EvalVid Wireless over the wireless network has received tremendous attention from academe and also industry due to increasing demand of wireless networks.
Challenges faced in wireless IP network:
- Staying fair to concurrent traffic also on the link.
- Calculating desired rates from current status and also collect statistics.
- Differentiating between congestion loss and also link error loss.
- Transporting network feedback to the sender.
- Providing stable transmission conditions also for mobile users.
- Minimizing delay and jitter for real-time applications.
- Interpreting the feedback and also notifying the transmitting applications.
- Scaling the multimedia output rate also from the sender.
Architecture of EvalVid Wireless Network
Goals of wireless network:
- Continue to serve existing mobile user applications.
- Drive down costs by encouraging competition among wireless product vendors.
- Define a class of wireless products suitable for computer LANs.
Features of wireless network:
- Security
- Mobility
- Power management
- Range and throughput
- Ease of management etc.
Sample Code for EvalVid Wireless Projects
proc mylog { s } {
puts "proc mylog"
set now [ exec date ]
puts stdout "$now $s"
}
proc alive {} {
puts "proc alive"
global ns opt
set now_r [exec date]
set now_s [$ns now]
puts "$now_r $now_s"
$ns at [expr $now_s + $opt(alive_time)] "alive"
}
proc hcca-start {} {
puts "proc hcca-start"
global ns qap qsta val opt ;
[$qap getMac 0] start-hcca
for {set i 0} {$i < $val(n)} {incr i} {
[$qsta($i) getMac 0] start-hcca
}}
proc hcca-stop {} {
puts "proc hcca-stop"
global ns qap qsta val opt ;
[$qap getMac 0] stop-hcca
for {set i 0} {$i < $val(n)} {incr i} {
[$qsta($i) getMac 0] stop-hcca
}}
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