This question appears in Mumbai University > Wireless Networks subject

Marks: 10 M

Middleware Principles:

• Data centricity :

i. A conventional communication system normally depends upon the relationship between the sender and receiver.

ii. Communication in a WSN is data centric, wherein the application is not interested in nodes itself but rather in the data it senses.

iii. Hence middleware designed for WSN should support data centric communication.

• Energy efficiency and resource management :

i. Researches in microelectronics have made it possible to produce very tiny sensor devices.

ii. Due to small size, sensor-nodes suffer with limited resources like energy, memory etc.

. So the middleware on these devices should be lightweight, energy efficient and should smartly manage restrained resources in order to provide the required services while increasing the device’s life.

• In-network Processing and scalability :

i. Involving the nodes also in taking decisions about how to operate a network by considering the data that they transmit is called in-network processing.

ii. Ex. Data Aggregation, Encoding and compression.

iii. In- network processing is a very important feature required for a WSN as it is a resource constrained network.

iv. Middleware designed for WSN should support in network processing and should provide acceptable level of performance even if the network grows in future.

• Quality of Service (QoS) :

i. Due to constraints in resource and topology, traditional QoS mechanisms cannot be used in WSN.

ii. In sensor networks nodes work collaboratively in monitoring and controlling the physical environment.

iii. They process each other’s data thus they have to be aware of the data that they are forwarding.

iv. Hence applications for WSN have more requirements than traditional networks.

v. Middleware designed for WSN should support application level QoSmetrics like accuracy, coverage and deployment, detection reliability etc., apart from network level QoS metrics like throughput, delay etc.

• Dynamic network Organization :

Topology of WSN may change frequently and hence, middleware must be designed in such a way so as to support the robust sensor network operation by adapting to the changes in the networks.

• Localized algorithms :

i. should be used to collectively achieve a desired global objective while providing good system scalability and robustness.

ii. Since the cluster-based architecture localizes the interaction of sensor nodes and hence the cordination and control overhead within a restricted vicinity, it isreasonable to regard each cluster as a basic function unit ofthe middleware.

iii. Consequently, the middleware performs as adistributed software composed of multiple clusters.

• Heterogeneity :

i. A major challenge for WSN is to bridge the gap between hardware technology’s raw potentials and necessary activities like reconfiguration, execution and communication.

ii. Hence middleware has to support system devices interfacing to the various types of hardware and networks.

• Application Challenges :

i. Application knowledge’s have great influence on design principles of WSN middleware.

ii. To design middleware, it must have some resourceful mechanism to inject application knowledge into WSN’s infrastructure.

iii. This allows the developers to build proper network topologies and also to frame proper QoS.

iv. For this reason, including application knowledge into middleware infrastructure is of great importance.