Showing papers on "Routing (electronic design automation) published in 2006"

In VINI veritas: realistic and controlled network experimentation

Abstract: This paper describes VINI, a virtual network infrastructure that allows network researchers to evaluate their protocols and services in a realistic environment that also provides a high degree of control over network conditions. VINI allows researchers to deploy and evaluate their ideas with real routing software, traffic loads, and network events. To provide researchers flexibility in designing their experiments, VINI supports simultaneous experiments with arbitrary network topologies on a shared physical infrastructure. This paper tackles the following important design question: What set of concepts and techniques facilitate flexible, realistic, and controlled experimentation (e.g., multiple topologies and the ability to tweak routing algorithms) on a fixed physical infrastructure? We first present VINI's high-level design and the challenges of virtualizing a single network. We then present PL-VINI, an implementation of VINI on PlanetLab, running the "Internet In a Slice". Our evaluation of PL-VINI shows that it provides a realistic and controlled environment for evaluating new protocols and services.

Distributed algorithms for maximum lifetime routing in wireless sensor networks

Abstract: A sensor network of nodes with wireless transceiver capabilities and limited energy is considered. We propose distributed algorithms to compute an optimal routing scheme that maximizes the time at which the first node in the network drains out of energy. The problem is formulated as a linear programming problem and subgradient algorithms are used to solve it in a distributed manner. The resulting algorithms have low computational complexity and are guaranteed to converge to an optimal routing scheme that maximizes the network lifetime. The algorithms are illustrated by an example in which an optimal flow is computed for a network of randomly distributed nodes. We also show how our approach can be used to obtain distributed algorithms for many different extensions to the problem. Finally, we extend our problem formulation to more general definitions of network lifetime to model realistic scenarios in sensor networks

A Tabu Search Algorithm for a Routing and Container Loading Problem

Abstract: This article considers a combination of capacitated vehicle routing and three-dimensional loading, with additional constraints frequently encountered in freight transportation. It proposes a tabu search algorithm that iteratively invokes an inner tabu search procedure for the solution of the loading subproblem. The algorithm is experimentally evaluated both on instances adapted from vehicle routing instances from the literature and on new real-world instances.

A Tabu Search Algorithm for the Split Delivery Vehicle Routing Problem

Abstract: We describe a tabu search algorithm for the vehicle routing problem with split deliveries. At each iteration, a neighbor solution is obtained by removing a customer from a set of routes where it is currently visited and inserting it either into a new route or into an existing route that has enough residual capacity. The algorithm also considers the possibility of inserting a customer into a route without removing it from another route. The insertion of a customer into a route is done by means of the cheapest insertion method. Computational experiments are reported for a set of benchmark problems, and the results are compared with those obtained by the algorithm proposed by Dror and Trudeau.

Optimal routing policy problems in stochastic time-dependent networks

Abstract: We study optimal routing policy problems in stochastic time-dependent networks, where link travel times are modeled as random variables with time-dependent distributions. These are fundamental network optimization problems for a wide variety of applications, such as transportation and telecommunication systems. The routing problems studied can be viewed as counterparts of shortest path problems in deterministic networks. A routing policy is defined as a decision rule that specifies what node to take next at each decision node based on realized link travel times and the current time. We establish a framework for optimal routing policy problems in stochastic time-dependent networks, which we believe is the first in the literature. We give a comprehensive taxonomy and an in-depth discussion of variants of the problem. We then study in detail one variant that is particularly pertinent in traffic networks, where both link-wise and time-wise stochastic dependencies of link travel times are considered and online information is represented. We give an exact algorithm to this variant, analyze its complexity and point out the importance of finding good approximations to the exact solution. We then overview several approximations, and present a summary of a theoretical and computational analysis of their effectiveness against the exact algorithm.

Solving the capacitated location-routing problem by a GRASP complemented by a learning process and a path relinking

Abstract: As shown in recent researches, the costs in distribution systems may be excessive if routes are ignored when locating depots. The location routing problem (LRP) overcomes this drawback by simultaneously tackling location and routing decisions. This paper presents a new metaheuristic to solve the LRP with capacitated routes and depots. A first phase executes a GRASP, based on an extended and randomized version of Clarke and Wright algorithm. This phase is implemented with a learning process on the choice of depots. In a second phase, new solutions are generated by a post-optimization using a path relinking. The method is evaluated on sets of randomly generated instances, and compared to other heuristics and a lower bound. Solutions are obtained in a reasonable amount of time for such a strategic problem. Furthermore, the algorithm is competitive with a metaheuristic published for the case of uncapacitated depots.

