Services that demanded by users via internet network are classified in two main
kinds, Services work in real time such as video and voice in real time and use UDP
protocol, and other services that work in non-real time such as web browsing (HTTP) a
nd
file transfer (FTP) which use TCP Protocol.
In this research, we study and analyze algorithms that enhance the quality of service
for various applications. For real time application, we use queues disciplines, which gives
high priority for these services and achieves minimum delay. For non-real time application,
we study congestion control algorithms, which achieve best performance for reliable
transfer process with existing the congestion in the network. We used OPNET 14.5
program for simulating various services via internet network. Simulation results show
achieving minimum delay for voice service, and achieving high transmission rate for FTP
application with existing of packets loss in the network.
تطبيقات الزمن الحقيقي
التحكم بالازدحام
Congestion Control
تطبيقات الزمن غير الحقيقي
قواعد الرتل
خوارزمية البداية البطيئة
تجنب الازدحام
خوارزمية إعادة الإرسال السريع و الاستعادة السريعة
Real Time application
non-real time application
Queue disciplines
Slow start algorithms
Congestion avoidance algorithms
Fast retransmit and Fast recovery
المزيد..
Random Linear Network Coding (RLNC) is considered to be one of the promised
solutions to achieve the reliability of transmission in multi hop wireless networks, Since it
is based on correcting the loss of the packets in the medium through the conti
nuity of
transmitting coded packets from each segment until receiving acknowledgment of getting
the required number of these packets for decoding. However, because of the nature of
wireless medium and multi hops transfer, a loss or delay of the ACK may occur, which
causes transmitting extra packets and time delay to the next segments, consequently
decreasing the throughput of these networks.
In this research, we propose a new transmission mechanism for reliable transfer in
multi hops wireless networks through using the concepts of sliding window and fast
retransmit with RLNC, for transmitting packets of consequent segments in specific
continues flow and fast correcting the loss in these segments. Simulation results show that
proposed mechanism decreases the time delay for transmission process and increases the
transfer throughput of these networks.
In this research, We interest to studying two methods of ways to increase the reliability of wireless communication, namely: hybrid retransmission protocols (HARQ Protocols) and adaptive coding data (Adaptive Coding), in order for the wireless commun
ication system between two points: the first is fixed and represents the control and leadership station .The second represents a body moving and it is controlled from the command station , it performs various measurements and sent it to the command station.