Qingya She

Manycasting Over Optical Burst-Switched Networks

In this paper, we discuss for the first time the issue of supporting manycasting service over optical burst- switched (OBS) networks. One of the primary challenges in providing manycasting service over OBS networks is to reduce data loss due to burst contentions. We propose two new schemes, static over-provisioning (SOP) and dynamic membership (DM), to alleviate this data loss problem. The proposed schemes take into consideration the specific properties of manycasting, and the schemes may complement existing contention resolution schemes. The effectiveness of the proposed schemes is verified through simulation.

How reliable can two-path protection be?

This paper investigates the subject of reliability via two link-disjoint paths in mesh networks. We address the issues of how reliable two-path protection can be and how to achieve the maximum reliability. This work differs from traditional studies, such as MIN-SUM, MIN-MAX, and MIN-MIN, in that the objective in this paper is to maximize the reliability of the two-path connection given the link reliability, or equivalently, to minimize the end-to-end failure probability. We refer to this problem as MAX-REL. Solving MAX-REL provides 100% protection against a single failure while maximizing the reliability regardless of how many link failures occur in the network. We prove that this problem is NP-complete and derive a corresponding upper bound, which is the theoretical maximum reliability for a source-destination pair, and a lower bound, which is the worst case of the proposed algorithm. The time efficiency of the algorithms is analyzed, and the performance of the algorithms is evaluated through simulation. We demonstrate that our heuristic algorithms not only achieve a low computing complexity, but also achieve nearly equivalent performance to the upper bound.

Maximum survivability under multiple failures

This paper investigates the maximum survivability problem in mesh networks with multiple failures. A heuristic algorithm is proposed to maximize the end-to-end survivability. Simulation results show that the algorithm proposed in this paper is always better than the bounds of two link-disjoint paths protection scheme.

Multi-Resource Manycast over Optical Burst Switched Networks

We define and investigate the problem of multi-resource manycast over optical burst switched (OBS) networks for supporting distributed computing applications. In multi-resource manycast, each destination has multiple computing resources, and each source generates requests that require multiple resources. For a given request, the problem is to select a set of destinations that have the required available resources and to And routes to these destinations. This problem differs from the traditional manycast problem in that different destinations have different resource availability. The objective is to minimize the resource blocking rate, which results from burst contention in the OBS network and from resource unavailability at the destinations. We investigate various approaches to implement multi-resources manycast over OBS networks, and verify the effectiveness of the proposed schemes through simulation.

Survivable virtual optical network mapping in flexible-grid optical networks

In this paper, we study the problem of survivable impairment-aware virtual optical network mapping in flexible-grid optical networks (SIA-VONM). The objective is to minimize the total cost of transponders, regenerators, and shared infrastructure for a given set of virtual optical networks, which can survive single link failures. We first provide the problem definition of SIA-VONM, and then formulate the problem as an integer linear program (ILP). We also develop a novel heuristic algorithm together with a baseline algorithm and a lower bound. Numerical results show that our proposed heuristic achieves results that are very close to those of the ILP for small scale problems, and that our proposed heuristic can solve large scale problems very well.

On finding minimum cost tree for multi-resource manycast in mesh networks

We investigate the problem of multi-resource manycast in mesh networks. The problem of multi-resource manycast extends the traditional manycast problem or k-Steiner tree problem, which finds a minimum cost tree spanning any k vertices. For the traditional manycast, all the vertices in the set of candidate destinations will be regarded as identical. However, the computing capability of the resource at each vertex may be not equivalent in the realistic networks. In this paper, we consider the problem of multi-resource manycast, in which the computing capability of the resource at a vertex is decomposed into discrete units. That is, each vertex may have multiple units of computing resources. The objective is to find a minimum cost tree spanning any k units of computing resources distributed in the networks. We show that multi-resource manycast is NP-Complete. The ILP formulation and approximation analysis are given for this problem. Simple polynomial-time heuristic algorithms are also proposed for the problem of multi-resource manycast. We investigate various approaches to implement multi-resources manycast in mesh networks, and verify the effectiveness of the approaches through simulation.

OPN07-4: Maximum Survivability using Two Disjoint Paths under Multiple Failures in Mesh Networks

This paper investigates the problem of finding two link-disjoint paths in mesh networks. Different from traditional studies, such as MIN-SUM, MIN-MAX, and MIN-MIN, the objective in this paper is to minimize the end-to-end failure probability, or equivalently, maximize the survivability under multiple link failures. We refer to this problem as MAX-SURV. Solving MAX-SURV provides 100% protection against single failure while maximizing the survivability under multiple failures. We prove that this problem is NP-complete, and we propose a heuristic algorithm for finding a solution. The corresponding upper bound and lower bound for given networks are also found. The time efficiency of the algorithms is analyzed, and the performance of the algorithms is evaluated through simulation.

Survivable impairment-constrained virtual optical network mapping in flexible-grid optical networks

In this paper, we study the problem of survivable impairment-constrained virtual optical network mapping in flexible-grid optical networks (SIC-VONM). The objective is to minimize the total cost of working and backup resources, including transponders, regenerators, and shared infrastructure, for a given set of virtual optical networks, which can survive single link failures. We first provide the problem definition of SIC-VONM, and then formulate the problem as an integer linear program (ILP). We also develop a novel heuristic algorithm, together with a baseline algorithm and a lower bound for comparison. Numerical results show that our proposed heuristic achieves results that are very close to those of the ILP for small-scale problems and that our proposed heuristic can solve large-scale problems very well.

Survivable Traffic Grooming for Anycasting in WDM Mesh Networks

In this paper, we investigate the problem of survivable grooming for anycasting over wavelength division multiplexing (WDM) networks. Anycasting is a communication paradigm in which a source node sends data to any one out of multiple candidate destinations. In WDM networks, the standard anycasting problem involves the establishment of a connection from the source to any one destination with the objective of minimizing the resources used. In order to provide survivability, the problem can be extended to find both a connection to a primary destination and a connection to a backup destination. The connections, which may require an amount of bandwidth that may be less than the bandwidth of an entire wavelength, can be groomed with other connections in the WDM network. We propose an auxiliary graph approach to solving the survivable grooming problem for anycasting in WDM networks, and we propose three different protection approaches for providing different degrees of survivability against link failures and destination failures. The effectiveness of the proposed schemes is verified through simulation.

Survivable resource orchestration for optically interconnected data center networks

We propose resource orchestration schemes in overlay networks enabled by optical network virtualization. Based on the information from underlying optical networks, our proposed schemes provision the fewest data centers to guarantee K-connect survivability, thus maintaining resource availability for cloud applications under any failure.