core are Microcontrollers (For general purposes, optimized for embedded
applications), Digital signal processors (Optimized for signal processing, low
cost), Application specific Integrated circuits-ASICs (High performance for
special purpose, flexible), Field programmable gate Arrays –FPGAs (Cost lower
than ASICs, Processing speed lower than ASICs).Traditionally, a sensor node has
been generally designed based on microcontroller unit platform. Stringent
requirements in terms of real time, low cost and low energy forced researchers
to think about higher performance platforms: DSP, ASIC and FPGA.
module task is to transmit and receive data between a pair of nodes. The two
important energy characteristics are Power consumption to send, receive data, Time
and energy consumption to change between different states.
In many WSN applications,
the sensor nodes are battery driven. Energy efficiency is needed to prolong
network life time and ensure network performance. Almost 90% of the energy
consumed by a sensor node is due to data transmission. Hence by minimizing the
data size, a sensor node can save energy 22.Sensor nodes do not just make
measurements, they also perform data processing. Processed data contain the
compact event patterns rather than raw data. It is very important to address
the issue of communication overhead, data transfer, energy consumption, as well
as the storage space and network bandwidth requirements. Microcontrollers show
poor execution time and energy efficiency in many complex computational cases.
DSPs cannot usually meet the high performance and low power consumption
requirements of sensor nodes. ASICs are able to perform specific calculations
much faster than a similar software routine, and more energy efficient. But on
the other hand are more expensive, and less flexible. Integrating a hardware
accelerator would be a better alternative to ASICs and general purpose
processors. FPGAs offer a balance between the speed of ASICS and the
flexibility of software. 23.FPGAs have been favored due to the high
efficiency provided by their architectural flexibility.
parallelism of FPGA whose only limitation is the amount of chip space, FPGA
Corresponds to a replication of components on the chip area, The process can be
parallelized such that many independent calculations can be performed