scholarly journals An Adaptive Hierarchical Hybrid Multicast Based on Information-Centric Networking

Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 3002
Author(s):  
Bo Li ◽  
Jinlin Wang ◽  
Xiaoyong Zhu ◽  
Jiali You ◽  
Linlin Hu
Keyword(s):  
Lower Layer ◽  
Layer Structure ◽  
Minimum Cost ◽  
Multicast Tree ◽  
Selection Strategy ◽  
Multicast Communication ◽  
Information Centric Networking ◽  
Control Overhead ◽  
Resolution System ◽  
Multicast Forwarding

Many information-centric services have emerged, such as IPTV and video conferencing. These services put a lot of demands on scalable multicast communication. However, traditional IP multicast has low adoption because of its poor scalability. Therefore, some stateless multicast methods were proposed, which encapsulate the destination’s information into the packet header without requiring routers to maintain the multicast forwarding state. However, stateless multicast also faces some problems, such as ingress router overload, high forwarding overhead, packet redundancy, etc. In addition, most multicast methods cannot optimize the multicast tree because the multicast flow is simply forwarded along the shortest path tree from the source to receivers. This paper proposes an Adaptive Hierarchical Hybrid Multicast (AHHM) based on Information-Centric Networking. To balance the forwarding states and forwarding overhead, AHHM is designed as a two-layer structure, in which the upper layer establishes a stateful main tree and the lower layer establishes several stateless sub trees. The router on the main tree is defined as the multicast join node (MJN), and AHHM uses the Name Resolution System to maintain the mapping between each multicast group name and corresponding MJNs. To optimize the multicast transmission path, we designed the minimum cost selection strategy for users to select the appropriate MJN to join. Simulation results show that compared with Source-Specific Multicast (SSM) and Bit Index Explicit Replication (BIER), AHHM can not only reduce the multicast forwarding states but also reduce the control overhead and link load.

scholarly journals A Register Access Control Scheme for SNR System to Counter CPA Attack Based on Malicious User Blacklist

2021 ◽  
Vol 13 (10) ◽  
pp. 262
Author(s):  
Jia Shi ◽  
Xuewen Zeng ◽  
Yang Li
Keyword(s):  
Access Control ◽  
System Component ◽  
Information Centric Networking ◽  
Collusion Attack ◽  
Malicious User ◽  
Malicious Behavior ◽  
Pollution Attack ◽  
Resolution System ◽  
Control Scheme ◽  
Registration Phase

Standalone Name Resolution (SNR) is an essential component of many Information-Centric Networking (ICN) infrastructures that maps and stores the mappings of IDs and locators. The delivery of data can be realized only when the name resolution process is completed correctly. It also makes the SNR become the key target of network attackers. In this paper, our research focuses on the more covert and complex Content Pollution Attack (CPA). By continuously sending invalid content to the network at a low speed, attackers will consume a lot of the resources and time of the SNR system, resulting in a serious increase in the resolution delay of normal users and further cache pollution in ICN. It is difficult to be quickly detected because the characteristics of attack are inconspicuous. To address the challenge, a register access control scheme for an SNR system based on a malicious user blacklist query is proposed. A neighbor voting algorithm is designed to discover possible attacks in the network quickly and build a blacklist of malicious users reasonably. Users on the blacklist will be restricted from accessing the ICN network during the registration phase with the resolution system. Incentives and punishments for network users are introduced to automate responses about the potential malicious behavior reports. Our scheme is more efficient as users do not have to wait for an additional system component to perform operations. In addition, our algorithm can better solve the collusion problem in the voting process when compared with the others. We experimentally evaluate our protocol to demonstrate that the probability of successful collusion attack can be reduced to less than 0.1 when the attacker ratio is 0.5.

scholarly journals Double-layer structure in polar mesospheric clouds observed from SOFIE/AIM

2017 ◽  
Vol 35 (2) ◽  
pp. 295-309 ◽  
Author(s):  
Haiyang Gao ◽  
Gordon G. Shepherd ◽  
Yuanhe Tang ◽  
Lingbing Bu ◽  
Zhen Wang
Keyword(s):  
Double Layer ◽  
Lower Layer ◽  
Layer Structure ◽  
Polar Mesospheric Clouds ◽  
Double Peaks ◽  
Double Layer Structure ◽  
Ice Water Content ◽  
Background Temperature ◽  
Mesospheric Clouds ◽  
Ice Water

