Mesh routing topologies for multi-FPGA systems

There is currently great interest in using fixed arrays of FPGAs for logic emulators, custom computing devices, and software accelerators. An important part of designing such a system is determining the proper routing topology to use to interconnect the FPGAs. This topology can have a great effect on the area and delay of the resulting system. Crossbar, Hierarchical Crossbar, and Mesh interconnection schemes have all been proposed for use in FPGA-based systems. In this paper, we examine Mesh interconnection schemes, and propose several constructs for more efficient topologies. These reduce interchip delays by more than 60% over the basic four-way Mesh     

Multiterminal net routing for partial crossbar-based multi-FPGA systems

Multi-FPGA (field-programmable gate arrays) systems are used as custom computing machines to solve compute-intensive problems and also in the verification and prototyping of large circuits. In this paper, we address the problem of routing multiterminal nets in a multi-FPGA system that uses partial crossbars as interconnect structures. First, we model the multiterminal routing problem as a partitioned bin-packing problem and formulate it as an integer linear programming problem where the number of variables is exponential. A fast heuristic is applied to compute an upper bound on the routing solution. Then, a column generation technique is used to solve the linear relaxation of the initial master problem in order to obtain a lower bound on the routing solution. This is followed by an iterative branch-and-price procedure that attempts to find a routing solution somewhere between the two established bounds. In this regard, the proposed algorithm guarantees an exact-routing solution by searching a branch-and-price tree. Due to the tightness of the bounds, the branch-and-price tree is small resulting in shorter execution times. Experimental results are provided for different netlists and board configurations in order to demonstrate the algorithms performance. The obtained results show that the algorithm finds an exact routing solution in a very short time.     

A novel four-tier software-defined network architecture for scalable secure routing and load balancing

Software-defined networking is an emerging paradigm for supporting flexible network management. In the traditional architecture for a software-defined network (SDN), the controller commonly uses a general routing algorithm such as Open Shortest Path First (OSPF), which chooses the shortest path for communication. This may cause the largest amount of network traffic, especially in large-scale environments. In this paper, we present the design for a novel SDN-based four-tier architecture for scalable secure routing and load balancing. In Tier 1, user authentication is conducted using elliptic curve cryptography (ECC); this avoids unnecessary loads from unauthorized users. In Tier 2, packet classification is performed based on the packet characteristics using the fuzzy analytical hierarchy process (fuzzy AHP), and packets are placed into three individual queues. In Tier 3, scalable secure routing is achieved by selecting the optimal path using the improved particle swarm optimization and ant colony optimization algorithms. With these optimization algorithms, we can adaptively change the number of users, the number of switches, and other parameters. In Tier 4, the recommended secure cluster (multicontroller) management is accomplished using an algorithm that employs modified k-means clustering and a recurrent neural network. Deep reinforcement learning (DRL) is also proposed for updating the controller information. Experimental results are analyzed using the OMNeT++ network simulator, and the evaluated performance displayed improvement over a variety of existing methods in terms of response time (50% to 60%), load (55%), execution time (3.2%), throughput (9.8%), packet loss rate (1.02%), end-to-end delay (50%), and bandwidth consumption (45%).     

A novel self-pilot-based transmit-receive architecture for multipath-impaired UWB systems

In the last few years, ultra-wideband (UWB) systems became an appealing technology for wireless communication applications. Unfortunately, when the transmission channel is affected by intersymbol interference (ISI), system performance of UWB systems equipped with receivers based on conventional matched filters presents error-floor phenomena. Aimed by these considerations, in this letter, we present a novel transmit-receive scheme allowing blind channel estimation and minimum mean-square error linear channel equalization. Essentially, the proposed scheme exploits a very short duration of the UWB pulse for achieving reliable blind deconvolution of the received signal. A nice feature of the resulting system is that blind deconvolution of the received signal is achieved without power and throughput losses. Simulation results support the effectiveness of the proposed scheme, and show that it is able to gain about 8 dB over current UWB receivers based on matched filtering on several test channels impaired by ISI.     

