Rate-based transport control for mobile ad hoc networks

Detection of malicious, compromised and selfish node attacks is urgently needed to protect Mobile Ad hoc Networks (MANET) and their applications from failures. Once a MANET component is affected by a malicious, compromised or selfish node its operational state shifts from normal state to vulnerable state. Online monitoring mechanisms can collect important MANET network data that can be effectively used to detect abnormal behaviors caused by attacks. In this article we develop an online multivariate analysis algorithm to analyze the behavior of network resources and protocols to proactively detect MANET attacks. This algorithm is based on multivariate fuzzy analysis technique. We have validated the algorithm and demonstrated how it can effectively detect wellknown attacks such as Denial of Service in MANET.

A Congestion control is a key problem in mobile adhoc networks. The standard TCP congestion control mechanism is not able to handle the special properties of a shared wireless channel. Many approaches have been proposed to overcome these difficulties. ideas and show their interrelations. mobile agent based congestion control Technique routing is proposed to avoid congestion in ad hoc network. Some mobile agents are added in ad hoc network, which carry routing information and nodes congestion status. When mobile agent travels through the network, it can select a less-loaded neighbor node as its next hop and update the routing table according to the node’s congestion status. With the aid of mobile agents, the nodes can get the dynamic network topology in time. In this paper, we give an verview over existing proposals, explain their key ideas, TCP Issues, Reduce the Congestion, delay in mobile ad-hoc network and proposed solution

Fast-growing applications like streaming media make TCP a poor fit. Because the UDP protocol lacks congestion control, Equation-based and AIMD-based congestion control schemes have been two promising alternative to TCP for real-time multimedia streaming over the Internet. Past studies have shown that they are able to maintain throughput smoothness and achieve reasonable fairness with competing TCP flows in wireline networks. However, their behavior remains not clear in mobile ad hoc network (MANET). In this paper, we compare the general AIMD-based congestion control mechanism (GAIMD) with Equation-based congestion control mechanism (TFRC TCP-Friendly Rate control) over a wide range of MANET scenario, in terms of throughput fairness and smoothness. Our results show that TFRC and GAIMD (0.2, 0.125) are able to maintain throughput smoothness in MANET, but at the same time, they obtain less throughput than the competing TCP flows. Our results also show that TFRC changes its sending rate more smoothly than GAIMD (0.2, 0.125) does, but it gets the least throughput compares with TCP and GAIMD (0.2, 0.125).

Fuzzy logic based cross-layer design to improve Quality of Service in Mobile ad-hoc networks for Next-gen Cyber Physical System

User Datagram Protocol (UDP) is proposed for the efficient servicing of multimedia traffic flows in Internet and it does not make use of any congestion control mechanism. The Internet Engineering Task Force (IETF) is working on development of a protocol standard that is suited to the needs of multimedia applications, known as the Datagram Congestion Control Protocol (DCCP) [6]. DCCP combines the end-to-end transport and congestion control semantics of TCP with the low-delay unreliable service provided by UDP. DCCP performance over the wired network with bursty traffic has been tested and has shown that DCCP holds promise as a wired network transport protocol [4]. However, to the best of our knowledge, the working of DCCP over Mobile Ad hoc Networks has not been evaluated. In this paper, we have evaluated the performance of DCCP over Mobile Ad Hoc Networks [10]. The two congestion control schemes made available under DCCP (TCP-like - CCID2 and TFRC - CCID3) were evaluated in a simulation environment, comparing with TCP considering throughput, end-to-end delay and packet loss as metrics [7,8]. Our results show that DCCP achieves considerably better throughput than TCP.

