[ns] two state markov error model in mobile ip2

[squal xenogear]

Hello ns users,
I just want to know if any one know how to insert a
two
state markov chain error model in the mobile ip (mip)
environment in the ns simulator(the wireless part).
## wireless-mobileIP-simulation

#                       o W1                 WIRED
NODES
#                       |
#                       o W2
#                      / \
#                     /   \                    
#--*--*--*--*--*--*- o     o base-stn nodes 
--*-*-*-*-*-*-*-
#                   HA      FA               
#                       o
#                  o    WL       o          WIRELESS
NODE MOVING
#                WL               WL    FROM HA TO FA.
#
#



The following is how to create the error model 


***create a 2-state Markov model:

# Create 2 exponential random variable (for Markov
model)
set $rvGood [new RandomVariable/Exponential]
$rvgood set avg_ xxx # xxx is the error-free parameter
set $rvLoss [new RandomVariable/Exponential]
$rvloss set avg_ xxx # xxx is the error parameter

# Now create a 2 state Gilbert error model and assign
the parameters
set em [new ErrorModel/TwoState]
$em ranvar 0 $rvgood
$em ranvar 1 $rvloss
****************************

what i need is how to insert this model in the packet
data path ( for wireless part of the mip, the packets
that is received to the mobile host)

i think that is simple and i need just a guide (eg.
example script of inserting an error model in the data
path in wireless environment).

please if any one can advice me any thing ,i'll be so
greatfull.

thank you very much for your help and support.
i simulate in ns 2.27

please help me
Please~~~~near to the deadline..

Best regards,


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