Stationary Relay Nodes Deployment on Vehicular Opportunistic Networks

2011 ◽  
Author(s):  
Joel Rodrigues ◽  
Vasco Soares ◽  
Farid Farahmand
Keyword(s):  
Opportunistic Networks ◽  
Relay Nodes

scholarly journals A Data Dissemination Method Based on Region Type Correlations for Mobile Opportunistic Networks

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Linfeng Liu ◽  
Daoliang Chen
Keyword(s):  
Data Dissemination ◽  
Opportunistic Networks ◽  
Delivery Ratio ◽  
Mobility Patterns ◽  
Relay Nodes ◽  
Data Packets ◽  
Mobile Opportunistic Networks ◽  
Communication Devices ◽  
Markov Decision ◽  
Markov Decision Model

In Mobile Opportunistic Networks (MONs), due to the node movements and the uncontrollable on/off switches of the carried communication devices, the contacts between nodes may be scarce and momentary, and thus a data packet should be transferred through some discrete hops. To avoid the costly flooding of data packets, the data packets are typically disseminated to some relay nodes selected by data holders. However, the mobility patterns of nodes will become different in different types of regions (such as residential regions, commercial regions, scenery regions, or industrial regions); i.e., the movement directions and movement ranges of nodes are frequently varied when the nodes move among various regions. At present, the issues regarding the region types and region type correlations have not been investigated for the data dissemination in existing works. To this end, we propose a Region Type based Data Dissemination Method (RTDDM) for MONs, which exploits the region type correlations and selects the proper relay nodes through a Markov decision model. To verify the performance of RTDDM, we give some theoretical analysis as well as an elaborated simulation study, the results of which show that RTDDM can improve the delivery ratio and reduce the delivery delay, especially in the applications with various region types.

scholarly journals Impact of overlapping in the radio coverage areas Of multiple Wi-Fi access points on detecting encounters

2018 ◽  
pp. 1-18
Keyword(s):  
Mobile Devices ◽  
Opportunistic Networks ◽  
Wireless Devices ◽  
Mobile Nodes ◽  
Relay Nodes ◽  
Coverage Area ◽  
Access Points ◽  
Significant Difference ◽  
Radio Coverage ◽  
Delay Tolerant

Understanding the potential role of Smartphones and other portable wireless devices as relay nodes in message dissemination and content delivery in Delay Tolerant and Opportunistic networks, depends on the knowledge about patterns and the number of encounter events among mobile nodes. One of the main challenges for extracting encounters is overlapping in the radio coverage areas of nearby access points (APs). Data about the usage of Wi-Fi networks can be used to perform an analysis of encounters among mobile devices. A realistic estimation of the number of encounters among mobile nodes is now a big challenge. In this paper, the effects of overlapping of radio coverage area among multiple APs for extracting realistic encounters among mobile devices has been discussed, and also an analytical approach has been proposed for extracting realistic encounters from overlapping in the coverage areas of multiple nearby APs. A significant difference was observed between the number of encounters by considering and ignoring overlapping. Our study finds that Wi-Fi datasets are not reliable source to estimate the number of encounters when there is overlapping in radio coverage areas of multiple APs.

scholarly journals Predict and Forward: An Efficient Routing-Delivery Scheme Based on Node Profile in Opportunistic Networks

2018 ◽  
Vol 10 (8) ◽  
pp. 74 ◽  
Author(s):  
Kanghuai Liu ◽  
Zhigang Chen ◽  
Jia Wu ◽  
Yutong Xiao ◽  
Heng Zhang
Keyword(s):  
Opportunistic Networks ◽  
Routing Algorithms ◽  
Delivery Ratio ◽  
Complex Data ◽  
Relay Nodes ◽  
End To End Delay ◽  
The Social ◽  
Optimal Stopping Theory ◽  
Social Scene ◽  
End To End

In the social scene of opportunistic networks, message applications find suitable relay nodes or certain transmission destinations from the surrounding neighbors through specific network addresses of users. However, at the dawn of big data and 5G networks, the variational location information of nodes is difficult to be available to mobile devices all the time, and a long wait for the destination may cause severe end-to-end delay. To improve the transmission environment, this study constructs an efficient routing-delivery scheme (Predict and Forward) based on node profile for the opportunistic networks. The node profile effectively characterizes nodes by analyzing and comparing their attributes instead of network addresses, such as physical characteristics, places of residence, workplaces, occupations or hobbies. According to the optimal stopping theory, this algorithm implements the optimal transmission for Prelearn messages by dividing the complex data transmission process into two different phases (Predict and Forward). Through simulations and the comparison of routing algorithms in opportunistic networks, the proposed strategy increases the delivery ratio by 80% with the traditional methods on average, and the average end-to-end delay in this algorithm is the lowest.

