From Fig. 13 we can observe that the energy
consumption is uniformly distributed between
nodes; in Fig. 14, instead, we can note that the nodes
that are not in the main lobe region preserve its en-
ergy amount. In particular, all energy is conveyed
toward the host that is within the main lobe region.
Furthermore, in Fig. 15 the energy consumption is
preserved, except from host 0 that suffers from the
effect of the sidelobes. Because energy consumption
results clearly reflect values obtained in packet sta-
tistics, we can conclude that our designed module is
functional and could be used for allowing asymmet-
rical and directional communications as extension of
Omnet++ features. Finally, it is shown a summary
Table that compares the main features of the most
used network simulators discussed in sec. 3:
Table 2: Network simulators features comparison.
Network Simulator
Open
Source
Asymmetrical
Comms Sup-
port
SAS Sup-
port
NS-2 yes partial no
NS-3 yes no no
OPNET no partial no
OMNET++
(default Inet)
yes no no
OMNET++
(our Inet)
yes yes yes
Although Opnet and Ns-2 provide some patches
to support asymmetrical communications between
nodes, they do not provide any Smart Antenna Mod-
ule by default; therefore, with respect to Opnet, Om-
net++ is an open source Software that can be en-
hanced by developers. In this regard, our work
demonstrated that, through some appropriate modi-
fications, Omnet++ could be improved in terms of
features, becoming more useful for end users espe-
cially in beamforming and directional antenna con-
texts.
7 CONCLUSIONS
We proposed to extend Inet framework of Omnet++
simulator adapting original source logical structure
also to network systems that supports directional and
asymmetric communications. For this purpose, we
presented a Switched beam smart antenna approach
applied to a real network scenario where mobile
nodes are equipped with directional antennas. After
designing directional antenna module, through sev-
eral modifications accomplished on original mod-
ules, we demonstrated that, applying a very simple
algorithm for managing the power of nodes, de-
pendently on their positions, we can convey data
traffic flows only towards a specific direction; re-
sults showed that, using this approach, instead of the
classical omnidirectional mode, it can be achieved a
considerable energy saving also obtaining a larger
coverage range due to gain value in the main beam
region. Typically, this value is greater than 1 and
depends on geometrical structure of used array. An-
yway, when we drive the main lobe in a certain di-
rection, we have to consider the entity of sidelobes.
Our analysis, also investigated about this situation,
evaluating a case in which sidelobes power value is
not negligible with respect to main lobe power; in
this regard simulation results demonstrated that
some nodes which are not located in main lobe re-
gion could receive sent packets. This effect need to
be accounted in the protocol design at higher layers
such as Mac and Network Layers.
REFERENCES
Chu L.J., 1948 “Physical limitations of omnidirectional
antennas, ”Journ.Appl.Phys., vol. 19, pp. 1163–1175
Khuzhali, S., 2014 “Energy Efficient Topology Based on
Demand for MANETS Using Directional Antenna”
Middle-East Journal of Scientific Research
Dimitrou T., Kalis A., 2004” Efficient Delivery of Infor-
mation in Sensor Networks Using Smart Antennas”,
Chapter “Algorithmic Aspects of Wireless Sensor
Networks Volume” 3121. pp 109-122
Sengar K., Rani N.,Singhal A.,Sharma D., Verma S.,
Singh T., 2014 “Study and CapacityEvaluation of SI-
SO, MISO and MIMO RF Wireless Communication
Systems” IJETT – Vol.9.
Kulkarni S., Bhavani V., 2014 “Study on Smart Antenna
Systems and Implementation in Mobile Ad Hoc Net-
works”, IJERA, Vol. 4.
Balanis C., Ioannides P.,2007” Introduction to Smart An-
tennas”, Lecture #5, Morgan & Claypool.
Wei L.,2004” Smart antennas and MAC protocols in
MANET”,
Christu M.R., Namrata C., John M., Shibin D. , 2013 “A
Comprehensive Overview on Different Network
Simulators”, IJET
Patel P.D., 2007 “Fundamentals of Phased Arrays”, As
tron, Netherland
Orfanidis S.J., ”Electromagnetic Waves and Antennas”
Ch.20: Antenna Arrays , Rutgers ECE
Uribe P., Maureira J.C., Dalle O. 2010 “Extending INET
Framework for Directional and Asymmetrical Wire-
less Communications”. ICST Workshop
Nasipuri A., Li K., Sappidi, U.R. 2002 “Power Consump-
tion and Throughput in Mobile Ad Hoc Networks us-
ing Directional Antennas”, IEEE Int. Conf. on Comm.
And Networking