Commercial Router Research Articles

A Dual-Band Conformal Antenna Based on Highly Conductive Graphene-Assembled Films for 5G WLAN Applications.

Flexible electronic devices are widely used in the Internet of Things, smart home and wearable devices, especially in carriers with irregular curved surfaces. Light weight, flexible and corrosion-resistant carbon-based materials have been extensively investigated in RF electronics. However, the insufficient electrical conductivity limits their further application. In this work, a flexible and low-profile dual-band Vivaldi antenna based on highly conductive graphene-assembled films (GAF) is proposed for 5G Wi-Fi applications. The proposed GAF antenna with the profile of 0.548 mm comprises a split ring resonator and open circuit half wavelength resonator to implement the dual band-notched characteristic. The operating frequency of the flexible GAF antenna covers the Wi-Fi 6e band, 2.4–2.45 GHz and 5.15–7.1 GHz. Different conformal applications are simulated by attaching the antenna to the surface of cylinders with different radii. The measured results show that the working frequency bands and the radiation patterns of the GAF antenna are relatively stable, with a bending angle of 180°. For demonstration of practical application, the GAF antennas are conformed to a commercial router. The spectral power of the GAF antenna router is greater than the copper antenna router, which means a higher signal-to-noise ratio and a longer transmission range can be achieved. All results indicate that the proposed GAF antenna has broad application prospects in next generation Wi-Fi.

Design of an Interactive Cellular System for the Remote Operation of Ocean Sensors: A Pilot Study Integrating Radioactivity Sensors

Ocean in-situ sensors are crucial for measuring oceanic parameters directly from the sea in a spatial and temporal basis. Real-time operation is used in many applications related to decision support tools and early warning services in case of accidents, incidents and/or disasters. The design of the proposed system is described as a rapid-response detection system, which aims to measure natural and artificial radioactive contaminants or other crucial ocean parameters, to replace the traditional method of sampling. The development of an interactive cellular system is undertaken using a commercial router that is programmed according to sensor specifications. A radioactivity sensor is integrated in a communication box enabling self-powered operation with a solar panel. The proposed system operates in (near) real-time mode and provides gamma-ray spectra by integrating the sensor and the appropriate electronic modules in it. Additionally, an on-site experiment was conducted to test the operability of the system in a real environment close to the sea, for monitoring fallout due to rainfall and snowfall events. The main intense radionuclides that were observed by different energy lines, were radon progenies (214Bi, 214Pb). The continuous operation of the whole system was controlled by operating the system during the winter period.

Recycling Ambient Wi-Fi Signals for Low Energy Wake-Up of Wireless Sensors

In this letter, waking-up wireless sensors is achieved by solely relying on existing ambient radio frequency signals from commercial Wi-Fi routers. The wake-up is accomplished based on the captured Wi-Fi signal that is received by an antenna and then fed into a rectifier circuit. A novel packet injection algorithm is developed to enable the rectifier to efficiently convert the captured Wi-Fi signal into a dc power. This algorithm can be implemented on any commercial router with no modifications to the router's hardware or protocol stack and without compromising the performance of the Wi-Fi network. The design is experimentally validated under controlled conditions.

FISE: A Forwarding Table Structure for Enterprise Networks

With increasing demands for more flexible services, the routing policies in enterprise networks become much richer. This has placed a heavy burden to the current router forwarding plane in support of the increasing number of policies, primarily due to the limited capacity in TCAM, which further hinders the development of new network services and applications. The scalable forwarding table structures for enterprise networks have therefore attracted numerous attentions from both academia and industry. To tackle this challenge, in this paper we present the design and implementation of a new forwarding table structure. It separates the functions of TCAM and SRAM, and maximally utilizes the large and flexible SRAM. A set of schemes are progressively designed, to compress storage of forwarding rules, and maintain correctness and achieve line-card speeds of packet forwarding. We further design an incremental update algorithm that allows less access to memory. The proposed scheme is validated and evaluated through a realistic implementation on a commercial router using real datasets. Our proposal can be easily implemented in the existing devices. The evaluation results show that the performance of forwarding tables under the proposed scheme is promising.

Ripple 2.0

Routability is one of the most important problems in high-performance circuit designs. From the viewpoint of placement design, two major factors cause routing congestion: (i) interconnections between cells and (ii) connections on macro blockages. In this article, we present a routability-driven placer, Ripple 2.0, which emphasizes both kinds of routing congestion. Several techniques will be presented, including (i) cell inflation with routing path consideration, (ii) congested cluster optimization, (iii) routability-driven cell spreading, and (iv) simultaneous routing and placement for routability refinement. With the official evaluation protocol, Ripple 2.0 outperforms other published academic routability-driven placers. Compared with top results in the ICCAD 2012 contest, Ripple 2.0 achieves a better detailed routing solution obtained by a commercial router.

