Showing papers by "Xia Zhou published in 2008"
14 Sep 2008
TL;DR: Analytically, it is shown that VERITAS is truthful, efficient, and has a polynomial complexity of O(n3k) when n bidders compete for k spectrum bands, which makes an important contribution of maintaining truthfulness while maximizing spectrum utilization.
Abstract: Market-driven dynamic spectrum auctions can drastically improve the spectrum availability for wireless networks struggling to obtain additional spectrum. However, they face significant challenges due to the fear of market manipulation. A truthful or strategy-proof spectrum auction eliminates the fear by enforcing players to bid their true valuations of the spectrum. Hence bidders can avoid the expensive overhead of strategizing over others and the auctioneer can maximize its revenue by assigning spectrum to bidders who value it the most. Conventional truthful designs, however, either fail or become computationally intractable when applied to spectrum auctions. In this paper, we propose VERITAS, a truthful and computationally-efficient spectrum auction to support an eBay-like dynamic spectrum market. VERITAS makes an important contribution of maintaining truthfulness while maximizing spectrum utilization. We show analytically that VERITAS is truthful, efficient, and has a polynomial complexity of O(n3k) when n bidders compete for k spectrum bands. Simulation results show that VERITAS outperforms the extensions of conventional truthful designs by up to 200% in spectrum utilization. Finally, VERITAS supports diverse bidding formats and enables the auctioneer to reconfigure allocations for multiple market objectives.
465 citations
TL;DR: A feedback‐based secure routing protocol (FBSR), where feedback from the neighboring nodes serves as the dynamic information of the current network, with which sensor nodes make forwarding decisions in a secure and energy aware manner.
Abstract: Purpose – Wireless sensor networks, due to their potentially wide application perspectives, may proliferate in future. Two major stumbling blocks are the dynamic variance of the network caused by both the capacity constraint of sensor nodes and uncertainties of wireless links, and secure routing in the special security sensitive environment. Therefore, adaptable and defendable routing mechanism is in urgent need for the deployment of sensor networks. This paper aims to propose a feedback‐based secure routing protocol (FBSR).Design/methodology/approach – Feedback from the neighboring nodes serves as the dynamic information of the current network, with which sensor nodes make forwarding decisions in a secure and energy aware manner. Feedback message is included in the MAC layer acknowledgement frame to avoid network congestion, and it is authenticated with the proposed Keyed One Way Hash Chain (Keyed‐OWHC) to avoid feedback fabrication. FBSR's resilience to node compromise is enhanced by statistic efforts a...
16 citations
16 Jun 2008
TL;DR: The results show that short-term dynamic auctions with traffic-aware bidding can significantly improve system throughput and provide bidders with cost-effective spectrum usage.
Abstract: Wireless growth has been limited by the shortage of radio spectrum. While the spectrum assigned to legacy technologies remain unused, new prominent technologies such as Mesh/WiFi networks are forced to crowd into a small unlicensed band, suffering from significant interference and degraded performance. Using economic incentives, dynamic spectrum auctions redistribute spectrum to make it available to new technologies while providing financial benefits to legacy owners. In this paper, we investigate the performance of dynamic spectrum auctions under traffic dynamics. Using measured traffic traces from deployed WiFi access points, we evaluate the advantages and artifacts of dynamic auctions over plain channel sharing, and investigate the impact of bidding formats and auction intervals. Our results show that short-term dynamic auctions with traffic-aware bidding can significantly improve system throughput and provide bidders with cost-effective spectrum usage.
13 citations