High-throughput Routing Research Articles

Electromechanical Response of Dip-Coated Silver Films on Micro-Bumpy Polymer Surface

Mechanical performance of nanoparticle-based thin films depends on the method of fabrication and the properties of the underlying substrate. This study presents experimental results of electromechanical response of micrometer-thick dip-coated silver nanoparticle-based films on rough and highly compliant (Young’s modulus between 120 and 130 kPa) polydimethylsiloxane substrate having random micro-bumpy surface. The experimental results demonstrate stretchability of 13% and flexibility of 3.43% for the as-fabricated metal–polymer laminate. The entire process being amenable to mass production suggests a cost-effective and high-throughput route toward the fabrication of stretchable/flexible electronic devices and thin film sensors.

A Deadlock-Free and Connectivity-Guaranteed Methodology for Achieving Fault-Tolerance in On-Chip Networks

To improve the reliability of on-chip network based systems, we design a deadlock-free routing technique that is more resilient to component failures and guarantees a higher degree of node connectivity. The routing methodology consists of three key steps. First, we determine the maximal connected subgraph of the faulty network by checking whether the defective components happen to be the cut vertices and bridges of the network topology. A precise fault diagnosis mechanism is used to identify partial defective routers. Second, we construct an acyclic channel dependency graph that breaks all cycles and preserves connectivity of the maximal connected subgraph . This is done through the cycle-breaking and connectivity guaranteed (CBCG) algorithm. Finally, we introduce a fault-tolerant adaptive routing scheme that can be used with or without virtual channels for network congestion avoidance and high-throughput routing. The simulation results show both the effectiveness and robustness of the proposed approach. For an $8 \times 8$ 2D-Mesh with 40 percent of link damage, full connectivity and deadlock freedom are still archived without disabling any faultless router in 98.18 percent of the simulations. In a 2D-Torus, the simulation percentage is even higher (99.93 percent). The hardware overhead for supporting the introduced features is minimal. An on-line implementation of cbcg using TSMC 65nm library has only 0.966 and 1.139 percent area overhead for the $8\times8$ and $16 \times 16$ 2D-Meshes.

Bandwidth-Aware High-Throughput Routing With Successive Interference Cancelation in Multihop Wireless Networks

Successive interference cancelation (SIC) is a new physical-layer technique that enables the receiver to decode composite signals from multiple transmitters sequentially. The introduction of SIC improves the path bandwidth. In this paper, we focus on the design of a bandwidth-aware routing protocol with SIC, aiming at achieving high overall end-to-end throughput. We develop an SICable condition for a routing protocol to identify beneficial SIC opportunities that improve spatial reuse without impacting transmission quality. To further explore the benefits of SIC, we formulate the problem of SIC-aware path bandwidth computation as a linear program and design a distributed heuristic algorithm with polynomial complexity. A routing metric capturing the benefit of SIC in terms of bandwidth and network resource is proposed, by which our routing protocol can choose a path satisfying the bandwidth requirement of the current flow and reserving more network resource for the subsequent ones. Simulation results show that our routing protocol achieves significant gains in network throughput and SIC ratio compared with other routing protocols.

A High-throughput routing metric for multi-hop Underwater Acoustic Networks

In most wireless network architectures, a routing metric plays an important role for a routing protocol to select suitable paths (or, links) for communications. An inefficient routing metric may increase overall transmission cost per packet by selecting lossy links and thereby may lead to poor throughput. Underwater Acoustic Networks (UANs), where most of the nodes operate on battery power, prefer topology-based routing metrics over active probing based routing metrics. Considering this fact, in this paper, we investigate the performance of various topology-based routing metrics over UAN-architecture. We then apply the acquired knowledge to design a new routing metric called Cubic Min to Avg Signal-to-Noise Ratio (CMAS), which is capable of selecting high-throughput links. We evaluate the performance of the proposed metric with other available topology-based routing metrics in underwater scenario. Simulation results demonstrate that the proposed metric attains significantly higher throughput than that of the other compared metrics.