ANALISA DAN KOMPARASI PC ROUTER UBUNTU DENGAN ROUTER KOMERSIL (BELKIN) DI JARINGAN LAN

Router is a device that used to forward a packet from one network to other network such as from WAN to LAN and vice versa. A lot of commercial routers are available in market from low-end to high-end router. As an alternative router can be build and working properly from old PC installed with Unix- based operating system called as PC router. The quality of service of both commercial router and PC router are measured in this paper in order to find the characteristic of both routers. The result found out that commercial router has asymmetric speed for download and upload but PC router relatively has symmetric speed of download and upload. Keywords: Router, LAN, WAN, QoS

Transit tomography using probabilistic time geography: planning routes without a road map

Vehicle routing usually depends on a road map, and road maps are expensive to create and maintain. While crowdsourcing road maps from logged GPS data has proven effective, the limited availability of GPS data limits their coverage area. To overcome this limitation, we show how to use location data from geotagged tweets, which cover much of the world, to compute routes directly without making a road map. We compensate for the wide spacing of tweets' latitude/longitude points by using probabilistic time geography, which explicitly models the uncertain location of someone traveling between measured locations. In our formulation, each pair of temporally adjacent tweets contributes an estimate of the driving time along hypothesised roads in a regular grid. We show how to compute these estimates as expected values based on probabilistic Brownian bridges. We can compute routes on this regular grid using traditional A* search. Our experiments demonstrate that our computed routes match well with routes computed on the actual road network using a commercial router. Furthermore, we show that our computed routes vary sensibly with changes in traffic between rush hour and weekends. We also apply the same technique to compute reasonable airplane routes.

MANA: A Shortest Path Maze Algorithm Under Separation and Minimum Length NAnometer Rules

Due to process limitations, wiring rules are imposed on chip layout by foundries. Under nanometer wiring rules, the required separation between two wire ends is dependent on their surrounding wires, and there is a limit on the minimum length of each wire segment. However, traditional shortest path algorithms are not properly designed for these rules. In the paper, we propose a maze routing algorithm, called MANA, capable of finding legal shortest paths under these rules. Experiments with seven industrial cases show that by handling these rules during maze routing, 94% of the violations are prevented on average, and the overall runtime of a commercial router is reduced by 71%. In addition, the total wire length is also reduced by 3% on average.

Green OBS 망에서 LPI를 이용하는 코어 및 에지 라우터 구조의 에너지 절감 성능 분석

In this paper, we propose core and edge router architectures with LPI(Low Power Idle) for reducing energy consumption in OBS networks. The proposed core router architecture is comprised of a BCP switch, a burst switch, line cards and sleep/wake controller for LPI. When the offered load of network is low, sleep/wake controller can change the state of the core router line card from active to sleep state for saving the energy after receiving network control packet. The edge router consists of a switch for access line card, a SCU and OBS edge router line cards. The LPI function in edge router line card is performed through network level control by network control packet, individually. Additionally, PHY/transceiver modules can transition active state to sleep state when burst assemble engine generates new bursts. To evaluate the energy saving performance of proposed architecture with LPI, the power consumption of each router is analyzed by using data sheet of commercial router and optical device. And, simulation is also performed in terms of sleep time of PHY/Transceiver through OPNET.

Evaluation of Power Consumption in Low Spatial Complexity Optical Switching Fabrics

In this paper, we propose an analytical model to evaluate the power consumption in the switching fabric of a bufferless shared-per-wavelength (SPW) optical packet switch architecture in which one bank of wavelength converters (WC) is dedicated to each wavelength. We assume that both optical gates and WCs are realized in semiconductor optical amplifier technology. In our evaluation, we account for the power consumption of the current drivers needed to both controlling the used active devices and supplying the thermoelectric coolers. SPW allows for a complexity reduction of the spatial switching matrix that leads to reduced power consumption with respect to other switching architectures. Results show the effectiveness in terms of consumed power of the considered architecture with respect to the shared-per-node reference architecture, where a fully sharing strategy of WCs is adopted. The main results show that SPW allows us to reduce the power consumption in the order of 26% for offered traffic equal to 0.6. The obtained results also show how the fabric switching of the SPW optical packet switch consumes much less power per gigabits per second carried than the one of a typical commercial core router.

An open router virtualization framework using a programmable forwarding plane

Network virtualization promises to spur innovation and add flexibility to the Future Internet infrastructure. Routers supporting virtualization allow the deployment of concurrent virtual networks, and can be employed to consolidate resources and improve energy efficiency in data centers. The closed nature of commercial router systems poses a significant problem for research in the field of virtual network architectures. On the other hand, the performance of software-based, open routing solutions is typically limited. In this work we outline an open router virtualization framework utilizing OpenFlow enabled hardware as a fast, programmable forwarding plane.

