On the complexity of bandwidth allocation in radio networks
Theoretical Computer Science
Improved bounds for data-gathering time in sensor networks
Computer Communications
Minimum Delay Data Gathering in Radio Networks
ADHOC-NOW '09 Proceedings of the 8th International Conference on Ad-Hoc, Mobile and Wireless Networks
Optimal time data gathering in wireless networks with omni-directional antennas
SIROCCO'11 Proceedings of the 18th international conference on Structural information and communication complexity
Optimally fast data gathering in sensor networks
MFCS'06 Proceedings of the 31st international conference on Mathematical Foundations of Computer Science
An approximation algorithm for the wireless gathering problem
Operations Research Letters
Lower bounds on data collection time in sensory networks
IEEE Journal on Selected Areas in Communications
| Hi-index | 5.23 |
We study the problem of gathering information from the nodes of a radio network into a central node. We model the network of possible transmissions by a graph and consider a binary model of interference in which two transmissions interfere if the distance in the graph from the sender of one transmission to the receiver of the other is d"I or less. A round is a set of compatible (i.e., non-interfering) transmissions. In this paper, we determine the exact number of rounds required to gather one piece of information from each node of a square two-dimensional grid into the central node. If d"I=2k-1 is odd, then the number of rounds is k(N-1)-c"k where N is the number of nodes and c"k is a constant that depends on k. If d"I=2k is even, then the number of rounds is (k+14)(N-1)-c"k^' where c"k^' is a constant that depends on k. The even case uses a method based on linear programming duality to prove the lower bound, and sophisticated algorithms using the symmetry of the grid and non-shortest paths to establish the matching upper bound. We then generalize our results to hexagonal grids.