Research of novel complex optical network routing architecture

This article puts forward a novel routing architecture for complex optical network,which core component is path calculation element(PCE).As is well known,the PCE-based distributed path computation structure is making the routing control and computation loosely coupled from traditional control plane.In the study,the resource allocation and routing algorithm are the critical part of PCE hierarchy.To compare the performance of new architecture and the traditional one,the user uses the flooding suppression,routing delay,resource utilization and traffic blocking probability as performance simulation parameters and taking the verification simulation on objective modular network testbed(OMNeT)platform against to source-node routing architecture.The numerical analysis,computer simulation and experiment work indicate that the operation of PCE-based routing architecture can reduce the flooding information of path calculation request as well as the routing hops significantly and improve the quality of service(QoS)by decreasing the blocking probability when failure happened.     

Multicast-based mobility: a novel architecture for efficient micromobility

Handover performance is very important when evaluating IP mobility protocols. If not performed efficiently, handover delays, jitters, and packet loss directly impact application performance. We propose a new architecture for providing efficient handover, while being able to coexist with other protocols. We propose a paradigm for multicast-based micromobility (M&M), where a visiting mobile is assigned a multicast address to use while moving within a domain. The multicast address is obtained using algorithmic mapping, and handover is achieved using multicast join/prune mechanisms. This paper outlines a framework for the design and evaluation of micromobility protocols. We define a suite of protocols (called candidate access router set) to enable multiple-access routers to receive traffic for the mobile node. By changing the number of such routers, timing, and buffering parameters, the protocol may be fine-tuned for specific technologies (e.g., 802.11) and handover scenarios. Extensive NS-2 simulations are used to compare M&M with other micromobility schemes-cellular Internet protocol (CIP) and handoff-aware wireless access Internet infrastructure (HAWAII). For proactive handover scenarios, our results show that M&M and CIP show lower handover delay and packet reordering than HAWAII. M&M, however, handles multiple border routers in a domain, where CIP fails. Also, for scenarios of reactive handover and coverage gaps M&M clearly outperforms CIP and HAWAII.     

A novel efficient multicast routing algorithm in sparse splitting optical networks

The advances in wavelength-division multiplexing (WDM) technology are expected to facilitate bandwidth-intensive multicast applications through light splitting. Due to complexity and cost constraints, light splitting (or optical multicast) nodes are sparsely configured in a practical WDM network. In this article, we investigate the multicast routing problem under the sparse light-splitting constraint. An efficient sparse splitting constrained multicast routing algorithm called Multicast Capable Node First Heuristic (MCNFH) is proposed. The key idea of MCNFH is to include the shortest path, that includes most of the multicast capable nodes, for configuring the multicast tree. Simulations and comparisons are used to demonstrate the performance of MCNFH. Simulation results and analysis show that MCNFH builds multicast trees with the least wavelength channel cost and with the smallest number of wavelengths used per link. In addition, MCNFH requires only one transmitter at the source node.     

A routing architecture for mobile integrated services networks

A drawback of the conventional Internet routing architecture is that its route computation and packet forwarding mechanisms are poorly integrated with congestion control mechanisms. Any datagram offered to the network is accepted; routers forward packets on a best-effort basis and react to congestion only after the network resources have already been wasted. A number of proposals improve on this to support multimedia applications; a promising example is the Integrated Services Packet Network (ISPN) architecture. However, these proposals are oriented to networks with fairly static topologies and rely on the same conventional Internet routing protocols to operate. This paper presents a routing architecture for mobile integrated services networks in which network nodes (routers) can move constantly while providing end-to-end performance guarantees. In the proposed connectionless routing architecture, packets are individually routed towards their destinations on a hop by hop basis. A packet intended for a given destination is allowed to enter the network if and only if there is at least one path of routers with enough resources to ensure its delivery within a finite time. Once a packet is accepted into the network, it is delivered to its destination, unless resource failures prevent it. Each router reserves resources for each active destination, rather than for each source–destination session, and forwards a received packet along one of multiple loop-free paths towards the destination. The resources and available paths for each destination are updated to adapt to congestion and topology changes. This mechanism could be extended to aggregate dissimilar flows as well. This revised version was published online in June 2006 with corrections to the Cover Date.     

