Oblivious routing on geometric networks

In this paper, we introduce a novel oblivious routing scheme based on valiant load-balancing for the model of polyhedral uncertainty (i.e., hose model), and the scheme is implemented with traffic-grooming approach in WDM mesh networks. Considering that a high-speed connection request in optical networks is difficult to be divided into low-speed connections, we propose the method of hose-model separation to support the multi-granularity connections for valiant load-balanced oblivious routing in WDM mesh networks. Our Objective is to minimize total network cost. Two fast heuristic algorithms-MPCF and MRUF are proposed. Simulation results show MRUF performs better than MPCF

In this paper we consider the routing and wavelength assignment problem in a wavelength routed all optical network. Inspired by techniques from artificial intelligence, in particular the Blocking Island (BI) abstraction, we propose a simple and intelligent routing and wavelength assignment (RWA) algorithm: BI_RWA. This algorithm can be used in arbitrarily connected optical networks. In addition, it is general enough such that with some simple modifications, it can be applied to different optical networking scenarios: static or dynamic traffic, single or multiple fiber links between node pairs, with or without wavelength converters. We have conducted simulation experiments to evaluate the performance of our algorithm. The simulation is carried out in two parts: static traffic and dynamic traffic. The results will demonstrate that our RWA algorithm outperforms state-of-the-art related algorithms.

Data networking now plays a major role in everyday life and new applications continue to appear at a blinding pace. Yet we still do not have a sound foundation for designing, evaluating and managing these networks. This book covers topics at the intersection of algorithms and networking. It builds a complete picture of the current state of research on Next Generation Networks and the challenges for the years ahead. Particular focus is given to evolving research initiatives and the architecture they propose and implications for networking. Topics: Network design and provisioning, hardware issues, layer-3 algorithms and MPLS, BGP and Inter AS routing, packet processing for routing, security and network management, load balancing, oblivious routing and stochastic algorithms, network coding for multicast, overlay routing for P2P networking and content delivery. This timely volume will be of interest to a broad readership from graduate students to researchers looking to survey recent research its open questions.

Oblivious routing algorithms use only locally avail¬able information at network nodes to forward traffic, and as such, a plausible choice for distributed implementations. It is a natural desire to quantify the performance penalty we pay for this distributedness. Recently, Racke has shown that for general undirected graphs the competitive ratio is only O(log n), that is, the maximum congestion caused by the oblivious algorithm is within a logarithmic factor of the best possible congestion. And while the performance penalty is larger for directed networks (Azar gives a O(vn) lower bound), experiments on many real-world topologies show that it usually remains under 2. These competitive measures, however, are of worst-case type, and therefore do not always give adequate characterization. The more different combinations of demands a routing algorithm can accommodate in the network without congestion, the better. Driven by this observation, in this paper we introduce a new competitive measure, the volumetric competitive ratio, as the measure of all admissible demands compared to the measure of demands routed without congestion. The main result of the paper is a general lower bound on the volumetric ratio; and we also show a directed graph with O(1) competitive ratio that exhibits O(n) volumetric ratio. Our numerical evaluations show that the competitivity of oblivious routing in terms of the new measure quickly vanishes even in relatively small common-place topologies.

