routing algorithms play a crucial role in the efficient transmission of data within computer networks by determining the optimal paths for packet forwarding. This paper presents a comprehensive exploration of routing ...
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Adaptive routing algorithms have been widely utilized in Network-on-Chip (NoC) architectures and have shown to enhance overall throughput in numerous studies. The adaptive routing algorithms can effectively detect net...
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Adaptive routing algorithms have been widely utilized in Network-on-Chip (NoC) architectures and have shown to enhance overall throughput in numerous studies. The adaptive routing algorithms can effectively detect network congestion. On the one hand, one-hop awareness or local awareness can easily detect network congestion but may also result in local greed. On the other hand, global awareness is better for load balancing, but it is difficult to be aware of the network congestion status. This article proposes a lightweight adaptive on-chip routing algorithm based on the concentric circles theory and prior knowledge derived from real-life observations. The algorithm, named the Priori-Knowledge and Congestion-Awareness method (PKCA), aims to optimize the routing efficiency within the chip. PKCA is designed to be not only simple but also to have low time complexity, allowing it to calculate paths to destinations without local greed. We performed evaluations, and the results demonstrated that our design surpasses one-hop awareness, two-hop awareness, and global awareness by 31%, 25%, and 20%, respectively, in terms of latency, and by 22%, 14%, and 22%, respectively, in terms of throughput. Furthermore, the time complexity is only O(N)$$ O(N) $$ in an NxN$$ N\times N $$ 2D mesh. This article proposes a lightweight adaptive on-chip routing algorithm NoC based on the concentric circles theory and prior knowledge derived from real-life observations. The algorithm, named the Priori-Knowledge and Congestion-Awareness method (PKCA), aims to optimize the routing efficiency within the chip. image
Opportunistic Mobile Ad Hoc Networks (MANETs) offer versatile solutions in contexts where the Internet is unavailable. These networks facilitate the transmission between endpoints using a store-carry-forward strategy,...
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Opportunistic Mobile Ad Hoc Networks (MANETs) offer versatile solutions in contexts where the Internet is unavailable. These networks facilitate the transmission between endpoints using a store-carry-forward strategy, thereby allowing information to be stored during periods of disconnection. Consequently, selecting the next hop in the routing process becomes a significant challenge for nodes, particularly because of its impact on Quality of Service (QoS). Therefore, routing strategies are crucial in opportunistic MANETs;however, their deployment and evaluation in real scenarios can be challenging. In response to this context, this paper introduces a monitoring software-driven tool designed to evaluate the QoS of routing algorithms in physical opportunistic MANETs. The implementation and its components are detailed, along with a case study and the outcomes provided by an implementation of the proposed solution. The results demonstrate the effectiveness of the implementation in enabling the analysis of routing protocols in real scenarios, highlighting significant differences with simulation results: mobility patterns in simulations tend to be inaccurate and overly optimistic, leading to a higher delivery probability and lower latency than what is observed in the real testbed.
We study the performance of oblivious routing algorithms that follow minimal (shortest) paths, referred to as minimal oblivious routing algorithms in this paper, using competitive analysis on a d-dimensional, N = 2(d)...
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We study the performance of oblivious routing algorithms that follow minimal (shortest) paths, referred to as minimal oblivious routing algorithms in this paper, using competitive analysis on a d-dimensional, N = 2(d)-node hypercube. We assume that packets are injected into the hypercube arbitrarily and continuously, without ally (e.g., probalilistic) assumption on the arrival pattern of the packets. Minimal algorithms reduce the total load in the network in the first place and they preserve locality. First we show that the well known deterministic oblivious routing algorithm, namely, the greedy routing algorithm, has competitive ratio Omega (N-1/2). Then we show a problem lower bound of Omega (N-log2(5/4)/log(5) N). We also give a natural randomized minimal oblivious routing algorithm whose competitive ratio is close to thr problem lower bound we provide.
Mobile robots are extensively used in flexible manufacturing systems and intra-logistics on a 24/7 basis to address demand fluctuations, increase productivity and promote environmental, economic and social sustainabil...
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Mobile robots are extensively used in flexible manufacturing systems and intra-logistics on a 24/7 basis to address demand fluctuations, increase productivity and promote environmental, economic and social sustainability. In this regard, routing algorithms are used to navigate mobile industrial robots for optimizing shop-floor logistics operations. However, open-source tools and software libraries implementing routing algorithms provide limited real-world relevance via indicatively neglecting the physical operating environment's characteristics and the kinematics of mobile robots. To this effect, this research designs, analyzes and develops MIROR, a middleware software tool that interfaces mobile industrial robots with route optimization algorithms to deliver a sophisticated testing environment that: (i) applies routing algorithms for the optimal logistics of mobile robots in customized industrial facility layouts;(ii) allows the comparison of the resulting algorithmic outcomes to inform about effective and efficient routing options;and (iii) creates optimal routing plans for informing the logistics operations of equivalent real-world mobile robots in industrial manufacturing settings. Specifically, MIROR integrates open-source Operations Research tools and the Robot Operating System to simulate and explore alternative logistics scenarios for mobile robots in 3D recreated industrial manufacturing facilities. To a greater extent, MIROR allows the transfer of the optimal routing code to equivalent real-world vehicles. Specifically, the implemented middleware tool handles variations of the Traveling Salesman Problem and generates feasible routes in complex facility layouts considering a variety of mobile robots. Academics and practitioners could benefit from the user-friendly interface of MIROR to generate realistic scheduling and routing options for the optimal planning of the logistics operations of mobile industrial robots in manufacturing environments. (C) 2021 The
In this paper, we compared the existing routing algorithms in the context of Software Defined Networking (SDN), where a logically centralized controller acquires the global view of the network, selects the paths using...