A fuzzy-based check-and-spray geocast routing protocol for opportunistic networks

2021 ◽  
Vol 27 (1) ◽  
pp. 1-12
Author(s):  
Khuram Khalid ◽  
Isaac Woungang ◽  
Sanjay K. Dhurandher ◽  
Jagdeep Singh ◽  
Leonard Barolli
Keyword(s):  
Communication Networks ◽  
Wireless Ad Hoc Networks ◽  
Routing Protocol ◽  
Ad Hoc ◽  
Fuzzy Controller ◽  
Opportunistic Networks ◽  
Buffer Size ◽  
Delivery Ratio ◽  
Node Mobility ◽  
Relay Nodes

Unlike communication networks which are traditionally assumed to be connected, Opportunistic networks (OppNets) are a type of wireless ad hoc networks with no guarantee of end-to-end path for data routing, which is due to node mobility, volatile links, and frequent disconnections. As such, data transmission among the nodes relies on their cooperation and this is realized in a store-and-carry fashion. To this end, several opportunistic routing techniques have been proposed in the literature, some of which using geocasting, a technique that consists of scheduling the message to a specific region toward its destination. This paper proposes a Fuzzy-based Check-and-Spray Geocast (FCSG) routing protocol for OppNets, in which a Check-and-Spray mechanism is used to control the message flooding within the destination cast and a fuzzy controller is used for selecting the suitable relay nodes to carry the message toward the destination, with the aim to improve the delivery ratio. Using simulations, the proposed FCSG protocol is shown to outperform the F-GSAF, GeoEpidemic and EECSG routing protocols in terms of overhead ratio, average latency, and delivery ratio, under varying number of nodes, buffer size, and Time-to-Live.

Effect of CSI Imperfection on Cognitive Underlay Transmission over Nakagami-m Fading Channel

2015 ◽  
Vol 1 ◽  
pp. 59
Author(s):  
Nguyen Hong Giang ◽  
Vo Nguyen Quoc Bao ◽  
Hung Nguyen-Le
Keyword(s):  
Fading Channels ◽  
System Performance ◽  
Performance Metrics ◽  
Maximal Ratio Combining ◽  
Relay Nodes ◽  
Channel State ◽  
Primary Network ◽  
Secondary Network ◽  
System Designs ◽  
Approximate Expressions

This paper analyzes the performance of a cognitive underlay system over Nakagami-m fading channels, where maximal ratio combining (MRC) is employed at secondary destination and relay nodes. Under the condition of imperfect channel state information (CSI) of interfering channels, system performance metrics for the primary network and for the secondary network are formulated into exact and approximate expressions, which can be served as theoretical guidelines for system designs. To verify the performance analysis, several analytical and simulated results of the system performance are provided under various system and channel settings.

Erasure-Coding Algorithm in Mobile Low-Duty-Cycle Opportunistic Networks Based on Energy-Aware

2013 ◽  
Vol 24 (2) ◽  
pp. 230-242
Author(s):  
Liang-Yin CHEN ◽  
Zhen-Lei LIU ◽  
Xun ZOU ◽  
Zheng-Kun XU ◽  
Zhen-Qian GUO ◽  
...  
Keyword(s):  
Duty Cycle ◽  
Opportunistic Networks ◽  
Erasure Coding ◽  
Energy Aware ◽  
Low Duty Cycle

Periodic Intermittently Connected-Based Data Delivery in Opportunistic Networks

2014 ◽  
Vol 24 (3) ◽  
pp. 507-525 ◽  
Author(s):  
Lei WU ◽  
De-An WU ◽  
Ming LIU ◽  
Xiao-Min WANG ◽  
Hai-Gang GONG
Keyword(s):  
Opportunistic Networks ◽  
Data Delivery ◽  
Intermittently Connected

Routing protocols for opportunistic networks

2010 ◽  
Vol 30 (3) ◽  
pp. 723-728 ◽  
Author(s):  
Zhi REN ◽  
Yong HUANG ◽  
Qian-bin CHEN
Keyword(s):  
Routing Protocols ◽  
Opportunistic Networks
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