Deflection routing

Burst contention is a well-known challenging problem in Optical Burst Switching (OBS) networks. Deflection routing is used to resolve contention. Burst retransmission is used to reduce the Burst Loss Ratio (BLR) by retransmitting dropped bursts. Previous works show that combining deflection and retransmission outperforms both pure deflection and pure retransmission approaches. This paper proposes a new Adaptive Hybrid Deflection and Retransmission (AHDR) approach that dynamically combines deflection and retransmission approaches based on network conditions such as BLR and link utilization. Network Simulator 2 (ns-2) is used to simulate the proposed approach on different network topologies. Simulation results show that the proposed approach outperforms static approaches in terms of BLR by using an adaptive decision threshold.

Manhattan Street Networks (MSN) are bidimensional linear node sets arranged as the avenues and streets of Manhattan. Deflection routing is performed –either in the synchronous or in the asynchronous mode–by conveying incoming packets towards one of the two outputs. The simulation and analysis of all-optical MS networks is the central target of this paper. In order to avoid using complex

The scalability, modularity and massive parallelism exhibited by Network on chip(NoC) interconnects make them highly suitable for the inter core communication framework of multiprocessor system-on-chip (MPSoC) designs. Routers play the most vital role in transferring flits through the network, hence efficient microarchitecture and cost effective routing algorithms are highly essential for modern NoC routers. Elimination of buffers and deflection routing help to achieve energy and area efficiency of these routers. The advantages of bufferless and buffered designs can be combined by using a minimum number of side buffers to store a fraction of deflection flits in the router. In this paper, we propose a routing algorithm based on weighted deflection of flits for minimally buffered deflection routers. Evaluations on 4x4 and 8x8 mesh NoC using synthetic workloads as well as benchmark applications demonstrate that deflection rate and average network latency are significantly reduced in comparison with the state of the art NoC routers. Performance analysis of the newly proposed algorithm shows that the network saturation point improves by 26% compared to earlier designs in this domain.

Optical packet switching (OPS) is a promising technology to enable next-generation high-speed IP networks. A major issue in OPS is packet contention that occurs when two or more packets attempt to access the same output fiber. In such a case, packets may be dropped, leading to degraded overall switching performance. Several contention resolution techniques have been investigated in the literature including the use of fiber delay lines (FDLs), wavelength converters (WCs), and deflection routing. These solution typically induce extra complexity to the switch design. Accordingly, a key design objective for OPS is to reduce packet loss without increasing switching complexity and delay. In this paper, we investigate the performance of contention resolution in asynchronous OPS architectures with shared FDLs and WCs in terms of packet loss and average switching delay. In particular, an enhanced FDL-based and a novel Hybrid architecture with shared FLDs and WCs are proposed, and their packet scheduling algorithms are presented and evaluated. Extensive simulation studies show that the performance of proposed FDL-based architecture outperforms typical OPS architectures reported in the literature. In addition, it shown that, for the same packet loss ratio, the proposed hybrid architecture can achieve up to 30% reduction in the total number of ports and around 80% reduction in the overall length of fiber as compared to the FDL-based architectures.

Survivability is a critical network design issue for optical networks since even a single failure for a short duration may result in huge data loss due to the large capacity of optical fibers. However, few studies have been done on this issue for optical burst switching (OBS) networks. In this paper, we extend our early work on the fast restoration technique for OBS networks and present a novel fast restoration mechanism based on distributed deflection routing. Compared to other survivability schemes, the proposed mechanism has ...

Andrew Zalesky, Hai Le Vu, Moshe Zukerman ARC Special Research Centre for Ultra-Broadband Information Networks Dept. of Electrical and Electronic Eng. The University of Melbourne, Vic. 3010, Australia Email: {a.zalesky,h.vu,m.zukerman}@ee.mu.oz.au

Typically, bandwidth reservation is not made for data applications. Therefore, the only way to provide minimum bandwidth guarantees to such an application is by using a fairness mechanism to regulate the access to the network and by controlling the packet loss (i.e., congestion) inside the network. There are numerous works treating fairness in ring networks, however, there are almost no

Burst contention is a well-known challenging problem in Optical Burst Switching (OBS) networks. Deflection routing is used to resolve contention. Burst retransmission is used to reduce the Burst Loss Ratio (BLR) by retransmitting dropped bursts. Previous works show that combining deflection and retransmission outperforms both pure deflection and pure retransmission approaches. This paper proposes a new Adaptive Hybrid Deflection and Retransmission (AHDR) approach that dynamically combines deflection and retransmission approaches based on network conditions such as BLR and link utilization. Network Simulator 2 (ns-2) is used to simulate the proposed approach on different network topologies. Simulation results show that the proposed approach outperforms static approaches in terms of BLR by using an adaptive decision threshold.

In this paper, we propose a deflection routing scheme for throughput improvement to realize Gbps millimeter-wave wireless personal area network (mmWave WPAN) system. The upcoming mmWave WPAN system is designed to support transmission of uncompressed high definition TV (HDTV), high speed wireless downloading and docking etc. These data-rate-greedy applications require Gbps-order throughput which can be met by the capability of

Limited wavelength conversion and deflection routing are considered as viable methods to reduce the burst blocking probability in optical burst switched (OBS) networks. The question of which of the two methods is most effective has yet to be resolved. In this paper, an analytical model is derived that provides an accurate and quick means to evaluate and compare the effectiveness of limited wavelength conversion and deflection routing. First, an overflow load fixed point approximation model is derived for a single link in isolation. Then the single link model is integrated into a reduced load fixed point approximation model for a general network topology with deflection routing. The accuracy of the analytical model is verified through simulation.