Abstract. Double-layer structures in polar mesospheric clouds (PMCs) are observed by using Solar Occultation for Ice Experiment (SOFIE) data between 2007 and 2014. We find 816 and 301 events of double-layer structure with percentages of 10.32 and 7.25 % compared to total PMC events, and the mean distances between two peaks are 3.06 and 2.73 km for the Northern Hemisphere (NH) and Southern Hemisphere (SH) respectively. Double-layer PMCs almost always have less mean ice water content (IWC) than daily IWC during the core of the season, but they are close to each other at the beginning and the end. The result by averaging over all events shows that the particle concentration has obvious double peaks, while the particle radius exhibits an unexpected monotonic increase with decreasing altitude. By further analysis of the background temperature and water vapour residual profiles, we conclude that the lower layer is a reproduced one formed at the bottom of the upper layer. 56.00 and 47.51 % of all double-layer events for the NH and SH respectively have temperature enhancements larger than 2 K locating between their double peaks. The longitudinal anti-correlation between the gravity waves' (GWs') potential energies and occurrence frequencies of double-layer PMCs suggests that the double-layer PMCs tend to form in an environment where the GWs have weaker intensities.

scholarly journals An Incrementally Deployable IP-Compatible-Information-Centric Networking Hierarchical Cache System

2020 ◽  
Vol 10 (18) ◽  
pp. 6228
Author(s):  
Li Zeng ◽  
Hong Ni ◽  
Rui Han
Keyword(s):  
Analytical Model ◽  
High Performance ◽  
Behavior Pattern ◽  
Information Centric Networking ◽  
Network Bandwidth ◽  
Resolution System ◽  
Ip Network ◽  
Measurement Results ◽  
Nested Structure ◽  
Cache System

The major advantage of information-centric networking (ICN) lies in in-network caching. Ubiquitous cache nodes reduce the user’s download latency of content and the drain of network bandwidth, which enables efficient content distribution. Due to the huge cost of updating an entire network infrastructure, it is realistic for ICN to be integrated into an IP network, which poses new challenges to design a cache system and corresponding content router. In this paper, we firstly observed that the behavior pattern of data requests based on a name resolution system (NRS) makes an ICN cache system implicitly form a hierarchical and nested structure. We propose a complete design and an analytical model to characterize an uncooperative hierarchical ICN caching system compatible with IP. Secondly, to facilitate the incremental deployment of an ICN cache system in an IP network, we designed and implemented a cache-supported router with multi-terabyte cache capabilities. Finally, the simulation and measurement results show the accuracy of proposed analytical model, the significant gains on hit ratio, and the access latency of the hierarchical ICN cache system compared with a flat cache system based on naming routing, as well as the high performance of the implemented ICN router.

Delay-constrained minimum cost multicast tree algorithm

2009 ◽  
Vol 29 (1) ◽  
pp. 25-27
Author(s):  
Chun-de YANG ◽  
Jing-jing REN
Keyword(s):  
Minimum Cost ◽  
Multicast Tree ◽  
Tree Algorithm

Two-Silicon-Nanocrystal Layer Memory Structure with Improved Retention Characteristics

2007 ◽  
Vol 7 (1) ◽  
pp. 368-373 ◽  
Author(s):  
A. G. Nassiopoulou ◽  
A. Salonidou
Keyword(s):  
Silicon Nanocrystals ◽  
Gate Dielectric ◽  
Lower Layer ◽  
Layer Structure ◽  
Use Of Self ◽  
First Case ◽  
Layer Structures ◽  
Charge Loss ◽  
Retention Characteristics ◽  
Nanocrystal Memory

