Enhancing Datagram Congestion Control Protocol for Efficient Long Delay Link

Most of the multimedia applications use the User Datagram Protocol (UDP) as a transport layer protocol because it is suitable for the delivery of multimedia data over the Internet. However, the use of UDP could endanger the stability of the network because there is no congestion control applied. To a certain extent, the network can collapse if too many applications deliberately use this protocol. Subsequently, instead of using the UDP, the applications have choices to use the Datagram Congestion Control Protocol (DCCP), which has a built-in congestion control that can provide a better network. Nevertheless, the congestion control mechanism in the CCID-2 TCP-like can cause problems when delivering multimedia data over a long delay link. To alleviate the problems, such as longer time taken for achieving maximum throughput, and throughput fluctuation during a congestion avoidance phase, two approaches have been used, i.e. setting of an appropriate slow-start threshold value and manipulating congestion window during a congestion avoidance phase. A new congestion control mechanism presented in this thesis, namely the "TCP-like Threshold Window (TCP-like TW)" is designed based on the advantages of the two approaches. It has been developed and modeled in the Network Simulator 2 (ns-2). The TCP-like TW has proven to enhance the performance of the DCCP when delivering multimedia data over long delay link networks, as well as over short delay. For a long delay link, the TCP-like TW congestion control mechanism is able to minimize the time taken to achieve the maximum throughput. It can smooth the fluctuation of throughput after achieving the maximum throughput. Furthermore, for the short delay link, the maximum throughput will be increased while maintaining the friendliness towards other congestion-controlled protocols

Analytical modelling solution of producer mobility support scheme for named data networking

Named Data Networking (NDN) is a clean-slate future Internet architecture proposed to support content mobility. However, content producer mobility is not supported fundamentally and faces many challenges such as, high handoff latency, signaling overhead cost and unnecessary Interest packet losses. Hence, many approaches indirection-based approach, mapping-based approach, locator-based approach and control/data plane-based approach were proposed to address these problems. Mapping-based and control/data plane-based approach deployed servers for name resolution serveces to provide optimal data path after handoff, but introduces high handoff latency and signalling overhead cost. Indirection-based and locator-based approach schemes provide normal handoff delay, but introduces sub-optimal or tiangular routing path. Therefore, there is needs to provide substantial producer mobility support that minimizes the handoff latency, signaling cost and improve data packets delivery via optimal path once a content producer relocates to new location. This paper proposed a scheme that provides optimal data path using mobility Interest packets and broadcasting strategy. Analytical investigation result shows that our proposed scheme outperforms existing approaches in terms of handoff latency, signaling cost and path optimization

Producer Mobility Support Schemes for Named Data Networking: A Survey

Mobile devices connectivity and data traffic growth requires scalable and efficient means of data distribution over the Internet. Thus, influenced the needs for upgrading or replacing the current Internet architecture to cater the situation as Named Data Networking (NDN) was proposed. NDN is clean-slate Internet architecture, proposed to replace IP with hierarchical named content that utilizes route aggregation to improve scalability and support mobility. Although, NDN provides supports for content consumer mobility with the help of catching capabilities, however, content producer faces many problems similar to mobility in IP architecture, such as, long handoff delay, unnecessary Interest packet losses and high bandwidth utilization. Hence, many concepts and schemes were proposed to address these problems. This paper reviewed and conceptually analyzed the schemes based on their fundamental design that broadly categorized into indirection-based approach, mapping-based approach, locator-based approach and control/data plane-based approach. In the review analysis, mapping-based approach schemes provide optimal path for packets delivery, high handoff delay Indirection-based and locator-based approach schemes provide normal handoff delay, but introduces tiangular routing path. The control/data plane-based approach schemes provide sub-optimal routing path and high handoff delay. The paper provided both strength and weakness of each scheme for further research

Comparative study on the performance of TFRC and SCTP over AODV in MANET

This study aims at comparing study the performance of two transport protocols in MANET environment, which are TFRC and SCTP.Because fairness is one of the features in TFRC, it has attracted real-time applications, whereas multi-homing and multi streaming features in SCTP attracted multimedia applications to use it as a transport protocol instead of TCP and UDP.However, both TFRC and SCTP are facing challenges.The challenge faced by TFRC, which uses additive increase, is to adjust the sending rate during periods with no congestion. This may lead to the short-term congestion that can degrade the quality of voice applications.On the other hand, SCTP faces challenges in the best-effort network.The simulation study was conducted in two scenarios; the first one is with the absence of background traffic, which is single traffic, whereas the second one is in the presence of background traffic, which is non-single traffic.For the simulation, NS-2 simulator was used, the mobility of the nodes was set randomly and the traffic type is CBR.In both scenarios, SCTP has better performance in terms of throughput, whereas TFRC has less delay than SCTP. AODV was chosen as a routing protocol for TFRC and SCTP with throughput and delay as the performance metrics

