Approximating call-scheduling makespan in all-optical networks

Approximation Algorithms for Routing and Call Scheduling in All-Optical Chains and Rings

We study the problem of routing and scheduling requests of limited durations in an all-optical network. The task is servicing the requests, assigning each of them a starting time and a wavelength, with restrictions on the number of available wavelengths. The goal is minimizing the overall time needed to serve all requests. We propose constant approximation algorithms for both ring and chain net...

Distributed Call Scheduling in Wireless Networks

This work investigates distributed transmission scheduling in wireless networks. Due to interference constraints, “neighboring links” cannot be simultaneously activated, otherwise transmissions will fail. Here, we consider any binary model of interference. We follow the model described by Bui, Sanghavi, and Srikant in [5, 21]. We suppose that time is slotted and during each slot we have two pha...

Minimum Makespan Scheduling

8.1 Makespan Scheduling

Definition 8.1.1 Let P = ∑ i∈J Pi. Clearly 1 ≤ OPT ≤ P . Since 1 ≤ OPT ≤ P , if we have access to a (1 + )-relaxed decision procedure we can use it O(logP ) times to do a binary search on different values of T (between 1 and P ) to find a (1 + )approximation. Since logP is polynomial in the input size, if the relaxed decision procedure runs in polynomial time then we have a (1 + )-approximation...

Securing All-Optical Networks

All-optical networks (AONs) are a relatively new technology for high data-rate communications. They contain only optical components and are intrinsically different from optical networks currently being used. More specifically, AONs provide transparent features that allow routing and data switching without necessitating the interpretation or regression of signals within the network. Consequently...