A new technique is proposed that enables TCP to early detect packet losses, which cannot be detected and retransmitted using the standard fast retransmit mechanism, and to quickly retransmit those packets without waiting for a timeout to occur, thereby improving TCP performance. Early Packet Loss Recovery (EPLR) is achieved by considering the expected number of acknowledgements and the number o...

We focus on implementing a modified TCP/IP protocol stack by positioning network coding functionalities in the form of a new layer in between the transport and the network layer, thereby allowing incremental deployment. We implement this proposed modification for the TCP/IP stack in the OPNET Modeler and analyze implemented functionalities for heterogeneous wireless environments where a mobile ...

In IEEE 802.11 Wireless Mesh networks, tuning of the Physical Carrier Sensing (PCS) threshold based has been shown to be an efficient way to balance the hidden vs. exposed terminal trade-off and hence improve aggregate network throughput. Clear Channel Assessment (CCA) indicates channel status by comparing the net RF energy with a suitable chosen PCS threshold to control which nodes may attempt...

The name "WiMAX" was created by the “WiMAX Forum”, which was formed in June. WiMAX (Worldwide Interoperability for Microwave Access) standards define formal specifications for deployment of broadband wireless metropolitan area networks (wireless MANs).Wireless MANs as needed in WiMAX standards provide wireless broadband access anywhere, anytime, and on virtually any device. Introducing the vari...

ATM is becoming a widely used technology as a backbone for connecting data networks. An important consideration when analyzing the performance of data traffic over switched networks such as ATM is the routing scheme utilized. The IP layer traditionally handles all routing processes in TCP/IP networks. For ATM, OPNET contains standard models that map IP packet traffic to ATM virtual circuits. Ho...

AbstractIn this paper analyze the performance of Wireless Local Area Networks (WLANs), it is important to identify what types of network settings can cause bad performance. Low throughput, high packet loss rate, delayed round trip time (RTT) for packets, increased retransmissions, and increased collisions are the main attributes to look for when analyzing poor network performance. We use the OP...

ABSTRCT This paper focuses some simulation methods and performance analyses of Code division multiple access (CDMA) soft handoff using OPNET that are useful for the research of CDMA system and management modeling. CDMA is an advanced digital wireless transmission technique over radio waves. It uses mathematical codes, instead of frequencies or time slots, to transmit wireless conversations. Top...

Designing an integrated telecommunications and computer network using a simulation model requires defining all the communication elements that make up communication. The accuracy, quality, usability of results depend on accuracy way traffic as timed event between source destination in network. In this paper, method for more accurate definition required development software tool OPNET is propose...