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Data communication over the Internet has increased significantly, resulting in high data traffic and concerns over data security. Information sent over the Internet always gets the attention of intruders, which causes the effort to increase the security of sensitive data and the need to prevent leakage. Steganography is one of the techniques to protect the confidentiality of data that can be accomplished by hiding secret information within the medium of text, images, audio, and video. Hiding a secret message using text steganography can be done on character properties such as size, colour, style, etc. Colour- based steganography has always raised suspicions about the generated stego text, which is a major issue in this study. Therefore, the Red, Green, and Blue (RGB) colour technique and the Second Quotient Remainder Theorem (SQRT) were introduced in this study to perform the hiding process. RGB (0,0,0) to RGB (15,15,15) colours were used for the hiding process to avoid colour suspicion. In addition, the pseudorandom number generator (PRNG) was also used to generate dynamic hidden messages with Homophonic table generation. The results showed that the secret message can be represented dynamically and has increased the hiding capacity to 77.4%. Other than that, the selected colour has successfully avoided the suspicion of the generated stego text. Hence, the results suggested that SQRT could be employed as a method in text steganography for securing information.

Data Grid is an infrastructure that manages huge amount of data files, and provides intensive computational resources across geographically distributed collaboration.Increasing the performance of such system can be achieved by improving the overall resource usage, which includes network and storage resources.Improving network resource usage is achieved by good utilization of network bandwidth that is considered as an important factor affecting job execution time.Meanwhile, improving storage resource usage is achieved by good utilization of storage space usage. Data replication is one of the methods used to improve the performance of data access in distributed systems by replicating multiple copies of data files in the distributed sites.Having distributed the replicas to various locations, they need to be monitored.As a result of dynamic changes in the data grid environment, some of the replicas need to be relocated.In this paper we proposed a maintenance replica placement strategy termed as Unwanted Replica Deletion Strategy (URDS) as a part of Replica maintenance service.The main purpose of the proposed strategy is to find the placement of unwanted replicas to be deleted.OptorSim is used to evaluate the performance of the proposed strategy. The simulation results show that URDS requires less execution time and consumes less network usage and has a best utilization of storage space usage compared to existing approaches.

In an integrated wireless and mobile network, selecting a desired a network is an important issue. Parameters such as system load, service characteristics and user mobility are the main criteria in network selection strategy. In this paper, we devise a mobility estimation method for a Mobile Node (MN) during initial network selection and Vertical Handover (VHO). The method relies on a new prediction dwelling time and the Call Holding Time (CHT) of a user. By comparing the predicted dwelling time with the CHT, a MN is able to make decision which network is suitable to be used in order to minimize the VHO. The proposed theoretical model has been validated by the MonteCarlo experiments. The simulation results demonstrate the validity of the proposed method.

Today, there is a growing research study of IEEE 802.11p as one of option to help the drivers to travel more safely.Message dissemination protocols are primordial for safety vehicular applications. Periodic safety message (PSM) and Warning safety message (WSM) are two types of safety messages which may be exchanged between vehicles. In this paper we investigate the feasibility of deploying safety applications based on periodic message dissemination through simulation study with safety requirements as our priority concern.Vehicles are supposed to issue these messages constantly to inform their neighboring vehicles about their current status and use received messages for preventing possible unsafe situations on time. As reliability is the main concern in periodic message dissemination, a new metric called TGFD (Time Gap Following Distance) is defined which gives us more accurate benchmark for evaluating QoS in safety applications specifically.Thus, in order to improve the performance, the effective transmission TGFD studied.

WLAN has been considered as a compliment technology for cellular network in the heterogeneous wireless network. Thus, seamless connection between these technologies play important role as the performance indicator. In this paper, we consider the user's velocity and channel holding time to predict the user's dwelling time in the WLAN area to assist in the initial network selection. Based on the mobility prediction, network load and type of services, the proposed algorithm will select the most suitable radio access network for the user. In addition, we also incorporate the traffic offloading method in order to accept as many users to the system while maintaining the quality of service of the users. Through extensive discrete-event simulation, the results show that the proposed solution has better performance as compared to the location-based (WLAN First) and mobility threshold proposals.