It was demonstrated in the literature that the use of self-aligned doubly-stacked Si dots improves retention characteristics of a nanocrystal memory. In this paper, we show that a similar effect may be obtained by using two distinct layers of silicon nanocrystals within the gate dielectric of the MOS structure, if the nanocrystal density in each layer is high enough (above 1012 dots/cm2) so as to get an average effect of at least one smaller dot underneath each larger one. The relative distance of the layers and their position from the silicon substrate and the gate metal are critical for optimum memory operation. Two different double-nanocrystal-layer structures were investigated. In the first structure the two nanocrystal layers were close together and they were composed of dots of different size (lower layer: 3 nm, upper layer: 5 nm), while in the second structure the dot layers were composed of dots of equal diameter (d = 3 nm) and their inter-distance was much larger. In both cases, the retention characteristics of the structure were improved compared with a single dot layer structure. In the second case this improvement was significantly larger than in the first case. Extrapolation of the data to ten years memory operation, showed that the charge loss after this time was only ≈ 12%.

Frontal Instability and Energy Dissipation in a Submesoscale Upwelling Filament

2020 ◽  
Vol 50 (7) ◽  
pp. 2017-2035 ◽  
Author(s):  
Jen-Ping Peng ◽  
Peter Holtermann ◽  
Lars Umlauf
Keyword(s):  
Energy Dissipation ◽  
Lower Layer ◽  
Layer Structure ◽  
Quantitative Agreement ◽  
Shear Instability ◽  
Surface Velocity ◽  
Near Surface ◽  
Light Side ◽  
Frontal Instability ◽  
Symmetric Instability

AbstractBased on high-resolution turbulence microstructure and near-surface velocity data, frontal instability and its relation to turbulence are investigated inside a transient upwelling filament in the Benguela upwelling system (southeast Atlantic). The focus of our study is a sharp submesoscale front located at the edge of the filament, characterized by persistent downfront winds, a strong frontal jet, and vigorous turbulence. Our analysis reveals three distinct frontal stability regimes. (i) On the light side of the front, a 30–40-m-deep turbulent surface layer with low potential vorticity (PV) was identified. This low-PV region exhibited a well-defined two-layer structure with a convective (Ekman-forced) upper layer and a stably stratified lower layer, where turbulence was driven by forced symmetric instability (FSI). Dissipation rates in this region scaled with the Ekman buoyancy flux, in excellent quantitative agreement with recent numerical simulations of FSI. (ii) Inside the cyclonic flank of the frontal jet, near the maximum of the cross-front density gradient, the cyclonic vorticity was sufficiently strong to suppress FSI. Turbulence in this region was driven by marginal shear instability. (iii) Inside the anticyclonic flank of the frontal jet, conditions for mixed inertial/symmetric instability were satisfied. Our data provide direct evidence for the relevance of FSI, inertial instability, and marginal shear instability for overall kinetic energy dissipation in submesoscale fronts and filaments.

Buoyancy transfer across a diffusive interface

1989 ◽  
Vol 209 ◽  
pp. 1-34 ◽  
Author(s):  
Harindra J. S. Fernando
Keyword(s):  
Interfacial Layer ◽  
Cold Water ◽  
Lower Layer ◽  
Layer Structure ◽  
Constant Heat Flux ◽  
Time Interval ◽  
Interfacial Layers ◽  
Density Interface ◽  
Turbulent Eddies ◽  
Opposing Effects

An experimental investigation of various aspects of buoyancy transfer across a diffusive density interface that separates stably stratified, turbulently convecting layers of relatively fresh cold water overlying hot salty water is described. It is argued that the interfacial layer should possess a double boundary-layer structure, in which the thicknesses of the salt and heat interfacial layers are determined by a balance between the opposing effects of diffusion and entrainment. Based on this argument, a simple theory, that predicts the interfacial-layer thickness, the diffusive heat and salt fluxes across the density interface, and the time variation of the temperature and salt concentrations in the convecting layers, is proposed for the case in which the convection is driven by a constant heat flux supplied to the lower layer. During a certain time interval, the theory and experiment agree well, but thereafter distinct differences can be seen. Measurements suggest that these differences may be due to the distortion of the density interface at low interfacial stabilities by turbulent eddies, which leads to a change in the buoyancy transfer mechanism. When the Richardson number falls below a critical value Riv, the interface was found to migrate slowly upwards and the mechanism of entrainment was the detachment of thin sheets of fluid by eddies scouring the interface.

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