Quality-Aware Routing Metrics for Time-Varying Wireless Mesh Networks

Abstract: This paper considers the problem of selecting good paths in a wireless mesh network. It is well-known that picking the path with the smallest number of hops between two nodes often leads to poor performance, because such paths tend to use links that could have marginal quality. As a result, quality-aware routing metrics are desired for networks that are built solely from wireless radios. Previous work has developed metrics (such as ETX) that work well when wireless channel conditions are relatively static (DeCouto , 2003), but typical wireless channels experience variations at many time-scales. For example, channels may have low average packet loss ratios, but with high variability, implying that metrics that use the mean loss ratio will perform poorly. In this paper, we describe two new metrics, called modified expected number of transmissions (mETX) and effective number of transmissions (ENT) that work well under a wide variety of channel conditions. In addition to analyzing and evaluating the performance of these metrics, we provide a unified geometric interpretation for wireless quality-aware routing metrics. Empirical observations of a real-world wireless mesh network suggest that mETX and ENT could achieve a 50% reduction in the average packet loss rate compared with ETX

Droplet Routing in the Synthesis of Digital Microfluidic Biochips

Abstract: Recent advances in microfluidics are expected to lead to sensor systems for high-throughput biochemical analysis. CAD tools are needed to handle increased design complexity for such systems. Analogous to classical VLSI synthesis, a top-down design automation approach can shorten the design cycle and reduce human effort. We focus here on the droplet routing problem, which is a key issue in biochip physical design automation. We develop the first systematic droplet routing method that can be integrated with biochip synthesis. The proposed approach minimizes the number of cells used for droplet routing, while satisfying constraints imposed by throughput considerations and fluidic properties. A real-life biochemical application is used to evaluate the proposed method.

On the integrated production, inventory and distribution routing problem

Abstract: The integrated Production, Inventory, and Distribution Routing Problem (PIDRP) is concerned with coordinating production, inventory, and delivery operations to meet customer demand with the objective of minimizing the cost. The PIDRP considered in this paper also involves heterogeneous transporters with noninstantaneous traveling times and multiple customer demand centers each with its own inventory capacity. Optimally solving such an integrated problem is in general difficult due to its combinatorial nature, especially when transporter routing is involved. We propose a two-phase solution approach to this problem. Phase I solves a mixed-integer program which includes all the constraints in the original model but with the transporter routings being restricted to direct shipments between facilities and customer demand centers. The resulting optimal solution to phase I is always feasible to the original model. Phase II solves an associated consolidation problem to handle the potential inefficiency of direct ...

Designing application-specific networks on chips with floorplan information

Abstract: With increasing communication demands of processor and memory cores in systems on chips (SoCs), scalable networks on chips (NoCs) are needed to interconnect the cores. For the use of NoCs to be feasible in today's industrial designs, a custom-tailored, application-specific NoC that satisfies the design objectives and constraints of the targeted application domain is required. In this work, we present a design methodology that automates the synthesis of such application-specific NoC architectures. We present a floorplan aware design method that considers the wiring complexity of the NoC during the topology synthesis process. This leads to detecting timing violations on the NoC links early in the design cycle and to have accurate power estimations of the interconnect. We incorporate mechanisms to prevent deadlocks during routing, which is critical for proper operation of NoCs. We integrate the NoC synthesis method with an existing design flow, automating NoC synthesis, generation, simulation and physical design processes. We also present ways to ensure design convergence across the levels. Experiments on several SoC benchmarks are presented, which show that the synthesized topologies provide a large reduction in network power consumption (2.78 times on average) and improvement in performance (1.59 times on average) over the best mesh and mesh-based custom topologies. An actual layout of a multimedia SoC with the NoC designed using our methodology is presented, which shows that the designed NoC supports the required frequency of operation (close to 900 MHz) without any timing violations. We could design the NoC from input specifications to layout in 4 hours, a process that usually takes several weeks

Splitting interfaces: making trust between applications and operating systems configurable

