Routing Allocation Research Articles

A tabu search algorithm for the single vehicle routing allocation problem

In the single vehicle routing allocation problem (SVRAP) we have a single vehicle, together with a set of customers, and the problem is one of deciding a route for the vehicle (starting and ending at given locations) such that it visits some of the customers. Customers not visited by the vehicle can either be allocated to a customer on the vehicle route, or they can be isolated. The objective is to minimize a weighted sum of routing, allocation and isolation costs. One special case of the general SVRAP is the median cycle problem, also known as the ring star problem, where no isolated vertices are allowed. Other special cases include the covering tour problem, the covering salesman problem and the shortest covering path problem. In this paper, we present a tabu search algorithm for the SVRAP. Our tabu search algorithm includes aspiration, path relinking and frequency-based diversification. Computational results are presented for test problems used previously in the literature and our algorithm is compared with the results obtained by other researchers. We also report results for much larger problems than have been considered by others.

Joint routing and resource allocation in optical transport networks

A layered network model for optical transport networks is proposed in this paper, which involves IP, SDH and WDM layers. The strategy of Dynamic Joint Routing and Resource Allocation (DJRRA) and its algorithm description are also presented for the proposed layered network model. DJRRA optimizes the bandwidth usage of interface links between different layers and the logic links inside all layers. The simulation results show that in contrast to the classical separate sequential routing and resource allocation solutions, DJRRA can reduce the blocking probability and increase network throughput effectively.

Routing and Power Allocation in Asynchronous Gaussian Multiple-Relay Channels

We investigate the cooperation efficiency of the multiple-relay channel when carrier-level synchronization is not available and all nodes use a decode-forward scheme. We show that by using decode-forward relay signaling, the transmission is effectively interference-free even when all communications share one common physical medium. Furthermore, for any channel realization, we show that there always exist a sequential path and a corresponding simple power allocation policy, which are optimal. Although this does not naturally lead to a polynomial algorithm for the optimization problem, it greatly reduces the search space and makes finding heuristic algorithms easier. To illustrate the efficiency of cooperation and provide prototypes for practical implementation of relay-channel signaling, we propose two heuristic algorithms. The numerical results show that in the low-rate regime, the gain from cooperation is limited, while the gain is considerable in the high-rate regime.

Differentiated-resilience provisioning for the wavelength-routed optical network

This paper evaluates the performance of a new scheme for the differentiated-resilience provisioning of lightpaths in a wavelength-routed optical network. A novel differentiated-resilience optical-services model (DROSM) is proposed to enhance the performance of the optical network. First, an analysis of optical-resilience options is presented. Then, a classification of optical services according to their resilience requirement is proposed with respective resilience options. In particular, a novel link-management mechanism is proposed to assist the routing and wavelength allocation. Our numerical results show that differentiated-resilience provisioning has significant merit over that of single resilience provisioning in the optical network.

Interference-aware routing and bandwidth allocation for QoS provisioning in multihop wireless networks

In this paper, we study the bandwidth guaranteed routing and timeslot allocation (BANDRA) in TDMA-based multihop wireless networks with dynamic traffic. We formally model BANDRA as an optimization ...

Routing of 40-gb/s streams in wavelength-routed heterogeneous optical networks

In this paper, we address the design and management issues in routing a mixture of OC-192 and OC-768 streams in wavelength-routed optical networks. We assume that fiber links in the network are heterogeneous with respect to their transmission capability (i.e., links are designed to handle a given maximum bit-rate imposed by regenerator spacing). We investigate the issues of routing connection demands of various bit-rate requirements in such heterogeneous networks. In this environment, we introduce the routing of multirate traffic (RMT) problem. The RMT problem is informally defined as the process of finding the best routing which maximizes the total bandwidth carried in the network, for a set of sessions, within a given TDM equipment budget. We propose a two-phase optimization scheme (two-phase RMT). This scheme first obtains a basis solution used in routing 40-Gb/s traffic only on OC-768 capable links without the use of TDM equipment. In the second phase, an iterative routing, rerouting, and resource allocation step is used to optimize the total bandwidth carried in the network, while allowing 40-Gb/s traffic to be routed on OC-768 incapable links by the proper installation of TDM multiplexors and demultiplexers at some strategic locations in the network. Numerical results reveal the following: 1) the two-phase RMT optimization algorithm provides substantial savings in terms of both the total TDM equipment installed and number of wavelengths used; 2) noticeable enhancements of the bandwidth utilization and the TDM budget are observed when the route-optimization takes into account the transmission quality of the links; and 3) the use of intermediate TDM multiplexing/demultiplexing functions provides substantial savings, in terms of the total number of channels, over the source-splitting scheme.

