Subcube Allocation in Hypercube Computers
IEEE Transactions on Computers
Communications of the ACM
Fast allocation and deallocation with an improved buddy system
Acta Informatica
Upper bound for defragmenting buddy heaps
LCTES '05 Proceedings of the 2005 ACM SIGPLAN/SIGBED conference on Languages, compilers, and tools for embedded systems
An Algorithmic View on OVSF Code Assignment
Algorithmica
Online frequency allocation in cellular networks
Proceedings of the nineteenth annual ACM symposium on Parallel algorithms and architectures
Online OVSF Code Assignment with Resource Augmentation
AAIM '07 Proceedings of the 3rd international conference on Algorithmic Aspects in Information and Management
Improving the Competitive Ratio of the Online OVSF Code Assignment Problem
ISAAC '08 Proceedings of the 19th International Symposium on Algorithms and Computation
A Constant-Competitive Algorithm for Online OVSF Code Assignment
Algorithmica - Special Issue: Algorithms and Computation; Guest Editor: Takeshi Tokuyama
ESA'07 Proceedings of the 15th annual European conference on Algorithms
Online tree node assignment with resource augmentation
Journal of Combinatorial Optimization
Theoretically good distributed CDMA/OVSF code assignment for wireless ad hoc networks
COCOON'05 Proceedings of the 11th annual international conference on Computing and Combinatorics
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In this paper, we study the online tree node assignment problem, which is a generalization of the well studied OVSF code assignment problem. Assigned nodes in a complete binary tree must follow the rule that each leaf-to-root path must contain at most one assigned node. At times, it is necessary to swap assigned nodes with unassigned nodes in order to accommodate some new node assignment. The target of this problem is to minimize the number of swaps in satisfying a sequence of node assignments and releases. This problem is fundamental, not only to the OVSF code assignment, but also to other applications, such as buddy memory allocation and hypercube subcube allocation. All the previous solutions to this problem are based on a sorted and compact configuration by assigning the nodes linearly and level by level, ignoring the intrinsic tree property in their assignments. Our contributions are: (1) give the concept of safe assignment, which is proved to be unique for any fixed set of node-assignment requests; (2) an 8-competitive algorithm by holding the safe assignment; and (3) an improved 6-competitive variant of this algorithm. Our algorithms are simple and easy to implement and our contributions represent meaningful improvements over recent results.