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INET Wireless Tutorial ======================
The INET Wireless Tutorial contains a series of simulation
models numbered 1through 19. The models are of increasing
complexity -- they start from thebasics and introduce ne INET
features and concepts related to irelesscommunication netor!s.
Each model is self-contained" ith its number in the #le names"
so e.g.Wireless$%.ned contains all the necessary NE&
de#nitions. 'The omnetpp.ini#le is shared among all simulation
steps(. It is recommended read thecommentsof the corresponding
NE& #le #rst to understand hat the gi)en step issupposed to
demonstrate.
*cript for the tutorial 'or! in
progress(==========================================
The INET Wireless Tutorial contains a series of simulation
models numbered. 1through 1+. The models are of increasing
complexity -- they start from thebasics and introduce ne INET
features and concepts related to irelesscommunication netor!s.
Each model is self-contained" ith its number in the #le names"
so e.g.Wireless$%.ned contains all the necessary NE&
de#nitions. 'The omnetpp.ini #leis shared among all simulation
steps(. It is recommended to read the commentsof the
corresponding NE& #le #rst to understand hat the gi)en step is
supposed
to demonstrate.
1( In the #rst step e set up a )ery basic netor! containing to
nodes incommunication range that exchange data. We demonstrate ho
to con#gurenodesith applications" place them in the physical
en)ironment" assign I, address tothem" con#gure the ireless
interface and set up statistics to measure thetrac. 'constant
bitrate &, trac( /t the moment e are not interestedhether the
actual ireless exchange is realistic or not" e 0ust ant the datato
get from one host to the other 'i.e. e assume a certain ell
de#nedtransmission range and no collisions" attenuation or other
physical eects(.
2( In this step e add a neat transmission animation so in the
future e illha)e a much better )ie hat is actually happening in the
netor!.
%( We ill add some more hosts and recon#gure 'decrease( the
transmissionrange. We ill #nd that the communication is no longer
possible beteen theoriginal hosts as they are no out of range" but
it ould be possible if ecould use the nely added hosts as a
relay.
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3( To establish the communication again e ha)e to enable static
routingbeteenthe nodes and add routes manually to some of the
nodes.
4( In this step e ill chec! the throuput of the netor!. We
expect that thecommunication bandidth beteen the original nodes
dropping because of theextrahop re5uired to bridge the distance
beteen the hosts. 6ollisions should happenbecuase of the
intermediate node. 7et8s enable interfence detection to modelalso
collisions.
+( No e see that the trhuhput dramatically drops as collisions
happen" but theradios do not care hether there is a transmission on
the channel 'as the macprotocol in ideal mac does not care(. /fter
setting up a more realistic /6protocol '6*/( e ill see that the
eects of the collisions are not sodramatic as the mac protocol no
chec!s the medium before transmission.
:( 7ife is not static. 6on#gure the relay nodes to actually mo)e
around. We areseeing that static routes are no longer )alid and the
communication brea!sdon.
;( 7et8s forget the static routing as it is no longer useful in
a dynamicen)ironment. We ill use a /NET protocol '/adio.
11( 7et8s sitch to a more realistic radio model that models the
transmission onpac!et le)el and ta!es into account the obstacles"
attenuation etc. We ha)e tocon#gure se)eral physical parameters and
the actual transmission range is no
calculated from these )alues. No e are seeing the eects from the
obstaclesintroduced in the pre)ious step.
12( /s e are no longer in free space" let8s ma!e the model e)en
more accurateby con#guring a better propagation model instead of
free space? To>ay@round>eAection
1%( *ome nodes are out of range" but not by much. *etting up
directional
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antennas ith better gain ould allo them to communicate
directly.
13( 7et8s add some more reality. We are introducing hea)y radio
noise on anad0acent communication channel 'on a neighboring
fre5uency channel(. Weouldexpect this to limit the trac" but e are
not seeing the eect because thecurrent radio model handles each
radio channel independently.
14( To support the modeling of the cross-tal! eect e ill sitch
todimensional analog radio model. This model re5uires much more
processingpoer"but allos much more accurate modelling of each
pac!ets as they tra)elthroughspace.
1+( No e are introducing some )ery short burst radio signals
'1nsB( that cancorrupt a single bitCsymbol during the pac!et
transmission. In real life this
ould not aect the throughput too much as lo le)el error
correction ould #xthese errors ithout introducing pac!et
errors.
1:( We are no sitching to bit precise radio model. This complex
radio modelproperly models all the layers of a real radio and allos
us to see the positi)eeect of the error correction.
1;( /dd forard error correction" scrambling" interlea)ing
19(