Abstract: In current commodity systems, applications have no way of limiting their trust in the underlying operating system (OS), leaving them at the complete mercy of an attacker who gains control over the OS. In this work, we describe the design and implementation of Proxos, a system that allows applications to configure their trust in the OS by partitioning the system call interface into trusted and untrusted components. System call routing rules that indicate which system calls are to be handled by the un-trusted commodity OS, and which are to be handled by a trusted private OS, are specified by the application developer. We find that rather than defining a new system call interface, routing system calls of an existing interface allows applications currently targeted towards commodity operating systems to isolate their most sensitive components from the commodity OS with only minor source code modifications.We have built a prototype of our system on top of the Xen Virtual Machine Monitor with Linux as the commodity OS. In practice, we find that the system call routing rules are short and simple -- on the order of 10's of lines of code. In addition, applications in Proxos incur only modest performance overhead, with most of the cost resulting from inter-VM context switches.

Integrating local static and dynamic information for routing traffic

Abstract: The efficiency of traffic routing on complex networks can be reflected by two key measurements, i.e., the network capacity and the average travel time of data packets. In this paper we propose a mixing routing strategy by integrating local static and dynamic information for enhancing the efficiency of traffic on scale-free networks. The strategy is governed by a single parameter. Simulation results show that maximizing the network capacity and reducing the packet travel time can generate an optimal parameter value. Compared with the strategy of adopting exclusive local static information, the new strategy shows its advantages in improving the efficiency of the system. The detailed analysis of the mixing strategy is provided for explaining its effects on traffic routing. The work indicates that effectively utilizing the larger degree nodes plays a key role in scale-free traffic systems.

Design and evaluation of basic standard encryption algorithm modules using nanosized complementary metal–oxide–semiconductor–molecular circuits

Abstract: We are proposing that the recently proposed semiconductor–nanowire–molecular architecture (CMOL) is an optimum platform to realize encryption algorithms. The basic modules for the advanced encryption standard algorithm (Rijndael) have been designed using CMOL architecture. The performance of this design has been evaluated with respect to chip area and speed. It is observed that CMOL provides considerable improvement over implementation with regular CMOS architecture even with a 20% defect rate. Pseudo-optimum gate placement and routing are provided for Rijndael building blocks and the possibility of designing high speed, attack tolerant and long key encryptions are discussed.

Sip routing customization

Abstract: Systems, methods, and machine-readable media are disclosed for providing customization to routing of messages in a system where routing is based on stored addresses, such as, for example, a Session Initiation Protocol (SIP) system. In one embodiment, a method of providing customized routing of messages can comprise receiving a message to a target endpoint at a system for signaling between endpoints. The system can have one or more stored addresses (Target SIP URIs) for each of a plurality of endpoints. One or more target Sip URIs for the target endpoint can be determined from the stored target SIP URIs. One or more policies can be applied to the one or more target SIP URIs for the target endpoint. The one or more policies can comprise a set of one or more conditions and one or more actions associated with each condition.

Solving a Dynamic and Stochastic Vehicle Routing Problem with a Sample Scenario Hedging Heuristic

Abstract: The statement of the standard vehicle routing problem cannot always capture all aspects of real-world applications. As a result, extensions or modifications to the model are warranted. Here we consider the case when customers can call in orders during the daily operations; i.e., both customer locations and demands may be unknown in advance. This is modeled as a combined dynamic and stochastic programming problem, and a heuristic solution method is developed where sample scenarios are generated, solved heuristically, and combined iteratively to form a solution to the overall problem.

Via-Configurable Routing Architectures and Fast Design Mappability Estimation for Regular Fabrics

Abstract: In this paper, we describe a new via-configurable routing architecture which shows a much better throughput and performance than the previous structures. We demonstrate how to construct a single-via-mask fabric to reduce the mask cost further, and we analyze the penalties which it incurs. To solve the routability problem commonly existing in fabric-based designs, an efficient white-space allocation and an incremental cell movement scheme are suggested, which help to provide a fast design convergence and early prediction of circuit's mappability to a given fabric