Co-UWSN: Cooperative Energy-Efficient Protocol for Underwater WSNs

Sensor networks feature low-cost sensor devices with wireless network capability, limited transmit power, resource constraints, and limited battery energy. Cooperative routing exploits the broadcast nature of wireless medium and transmits cooperatively using nearby sensor nodes as relays. It is a promising technique that utilizes cooperative communication to improve the communication quality of single-antenna sensor nodes. In this paper, we propose a cooperative transmission scheme for underwater sensor networks (UWSNs) to enhance the network performance. Cooperative diversity has been introduced to combat fading. Cooperative UWSN (Co-UWSN) is proposed, which is a reliable, energy-efficient, and high throughput routing protocol for UWSN. Destination and potential relays are selected that utilize distance and signal-to-noise ratio computation of the channel conditions as cost functions. This contributes to sufficient decrease in path losses occurring in the links and transferring of data with much reduced path loss. Simulation results show that Co-UWSN protocol performs better in terms of end-to-end delay, energy consumption, and network lifetime. Selected protocols for comparison are energy-efficient depth-based routing (EEDBR), improved adaptive mobility of courier nodes in threshold-optimized depth-based routing (iAMCTD), cooperative routing protocol for UWSN, and cooperative partner node selection criteria for cooperative routing Coop (Re and dth).

DTN-FLOW: Inter-Landmark Data Flow for High-Throughput Routing in DTNs

In this paper, we focus on the efficient routing of data among different areas in delay tolerant networks (DTNs). In current algorithms, packets are forwarded gradually through nodes with higher probability of visiting the destination node or area. However, the number of such nodes usually is limited, leading to insufficient throughput performance. To solve this problem, we propose an inter-landmark data routing algorithm, namely DTN-FLOW. It selects popular places that nodes visit frequently as landmarks and divides the entire DTN area into subareas represented by landmarks. Nodes transiting between landmarks relay packets among landmarks, even though they rarely visit the destinations of these packets. Specifically, the number of node transits between two landmarks is measured to represent the forwarding capacity between them, based on which routing tables are built on each landmark to guide packet routing. Each node predicts its transits based on its previous landmark visiting records using the order- k Markov predictor. When routing a packet, the landmark determines the next-hop landmark based on its routing table and forwards the packet to the node with the highest probability of transiting to the selected landmark. Thus, DTN-FLOW fully utilizes all node movements to route packets along landmark-based paths to their destinations. We analyzed two real DTN traces to support the design of DTN-FLOW. We deployed a small DTN-FLOW system on our campus for performance evaluation. We also proposed advanced extensions to improve its efficiency and stability. The real deployment and trace-driven simulation demonstrate the high efficiency of DTN-FLOW in comparison to state-of-the-art DTN routing algorithms.

Material descriptors for predicting thermoelectric performance

A high throughput route to screen thermoelectric materials is developed and validated across a broad material set.

ARCUN: Analytical Approach towards Reliability with Cooperation for Underwater WSNs

Cooperative routing is a hybrid approach utilizing routing techniques and cooperative communication to improve the communication quality of single-antenna sensor nodes. It exploits the broadcast nature of wireless medium and transmits cooperatively using nearby sensor nodes as relays. In this research, a cooperative transmission scheme is proposed for UnderWater Sensor Networks (UWSNs) to improve the network performance called ARCUN. The protocol is an energy-efficient and high-throughput routing scheme for UWSN. Potential relays are selected from a group of neighbor nodes that utilize signal-to-noise ratio and distance computation of the underwater channel. Optimal role of cooperation provides load balancing in the network and gives profound improvement in network stability period and packet delivery ratio.

Osmotically driven formation of double emulsions stabilized by amphiphilic block copolymers.

Double emulsions are valuable for the formation of multi-compartmental structures. A variety of pathways to prepare double emulsions have been developed, but high-throughput routes to droplets of controlled size and architecture remain scarce. A new single-step process is introduced for preparation of water-in-oil-in-water double emulsions by a previously unexplained process of self-emulsification. We show that the origin of this process is the osmotic stress resulting from the presence of salt impurities within the amphiphilic block copolymers used for emulsion stabilization. Further, we utilize osmotically driven emulsification to tailor the structures of multiple emulsions, which upon solvent evaporation can yield multi-compartmental capsules or hierarchically structured porous films.

Copper Shell Networks in Polymer Composites for Efficient Thermal Conduction

Thermal management of polymeric composites is a crucial issue to determine the performance and reliability of the devices. Here, we report a straightforward route to prepare polymeric composites with Cu thin film networks. Taking advantage of the fluidity of polymer melt and the ductile properties of Cu films, the polymeric composites were created by the Cu metallization of PS bead and the hot press molding of Cu-plated PS beads. The unique three-dimensional Cu shell-networks in the PS matrix demonstrated isotropic and ideal conductive performance at even extremely low Cu contents. In contrast to the conventional simple melt-mixed Cu beads/PS composites at the same concentration of 23.0 vol %, the PS composites with Cu shell networks indeed revealed 60 times larger thermal conductivity and 8 orders of magnitude larger electrical conductivity. Our strategy offers a straightforward and high-throughput route for the isotropic thermal and electrical conductive composites.

