The maximum k-colorable subgraph problem for chordal graphs
Information Processing Letters
Efficient routing in all-optical networks
STOC '94 Proceedings of the twenty-sixth annual ACM symposium on Theory of computing
Routing and wavelength assignment in all-optical networks
IEEE/ACM Transactions on Networking (TON)
On approximating arbitrary metrices by tree metrics
STOC '98 Proceedings of the thirtieth annual ACM symposium on Theory of computing
Optimal wavelength routing on directed fiber trees
Theoretical Computer Science
Improved access to optical bandwidth in trees
SODA '97 Proceedings of the eighth annual ACM-SIAM symposium on Discrete algorithms
Efficient routing and scheduling algorithms for optical networks
SODA '94 Proceedings of the fifth annual ACM-SIAM symposium on Discrete algorithms
Ring routing and wavelength translation
Proceedings of the ninth annual ACM-SIAM symposium on Discrete algorithms
Wavelength conversion in optical networks
Proceedings of the tenth annual ACM-SIAM symposium on Discrete algorithms
The complexity of path coloring and call scheduling
Theoretical Computer Science
Routing and path multicoloring
Information Processing Letters
The Maximum Edge-Disjoint Paths Problem in Bidirected Trees
SIAM Journal on Discrete Mathematics
Wavelength assignment and generalized interval graph coloring
SODA '03 Proceedings of the fourteenth annual ACM-SIAM symposium on Discrete algorithms
Approximating Circular Arc Colouring and Bandwidth Allocation in All-Optical Ring Networks
APPROX '98 Proceedings of the International Workshop on Approximation Algorithms for Combinatorial Optimization
A tight bound on approximating arbitrary metrics by tree metrics
Proceedings of the thirty-fifth annual ACM symposium on Theory of computing
Zero Knowledge and the Chromatic Number
CCC '96 Proceedings of the 11th Annual IEEE Conference on Computational Complexity
Efficient access to optical bandwidth
FOCS '95 Proceedings of the 36th Annual Symposium on Foundations of Computer Science
FOCS '97 Proceedings of the 38th Annual Symposium on Foundations of Computer Science
Probabilistic approximation of metric spaces and its algorithmic applications
FOCS '96 Proceedings of the 37th Annual Symposium on Foundations of Computer Science
Query Efficient PCPs with Perfect Completeness
FOCS '01 Proceedings of the 42nd IEEE symposium on Foundations of Computer Science
Improved Inapproximability Results for MaxClique, Chromatic Number and Approximate Graph Coloring
FOCS '01 Proceedings of the 42nd IEEE symposium on Foundations of Computer Science
Simplified layering and flexible bandwidth with TWIN
Proceedings of the ACM SIGCOMM workshop on Future directions in network architecture
On trading wavelengths with fibers: a cost-performance based study
IEEE/ACM Transactions on Networking (TON)
Hardness of the undirected edge-disjoint paths problem
Proceedings of the thirty-seventh annual ACM symposium on Theory of computing
Hardness of the undirected congestion minimization problem
Proceedings of the thirty-seventh annual ACM symposium on Theory of computing
Hardness of the Undirected Edge-Disjoint Paths Problem with Congestion
FOCS '05 Proceedings of the 46th Annual IEEE Symposium on Foundations of Computer Science
Multicommodity demand flow in a tree
ICALP'03 Proceedings of the 30th international conference on Automata, languages and programming
IEEE Journal on Selected Areas in Communications
Lighting fibers in a dark network
IEEE Journal on Selected Areas in Communications
On a noncooperative model for wavelength assignment in multifiber optical networks
IEEE/ACM Transactions on Networking (TON)
Hi-index | 0.00 |
We study the complexity of a set of design problems for optical networks. Under wavelength division multiplexing (WDM) technology, demands sharing a common fiber are transported on distinct wavelengths. Multiple fibers may be deployed on a physical link. Our basic goal is to design networks of minimum cost, minimum congestion and maximum throughput. This translates to three variants in the design objectives: 1) MIN-SUMFIBER: minimizing the total cost of fibers deployed to carry all demands; 2) MIN-MAXFIBER: minimizing the maximum number of fibers per link to carry all demands; and 3) MAX-THROUGHPUT: maximizing the carried demands using a given set of fibers. We also have two variants in the design constraints: 1) CHOOSEROUTE: Here we need to specify both a routing path and a wavelength for each demand; 2) FIXEDROUTE: Here we are given demand routes and we need to specify wavelengths only. The FIXEDROUTE variant allows us to study wavelength assignment in isolation. Combining these variants, we have six design problems. Previously we have shown that general instances of the problems MIN-SUMFIBER-CHOOSEROUTE and MIN-MAXFIBER-FIXEDROUTE have no constant-approximation algorithms. In this paper, we prove that a similar statement holds for all four other problems. Our main result shows that MIN-SUMFIBER-FIXEDROUTE cannot be approximated within any constant factor unless NP-hard problems have efficient algorithms. This, together with the previous hardness result of MIN-MAXFIBER-FIXEDROUTE, shows that the problem of wavelength assignment is inherently hard by itself. We also study the complexity of problems that arise when multiple demands can be time-multiplexed onto a single wavelength (as in time-domain wavelength interleaved networking (TWIN) networks) and when wavelength converters can be placed along the path of a demand.