Page 64 - ITU Journal Future and evolving technologies Volume 2 (2021), Issue 7 – Terahertz communications

ITU Journal on Future and Evolving Technologies, Volume 2 (2021), Issue 7

An even more severe limitation (and a main difference
from traditional wireless networks) lies in the inability
of a single node to process the whole channel capacity.
In the typical networks, a node may always listen to the
channel and take whatever packet concerns it. There is no
way for a tiny, energy constrained nanonode to sustain
Tb/s ic. This translates into a much smaller effective
channel capacity, as all nodes in an area may saturate their
reception capability way before saturating the channel itself.
A typical solution to this problem is to let the nodes sleep
from time to time. A traditional sleeping mechanism can‑
not be applied in a nano‑scale network. Our proposition
differs signi icantly from the previous schemes that Fig. 2 – Drug delivery in human body.
make nodes sleep or awaken for periods longer than a
body through the variation in the size and shape of the
packet. To cope with the very speci ic characteristics of
human organs [8]. Nanomedicine may be de ined as the
nanonet‑ works, our idea is to make the node inactive for
use of nano‑devices and nanostructures for monitoring,
a fraction of (the time between two consecutive bits).

repairing or controlling human biological systems at the
We then make it awake in order to receive the intended
molecular level [9]. The nanonodes spreading in blood
bit. Such a mechanism aims to preserve node resources
vessels can monitor the glucose level, and at the same
(CPU, mem‑ ory, energy), therefore extending network
lifetime. time release the insulin to regulate the glucose level. The
risk lies when the patient forgets to take his medicine
In this paper: (1) we show that the sleeping mechanism
especially those related to the control of certain levels of
works in a heterogeneous nano‑scale network, (2) we
enzymes in the blood (as in the example above). With
propose a method to automatically tune the awaken dura‑
this type of technology, the patient becomes more able to
tion of a node depending on the average density of neigh‑
con‑ trol his health troubles.
bours (awakenNodes), (3) we propose an algorithm for
packet retransmission at the destination zone, and (4) we This heterogeneity of the human body poses a major
test this method and show its impact on increasing re‑ challenge to the routing protocol by traversing areas of
ceived packets by the destination node. different densities.
The rest of this paper is organized as follows. Section 2
introduces applications used within heterogeneous net‑ 2.2 Agriculture sector
works. Section 3 describes the algorithms used in the
paper. Packet retransmission algorithm is explained in Agriculture is an important source of livelihood in most
the Section 4. Evaluation via simulations takes place in parts of the world. Wireless nano‑sensor(s) have been
Section 5. Finally, we conclude in Section 6. used in modern agriculture and farming (Precision
Agriculture (PA)), de ined as the techniques of applying
2. APPLICATION FIELDS farming parameters and resources for production
optimization, and reducing human effort [10].
Different approaches in the literature focus on designing
and developing routing protocols for heterogeneous elec‑
tromagnetic nanonetworks. Nowadays, the nano‑scale
communication technology enters into many important
sectors such as health, military, and agriculture.

2.1 Health sector

Heterogeneous networks pervade many applications
where nodes are distributed depending on the environ‑
ment conditions. Due to their nanoscale size, nanon‑
odes can be deployed at different scales [7] inside the hu‑
man body and across a variety of environmental contexts.
Nanonode uses are not limited to sensing and monitoring
human vital signs, but it may cover some other operations
when needed.

An example of a medical application that can be assigned
to nanonodes and needs high reliability and accuracy is
drug delivery (Fig. 2). Heterogeneity resides in the human Fig. 3 – Nanonetwork technology impact in agriculture.

52 © International Telecommunication Union, 2021