657 research outputs found
Structured Peer-to-Peer Overlay Deployment on MANET: A Survey
There are many common characteristics between Peer-to-Peer (P2P) overlay networks and Mobile Ad-hoc Networks (MANET). Self-organization, decentralization, dynamicity and changing topology are the most shared features. Furthermore, when used together, the two approaches complement each other. P2P overlays provide data storage/retrieval functionality, and their routing information can complement that of MANET. MANET provides wireless connectivity between clients without depending on any pre-existing infrastructure. The aim of this paper is to survey current P2P over MANET systems. Specifically, this paper focuses on and investigates structured P2P over MANET. Overall, more than thirty distinct approaches have been classified into groups and introduced in tables providing a structured overview of the area. The survey addresses the identified approaches in terms of P2P systems, MANET underlay systems and the performance of the reviewed systems
A one hop overlay system for Mobile Ad Hoc Networks
Peer-to-Peer (P2P) overlays were initially proposed for use with wired networks.
However, the very rapid proliferation of wireless communication technology has
prompted a need for adoption of P2P systems in mobile networks too. There are
many common characteristics between P2P overlay networks and Mobile Ad-hoc
Networks (MANET). Self-organization, decentralization, a dynamic nature and
changing topology are the most commonly shared features. Furthermore, when
used together, the two approaches complement each other. P2P overlays provide
data storage/retrieval functionality and MANET provides wireless connectivity
between clients without depending on any pre-existing infrastructure. P2P overlay
networks can be deployed over MANET to address content discovery issues.
However, previous research has shown that deploying P2P systems straight over
MANET does not exhibit satisfactory performance. Bandwidth limitation, limited
resources and node mobility are some of the key constraints.
This thesis proposes a novel approach, OneHopOverlay4MANET, to exploit the
synergies between MANET and P2P overlays through cross-layering. It combines
Distributed Hash Table (DHT) based structured P2P overlays with MANET underlay
routing protocols to achieve one logical hop between any pair of overlay
nodes. OneHopOverlay4MANET constructs a cross-layer channel to permit direct
exchange of routing information between the Application layer, where the overlay
operates, and the MANET underlay layer. Consequently, underlay routing information
can be shared and used by the overlay. Thus, OneHopOverlay4MANET
reduces the typical management traffic when deploying traditional P2P systems
over MANET. Moreover, as a result of building one hop overlay, OneHopOverlay4MANET
can eliminate the mismatching issue between overlay and underlay
and hence resolve key lookups in a short time, enhancing the performance of the
overlay.
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In this thesis, we present OneHopOverlay4MANET and evaluate its performance
when combined with different underlay routing protocols. OneHopOverlay4MANET
has been combined with two proactive underlays (OLSR and BATMAN)
and with three reactive underlay routing protocols (DSR, AODV and
DYMO). In addition, the performance of the proposed system over OLSR has
been compared to two recent structured P2P over MANET systems (MA-SP2P
and E-SP2P) that adopted OLSR as the routing protocol. The results show that
better performance can be achieved using OneHopOverlay4MANET
Fairness-oriented overlay VPN topology construction
An important issue in dynamically constructed Virtual Private Networks (VPN) is how the overlay topology is created and maintained. Classical VPN topologies, such as hub-and-spoke or full-mesh, fail to remain convenient and viable when the number of nodes grows to as little as a few tens. Convenient topology formation mechanisms should be distributed, should permit incremental and dynamic operations, and should limit the number of nodes a new entry connects with. In this work, we show that approaches devised to create “short” networks, while yielding a significant total network throughput, may be severely affected by unfairness issues, i.e., different pair of nodes may experience a widely different throughput performance. Hence, we introduce a fairness-oriented topology formation algorithm for VPN. The proposed algorithm is incremental, meaning that the addition of a new node to the overlay topology does not imply rewiring of already established overlay links. Simulation results show that our proposed approach achieves high fairness levels, as quantified in terms of well known Jain's fairness index, meanwhile retaining satisfactory throughput performance
Cross Layer Routing in Cognitive Radio Network Using Deep Reinforcement Learning
Development of 5G technology and Internet of Things (IoT) devices has resulted in higher bandwidth requirements leading to increased scarcity of wireless spectrum. Cognitive Radio Networks (CRNs) provide an efficient solution to this problem. In CRNs, multiple secondary users share the spectrum band that is allocated to a primary network. This spectrum sharing of the primary spectrum band is achieved in this work by using an underlay scheme. In this scheme, the Signal to Interference plus Noise Ratio (SINR) caused to the primary due to communication between secondary users is kept below a threshold level.
