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. 
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