A novel networking architecture for mobile content delivery in urban transport systems

Today, the media content delivery in intermittent connected networks has become increasingly critical. This paper studies content exchange among mobile commuters in urban transport systems. Our work is inspired by two facts: (1) the commuters in urban transport systems tend to take regular routes to the same place every weekday and their paths exhibit a high degree of temporal and spatial regularities; (2) the rapid development of broadband wireless technologies such as IEEE 802.11n makes fast data transfer possible. We first propose a new disconnection-tolerant network infrastructure, which reinforces the connectivity of intermittent connected mobile commuters and uses store-and-forward routers to increase their encounter opportunity, and in turn achieves efficient media content delivery among them. Then a router-centric prediction method is designed to collect passengers’ historical path information to determine the best delivery scheme. We evaluate the feasibility and the performance of the proposed infrastructure as well as the delivery scheme, using real data set from an urban transport system. The simulation results demonstrate the proposed system is highly practical in terms of the memory usage of routers and the maximum achievable data transfer rate.     

A novel architecture of optical code label processing in parallel designed for all optical routing system

A novel architecture of optical code label routing is designed based on optical code division multiplexing techniques, which performs the data packet forwarding and processing in parallel with a way of making the label and payload encoded and decoded separately. It uses optical polarity characteristics to realize the separation of the label and payload, employs fiber Bragg grating to encode/decode the label and payload so as to process them in parallel, and makes the forwarding and routing process realized in the optical domain. In the core router, the separation of the label and payload guarantees that the switch processing only includes the short label code recognition, without processing the payload. The payload recognition is carried out in the edge router. Thus, the router can simplify the processing of encoding and decoding in the core router, accelerating the switching, and increase the throughput greatly. Moreover, the novel routing scheme not only supports the varying of data packets, transparent transmission, fine granularity switching, and so on, but also is suitable for the aggregation of data service. It is attractive for the future development of all optical routing.     

A highly efficient residue-combinatorial architecture for digital filters

A hybrid digital filter structure is presented that combines a combinatorial multiplication technique with a residue number architecture. The hybrid technique eliminates general multiplication and results in a parallel structure inherent in the residue number system. Results indicate that better speed/cost ratios can be obtained with the hybrid architecture than with either structure alone for applications in which high performance is a predominant factor.     

A communication architecture for spontaneous systems

In this article a communication architecture concept for spontaneous systems is provided. The concept integrates application-level spontaneous group communication and ad hoc networking together. A service gateway is applied as a key architecture element to connect multiple technologies and networks together. A set of methods to enable plug and play, addressing and mobility, peer-to-peer connectivity, and use of services is provided. Finally, the provided methods are discussed based on the realized research experiments.     

A simple and efficient routing protocol for the UMTSA Access network

This paper presents a simple network layer protocol that integrates routing and connectionless transfer of data in a wireless environment. The protocol is specifically geared towards supporting transfer of signalling in mobile networks based on a rooted tree topology. Exploiting the special characteristics of such a topology allows the specification of a very simple and processing efficient routing function. Using the routing function, a connectionless message transport service is implemented. The connectionless transport service is comparable to that of typical network layer protocols of existing data networks. The protocol has originally been specified to carry signalling messages in the control plane of mobile, cellular systems but has the potential to be used also in other environments.     

A novel optimization algorithm for video placement and routing

In this paper, we propose a novel optimization algorithm for the solution of the video placement and routing problem based on Lagrangean relaxation,and decomposition. The main contribution can be stated as the use of integer programming models to obtain feasible solutions to the problem within the algorithm. Computational experimentation reveals that the use of such integer models help greatly in obtaining good quality solutions in a small amount of solution time.     