Two new algorithms for worm-hole routing in the hypercube are presented. The first hypercube algorithm is adaptive, but non-minimal in the sense that some derouting is permitted. Then another deadlock-free adaptive worm-hole based routing algorithm for the hypercube interconnection is presented which is minimal. Finally some well-known worm-hole algorithms for the hypercube were evaluated together with the new ones on a hypercube of 2/sup 10/ nodes. One oblivious algorithm, the Dimension-Order, or E-Cube routing algorithm (W. Dally, C. Seitz, 1987) was tried. In addition, three partially adaptive algorithms were considered: the Hanging algorithm (Y. Birk, P. Gibbons, D. Soroker, J. Sanz, 1989 and S. Konstantinidou, 1990), the Zenith algorithm (S. Konstantinidou, 1990), and the Hanging-Order algorithm (G.-M. Chia, S. Chalasani, C.S. Raghavendra, 1991). Finally, a fully adaptive minimal algorithm presented independently by L. Gravano, G. Pifarre, S.A. Felperin and J. Sanz (1991) and J. Duato was tried. This algorithm allows each message to choose adaptively among all the shortest paths from its source to its destination. Only four virtual channels per physical link are needed to achieve this. This technique is referred to as Fully. The results obtained show that the two new algorithms are good candidates as a choice for worm-hole routing in the hypercube network.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Popularity of Mobile Wireless Sensor Network (MWSN) has increased tremendously due to the ability to connect the physical world with the virtual world. In MWSN, Sensor nodes move freely in a target area without the need of any special infrastructure. MWSN has attracted many researchers as it has introduced unique challenges in aspects like resource management, coverage, routing protocols, security in many applications such as target tracking in military applications, detection of catastrophic events, environment monitoring, health applications etc. Due to mobility, routing process in MWSN has become more complicated as connections in the network can change dynamically. This paper proposes a Mobility-Aware Multi-Objective Hybrid Routing Algorithm (MMOHRA) for Wireless Sensor Network (WSN). MMOHRA selects the best route and forwards the data packets from source to sink using multiple metrics such as Average Energy consumption, Control Overhead, Reaction Time, LQI, and HOP Count. Performance of MMOHRA is compared with Simple Hybrid Routing Protocol (SHRP) and Dynamic Multi-objective Routing Algorithm (DyMORA) using metrics such as Average Energy Consumption, Packet Delivery Ratio, and Jitter. MMOHRA improves the Average Energy Consumption (AEC) by a factor of 14.1% as compared with SHRP and 8.13 % as compared to DyMORA. MMOHRA outperformed SHRP and DyMORA in terms of packet Delivery Ratio (PDR) by 10.17 % and 9.83 % respectively.

Routing is critical for WSNs due to the nature of multi-hop message delivery and the restricted power supply and computation capacity. Routing mechanisms with efficient power utilization and low computation complexity are of fundamental importance to meet the future application demand of WSNs. In this paper, a novel location-based routing technique, the Artificial Potential Field based Routing (APFR), is proposed. APFR establishes an Artificial Potential Field (APF) for the tagged sensor node and then uses a greedy selection algorithm to determine the next hop based on the direction obtained from the APF. In addition, a backup scheme is presented to recover the route in the case of routing voids. The advantages of APFR are three-fold. First, the routing tends to point to the areas with high node density, so the transmission load is balanced among the sensor nodes. Second, when some nodes are running out of energy, the APF will be updated and the routing will change automatically according to the new APF. Third, APFR only requires local geographic information and is of low computational complexity. The simulation results show that APFR can prolong the network lifetime and improve the routing success rate compared to other routing protocols such as GEAR and GPSR, especially for densely deployed networks.

A theory for the design of deadlock-free adaptive routing algorithms for wormhole networks, proposed by the author (1991, 1993), supplies sufficient conditions for an adaptive routing algorithm to be deadlock-free, even when there are cyclic dependencies between channels. Also, two design methodologies were proposed. Multicast communication refers to the delivery of the same message from one source node to an arbitrary number of destination nodes. A tree-like routing scheme is not suitable for hardware-supported multicast in wormhole networks because it produces many headers for each message, drastically increasing the probability of a message being blocked. A path-based multicast routing model was proposed by Lin and Ni (1991) for multicomputers with 2D-mesh and hypercube topologies. In this model, messages are not replicated at intermediate nodes. This paper develops the theoretical background for the design of deadlock-free adaptive multicast routing algorithms. This theory is valid for wormhole networks using the path-based routing model. It is also valid when messages with a single destination and multiple destinations are mixed together. The new channel dependencies produced by messages with several destinations are studied. Also, two theorems are proposed, developing conditions to verify that an adaptive multicast routing algorithm is deadlock-free, even when there are cyclic dependencies between channels. As an example, the multicast routing algorithms of Lin and Ni are extended, so that they can take advantage of the alternative paths offered by the network.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Delay Tolerant Networks are characterized by (i) intermittent connectivity that is there is no reliable end-to-end path,(ii) long delay in delivery of packets from source to destination and (iii) the nodes are sparse and mobile. Traditional protocols do not work for such an environment. DTN is deployed in interplanetary networks, wild life tracking, disaster management, underwater networks. Routing in DTN is by store-carry-forward technique, where the source or the intermediate node stores the packet until it meets the node for forwarding. The major constraints or challenges are energy level constraint, mobility patterns, selection of intermediate nodes, effective usage of the limited network resources like buffer space etc. This paper provides the study of various DTN routing algorithms and their categories are summarized.

