**1. Introduction**

Wireless Sensor Networks (WSNs) will be the dominating field in the future era. Right now it is in the transformation phase [1]. It unfolds its capacity and is sorting out its limitations. CISCO is a giant player in the networking field. According to CISCO, the number of devices connected to the internet will be around 50 billion by 2021 which is shown in **Figure 1**. We will be surrounded by the sensors, rather on a lighter note, we can say that we will be captured by the sensors. The sensor networks will generate more than 500 zettabytes of data, which may be structured or unstructured data (Cisco Press release, 2018). The WSNs market was valued at USD 46.76 billion and expected that it will reach USD 123.93 by 2025 as depicted in **Figure 2**. The application range of the wireless sensor network is broad, from simple house automation to emergency response robots for forest fire detection.

The number of devices connected with the internet creates the network of the device which enables the controlling of a physical quantity (i.e. room temperature, fan speed, etc. …) remotely through the internet. This is nothing but the IoT. WSNs and IoT go hand to hand with small differences. So let's first understand the relationship between IoT and the WSNs. If we consider the tree as IoT then the leaf of the tree is the WSNs. WSNs architecture consist of sensor nodes and a sink node as shown in **Figure 3**. The sensor node has to perform two operations: sensing the physical quantity and forward the sensed data. In other words, it has to play two

#### **Figure 1.**

*Number of devices connected to internet (Cisco Press release) [2].*

**319**

**Figure 5.**

*Interrelation between IoT and WSNs.*

*Challenges of WSNs in IoT*

**Figure 3.** *WSNs architecture.*

**Figure 4.** *IoT architecture.*

*DOI: http://dx.doi.org/10.5772/intechopen.95352*

ered as the subpart of the WSNs as shown in **Figure 5**.

roles, as data generating and data forwarding. IoT works at a higher level, which integrate WSNs, any physical object connected to the internet, Internet, Apps, cloud computing, etc. as shown in **Figure 4**. We can say that WSNs can be consid-

**Figure 2.** *Market growths of WSNs (ETNO) [2].*

roles, as data generating and data forwarding. IoT works at a higher level, which integrate WSNs, any physical object connected to the internet, Internet, Apps, cloud computing, etc. as shown in **Figure 4**. We can say that WSNs can be considered as the subpart of the WSNs as shown in **Figure 5**.

**Figure 3.** *WSNs architecture.*

*Wireless Sensor Networks - Design, Deployment and Applications*

*Number of devices connected to internet (Cisco Press release) [2].*

**318**

**Figure 2.**

**Figure 1.**

*Market growths of WSNs (ETNO) [2].*

**Figure 5.** *Interrelation between IoT and WSNs.*