面向数据的因特网路由架构

提出了一种支持节点移动,数据复制和迁移的面向数据的因特网路由架构。它可直接在节点和数据的平面空间名称上路由,无需IP地址和像DNS这样的名称解析服务器,它把数据和服务看作是和终端同样重要的网络对象,同时在逻辑上把终端看作是数据和服务的集合,用简单的路由机制为未来因特网提供了一种可扩展的安全框架。     

Intelligent energy-aware efficient routing for MANET

Designing an energy efficient routing protocol is one of the main issue of Mobile Ad-hoc Networks (MANETs). It is challenging task to provide energy efficient routes because MANET is dynamic and mobile nodes are fitted with limited capacity of batteries. The high mobility of nodes results in quick changes in the routes, thus requiring some mechanism for determining efficient routes. In this paper, an Intelligent Energy-aware Efficient Routing protocol for MANET (IE2R) is proposed. In IE2R, Multi Criteria Decision Making (MCDM) technique is used based on entropy and Preference Ranking Organization METHod for Enrichment of Evaluations-II (PROMETHEE-II) method to determine efficient route. MCDM technique combines with an intelligent method, namely, Intuitionistic Fuzzy Soft Set (IFSS) which reduces uncertainty related to the mobile node and offers energy efficient route. The proposed protocol is simulated using the NS-2 simulator. The performance of the proposed protocol is compared with the existing routing protocols, and the results obtained outperforms existing protocols in terms of several network metrics.     

The PIM architecture for wide-area multicast routing

The purpose of multicast routing is to reduce the communication costs for applications that send the same data to multiple recipients. Existing multicast routing mechanisms were intended for use within regions where a group is widely represented or bandwidth is universally plentiful. When group members, and senders to those group members, are distributed sparsely across a wide area, these schemes are not efficient; data packets or membership report information are occasionally sent over many links that do not lead to receivers or senders, respectively. We have developed a multicast routing architecture that efficiently establishes distribution trees across wide area internets, where many groups will be sparsely represented. Efficiency is measured in terms of the router state, control message processing, and data packet processing, required across the entire network in order to deliver data packets to the members of the group. Our protocol independent multicast (PIM) architecture: (a) maintains the traditional IP multicast service model of receiver-initiated membership, (b) supports both shared and source-specific (shortest-path) distribution trees, (c) is not dependent on a specific unicast routing protocol, and (d) uses soft-state mechanisms to adapt to underlying network conditions and group dynamics. The robustness, flexibility, and scaling properties of this architecture make it well-suited to large heterogeneous internetworks     

QoS routing across multiple autonomous systems using the path computation element architecture

We examine various algorithms for calculating quality of service (QoS)-enabled paths spanning multiple autonomous systems (ASs) using the path computation element (PCE) architecture. The problem is divided into two parts. We first calculate an AS path, then the node-by-node path. Using extensive simulation, we compared various AS-path calculation algorithms based on border gateway protocol (BGP) and various AS-aggregation procedures, such as mesh, star and nodal aggregation. For node-to-node path calculation, we employed the per-domain backward algorithm and the per-domain backward tree algorithm (also known as backward recursive PCE-based computation). Results point to the fact that complex AS-path calculation algorithms do not perform significantly better than BGP. However, if the service quality provided by ASs varies greatly, either in time or space, then we expect a QoS-aware AS-path computation algorithm, e.g., static nodal aggregation, to outperform BGP. Although the per-domain backward tree algorithm generally performs better than the per-domain backward algorithm, using a persistent variant of the latter makes it outperform the per-domain backward tree algorithm. The cost is a negligible increase in computational complexity and a slightly increased connection setup delay.     

A novel switching architecture for ATM networks

It is known that the flexibility and capacity of asynchronous transfer mode (ATM) networks can meet the bandwidth requirements of multimedia applications. In ATM networks, switching is one of the major bottlenecks of end-to-end communication. We propose using a multiple partitionable circular bus network (MPCBN) as an ATM switch. Connection requests are first transformed into a graph where vertices and edges represent connection requests and conflicts among connection requests, respectively. We then use a graph traversal algorithm to select a maximal set of requests for execution in physically partitioned buses. An approach of using finite projective planes is then used to reduce the number of switch points from O(N²) to O(N √N), where N is the number of ports of a switch. A performance evaluation for both uniform and bursty data sources shows that the approach of using finite projective planes to reduce the number of switch points results in a small increase of cell loss probability