Question

In Ad hoc and Sensor Networks

What are challenges in designing routing algorithms for WSN?

draw figure that explain how it is work. and if not draw figure to explain your answer by figure

Answer 1

Design challenges in WSNs
There are some major design challenges in wireless sensor networks due to lack of resources such as energy, bandwidth, and storage of processing. While designing new routing protocols, the following essentials should be fulfilled by a network engineer.

Energy efficiency
Wireless sensor networks are mostly battery powered. Energy shortage is a major issue in these sensor networks especially in aggressive environments such as battlefields etc. The performance of sensor nodes is adversely affected when the battery is fallen below a pre-defined battery threshold level. Energy presents the main challenge for designers while designing sensor networks. In a wireless sensor network, there are millions of motes. Each node in this network has restricted energy resources due to the partial amount of power. So, the routing protocol should be energy efficient [1].

Complexity
The complexity of a routing protocol may affect the performance of the entire wireless network. The reason behind is that we have inadequate hardware competences and we also face extreme energy limitations in wireless sensor networks.

Scalability
As sensors are becoming cheaper day by day, hundreds or even thousands of sensors can be installed in wireless sensor networks easily. So, the routing protocol must support the scalability of the network. If further nodes are to be added in the network any time then routing protocol should not interrupt this.

Delay
Some applications require instant reaction or response without any substantial delay such as temperature sensor or alarm monitoring etc. So, the routing protocol should offer minimum delay. The time needed to transmit the sensed data is required to be as little as possible in the above-cited WSN applications.

Robustness
Wireless sensor networks are deployed in very crucial and loss environments frequently. Occasionally, a sensor node might be expired or leaving the wireless sensor network. Thus, the routing protocol should be capable to accept all sorts of environments including severe and loss environments. The functionality of the routing protocol should be fine also [2].

Data transmission and transmission models
There are four modes of data transmission depending on the applications in wireless sensor networks namely as a query-driven, event-driven and continuous type, and hybrid type. A node begins to transmit the data only when sink creates the query or an event occurs in query-driven model and event-driven model. The data is sent out periodically in continuous transmission mode. The performance of the routing protocol is a function of network size and transmission media. So, transmission media of good quality enhances the network performance directly [3].

Sensor location
Another major challenge that is faced by wireless sensor network designers is to correctly locate the sensor nodes. Most routing protocols use some localization techniques to obtain knowledge concerning their locations. Global positioning system (GPS) receivers are used in some scenarios.