WLAN has been considered as a compliment technology for cellular network in the heterogeneous wireless network. Thus, seamless connection between these technologies play important role as the performance indicator. In this paper, we consider the user's velocity and channel holding time to predict the user's dwelling time in the WLAN area to assist in the initial network selection. If the expected completion time is lower than the predictive travelling time within the coverage area, together with the load and service characteristics, the algorithm will select WLAN instead of cellular network. Based on the discrete-event simulation, the results show that the proposed solution has better performance as compared to the location-based (WLAN First) and mobility threshold proposals.

The expanded growth in smartphones and applications, hence data traffic resulted in cellular networks being conspicuously overwhelmed with demand for resources. Service providers constantly looking for suitable technologies and mechanisms to reduce the network congestion by offloading the data traffic, where Wi-Fi is an excellent option. In the traffic steering process, network selection is the most vital process, as it affects the user’s network experience. This paper focuses on enhancing the procedure of Call Admission Control (CAC). Two key functions were introduced into the call admission procedure, namely Channel Reserve Engine (CRE) and Traffic Steering Policy (TSP). Based on the simulation results, it is found the proposed CAC reduces the call blocking probability as compared with conventional CAC. Thus, it is suitable to be implemented in WLAN/Cellular integration.

Common Radio Resource Management (CRRM) and traffic offloading are both promising approaches in the heterogeneous wireless networks (HWN) to increase overall resource efficiency and system performance. WLAN has been widely used as a complementary service for cellular network operator to offload their traffic. Based on traffic characteristics, user mobility and load balance we propose a new CRRM scheme that include traffic offloading functionality. When a user arrives in out of hot-spot area and no resource is available, the algorithm will identify some of the traffic to be offloaded in the overlap area from cellular network to WLAN and release the resource for the new user to use. The proposed approach also attempts to minimize unnecessary vertical handover (VHO) between cellular and WLAN. The effectiveness of the scheme is assessed analytically using the theory of 3D-Markov Chain. Numerical results demonstrate that the proposed CRRM scheme increase the overall system throughput, reduce the new call blocking probability and provide less service costs to the users.

The demand for Internet services and network resources in Educational networks are increasing rapidly.Specifically, the revolution of web 2.0 "also referred to as the Read-Write Web" has changed the way of information exchange and distribution. Although web 2.0 has gained attraction in all sectors of the education industry, but it results in high-traffic loads on networks which often leads to the Internet users" dissatisfaction.Therefore, analyzing Internet traffic becomes an urgent need to provide high-quality service, monitoring bandwidth usage.In this study, we focus on analyzing the Internet traffic in Universiti Utara Malaysia (UUM) main campus. We performed measurement analysis form the application level characteristics based on users' preferences.A total of three methodological steps are carried out to meet the objective of this study namely data collection, data analysis and data presentation.The finding shows that social networks are the most web applications visited in UUM.These findings lead to facilitate the enhancement of Educational network performance and Internet bandwidth strategies.

Problem statement: Although many efforts have been done on studying the behaviour of TCP in MANET, but the behaviour of TFRC remain unclear in MANET. The purpose of this research is two folds.First, we studied the behaviour of TFRC and TCP over AODV and DSR as the underlying routing protocols in terms of throughput, delay and jitter.The second objective was to identify whether MANET routing protocols have an impact on transport protocols or not.Approach: Network Simulator 2 (NS-2) was used to conduct all of the experiments, i.e., TFRC over AODV, TFRC over DSR, TCP over AODV and TCP over DSR.We created 30 nodes on a 1000×1000 m location area and each node was assigned CBR traffic, transport protocol and routing protocol.In order to simulate the nodes mobility, we implemented a Random Waypoint mobility model with varying speeds of 5, 10, 15 and 20 m sec−1 (m/sec) with a 10 sec pause time.Results: We observed that TFRC throughput increases almost 55% when using DSR as its routing protocol, but TCP throughput has no significant difference with different underlying protocols.However, in terms of jitter and delay, both routing protocols, i.e., AODV and DSR have the impact of more than 50% on TFRC and TCP. Conclusion/Recommendations: The results obtained also show us that TFRC or TCP should choose AODV as its routing protocol because it has less jitter which is one of the critical performance metrics for multimedia applications.