Placement of thermal vias in 3-D ICs using various thermal objectives

Abstract: As thermal problems become more evident, new physical design paradigms and tools are needed to alleviate them. Incorporating thermal vias into integrated circuits (ICs) is a promising way of mitigating thermal issues by lowering the effective-thermal resistance of the chip. However, thermal vias take up valuable routing space, and therefore, algorithms are needed to minimize their usage while placing them in areas where they would make the greatest impact. With the developing technology of three-dimensional integrated circuits (3-D ICs), thermal problems are expected to be more prominent, and thermal vias can have a larger impact on them than in traditional two-dimensional integrated circuits (2-D ICs). In this paper, thermal vias are assigned to specific areas of a 3-D IC and used to adjust their effective-thermal conductivities. The method, which uses finite-element analysis (FEA) to calculate temperatures quickly during each iteration, makes iterative adjustments to these thermal conductivities in order to achieve a desired thermal objective and is general enough to handle a number of different thermal objectives such as achieving a desired maximum operating temperature. With this method, 49% fewer thermal vias are needed to obtain a 47% reduction in the maximum temperatures, and 57% fewer thermal vias are needed to obtain a 68% reduction in the maximum thermal gradients than would be needed using a uniform distribution of thermal vias to obtain these same thermal improvements. Similar results were seen for other thermal objectives, and the method efficiently achieves its thermal objective while minimizing the thermal-via utilization.

Three-phase dual-rail pre-charge logic

Abstract: This paper investigates the design of a dual-rail pre-charge logic family whose power consumption is insensitive to unbalanced load conditions thus allowing adopting a semi-custom design flow (automatic place & route) without any constraint on the routing of the complementary wires. The proposed logic is based on a three phase operation where, in order to obtain a constant energy consumption over the operating cycle, an additional discharge phase is performed after pre-charge and evaluation. In this work, the proposed concept has been implemented as an enhancement of the SABL logic with a limited increase in circuit complexity. Implementation details and simulation results are reported which show a power consumption independent of the sequence of processed data and load capacitances. An improvement in the energy consumption balancing up to 100 times with respect to SABL has been obtained.

Dynamic Column Generation for Dynamic Vehicle Routing with Time Windows

Abstract: We consider a dynamic vehicle routing problem with hard time windows, in which a set of customer orders arrives randomly over time to be picked up within their time windows. The dispatcher does not have any deterministic or probabilistic information on the location and size of a customer order until it arrives. The objective is to minimize the sum of the total distance of the routes used to cover all the orders. We propose a column-generation-based dynamic approach for the problem. The approach generates single-vehicle trips (i.e., columns) over time in a real-time fashion by utilizing existing columns, and solves at each decision epoch a set-partitioning-type formulation of the static problem consisting of the columns generated up to this time point. We evaluate the performance of our approach by comparing it to an insertion-based heuristic and an approach similar to ours, but without computational time limit for handling the static problem at each decision epoch. Computational results on various test problems generalized from a set of static benchmark problems in the literature show that our approach outperforms the insertion-based heuristic on most test problems.

Apparatus for a routing system

Abstract: The invention details methods and apparatus for a routing system or router that includes a model. The model can be in many different forms including but not limited to: resolution enhancement technologies such as OPC; lithography model including but not limited to aerial image; pattern-dependent functions; functions for timing/signal integrity/power; manufacturing process variations; and measured silicon data. In one embodiment, the model can be described as input to the system and the model calculator can interact either with the data structure or the query engine of the detail router or both. The model calculator can accept input as a set of geometry description and produce output to guide the query functions. An example technique called set intersection is disclosed herein to combine multiple models in the system. A preferred embodiment of this invention includes a full chip grid-based router being aware of manufacturability.

Rbridges: Base Protocol Specification

Abstract: RBridges provide the ability to have an entire campus, with multiple physical links, look to IP like a single subnet. The design allows for zero configuration of switches within a campus, optimal pair-wise routing, safe forwarding even during periods of temporary loops, and the ability to cut down on ARP/ND traffic. The design also supports VLANs, and allows forwarding tables to be based on RBridge destinations (rather than endnode destinations), which allows internal routing tables to be substantially smaller than in conventional bridge systems.