CASCADE: A Standard Supercell Design Methodology With Congestion-Driven Placement for Three-Dimensional Interconnect-Heavy Very Large-Scale Integrated Circuits

In this paper, CASCADE, a standard supercell-based design methodology, its supporting automated design flow, and associated design tools, are presented for 3D implementations of a class of interconnect-heavy application-specific very large-scale integrated circuits. In CASCADE, a system is first partitioned and synthesized using standard 2D design tools to a set of supercells with the same height and varying widths. With this, the 3D design is reduced to 3D supercell placement and 3D-via assignment. A congestion-driven simulated-annealing method is used to find a 3D placement of supercells to minimize the total wire length, the longest wire length, and the number of 3D vias and routing density. To efficiently estimate the routing density of a 3D grid space within the optimization loop, a simple probabilistic congestion model with an incremental congestion computation has been developed. Once the supercell placement is fixed, the problem of assigning 3D vias to accomplish minimal 2D routing densities and uniform 3D-via distribution is solved by an efficient min-cost-max-flow method. The proposed methods have been implemented and tested on a set of ISPD98 circuit benchmarks. Experimental results have shown that the proposed congestion-driven 3D supercell placement and flow-based 3D-via-assignment tools have yielded satisfactory placement with small-area, low-congestion, short-wire-length, few, and uniformly distributed 3D vias. Furthermore, an excellent correlation between routing-density estimation by our model and the actual routing performed by a commercial router has been observed. We have applied the proposed 3D design methodology, tools, and flows to tape out an over 4-million-gate low-density parity-check decoder in a three-tier 0.18- fully depleted silicon-on-insulator 3D CMOS process manufactured by MIT Lincoln Laboratory. The postlayout simulation of this DRC-clean layout design showed an about ten times improvement on the power-delay-area product compared to a 2D implementation in the same process.

Dynamics of hot-potato routing in IP networks

Despite the architectural separation between intradomain and interdomain routing in the Internet, intradomain protocols do influence the path-selection process in the Border Gateway Protocol (BGP). When choosing between multiple equally-good BGP routes, a router selects the one with the closest egress point, based on the intradomain path cost. Under such hot-potato routing, an intradomain event can trigger BGP routing changes. To characterize the influence of hot-potato routing, we conduct controlled experiments with a commercial router. Then, we propose a technique for associating BGP routing changes with events visible in the intradomain protocol, and apply our algorithm to AT&T's backbone network. We show that (i) hot-potato routing can be a significant source of BGP updates, (ii) BGP updates can lag 60 seconds or more behind the intradomain event, (iii) the number of BGP path changes triggered by hot-potato routing has a nearly uniform distribution across destination prefixes, and (iv) the fraction of BGP messages triggered by intradomain changes varies significantly across time and router locations. We show that hot-potato routing changes lead to longer delays in forwarding-plane convergence, shifts in the flow of traffic to neighboring domains, extra externally-visible BGP update messages, and inaccuracies in Internet performance measurements.

Performance analysis of an RSVP-capable router

RSVP is a bandwidth reservation protocol that allows distributed real-time applications such as videoconferencing software to make bandwidth reservations over packet-switched networks. Coupled with real-time scheduling mechanisms built into packet routers, the network guarantees to provide the reserved bandwidth throughout the lifetime of the applications. Although guaranteed services are of great value to both end users and carrier providers, their performance cost, due to additional control and data processing overhead, can potentially have a negative impact on the packet throughput and latency of RSVP-capable routers. The goal of this article is to examine the performance cost of RSVP based on measurements from an industrial-strength RSVP implementation on a commercial IP router. The focus is on the detailed evaluation of the performance implications of various architectural decisions in RSVP. We found that RSVP's control messages do not incur significant overhead in terms of processing delay and bandwidth consumption. However, the performance overhead of real-time packet scheduling is noticeable in the presence of a large number of real-time connections. In extreme cases, the performance guarantees of existing real-time connections may not be kept, and some best-effort packets are actually dropped, although the overall bandwidth requirement from these connections is smaller than the available link bandwidth.

VLSI/PCB placement with obstacles based on sequence pair

In a typical very large scale integration/printed circuit board (VLSI/PCB) design, some modules are preplaced in advance, and the other modules are requested to be placed without overlap with each other and with these preplaced modules. The presence of such obstacles introduces inconsistency to a coding scheme, called sequence pair, which has been proposed for an obstacle free placement problem. We solve this difficulty by proposing a procedure called which transforms an inconsistent sequence pair to a consistent one with the utmost consideration for minimizing the modification. It is shown that a simulated annealing is well organized so that it tests only feasible placements by the adaptation procedure. As a design example, a Microelectronics Center of North Carolina (MCNC) benchmark data ami49 is packed with treating ten modules among 49 modules as preplaced ones. Further, a PCB example which includes 32 free modules and four preplaced modules (connectors) is laid out successfully by our method with a conventional wiring estimation followed by a commercial router.

Bandwidth reservation on a commercial router

In this paper we present the development experience of implementing a protocol supporting Quality of Service guarantees. We believe that this work is of interest to researchers and engineers who are interested in real-life experience with such a protocol on a high-performance commercial router. The emphasis of this paper is the study of queueing algorithms intended to support QoS guarantees in a mixed traffic environment. We present practical results that demonstrate the feasibility as well as some limitations of the idea of mixing real-time traffic with traditional data traffic in a commercial router.

MCM routing algorithm based on a compatibility graph approach

A new algorithm for general area multichip module routing using a multi-candidate and compatibility graph approach, which maximises routing density while minimising vias and total wire length, is presented. Experimental results using standard industrial benchmarks show improved results relative to a commercial router and other previously proposed routers while offering flexibility for future incorporation of noise and delay constraints.