• **Advantages of TEEN Protocol**


#### • **Disadvantages of TEEN Protocol**


#### *3.2.4 APTEEN – (adaptive threshold sensitive energy efficient sensor network protocol)*

APTEEN was introduced as an improved version of TEEN to enhance the performance of the TEEN protocol to support the regular data collection process. The architecture of APTEEN is similar to the architecture of TEEN. APTEEN also follows a hierarchical clustering approach to achieve energy efficient communication between source sensors and receivers (SINK nodes). An enhanced feature of this protocol is that it allows the node to periodically transmit its sensed data, and if any rapid variations are found in the sensed attributes, then the sensor accordingly respond its report to CH. In this version, CH is also responsible for performing data aggregation operations to reduce power consumption in data processing tasks. Once

ii. The second disadvantage is that it requires additional complexity to

HEED Protocol is introduced as an extension of LEACH feature in order to acquire power balancing feature for cluster selection by utilizing residual energy and node density. It works in multi-hop pattern within inter-cluster communication through adaptive power transmission. The HEED protocol is mainly introduced for

i. Extends network life-span by allocating energy consumption.

*NCH*�*prob* ¼ *Cprob*

maximum power equivalent to a charged battery source.

ii. The clustering process ends within a constant number of iterations.

iv. Provide a homogeneous distribution of CH and a solid pattern of clusters.

In this protocol the cluster formation processes perform in various cycles. Each cycle takes long duration to get messages from corresponded nodes in the cluster. A probability factor is used to bound the initialization of CH selection at first cycle. In this, every sensor node uses a probability factor to become a CH. The mathematical

The above Eq. (5), NCHprob is the probability of node that wants to be becomes CH, Rresidual is the estimated remaining energy in the senor node and Pmax is the

In this the Value of NCHprob must be higher than the minimum threshold value Tmin. If NCHprob < 1, then CH is an temporary-CH or if its NCHprob equal to 1, then NCH will become is the final CH. The recent elected CHs will be added to the current CHs set. If the sensor node is elected to be CH, then it broadcasts the message as it becomes temporary CH or a final CH. The node that hearing the CH lists chooses the CH with the minimal cost from the group of CHs. Afterwards, each nodes increase its probability value to become CH in next round. If the sensor node completes cycle of HEED execution without choosing to become a CH or to connect to the cluster, it will declare itself to be the final CH. If a temporary CH node hears from a lower cost CH, it can become a regular node in a later iteration

i. This protocol enhances the life of network, thereby stabilizing adjacent

ii. It does not require any information about the network such as

iii. It also does consider the distribution of nodes.

*PRresidual*

*<sup>P</sup>*max (5)

threshold-function and time count.

*Energy Saving Hierarchical Routing Protocol in WSN DOI: http://dx.doi.org/10.5772/intechopen.93595*

achieving following features:

expression is given as follows:

(**Table 1**).

**167**

• **Advantage of HEED protocols**

nodes.

location.

iii. Lowering the overhead problem.

*3.2.5 HEED – (hybrid, energy-efficient distributed clustering protocol)*

**Figure 8.** *Operation of APTEEN.*

Sink node decides the cluster, the following are the parameters that are broadcasted by the CH (**Figure 8**):


The node continuously observes its surroundings, whose sense value is higher than the hard threshold value. Once the node senses a value that exceeds the threshold value, then it only sends the data when the value of the sensed attribute changes to the total quantity equal to or greater than the defined soft threshold value. If the node fails to send data for the duration set equal to the count time, then the system asks to recollect and resend the data. TDMA is used to set up scheduling in which each node in the cluster is assigned a transmission slot.