On modelling of an adaptive routing algorithm for massively parallel processing systems

We study here deterministic broadcasting in geometric radio networks (GRN) whose nodes have complete knowledge of the network. Nodes of a GRN are deployed in the Euclidean plane (R 2) and each of them can transmit within some range r assigned to it. We adopt model in which ranges of nodes are non-uniform and they are drawn from the predefined interval 0 ≤ r min ≤ r max . All our results are in the conflict-embodied model where a receiving node must be in the range of exactly one transmitting node in order to receive the message.We derive several lower and upper bounds on the time of deterministic broadcasting in GRNs in terms of the number of nodes n, a distribution of nodes ranges, and the eccentricity D of the source node (i.e., the maximum length of a shortest directed path from the source node to another node in the network). In particular:(1) We show that D + Ω(log(n − D)) rounds are required to accomplish broadcasting in some GRN where each node has the transmission range set either to 1 or to 0. We also prove that the bound D + Ω(log(n − D)) is almost tight providing a broadcasting procedure that works in this type of GRN in time D + O(logn).(2) In GRNs with a wider choice of positive node ranges from r min , ...,r max , we show that broadcasting requires \(D+\Omega (\min\{\log {\frac {r_{max}}{r_{min}}},\log (n-D)\})\) rounds and that it can be accomplished in \(O (D\log^2 \frac {r_{max}} {r_{min}})\) rounds subsuming the best currently known upper bound \(O (D (\frac {r_{max}} {r_{min}})^4)\) provided in [15].(3) We also study the problem of simulation of minimum energy broadcasting in arbitrary GRNs. We show that energy optimal broadcasting that can be completed in h rounds in a conflict-free model may require up to h/2 additional rounds in the conflict-embodied model. This lower bound should be seen as a separation result between conflict-free and conflict-embodied geometric radio networks. Finally, we also prove that any h-hop broadcasting algorithm with the energy consumption \({\cal E}\) in a GRN can be simulated within O(hlogψ) rounds in the conflict-embodied model using energy \(O({\cal E})\), where ψ is the ratio between the largest and the shortest Euclidean distance between a pair of nodes in the network.

Two quasi-static minimax open shortest path first (OSPF) routing algorithms in networks supporting the Switched Multi-megabit Data Service (SMDS) are presented and compared. In OSPF routing, the network is modeled as a graph and each link is associated with a nonnegative arc weight. A shortest path spanning tree is calculated for each origin to carry both the individually addressed and the group addressed (multicast) traffic. The OSPF routing protocol is adopted as a major part of the default inter-switching system interface (ISSI) routing algorithm for SMDS networks where arc weights are inversely proportional to the aggregate link set capacities. The problem of choosing a set of link set metrics is considered so that the maximum link utilization factor is minimized in an SMDS network. The problem is formulated as a nonlinear mixed integer programming problem.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Wireless Mesh Networks offer a high-performance and low-cost solution to last-mile broadband Internet access. Routing and Scheduling play a critical role in determining the performance of a wireless mesh network. Efficiency of Routing and Scheduling algorithms is highly dependent on the availability of accurate traffic information. In this paper, we predict network traffic based on past data using ARIMA model, and provide that input to the routing and scheduling algorithm. Joint routing and scheduling results in significant performance improvement over the routing only algorithms. So, we provide predicted network traffic information to a Joint routing and scheduling algorithm known as Traffic Oblivious Routing and Scheduling. Traffic Oblivious Routing and Scheduling algorithm optimizes the worst case performance under traffic uncertainty but when accurate traffic information is available to the algorithm, its performance is enhanced. In the Traffic Oblivious Routing and Scheduling algorithm, computing the routing and the scheduling values is a one time overhead. In this paper, we present a system where we predict network traffic information using past data, then use the predicted information to formulate the input for the Traffic Oblivious routing and scheduling algorithm and finally we evaluate the performance of the algorithm using simulations.

Network coding is a promising technology to improve throughput and reliability. However, the benefit of network coding is restricted and affected by network topology, especially in peer-to-peer system. Precise topology awareness can be helpful to improve system performance of network coding in terms of throughput and reliability. In this paper, we propose an innovative scheme TANCF (Topology Awareness based on Network Coding with Feedback), to detect the path in hierarchical P2P network based on the feedback from the intermediate nodes and the receiver nodes of network coding system. It is a first attempt to use network coding with feedback to reveal the network connectivity and to construct the network topology. In the TANCF scheme, the path matrix of network can be obtained by the feedback from intermediate nodes and receiver nodes, which has a close relationship with the adjacency matrix of topology, so that it can be used to construct the network topology that lead to optimize the parameters of network coding. Through the matrix analysis and simulation experiment, it can be proved that TANCF scheme can obtain the path matrix correctly with a high probability.

PathZip: A lightweight scheme for tracing packet path in wireless sensor networks