TY - GEN

T1 - The wireless synchronization problem

AU - Dolev, Shlomi

AU - Gilbert, Seth

AU - Guerraoui, Rachid

AU - Kuhn, Fabian

AU - Newport, Calvin

PY - 2009/11/9

Y1 - 2009/11/9

N2 - In this paper, we study the wireless synchronization problem which requires devices activated at different times on a congested single-hop radio network to synchronize their round numbering. We assume a collection of n synchronous devices with access to a shared band of the radio spectrum, divided into F narrowband frequencies. We assume that the communication medium suffers from unpredictable, perhaps even malicious interference, which we model by an adversary that can disrupt up to t frequencies per round. Devices begin executing in different rounds and the exact number of participants is not known in advance. We first prove a lower bound, demonstrating that at least Ω (log2 n/(F-t) log log n + Ft/F-t log n) rounds are needed to synchronize. We then describe two algorithms. The first algorithm almost matches the lower bound, yielding a running time of Ω (F/F-t log2 n + Ft/F-t log n) rounds. The second algorithm is adaptive, terminating in O (t′ log3 n) rounds in good executions, that is, when the devices begin executing at the same time, and there are never more than t′ frequencies disrupted in any given round, for some t′ < t. In all executions, even those that are not good, it terminates in O (F log3 n) rounds.

AB - In this paper, we study the wireless synchronization problem which requires devices activated at different times on a congested single-hop radio network to synchronize their round numbering. We assume a collection of n synchronous devices with access to a shared band of the radio spectrum, divided into F narrowband frequencies. We assume that the communication medium suffers from unpredictable, perhaps even malicious interference, which we model by an adversary that can disrupt up to t frequencies per round. Devices begin executing in different rounds and the exact number of participants is not known in advance. We first prove a lower bound, demonstrating that at least Ω (log2 n/(F-t) log log n + Ft/F-t log n) rounds are needed to synchronize. We then describe two algorithms. The first algorithm almost matches the lower bound, yielding a running time of Ω (F/F-t log2 n + Ft/F-t log n) rounds. The second algorithm is adaptive, terminating in O (t′ log3 n) rounds in good executions, that is, when the devices begin executing at the same time, and there are never more than t′ frequencies disrupted in any given round, for some t′ < t. In all executions, even those that are not good, it terminates in O (F log3 n) rounds.

KW - Algorithms

KW - C.2.1 [network architecture and design]: wireless networks

KW - Theory

UR - http://www.scopus.com/inward/record.url?scp=70350641370&partnerID=8YFLogxK

U2 - 10.1145/1582716.1582749

DO - 10.1145/1582716.1582749

M3 - Conference contribution

AN - SCOPUS:70350641370

SN - 9781605583969

T3 - Proceedings of the Annual ACM Symposium on Principles of Distributed Computing

SP - 190

EP - 199

BT - PODC'09 - Proceedings of the 2009 ACM Symposium on Principles of Distributed Computing

T2 - 2009 ACM Symposium on Principles of Distributed Computing, PODC'09

Y2 - 10 August 2009 through 12 August 2009

ER -