Online tracking of mobile users
Journal of the ACM (JACM)
Adaptive paging algorithms for cellular systems
Wireless information networks
Perspectives of Monge properties in optimization
Discrete Applied Mathematics
Minimizing queuing delays and number of messages in mobile phone location
Mobile Networks and Applications - Special issue: mobility management
Minimizing the average cost of paging under delay constraints
Wireless Networks
Concurrent search of mobile users in cellular networks
IEEE/ACM Transactions on Networking (TON)
Optimal sequential paging in cellular wireless networks
Wireless Networks
Establishing wireless conference calls under delay constraints
Journal of Algorithms
Competitive on-line paging strategies for mobile users under delay constraints
Proceedings of the twenty-third annual ACM symposium on Principles of distributed computing
Location Management of Correlated Mobile Users in the UMTS
IEEE Transactions on Mobile Computing
The conference call search problem in wireless networks
Theoretical Computer Science
A cost-minimization algorithm for fast location tracking in mobile wireless networks
Computer Networks: The International Journal of Computer and Telecommunications Networking
Efficient multicast search under delay and bandwidth constraints
Wireless Networks
Finding mobile data: efficiency vs. location inaccuracy
ESA'07 Proceedings of the 15th annual European conference on Algorithms
A PTAS for delay minimization in establishing wireless conference calls
Discrete Optimization
| Hi-index | 5.23 |
A mobile user is roaming in a zone composed of many cells in a cellular network system. When a call arrives, the system pages the user in these cells since the user never reports its location unless it leaves the zone. Each cell is associated with a positive value which is the probability that the user resides in this cell. A delay constraint requires the user to be found within a predetermined number of paging rounds where in each round a subset of the cells is paged. The goal is to design a paging strategy that minimizes the expected number of paged cells until the user is found. Optimal solutions based on dynamic programming are known. The running time of former implementations is quadratic in the number of cells and linear in the number of rounds. We introduce two implementations whose running times are also linear in the number of cells, by proving that the dynamic programming formulation satisfies properties (like the Monge property) that enable us to use various dynamic programming speed-up techniques. We also propose a new heuristic of almost linear complexity that outperforms a known linear complexity heuristic while running faster when the number of rounds is far less than the number of cells. Our comprehensive simulations compare the non-optimal heuristics with the optimal solutions, demonstrating the trade-off between optimality and running time efficiency as well as implementation simplicity.