A MANET is an autonomous collection of mobile nodes that communicate all the other nodes within their radio ranges. Where the nodes that are not in the direct communication range use intermediate node to communicate with each other. In MANET each mobile node has mobility and move according to the specified locations in the network. Therefore the verification of node locations is an important issue in mobile adhoc networks, and it becomes particularly challenging in the presence of adversaries aiming at harming the system. In this research work proposed a protocol called Neighbor position verification (NPV), in order to verify the position of its communication neighbors and detect the adversaries in the mobile adhoc network, This protocol is used to exchanges the messages and verifies the position of communicating nodes in the network. The first scheme is deals with the identification of nodes with which a communication link can be established or that are within a given distance. This distance calculation is based on message exchange between the verifier and its communicated neighbors. After the distances are calculated verifier verifies the position of communicating nodes in networks by following three tests that to be done, they are: 1) Direct symmetry test 2) Cross symmetry test 3) The Multilateration Test. This protocol is implemented over the MANET network and simulated using Network Simulator (NS2). This research work carry out QOS based forwarding node selection scheme to reduce the delay and achieve the high throughput. Performance of the proposed system evaluated based on the parameters such as delay and throughput.

Mobility prediction in mobile ad hoc networks using neural learning machines

In a mobile ad hoc network (MANET), to determine delay-guarantee routes is difficult due to the common radio channel shared among neighboring hosts, and it is necessary for quality-of-service (QoS) routing services in MANETs. However, previously proposed QoS routing protocols do not take the bandwidth consumed by the hosts that are two hops’ distant from the determined routes. Thus, the delay violation problem occurs and the delay requirement of the services cannot be met. In the paper, a novel algorithm will be proposed to address the problem for constructing delay-sensitive routes for meeting the delay requirements of QoS applications.

Despite many years of improvements to it, TCP still suffers from an unsatisfactory performance. For services dominated by short flows (e.g., web search and e-commerce), TCP suffers from the flow startup problem and cannot fully utilize the available bandwidth in the modern Internet: TCP starts from a conservative and static initial window (IW, 2-4 or 10), while most of the web flows are too short to converge to the best sending rate before the session ends. For services dominated by long flows (e.g., video streaming and file downloading), the congestion control (CC) scheme manually and statically configured might not offer the best performance for the latest network conditions. To address these two challenges, we propose TCP-RL, which uses reinforcement learning (RL) techniques to dynamically configure IW and CC in order to improve the performance of TCP flow transmission. Basing on the latest network conditions observed at the server side of a web service, TCP-RL dynamically configures a suitable IW for short flows through group-based RL, and dynamically configures a suitable CC scheme for long flows through deep RL. Our extensive experiments show that for short flows, TCP-RL can reduce the average transmission time by about 23%; and for long flows, compared with the performance of 14 CC schemes, TCP-RL's performance ranks top 5 for about 85% of the 288 given static network conditions, whereas for about 90% of conditions, its performance drops by less than 12% compared with that of the best-performing CC schemes for the same network conditions.

Objective: The primary motive of this research is to improve the quality of service in Mobile Ad-hoc Networks by reducing the packet loss and average delay in the network. Methods: In this manuscript, an innovative metric called Node Encounter Rate (NER) is introduced based on the concept of nodes encountered during network operation. Findings: Network simulation results show that the dynamic estimation of the metric improves throughput by 47%, by this means reducing the loss and delay by 53% and 52% respectively. As per the comparison results, the proposed approach works better compared to the existing schemes also providing increased quality of service. The control packets are reduced because of routing through stable paths. In addition, the packets are forwarded over the paths that avoid high mobility scenarios. Novelty: The simulation outcome reveals that the Node Encounter Rate (NER) has high quality of service compared to the existing scheme under mobile scenarios.

In this paper the reliability of a real-time service for multicast transmission over lossy Mobile Ad-hoc NETwork (MANET) is addressed. The proposed system combines application layer channel coding based on Luby Transform (LT) code with multicast delivery in a wireless network exploiting PUMA (Protocol for Unified Multicasting through Announcements). The main goal is to achieve a real-time service with an high quality level in a lossy environment. The rateless property, the ability of adapt the code on the fly, makes fountain codes an attractive solution for data broadcast/multicast applications in a MANET scenario characterized by dynamic channel conditions and packets losses. The proposed novel approach leads to an improvement on arrival times of packets towards destination nodes.

