Abstract:
Constrained networks or Low Power and Lossy Network (LLN) are networks that consists of
spatially distributed autonomous sensors, which are tiny devices deployed to cooperatively
process, communicate and monitor the physical or environmental conditions, such as
temperature, sound, vibration, pressure, motion or pollutants and pass their data through the
network to a main location.
Constrained sensor nodes, in addition to their resource constrained (energy, processing power,
memory, and communication bandwidth), are often placed in a hard-to-reach location in harsh
and extreme environments, because of that, it is very difficult to maintenance and repair. Sensor
nodes must be self-managing meaning they must be able to autonomously configure, update
them, cooperate with other nodes and accommodate to failures and environmental changes
without human intervention. Considering such sensor deployment, LLNs are envisioned to be
deployed in the absence of permanent network infrastructure and in environments with limited or
no human accessibility.
In this thesis, we design a mechanism to aggregate data generated by multiple sensors in the
constrained networks using Constrained Application Protocol (CoAP) and send it to the next hop
node which may do further aggregation. In addition, it devises a method that can be remotely
deploying aggregation module to a remote node using Constrained Application Protocol blockwise transfer. It is implemented in Contiki with COOJA simulator and evaluated the
implementation by taking different measures such as energy consumption, delay and number of
packet transmitted in the network.
This solution makes flexibility to access and exchange sensor nodes application components and
minimize the number of packets in network which reduce battery consumption of each sensor
nodes and communication energy of overall constrained network.