Performance evaluation of TCP, UDP and DCCP traffic over 4G network

Fourth Generation (4G) mobile systems has been used more widely than the older generations 3G and 2G. Among the reasons are that the 4G’s transfer rate is higher and it supports all multimedia functions.Besides, its’ supports for wide geographical locus makes wireless technology gets more advanced.The essential goal of 4G is to enable voice-based communication being implemented endlessly.This study tries to evaluate if the old protocols suit with this new technology.And which one has the best performance and which one has the greatest effect on throughput, delay and packet loss.The aforementioned questions are crucial in the performance evaluation of the most famous protocols (particularly User Datagram Protocol (UDP), Transmission Control Protocol (TCP) and Datagram Congestion Control Protocol (DCCP)) within the 4G environment.Through the Network Simulation-3 (NS3), the performance of transporting video stream including throughput, delay, packet loss and packet delivery ratio are analyzed at the base station through UDP, TCP and DCCP protocols over 4G’s Long Term Evaluation (LTE) technology.The results show that DCCP has better throughput and lesser delay, but at the same time it has more packet loss than UDP and TCP. Based on the results, DCCP is recommended as a transport protocol for real time video

DCBRP: a deterministic chain-based routing protocol for wireless sensor networks

Background: Wireless sensor networks (WSNs) are a promising area for both researchers and industry because of their various applications The sensor node expends the majority of its energy on communication with other nodes. Therefore, the routing protocol plays an important role in delivering network data while minimizing energy consumption as much as possible. The chain-based routing approach is superior to other approaches. However, chain-based routing protocols still expend substantial energy in the Chain Head (CH) node. In addition, these protocols also have the bottleneck issues.Methods:A novel routing protocol which is Deterministic Chain-Based Routing Protocol (DCBRP). DCBRP consists of three mechanisms: Backbone Construction Mechanism, Chain Head Selection (CHS), and the Next Hop Connection Mechanism. The CHS mechanism is presented in detail, and it is evaluated through comparison with the CCM and TSCP using an ns-3 simulator. Results:It show that DCBRP outperforms both CCM and TSCP in terms of end-to-end delay by 19.3 and 65%, respectively, CH energy consumption by 18.3 and 23.0%, respectively, overall energy consumption by 23.7 and 31.4%, respectively, network lifetime by 22 and 38%, respectively, and the energy*delay metric by 44.85 and 77.54%, respectively.Conclusion:DCBRP can be used in any deterministic node deployment applications, such as smart cities or smart agriculture, to reduce energy depletion and prolong the lifetimes of WSNs

Performance of TCP variants over LTE network

One of the implementation of a wireless network is based on mobile broadband technology Long Term Evolution (LTE).LTE offers a variety of advantages, especially in terms of access speed, capacity, architectural simplicity and ease of implementation, as well as the breadth of choice of the type of user equipment (UE) that can establish the access.The majority of the Internet connections in the world happen using the TCP (Transmission Control Protocol) due to the TCP’s reliability in transmitting packets in the network.TCP reliability lies in the ability to control the congestion.TCP was originally designed for wired media, but LTE connected through a wireless medium that is not stable in comparison to wired media.A wide variety of TCP has been made to produce a better performance than its predecessor. In this study, we simulate the performance provided by the TCP NewReno and TCP Vegas based on simulation using network simulator version 2 (ns2).The TCP performance is analyzed in terms of throughput, packet loss and end-to-end delay.In comparing the performance of TCP NewReno and TCP Vegas, the simulation result shows that the throughput of TCP NewReno is slightly higher than TCP Vegas, while TCP Vegas gives significantly better end-to-end delay and packet loss. The analysis of throughput, packet loss and end-to-end delay are made to evaluate the simulation

A survey of content placement strategies for content-centric networking

Current Internet design is not sufficient to encounter the huge Internet traffic, so it is converted from the host based on content in formation based architecture.Some of new content, information based architectures are PSRIP, CCN, NetInf, and DONA. In these ICN architectures, CCN is more attractive to implement the idea of Information Centric Network. And in network cache is most important part of all ICN architectures to implement the main idea of ICN. Ubiquitous cache is not a proof of good performance of the cache.To produce a high performance of cache there is needed to manage a cache in a more efficient manner.There exist many content placement strategies to manage the cache. In this paper, we briefly explain cache and content placement strategies of Content Centric Network architecture

Signal detection algorithm for cognitive radio using singular value decomposition

This paper highlights an algorithm for detecting the presence of wireless signal using the Singular Value Decomposition (SVD) technique.We simulated the algorithm to detect common digital signals in wireless communication to test the performance of the signal detector.The SVD-based signal detector was found to be more efficient in detecting a signal without knowing the properties of the transmitted signal.The performance of the algorithm is better compared to the favorable energy detection.The algorithm is suitable for blind spectrum sensing where the properties of the signal to be detected are unknown.This is also the advantage of the algorithm since any signal would interfere and subsequently affect the quality of service (QoS) of the IEEE 802.22 connection.Furthermore, the algorithm performed better in the low signalto-noise ratio (SNR) environment