Content driven process routing for integrated enterprise applications

Abstract: In one embodiment, an application integration system receives business application information and generates certain business flow and state information for the application, users based on the shared business content within the system. The content driven routing process facilitates the routing of application processes and user communication on the basis of the business content. The content-based routing process establishes integration connections on demand among users and or applications based on the business content utilized by their respective applications. Content data is encapsulated within a content table that consists of a number of tags that describe various parameters related to the content, such as user profiles, application that use the content, and data types within the content, so that it can be properly routed within the hub and processed by the integrated applications. The routing process of the collaboration hub routes the content or task to the appropriate user in the system and provides the hooks to invoke the appropriate application or otherwise process the content.

Traffic routing based on segment travel time

Abstract: A system for identifying a fastest possible travel route is disclosed. A traveler data processor collects traffic speed data and associates the traffic speed data with road segments. The road segments collectively represent one or more possible travel routes from a start point to an end point. A forecast engine determines a predicted travel time for each of the road segments based on, for example, the traffic speed data for each of the road segments. A routing engine determines the fastest possible travel route from the start point to the end point. The fastest possible travel route is the possible travel route from the one or more possible travel routes with the shortest predicted travel time.

FastRoute: a step to integrate global routing into placement

Abstract: Because of the increasing dominance of interconnect issues in advanced IC technology, placement has become a critical step in the IC design flow. To get accurate interconnect information during the placement process, it is desirable to incorporate global routing into it. However, previous global routers are computationally expensive. It is impractical to perform global routing repeatedly during placement. In this paper, we present an extremely fast and high-quality global router called FastRoute. In traditional global routing approaches, congestion is not considered during Steiner tree construction. So they have to rely on the time-consuming maze routing technique to eliminate routing congestion. Different from traditional approaches, we proposed a congestion-driven Steiner tree topology generation technique and an edge shifting technique to determine the good Steiner tree topologies and Steiner node positions. Based on the congestion-driven Steiner trees, we only need to apply maze routing to a small percentage of the two-pin nets once to obtain high quality global routing solutions. We also proposed a new cost function based on logistic function to direct the maze routing. Experimental results show that FastRoute generates less congested solutions in 132times and 64times faster runtimes than the state-of-the-art academic global routers Labyrinth (R. Kastner et al, 2000) and Chi Dispersion router (R. T. Hadsell and P. H. Madden, 2003), respectively. It is even faster than the highly-efficient congestion estimator FaDGloR (J. Westra and P. Groeneveld, 2005). The promising results make it possible to incorporate global routing directly into placement process without much runtime penalty. This could dramatically improve the placement solution quality. We believe this work will fundamentally change the way the EDA community look at and make use of global routing in the whole design flow

Cable management system

Abstract: A cable management system for routing cable with respect to electronic equipment. This system has a variety of improvements providing greater flexibility in routing cable to and from the equipment.

AES-Based Security Coprocessor IC in 0.18- $muhbox m$ CMOS With Resistance to Differential Power Analysis Side-Channel Attacks

Abstract: Security ICs are vulnerable to side-channel attacks (SCAs) that find the secret key by monitoring the power consumption or other information that is leaked by the switching behavior of digital CMOS gates. This paper describes a side-channel attack resistant coprocessor IC fabricated in 0.18- $muhbox m$ CMOS consisting of an Advanced Encryption Standard (AES) based cryptographic engine, a fingerprint-matching engine, template storage, and an interface unit. Two functionally identical coprocessors have been fabricated on the same die. The first coprocessor was implemented using standard cells and regular routing techniques. The second coprocessor was implemented using a logic style called wave dynamic differential logic (WDDL) and a layout technique called differential routing to combat the differential power analysis (DPA) side-channel attack. Measurement-based experimental results show that a DPA attack on the insecure coprocessor requires only 8000 encryptions to disclose the entire 128-bit secret key. The same attack on the secure coprocessor does not disclose the entire secret key even after 1 500 000 encryptions.

Methods, systems, and computer program products for extensible, profile-and context-based information correlation, routing and distribution

Abstract: Methods, systems, and computer program products for extensible, profile- and context-based information correlation, routing, and distribution are disclosed. According to one system, source plug-ins receive output from a plurality of different sensors. A content manager merges data from individual sensors together with metadata that is representative of a context and aggregates the sensor data and the context metadata into knowledge items. A scenario engine achieves sensor fusion by comparing the sensor data and its context metadata against a defined set of policies and/or rules and provides for performance of an action when a rule or policy is satisfied.