consumption, size, cost and establishing a
marketplace.
Energy consumption is a major obstacle,
especially if multiple sensors are added. Some
sensing tasks also require the sensor device to be
switched on all the time. This is not compatible with
scenarios where animals are without supervision for
several months. Having to change the battery on all
the animals mid-season will in most cases be
unacceptable. There are two solutions to this issue.
The easiest is to fit a bigger battery. This solution is
limited in two ways. The first is size. Big batteries
are bulky and heavy. Forcing the animals to carry
these for months on end could be considered as
animal cruelty. The second problem is price as high
capacity batteries are quite costly. The other solution
is energy harvesting. As this study (Nadimi et al.,
2011) shows, an animal, such as a sheep, generate a
lot of energy while grazing. This could be used to
power the sensors. This technology is relatively new
and therefore it should be expected to become better,
cheaper and smaller over the next years. This will
most likely make energy harvesting a better solution
than using big batteries.
A similar problem to energy consumption is the
issue of size. If too many sensors are put on an
animal it is not possible for it to comfortably carry
the equipment. The size limit is of course animal-
specific. A big cow can carry more than a small
goat.
Cost is also a big factor. The cost of adding
another sensor cannot exceed the perceived benefit
of adding that sensor to the party responsible for
paying for it. Adding a temperature sensor to
measure the weather is not important to most
farmers. Therefore the cost of adding a new sensor
must be paid by those interested in using the data
produced by that sensor. This would involve the
weather service paying the farmer to be allowed to
put temperature sensors on his animals. This leads to
the last problem, the establishment of a common
marketplace where farmers with free sensor capacity
can offer that capacity to customers willing to pay
the extra cost of adding more sensors. A web-based
marketplace where customers can browse based on
area and sensor type would seem like a good option
for this kind of service. It should also be possible to
discover already existing sensor deployments to
allow new customers access to those data, for a
price.
6 CONCLUSIONS
Animal tracking is already being used by both
farmers and researchers to locate animals. By
applying some logic, it is possible to add value to the
location data. Location extrapolation to predict
future locations and optimized farming is just a
couple of examples. Since this can be done with the
equipment being used today, this is merely a
question of implementing the logic into the systems.
Adding more sensors could also be beneficial.
The best candidates are those that can work well
with discrete measurements, since they require less
energy. Temperature sensors and RFID stands out as
sensors that could be quite easily added and are very
useful both to farmers and scientists. Generally
adding more sensors are more complicated than
doing more reasoning on the location data.
Challenges such as energy consumption, cost and
size are all serious concerns. The biggest challenge
however is to establish a market for such a solution.
To be successful it needs to be easy for farmers to
offer sensor capacity to customers and for customers
to find available sensors in an area. On top of all this
it needs to be affordable. It is hard to tell if such a
service is economically viable, as that depends on
the application of the sensor data, but it would
definitely be interesting to see it developed.
Something so radically different could easily spawn
new inventions only made possible by effortless
access to mobile sensor data.
REFERENCES
Akyildiz, I. F., Su, W., Sankarasubramaniam, Y.,
Cayirci,E., 2002. Wireless sensor networks: a
survey.Computer Networks, 38(4), 393-422, Elsevier.
Finkenzeller K., Müller, D., 2010, RFID handbook:
Fundamentals and applications in contactless smart
cards, radio frequency identification and near-field
communication, Wiley.
Jonsen, I. D., Ransom, A. M., Flemming, J. M., 2003.
Meta-analysis of animal movement using state-space
models. Ecology, 84(11), 3055-3063, Ecological
society of America.
Mulder, H. A., Veerkamp, R. F., Ducro, B. J., van
Arendonk, J. A. M., Bijma, P., 2006. Optimization of
dairy cattle breeding programs for different
environments with genotype by environment
interaction, Journal of Dairy Science, 89(5), 1740-
1752, Elsevier.
Nadimi, E. S., Blanes-Vidal, V., Jørgensen, R. N.,
Christensen, S., 2011 Energy generation for an ad hoc
wireless sensor network-based monitoring system
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