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In this paper, we compared the existing routing algorithms in the context of Software Defined Networking (SDN), where a logically centralized controller acquires the global view of the network, selects the paths using a routing algorithm, and installs the determined routing rules to the switches. We divided existing routing algorithms (RA) into three categories: RA with static link cost (RA-SLC), RA with dynamic link cost (RA-DLC), and RA with dynamic link cost and minimum interference (RA-DLCMI). We then implemented various routing algorithms from each category using RYU SDN controller and compared their performances on Mininet emulator. For the network state information (NSI) needed for the routing algorithms, we first consider the idealistic case where the accurate NSI is available, as assumed in the literature. However, since this is not possible in practice, we also considered the practical case where the controller periodically collects the NSI with some inaccuracy. In our experiments, we observed that while RA-DLC and RA-DLCMI give similar performance, RA-SLC falls behind of RA-DLC and RA-DLCMI in the number of accepted flows and total throughput. We also showed that the performance of every algorithm is adversely affected from the inaccuracy of NSI, calling for further research on developing effective NSI collection methods.
Coherent diffractive imaging with x-ray free-electron lasers (XFEL) promises high-resolution structure determination of noncrystalline objects. Randomly oriented particles are exposed to XFEL pulses for acquisition of...
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Coherent diffractive imaging with x-ray free-electron lasers (XFEL) promises high-resolution structure determination of noncrystalline objects. Randomly oriented particles are exposed to XFEL pulses for acquisition of two-dimensional (2D) diffraction snapshots. The knowledge of their orientations enables 3D imaging by multiview reconstruction, combining 2D diffraction snapshots in different orientations. Here we introduce a globally optimal algorithm that can infer these orientations. We apply it to experimental XFEL data of nanoparticles and so determine their 3D electron density.
With the rapid development of 5G and 6G communications in recent years, there has been significant interest in space-air-ground integrated networks (SAGINs), which aim to achieve seamless all-area, all-time coverage. ...
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With the rapid development of 5G and 6G communications in recent years, there has been significant interest in space-air-ground integrated networks (SAGINs), which aim to achieve seamless all-area, all-time coverage. As a key component of SAGINs, flying ad hoc networks (FANETs) have been widely used in the agriculture and transportation sectors in recent years. Reliable communication in SAGINs requires efficient routing algorithms to support them. In this study, we analyze the unique communication architecture of FANETs in SAGINs. At the same time, existing routing protocols are presented and clustered. In addition, we review the latest research advances in routing algorithms over the last five years. Finally, we clarify the future research trends of FANET routing algorithms in SAGINs by discussing the algorithms and comparing the routing experiments with the characteristics of unmanned aerial vehicles.
Energy awareness is a vital design issue in wireless sensor networks. Since the amount of sensing data may be large and sensor nodes are usually battery-powered, it is critical to design energy-efficient routing algor...
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Energy awareness is a vital design issue in wireless sensor networks. Since the amount of sensing data may be large and sensor nodes are usually battery-powered, it is critical to design energy-efficient routing algorithms to prolong network lifetime. Given a certain sensor deployment, the routing strategy of sensor data would have profound effects on the communication cost. In this paper, based on low-energy adaptive clustering hierarchy (LEACH) series protocols which are low-energy consumption adaptive clustering routing protocols, we propose the OVSF mechanism based routing protocol and EERPP (Energy-Efficient routing Protocol based on Priority). Simulation results of OVSF mechanism based protocol and EERPP demonstrate a significant improvement on the network metrics such as the lifetime and the end-to-end delay.
A mobile ad-hoc network (MANET) is a continuously self-configuring, infrastructure-less network of the wireless mobile device. Nodes are connected wirelessly and also responsible for data forwarding (no data transfer ...
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A mobile ad-hoc network (MANET) is a continuously self-configuring, infrastructure-less network of the wireless mobile device. Nodes are connected wirelessly and also responsible for data forwarding (no data transfer or routing device is present that is a router, switch, etc.). The opportunistic network is a subcategory of MANET, typically wireless handheld device carried by people. This survey admits a summary of the acquirable OPPNETs routing algorithms, their categorization, and an assessment of five routing protocols (Epidemic, Spray and Wait, First Contact, Prophet, and Max-Prop) in terms of variable buffer size. Detailed computer simulation demonstrates that as the burden or load on the network growths, the efficiency of routing strategies decrease in terms of delivery probability and overhead ratio. The experiments establish that Maxprop routing delivery probability is highest than the others. It has been also observed that the ratio of packet dropped and relayed has been decreased according to buffer size increased. The First Contact routing delivery probability may not differ most with changes the buffer sizes. In terms of overhead ratio, the result of Epidemic is better than Spray and Wait, First Contact, Prophet, MaxProp routing algorithms. Results vary depending on the buffer size, contact times, and speed. The consequences indicate that some can carry and exchange information faster, and improve connectivity in OPPNETs.
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