**2.1 HUB selection process parameters**

At first sight, it looked like a typical problem for selecting a hub dynamically in WBANs. Wireless body area network has emerged their development through WSNs. Later on, by estimating the drawbacks of fixed HUB, a need for the selection of dynamic HUB has established. The wireless transmission density is neglected in the evaluating process.

A new hub is selected from the parameters like SAR, Battery Level, Priority of the sensor node, and SINR as in **Table 1**.

The parameter that we seek in the selection process plays an eminent role in the broadcast between sensor nodes and the gateway. This can be sorted for a multipurpose decision-making system using Fuzzy-based rules. The criterions used are SAR, Battery level, Priority, and SINR.

#### *Coding Theory - Recent Advances, New Perspectives and Applications*


#### **Table 1.**

*HUB selection parameters table.*

If the sensor node has values of SAR less than 1.6 w/kg, battery level in or around the range of 0–4 Joules, the priority of the sensor nodes which is given lowest priority is considered in selecting HUB. And SINR with a range above 20db is best for a new hub. The mentioned parameters above are according to the standard values based on LTE and IEEE fraternity. The illustration of the parameters considered in selecting HUB is depicted below.

#### **2.2 SAR**

In today's life, communication devices like mobiles, Wi-Fi have become a common part of the human lifecycle. The electromagnetic interference (EMI) radiation emitted from these devices is mean to be absorbed by a human being at a period of transmitting data. SAR expresses the amount of radiation absorbed by the body, generally represented in terms of Watt per kilogram. The SAR value is differently applicable for children [8]. Any of the communication devices near to tissue can cause damage as it continuously sends data to HUB, so a fuzzy-based rule with membership function as in **Figure 2** is implemented. The specified SAR rate according to FCC is 1.6 W/Kg [5].

This term is generated by

$$\text{Radiation} = \text{d}\left(\frac{dW}{dM}\right)dt\tag{1}$$

Here W is the power (W), M is the mass (Kg), and. t is the time (sec).

**Figure 2.** *SAR membership function.*

*Dynamic HUB Selection Process in Wireless Body Area Network (WBAN) DOI: http://dx.doi.org/10.5772/intechopen.98613*

**Figure 3.** *Battery level range.*