Mobile Ad hoc Network (MANET) is a wireless network of mobile nodes that has no fixed routers.In MANET, mobile nodes can communicate via the wireless interface while nodes are moving freely without using the network infrastructure.Nowadays the performance of a new existence Internet protocol technology, that is Stream Control Transportation Protocol ( SCTP) in a MANET Routing Protocol still unknown.The general objective of this research is to analyze and make the comparative performance of SCTP with Ad-hoc On-demand Distance Vector (AODV) and Dynamic Source Routing protocol (DSR) using Network Simulator (NS-2).Specifically, this research is to measure the behavior of SCTP in terms of throughput and smoothness and; to determine routing protocol in Mobile Ad-hoc Network (MANET) either it has significant effect in SCTP.This research used Network Simulator 2 (NS-2), type of the traffic is Constant Bit Rate ( CBR) and packet size is 1000.The data sent consists of five speeds at 5 m/s, 10 m/s, 15 m/s, 20 m/s, 25 m/s, and then these speeds are used in AODV and DSR simulation.The result, of our study suggested that the SCTP throughput over AODV is higher than DSR and the smoothness of SCTP over DSR was higher than AODV for the five types of speed.In addition, there was no significant impact on throughput between AODV and DSR as the percentage difference was small (i.e., 0 to 2.4%).Furthermore, the speed of node movement does not significant affect the smoothness.

The need for a reliable transmission protocol that can cover the Transport Control Protocol (TCP) and User Datagram Protocol (UDP) has prompted the Internet Engineering Task Force (IETF) to define a new protocol called the Stream Control Transmission Protocol (SCTP).This paper proposes adding Explicit Congestion Notification (ECN) mechanism into SCTP chunks (INIT chunk, and INIT-ACK chunk) to reduce the delay of transferring important data during congestion as compared with the TCP and UDP protocols.This paper also discusses the details of adding ECN, and the reason for choosing Random Early Detection (RED). Through the experimental analysis, we compare SCTP enabled ECN in INIT-ACK chunk to SCTP without ECN enabled in INIT-ACK chunk and demonstrate the result of ECN impact on SCTP delay time.

Nowadays, many researches in Mobile ad hoc network (MANET) focus mainly on the impact of MANET routing protocol to TCP variants, but none have been done on TFRC.In this paper, we present a comprehensive simulation study on the behavior of TCP-friendly Rate Control (TFRC) protocol over Ad-Hoc On Demand Vector (AODV) routing protocol and Destination-Sequenced Distance Vector (DSDV).The main objective is to measure the TFRC performance in terms of throughput, jitter and delay.In addition, this research also identifies whether or not MANET routing protocols have impact on TFRC. We conduct the experiment by sending multimedia streaming traffic carried by TFRC over AODV and DSDV respectively. Random-Waypoint mobility model is used for both experiments. Results obtained shows that TFRC has better throughput over DSDV. As for delay and jitter, TFRC over AODV has smoother results.

Problem statement: Although many efforts have been done on studying the behaviour of TCP in MANET, but the behaviour of TFRC remain unclear in MANET.The purpose of this research is two folds. First, we studied the behaviour of TFRC and TCP over AODV and DSR as the underlying routing protocols in terms of throughput, delay and jitter. The second objective was to identify whether MANET routing protocols have an impact on transport protocols or not. Approach: Network Simulator 2 (NS-2) was used to conduct all of the experiments, i.e., TFRC over AODV, TFRC over DSR, TCP over AODV and TCP over DSR.We created 30 nodes on a 1000×1000 m location area and each node was assigned CBR traffic, transport protocol and routing protocol.In order to simulate the nodes mobility, we implemented a Random Waypoint mobility model with varying speeds of 5, 10, 15 and 20 m sec−1 (m/sec) with a 10 sec pause time. Results: We observed that TFRC throughput increases almost 55% when using DSR as its routing protocol, but TCP throughput has no significant difference with different underlying protocols. However, in terms of jitter and delay, both routing protocols, i.e., AODV and DSR have the impact of more than 50% on TFRC and TCP. Conclusion/Recommendations: The results obtained also show us that TFRC or TCP should choose AODV as its routing protocol because it has less jitter which is one of the critical performance metrics for multimedia applications.