|
|
|
|
|
|
OPNET
Technologies OPNET
is a registered |
Team Members: Mr. Colin Chai ( Research Student) Department of Electrical and
Computer Systems Engineering,
Master Research Project using OPNET Simulations Research Interest: General Packet Radio Service (GPRS) is a packet
data technology based on the ETSI standard for exchanging packet-mode data
using the Global System for Various TCP parameters
subject to tuning in the simulations:- (1)
MSS (2)
Congestion
Window (cwnd) (3)
Advertised
Window ( awnd) (4)
Slow Start
Threshold (ssthresh) (5)
RTT – Round
Trip Time. (6)
RTO –
Retransmission Time Out. (7)
Others. The
research also looked at various TCPIP performance techniques
introduced by other researchers in the wireless networks areas. The comparison is made from those
techniques to the techniques proposed in the following paragraph. For my core research, the focus is on IP QOS
techniques. The research looks at ways
of introducing different service classes to different GPRS users by using the
Weighted Fair Queuing (WFQ) mechanism at the IP layer. The simulation results
show that with the WFQ algorithm applied in the GPRS core network, better
quality of service in web-page download throughput can be achieved by higher
class users provided the bandwidth asymmetry is kept at a moderate level. Further simulations are to be carried out to
determine other queuing techniques applied at IP layer so that performance
improvements can be accounted for and compared for each case study. Recent Publications: 1.
C. Chai and
J. Armstrong, "Simulation study of WFQ packet scheduling mechanism for different
coding schemes in GPRS networks", accepted for International
Symposium on Communication Systems Networks and Digital Signal Processing
(CSNDSP 2004), 2.
C. Chai and
J. Armstrong, "Simulation study of packet scheduling mechanisms by
providing different classes of services in GPRS network", presented in
5th Australian Communication Theory Workshop (AusCTW
2004), 3. H. A. Suraweera, C. Chai, J. Shentu and J. Armstrong, "Analysis of Impulse Noise
Mitigation techniques for Digital Television Systems", in Proc. 8th International OFDM Workshop
(InOWo '04), |
|