High-speed networks with large delays present a unique environment where TCP may have a problem utilizing the full bandwidth. Several congestion control proposals have been suggested to remedy this problem. The existing protocols consider mainly two properties: TCP friendliness and bandwidth scalability. That is, a protocol should not take away too much bandwidth from standard TCP flows while utilizing the full bandwidth of high-speed networks. This work presents another important constraint, namely, RTT (round trip time) unfairness where competing flows with different RTTs may consume vastly unfair bandwidth shares. Existing schemes have a severe RTT unfairness problem because the congestion window increase rate gets larger as the window grows ironically the very reason that makes them more scalable. RTT unfairness for high-speed networks occurs distinctly with drop tail routers for flows with large congestion windows where packet loss can be highly synchronized. After identifying the RTT unfairness problem of existing protocols, This work presents a new congestion control scheme that alleviates RTT unfairness while supporting TCP friendliness and bandwidth scalability. The proposed congestion control algorithm uses two window size control policies called additive increase and binary search increase. When the congestion window is large, additive increase with a large increment ensures square RTT unfairness as well as good scalability. Under small congestion windows, binary search increase supports TCP friendliness. The simulation results confirm these properties of the protocol.

One of the major issues in current routing protocols for mobile ad hoc networks (MANETs) is to develop a routing protocol that can satisfy different applications’ needs and optimize routing paths to cope with protocol topology changes. Thus, developing a new routing protocol to optimize routing paths based on dynamic topology changes is a challenging task in MANET. Position-based routing protocols are more suitable for high node mobility due to their dependability on local position information rather a global network knowledge. However, most existing position-based routing protocols forward packets greedily which leads to inaccurate location information and results in frequent route failures. Furthermore, incorporating fixed-interval beaconing to distribute local positions introduces high overheads. In this paper an on-demand geo-casting routing scheme which makes use of geographical information to establish cost-effective and reliable paths for packets to reach their destination is proposed. Through the proposed scheme, search area during route discovery process includes only promising search paths, which will alleviate the effect of control message overhead. Moreover, each node is able to independently adjust protocol parameters based on network environment, data traffic conditions, and node’s congestion level. The simulation results show that the proposed protocol outperforms existing routing protocols under different network conditions such as various mobility and traffic loads.

In today's world mobile agents and mobile ad- hoc networks are the two technologies that are contributing towards better connectivity and communicability. When the two technologies used jointly, the interest is increased. Due to the properties like self- configuration and infrastructure-less, the mobile ad-hoc networks provide various remarkable features. But the various challenges are also associated with mobile ad-hoc networks like dynamic topology, mobility, energy constraint etc. Mobile agent provides solution to these challenges. A mobile agent is a new way of computer interactions and provides better options for the developers to create applications based on connectivity. Mobile agents move around the ad-hoc networks in a different and better way than the other widespread client server architecture based applications. Due to their mobility and autonomy these agents can perform various functions in mobile ad-hoc networks like topology discovery, routing, key management, congestion control etc. The paper reviews the role of the mobile agents in the mobile ad-hoc networks, and emphasizes its application on the various layers of a layered architecture of mobile ad-hoc networks and concludes its merits as compared to other conventional approaches.

Content-Centric Networking (CCN) focuses on content acquisition rather than end-to-end communication by decoupling content resources from special hosts. CCN does not need maintain stable paths between nodes and is independent of IP addresses, which make CCN convenient and efficient for mobile ad hoc network (MANET). In this paper, we develop an analytical model of content acquisition for Content-Centric MANET (CCM) in two-dimensional case, which considers in-network caching and nodes mobility. Closed-form expressions for round trip time and throughput are derived as functions of miss probabilities. From the expressions, we can obtain the relationship among the round trip time, cache size and content popularity. Simulations show that our model can be used as a guide to design CCM and to evaluate its performance.