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Configuration for the LL/RLC/MAC is described below. Each can be used
seperately/independantly for any other stack implementation.
A GPRS/GSM configuration would require to use all together.
Configuration is similar to any wired-cum-wireless example (note - presence
of the BS makes it a wired-cum-wireless scenario).
- Setting the LL: Set the LL layer type while configuring the nodes
set opt(ll) LL ;# Link layer type
:
:
# configure for base-station/mobile nodes
:
$ns_ node-config -llType $opt(ll) \
- Setting the RLC: Introduce an RLC while configuring the nodes.
set opt(ll) RLC ;# Radio Link Control type
:
:
#configure for base-station node/mobile nodes
:
$ns_ node-config -rlcType $opt(rlc) \
- Setting the Mac: Set the MAC to GPRS. The Mac requires a non-adhoc
routing agent. Set the adhoc routing agent to NOAH.
set opt(mac) Mac/Gprs
set opt(adhoc) NOAH
:
:
# configure for base-station node/mobile nodes
$ns_ node-config -macType $opt(mac) \
$ns_ node-config -adhocRouting $opt(adhoc)\
- Configuring the Base Station (BS): The BS should be configured first ,
ie before any other wireless node. Therefore it will have a herarchical
address of the form 0.0.0 or 1.0.0 etc. This is requred by the Mac
implementation.
- Configuring the Mobile Stations (MS): The MS are normal ns-mobile node
and can be configured to act as GPRS mobiles or GSM mobiles. The only
difference being that GPRS mobiles release resources ( ie release the slot
reserved for them) if their IFQ is empty and there is no packet transfer
for a while. The slot can then be alloted to another GPRS mobile if
requred. The GPRS mobile can ask for resources again whenever it has
packets to send. GSM mobiles on the other hand, keep resources "forever".
This severly limits the number of GSM mobiles a system can support. To
configure the moble node as GPRS or GSM, for each mobile node set
Mac/Gprs set gprs_ 1 ; # for GPRS; default value=1
or
Mac/Gprs set gprs_ 0 ; # for GSM
Richa Jain (96D07007)
Tue Jul 24 22:29:53 IST 2001