization (ACO) that take idea from the social behavior of ants [2] and genetic algorithm (GA) which is based on the concept of Darwin‘s evolution of biological systems that use arbitrary search in the decision space via selection, crossover, and mutation operators in order to reach its destination [2] are designed and used for energy optimization. However, with the advancement of antenna technology and wireless power transfer through microwaves, the issue of limited energy can be addressed by transmitting power as well as data at the same time. Wireless powered communication network eliminates the requirement of frequent replacement of battery or charging thus perk up the performance [3]. In this paper, an extensive survey of energy optimization techniques based on simultaneous transfer of data and power has been presented. Furthermore, recent advances and future research challenges have been discussed.

2 Simultaneous Wireless Data and Energy Transfer (SWDET)

Nikola Tesla first envisage the idea of wireless power transmission (WPT) and demonstrated “the transmission of electrical energy without wires” that rely on electrical conductivity in 1891 [4]. In 1893, lighting of vacuum bulbs had been shown by Tesla without the use of wires for transmission of power, at the World Columbian Exposition [4]. The Wardenclyffe tower that is also called as Tesla tower was constructed by Tesla primarily for electrical power transmission without wires instead of telegraphy [4]. Later in 1961, William C. Brown an American electrical engineer published the foremost paper regarding microwave energy for transmission of power; later on in 1964, he demonstrated a helicopter that received power required for flight from a microwave beam of frequency 2.45 GHz [5]. In 2007 a research group of Massachusetts Institute of Technology (MIT) showed illumination of a light bulb of 60 W using wireless power with efficiency of 40% at a two-meter distance by using a couple of diameter coils of 60 cm [6]. The Same concept has been applied in simultaneous transfer of energy and data to wireless sensor nodes. The recent advances in microwave-based wireless transmission of power open a new way to deal with the issue of limited energy and frequent battery replacements. Any signal that is used for data transmission also bears energy that can be harvested by the node at receiver. This is the principle of simultaneous transfer of energy and data technique. The wireless devices (WD) can use this harvested energy to send out information to or from other nodes. It improves the experience of user and can provide a high throughput in comparison to conventional battery-powered wireless sensor networks. Furthermore, with the recent advances in antenna technology and much higher microwave power with an adequate efficiency can be transferred [7] (Fig. 1).

Fig. 1
figure 1

A model for wireless powered communication

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3 Literature Survey

(See Table 1).

Table 1 Literature survey
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4 Conclusion

In this paper, we have presented a comprehensive overview of research going on in the domain of wireless powered communication. Recent research articles on energy optimization techniques based on simultaneous transfer of data and power have been considered for the survey. Some authors have worked in the domain of antenna technology and exploited spatial characteristics. Various switching techniques such as time switching, antenna switching, power splitting, etc. have been presented by many authors. Optimization of energy in WSN is a challenging issue and a key area of research. Simulation results and comparative analysis of various parameters have been shown by authors. Trade-off between energy and interference was also discussed by many authors. This paper has provided a summary of recent advancement in the area of transmitting power as well as data to wireless sensor network at the same time. This paper summarizes and organizes recent research results in a way that adds understanding to work in this domain.