Multi-path routing and resource allocation in active network

An algorithm of traffic distribution called active multi-path routing (AMR) in active network is proposed. AMR adopts multi-path routing and applies nonlinear optimize approximate method to distribute network traffic among multiple paths. It is combined to bandwidth resource allocation and the congestion restraint mechanism to avoid congestion happening and worsen. So network performance can be improved greatly. The frame of AMR includes adaptive traffic allocation model, the conception of supply bandwidth and it's allocation model, the principle of congestion restraint and its' model, and the implement of AMR based on multi-agents system in active network. Through simulations, AMR has distinct effects on network performance. The results show AMR is a valid traffic regulation algorithm.

Dynamic power allocation and routing for time-varying wireless networks

We consider dynamic routing and power allocation for a wireless network with time-varying channels. The network consists of power constrained nodes that transmit over wireless links with adaptive transmission rates. Packets randomly enter the system at each node and wait in output queues to be transmitted through the network to their destinations. We establish the capacity region of all rate matrices (/spl lambda//sub ij/) that the system can stably support-where /spl lambda//sub ij/ represents the rate of traffic originating at node i and destined for node j. A joint routing and power allocation policy is developed that stabilizes the system and provides bounded average delay guarantees whenever the input rates are within this capacity region. Such performance holds for general arrival and channel state processes, even if these processes are unknown to the network controller. We then apply this control algorithm to an ad hoc wireless network, where channel variations are due to user mobility. Centralized and decentralized implementations are compared, and the stability region of the decentralized algorithm is shown to contain that of the mobile relay strategy developed by Grossglauser and Tse (2002).

Routing and dynamic resource assignment joint game: a non-cooperative model for QoS routing

In this paper we present an innovative game theoretic non-cooperative model for the quality of service (QoS) routing in communication networks implementing a differentiated service model for the QoS support. The proposed model allows us to solve a joint problem of non-cooperative QoS routing and dynamic capacity allocation over a network of parallel links. This problem is solved by playing a Nash game taking place among players belonging to two categories: (i) the category of individual users, whose objectives are to ship their macroflows from the source node to the destination node, by suitably splitting them over the parallel links, and (ii) the category of capacity players, whose task is to partition and to assign to the classes of traffic upon which the macroflows are mapped, the dynamic portion of capacity over each link. One of the main innovative aspects of our model is that the allocation of the dynamic portion of capacity to each class of traffic over each link is realised during the actual operation of the network, i.e. in conjunction with the QoS routing. Extensive simulation results validate the proposed model, show some of its interesting properties and highlight the remarkable performance enhancements that it achieves with respect to the other results present in the literature.

Routing and rate allocation in rate-based multi-class networks

In this paper, we investigate the performance of routing and rate allocation (RRA) algorithms in rate-based multi-class networks. On the arrival of a connection request, an RRA algorithm selects a route for the connection and allocates an appropriate rate on the route; failing this, it blocks the connection request. We measure the performance of an RRA algorithm in terms of its minimum weighted carried traffic. This performance criterion encompasses two widely used performance criteria, namely, weighted carried traffic and minimum carried traffic. We derive an upper bound on the minimum weighted carried traffic of any RRA algorithm. The bound can be computed by solving a linear program. Moreover, we show that the bound is achieved asymptotically, when the offered load and the link capacities are large, by a Partitioning RRA algorithm. Therefore the bound can be used as a performance benchmark for any RRA algorithm. We observe that the proposed Partitioning RRA algorithm, though asymptotically optimal, performs poorly at very low loads. We investigate the cause of this undesirable behaviour and obtain two improved asymptotically optimal RRA algorithms.

Integrated Routing Algorithms for Provisioning “Sub-Wavelength” Connections in IP-Over-WDM Networks

This work focuses on developing and implementing comprehensive unified constraint-based routing algorithms within the generalized multi-protocol label switching framework (GMPLS) to provision “sub-wavelength” circuits (low-rate traffic streams). Constraint-based routing is further augmented in this work by dynamically routing both an active and another alternate link/node-disjoint backup path at the same time in order to provision a given connection request. This new integrated approach combines both IP routing and optical resource allocation to setup end-to-end connections.