Accelerated processing route for KNN based piezoceramics

It is known that the properties of potassium–sodium–niobate (KNN, K0·46Na0·54NbO3) are sensitive to processing and that the most successful way of stabilising and improving material performance is proper doping of KNN. However, this leads to more complex material systems, whose synthesis is very time consuming to assess by conventional processing techniques. On the other hand, known high throughput routes impose a serious interference with conventional processing, resulting in significant differences of the findings, or inaccessibility of certain parameters. In this paper, an accelerated processing route is introduced and compared with conventional mixed oxide processing regarding the density, large signal piezoelectric charge constant, permittivity, loss tangent planar coupling factor, specific resistivity and microstructure. By means of three differently doped KNN based compositions, it is shown that the accelerated processing route yields reproducible results, which are equal or even superior to conventional techniques, while the processing time and the batch costs are significantly reduced.

ChemInform Abstract: Synthesis of Quinazolin‐4(3H)‐ones via Amidine N‐Arylation.

AbstractA high throughput route towards the orally active calcium‐sensing receptor antagonist (XIIIb) is developed.

One-step real time RT-PCR for detection of microRNAs

Rapid and simple methods for microRNA (miRNA) detection are essential for biological research of miRNAs and clinical diagnosis. Here we describe a sensitive and specific real time RT-PCR (also RT-qPCR) method for miRNA quantification. The whole detection process including reverse transcription and PCR is performed in one PCR tube by a one-step operation on a real-time PCR system. The results display a wide linear range from 0.1amol to 10fmol with a detection limit of 12.6zmol for miRNA let-7a detection. Let-7a in small RNA samples extracted from tumor cells has been successfully detected by this method. This method is cost-effective, simple and rapid, and has the advantages in the high-throughput routing assay of given miRNAs, as well as in non-model research that has less specific kits and reagents.

High-throughput route to Cu2−xS nanoparticles from single molecular precursor

The copper(II) complex of 1,1,5,5-tetra-iso-propyl-2-thiobiuret was used as a single source precursor for the synthesis of copper sulfide nanoparticles in a continuous flow process. The nanoparticles had a spherical morphology and were produced either as a pure Cu7S4 or Cu7S4 with minor impurities of Cu9S5.

A routing protocol using a reliable and high-throughput path metric for multi-hop multi-rate ad hoc networks

In this paper, a high-throughput routing protocol for multi-rate ad hoc networks using lower layer information is proposed. By choosing the route with the minimum value of the proposed “Route Assessment Index” metric which has the form of entropy function, the selected route is ensured to have high throughput and link reliability among route candidates. Link bottleneck is avoided in the chosen route; hence, the packet drop rate due to buffer overflow is alleviated. Furthermore, an effective route discovery strategy is also introduced along with new routing metric. The correctness of the proposal is proven, and the simulation results show that our new metric provides an accurate and efficient method for evaluating and selecting the best route in multi-rate ad hoc networks.

RAI: A High Throughput Routing Protocol for Multi-hop Multi-rate Ad hoc Networks

The advantages of using the multiple rates for wireless communications have been revealed in the recent years. To determine the appropriate rate and to make routing decision more precise, the communication nodes need the information from lower layer. Therefore, in this paper, a high throughput routing protocol using lower layer information for Multi-rate Ad-hoc Networks is proposed. We introduce a new routing metric named "Route Assessment Index" (RAI). The route with maximum RAI value is preferred to achieve the high throughput route, and to avoid the link bottleneck for reducing the packet drop rate. The chosen route also has a small number of hops. The routing protocol works in distributed manner, and correctness of the proposal is proven. The simulation results show that our new metric provides an accurate and efficient method for assessing and selecting the best route in Multi-rate Ad-hoc Networks.

