Nanonetwork Wireless Sensor Design Material Considerations
In this problem, we will use basic concepts to understand how the material used in semiconductor microelectronics and its properties affect the design of very small motes. We will also look at advanced material concepts such as carbon nanotubes. Our design specifications are quite demanding and call for a wireless sensor volume of not more than .
Inter-atomic distance is an important parameter for design purposes. If Silicon atoms are uniformly distributed from a probabilistic point-of-view, what is the inter-atomic distance? Assume that the atomic density of silicon is .
Carbon nanotubes are atomically thin and conduct electricity well. For these reasons and the facts that they are faster and have lower energy consumption, they compete well with silicon semiconductors. Furthermore, carbon nanotubes can be designed to act as an extremely small sensor. How many carbon nanotube sensing elements could fit within the volume of our wireless sensor assuming they are 1 cm long and laid next to each other? Assume a carbon nanotube has a length of 5 mm and a diameter of 5 nm.
Given your results from parts (a) and (b), argue, in your own words, which would be a better choice for our wireless sensor. Once you have made your choice, discuss what type of sensing could be performed, i.e., what type of phenomena would lend themselves well to being sensed by our small sensor.

Nanonetwork Transmission Rate
Not a great deal is known concerning the transmission rate of nanonetworks designed for specific applications. Generally, it is very important to know how fast we can move sensed information around the network and to the world outside the network. In this problem, we get a feel for nanonetwork transmission rate by realizing that scale is all-important.
We consider a conventional light wave (optical) channel where we transmit bits at the speed of light to a 1 nm link between motes of a nanoscale network where the bits move at the rate of 1 mile per hour (mph). What are the bit rates in each case?
What is the ratio of the nanonetwork transmission rate to the optical channel transmission rate?
Discuss the results obtained in parts (a) and (b). Consider using the nanonetwork for a medical sensing problem where the network elements are ingested into the human body, travel to a specific location, and form their infrastructure. Do you think that the transmission rate would be adequate to send useful information to antennas outside the human body in a timely manner? Explain in detail. Use a specific example, if appropriate.

Nanonetwork Frequency Range
When we take a conventional wireless sensor network of the type studied in class and compare it to an extremely physically scaled down nanonetwork, the frequency ranges used by both networks are quite different. In this problem, we will gain insight into this difference.
Consider first a conventional wireless sensor network with identical, randomly located nodes. Assume that each node can transmit at R bps and using a fixed range, form a wireless network. What is the approximate throughput obtainable by each node for a randomly chosen destination? Assume a noninterference protocol.
Consider a frequency of 256 Hz mechanically created by, say, a piano. If the scale of the mechanism that creates the frequency is shrunk by a billion, what frequency should then be created?
What is the density of nanoscale communication compared to the conventional wireless sensor networks we have discussed in class?
How can the principle of frequency scaling with physical size be an important element in communications for a nanonetwork? What scaling would be necessary to ensure that the nanonetwork communicates with light waves?

Nanonetwork Wireless Sensor Design Material Considerations In this...