Modelling and analysis of routing and resource allocation techniques in multi-service networks

Modelling and analysis of routing and resource allocation techniques in multi-service networks

Modelling and analysis of routing and resource allocation techniques in multi‐service networks

In this paper a novel call level model based on the extension of the classical Erlang multi-rate model for broadband integrated services networks is proposed. We use the model to study routing stra ...

Minimum cost wavelength-path routing and wavelength allocation using a genetic-algorithm/heuristic hybrid approach

Minimum cost wavelength-path routing and wavelength allocation of multiwavelength all-optical transport networks using a genetic-algorithm (GA)/heuristic hybrid approach is described. A cost model is adopted which incorporates a dependency on link wavelength requirements. The hybrid algorithm developed uses an object-oriented representation of networks, and incorporates four operators: path mutation, single-point crossover, reroute and shift-out. In addition, an operator-probability adaptation mechanism is employed to improve operator productivity. Experimental results from seven fifteen-node test networks, obtained using a tool for optical network optimisation, modelling and design (NOMaD), suggest the GA/heuristic hybrid approach provides superior results compared to three recent wavelength-allocation heuristics, except when the network cost depends most heavily on wavelength requirement.

Server allocation and routing in homogeneous queues with switching penalties

This paper considers a multiclass routing and server allocation problem in a queueing system of multiple stations in parallel with penalties for switching the server between stations. We proceed by dynamically ranking the queues so that if all arrivals ceased, switches of the server between queues would be maximally delayed by serving queues in order of rank. The main result of this paper shows that we may improve any policy by constructing a greedy version that routes arriving customers to the queue of highest acceptable rank and allocates the server to the queue of highest rank whenever it switches. We also establish analogous results for a variant of the problem that encourages fairness in server allocation by restricting attention to pseudocyclic policies which visit each queue periodically.

Fault-tolerant tree architecture with improved reconfiguration capabilities

A new approach is presented for the reconfiguration of VLSI tree architectures. It is based on a process of logical displacement for accomplishing reconfiguration with the global availability of redundant cells (or spares). A new and simple switch structure is proposed which allows flexibity in routing and spare allocation to accomplish a double displacement in the reconfiguration process. The proposed switch structure also permits a fully global execution of the reconfiguration process as the reconfigured tree spans the whole structure, not only a subtree as in previous approaches. Overhead issues with respect to the number of spares and redundant links are addressed. The conditions for reconfigurability are fully analysed; it is proved that the ability to reconfigure in the presence of a double displacement results in an improvement in reconfigurability. Faults in basic cells, links and switching circuits are considered. A lower bound on the improvement of reconfigurability is established. Simulation re...

Robust design and planning of a worldwide intelligent network

The authors describe the structure of the worldwide intelligent network (WIN), describe methods for its design and planning, investigate the adequacy of decentralized control for problem-free worldwide call completion, explore the feasibility of adaptive routing and control concepts, discuss network robustness/reliability objectives, and describe a strategy for achieving these objectives for all cooperating international carriers. Several decentralized adaptive routing policies that are particularly attractive in the WIN environment and network performance improvements that can be achieved with the introduction of flexible routing capabilities are characterized. It is shown by example that network integration coupled with flexible routing and bandwidth allocation for preferential treatment of new services provides an effective approach for robust and economical new service provisioning. >

The Multi-Depot Routing Allocation Problem

SYNOPTIC ABSTRACTCurrent mathematical models for analyzing distribution systems usually consider the long-term “strategic problem” of Distribution Center (DC) location, and the short-term “tactical problem” of vehicle routing, independently and sequentially. While in the short-term, both the capacities and variable costs at the DC's are given, existing vehicle routing models do not consider either the capacities of the variable costs at the DC's. The proposed Multi-Depot Routing Allocation Problem (MDRAP) is that of designing vehicle routes from multiple capacitated depots with different variable costs. It can be formulated as a zero-one integer programming problem. We present an efficient heuristic for the MDRAP based on a sequential savings approach. The computational analysis suggests that DC capacities and variable costs may have significant effects on vehicle routing.