Foreword by Guest Editor for the Special Issue on the 2010 ICUFN Conference

Welcome to this special issue ofWireless Personal Communication Journal.We have selected a set of best papers from the 2010 ICUFN (International Conference on Ubiquitous Future Networks) Conference. All these papers have been extended and reviewed again by 3 independent reviewers. ICUFN is an annual international conference (www.icufn.org) technically co-sponsored by IEEE Communications Society and organized by the KICS (Korean Information & Communications Society). The first paper is entitled “Infoshare: Design and Implementation of Scalable Multimedia Signage Architecture for Wireless Ubiquitous Environment”. The authors stated that communication disruptions are expected in a wireless environment and hence the there is a need for a generic architecture for a digital signage system using smart clients and XAML for expressing signage displays. The second paper is entitled “Analytical Expression of Maximum Throughput for LongFrameCommunications in One-way StringWirelessMultihopNetworks”. The authors urged that there is currently no analytical expression for maximum throughput for long-frame communications in IEEE802.11DistributedCoordination (DCF)multihop networks. The authors validated their assumptions and analysis through further simulation results. The partner selection problem for cooperative transmission is a recent topic of interest. The third paper—“Grouping Algorithm for Partner Selection in Cooperative Transmission” addresses this topic. The authors proposed a simple but optimal rate allocation algorithm for two cooperating nodes pairs and presented a grouping algorithm capable of reducing communication and computational overhead. The fourth paper—“RAI: A High Throughput Routing Protocol for Multi-hop Multi-rate AdHocNetworks” addresses the problem of finding the appropriate rate andmaking the right routing decision to choose a high throughput route while avoiding potential link bottlenecks, thereby reducing packet drop rate. The authors showed through simulation results that their proposed Route Assessment Index (RAI) is effective and efficient.

β-Molybdenum nitride: synthesis mechanism and catalytic response in the gas phase hydrogenation of p-chloronitrobenzene

A temperature programmed treatment of MoO3 in flowing N2 + H2 has been employed to prepare β-phase molybdenum nitride (β-Mo2N) which has been used to promote, for the first time, the catalytic hydrogenation of p-chloronitrobenzene. The reduction/nitridation synthesis steps have been monitored in situ and the starting oxide, reaction intermediates and nitride product have been identified and characterized by powder X-ray diffraction (XRD), diffuse reflectance UV-Vis (DRS UV-Vis), elemental analysis, scanning electron microscopy (SEM) and BET/pore volume measurements. Our results demonstrate that MoO3 → β-Mo2N is a kinetically controlled process where an initial reduction stage generates (sequentially) MoO2 and Mo as reaction intermediates with a subsequent incorporation of N to produce β-Mo2N. SEM analysis has established that the transformation is non-topotactic with a disruption to the platelet morphology that characterizes MoO3 and an increase in BET area (from 1 m2 g−1 to 17 m2 g−1). Moreover, temperature programmed desorption measurements have revealed a significant hydrogen uptake (0.71 μmol m−2) on β-Mo2N. This has been exploited in the hydrogenation of p-chloronitrobenzene where p-chloroaniline was generated as the sole product with an associated rate constant (k = 2.0 min−1) that is higher than values recorded for supported transition metals. Our study establishes the reaction mechanism involved in the synthesis of β-Mo2N and demonstrates its viability to promote selective –NO2group reduction as an alternative sustainable, high throughput route to commercially important haloamines.

EFT: a high throughput routing metric for IEEE 802.11s wireless mesh networks

In this paper, we present a throughput-maximizing routing metric, referred to as expected forwarding time (EFT), for IEEE 802.11s-based wireless mesh networks. Our study reveals that most of the existing routing metrics select the paths with minimum aggregate transmission time of a packet. However, we show by analyses that, due to the shared nature of the wireless medium, other factors, such as transmission time of the contending nodes and their densities and loads, also affect the performance of routing metrics. We therefore first identify the factors that hinder the forwarding time of a packet. Furthermore, we add a new dimension to our metric by introducing traffic priority into our routing metric design, which, to the best of our knowledge, is completely unaddressed by existing studies. We also show how EFT can be incorporated into the hybrid wireless mesh protocol (HWMP), the path selection protocol used in the IEEE 802.11s draft standard. Finally, we study the performance of EFT through simulations under different network scenarios. Simulation results show that EFT outperforms other routing metrics in terms of average network throughput, end-to-end delay, and packet loss rate.

Practical, distributed channel assignment and routing in dual-radio mesh networks

Realizing the full potential of a multi-radio mesh network involves two main challenges: how to assign channels to radios at each node to minimize interference and how to choose high throughput routing paths in the face of lossy links, variable channel conditions and external load. This paper presents ROMA, a practical, distributed channel assignment and routing protocol that achieves good multi-hop path performance between every node and one or more designated gateway nodes in a dual-radio network. ROMA assigns non-overlapping channels to links along each gateway path to eliminate intra-path interference. ROMA reduces inter-path interference by assigning different channels to paths destined for different gateways whenever possible. Evaluations on a 24-node dual-radio testbed show that ROMA achieves high throughput in a variety of scenarios.