In this work, the CRNs perform cross-layer optimization by learning the parameters from the physical and the network layer so as to improve the end-to-end quality of experience for video traffic. The developed system meets the design goal by using a Deep Q-Network (DQN) to choose the next hop for transmitting based on the delay seen at each router, while maintaining SINR below the threshold set by primary channel. A fully connected feed-forward Multilayer Perceptron (MLP) is used by secondary users to approximate the action value function. The action value comprises of SINR to the primary user (at the physical layer) and next hop to the routers for each packet (at the network layer). The reward to this neural network is Mean Opinion Score (MOS) for video traffic which depends on the packet loss rate and the bitrate used for transmission. As compared to the implementation of DQN learning at the physical layer only, this system provides 30\% increase in the video quality for routers with small queue lengths and also achieves a balanced load on a network with routers with unequal service rates
Device-to-device communications: a performance analysis in the context of social comparison-based relaying
Device-to-device (D2D) communications are recognized as a key enabler of future cellular networks which will help to drive improvements in spectral efficiency and assist with the offload of network traffic. Among the transmission modes of D2D communications are single-hop and relay assisted multi-hop transmission. Relay-assisted D2D communications will be essential when there is an extended distance between the source and destination or when the transmit power of D2D user equipments (UEs) is constrained below a certain level. Although a number of works on relay-assisted D2D communications have been presented in the literature, most of those assume that relay nodes cooperate unequivocally. In reality, this cannot be assumed since there is little incentive to cooperate without a guarantee of future reciprocal behavior. Cooperation is a social behavior that depends on various factors, such as peer comparison, incentives, the cost to the donor and the benefit to the recipient. To incorporate the social behavior of D2D relay nodes, we consider the decision to relay using the donation game based on social comparison and characterize the probability of cooperation in an evolutionary context. We then apply this within a stochastic geometric framework to evaluate the outage probability and transmission capacity of relay assisted D2D communications. Through numerical evaluations, we investigate the performance gap between the ideal case of 100% cooperation and practical scenarios with a lower cooperation probability. It shows that practical scenarios achieve lower transmission capacity and higher outage probability than idealistic network views which assume full cooperation. After a sufficient number of generations, however, the cooperation probability follows the natural rules of evolution and the transmission performance of practical scenarios approach that of the full cooperation case, indicating that all D2D relay nodes adopt the same dominant cooperative strategy based on social comparison, without the need for enforcement by an external authority
Hybrid routing in delay tolerant networks
This work addresses the integration of today\\u27s infrastructure-based networks with infrastructure-less networks. The resulting Hybrid Routing System allows for communication over both network types and can help to overcome cost, communication, and overload problems. Mobility aspect resulting from infrastructure-less networks are analyzed and analytical models developed. For development and deployment of the Hybrid Routing System an overlay-based framework is presented
Flexible Application-Layer Multicast in Heterogeneous Networks
This work develops a set of peer-to-peer-based protocols and extensions in order to provide Internet-wide group communication. The focus is put to the question how different access technologies can be integrated in order to face the growing traffic load problem. Thereby, protocols are developed that allow autonomous adaptation to the current network situation on the one hand and the integration of WiFi domains where applicable on the other hand
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