On the Privacy and Utility Tradeoff in Database-Assisted Dynamic Spectrum Access
On the Privacy and Utility Tradeoff in Database-Assisted Dynamic Spectrum Access
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DOI：
10.1109/dyspan.2018.8610485
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发表时间：
2018-10
期刊：
影响因子：
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通讯作者：
Ahmed M. Salama;Ming Li;Loukas Lazos;Yong Xiao;M. Krunz
中科院分区：
文献类型：
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作者：
Ahmed M. Salama;Ming Li;Loukas Lazos;Yong Xiao;M. Krunz
在动态频谱接入中，通常使用商业运营的数据库服务器来协助机会用户（opportunistic user）查询和接入在位用户（在职用户）的频谱空缺。这种DSA架构中的查询和回答过程带来了严重的隐私问题，可能会泄露iu的敏感操作细节，特别是它们的位置。现有的隐私保护机制，如位置隐藏或空间混淆，可用于隐藏u的位置。但是，它们不能保证来自周围所有允许访问的ou的干扰保持在给定的限制范围内。此外，在设计机制时还应考虑ou的频谱利用率（即传输机会）。在隐私、干扰和效用之间复杂的三方权衡尚未在文献中得到系统的研究。在本文中，我们首先尝试通过在隔离区中引入隐私区来解决这一挑战。在隐私区内，IU的位置是无法区分的，而隔离区则保证了隐私区内的干扰限制。在系统模型的两种变体（已知OU位置或已知密度的概率位置）下，我们制定并求解相应的优化问题，以找到其中一个目标与其他两个目标的最优权衡。仿真结果表明，在允许干扰固定的情况下，单元的隐私性随着单元效用的降低而增加。
In dynamic spectrum access, commercially-operated database servers are often used to assist the opportunistic users (OUs) to query and access spectrum vacancies of incumbent users (IUs). The query and answer process in such DSA architectures introduce significant privacy concerns for potential leakage of the sensitive operational details of the IUs, especially their locations. Existing privacy-preserving mechanisms such as location cloaking or spatial obfuscation can be used to hide IUs’ locations. They however cannot guarantee the interference from all surrounding access-allowed OUs staying under a given limit. In addition, the spectrum utilization (i.e., transmission opportunities) of OUs should also be considered in the design of mechanisms. The complex three-way tradeoff among privacy, interference and utility has not been systematically studied in the literature. In this paper, we first endeavor to tackle this challenge, by introducing a privacy zone within the exclusion zone. In the privacy zone the IU’s location is indistinguishable, while the exclusion zone guarantees the interference limit within the privacy zone. Under two variants of the system model (either known OU locations or probabilistic locations with known density), we formulate and solve corresponding optimization problems to find the optimal tradeoff of one versus the other two objectives. Simulation results with real-world maps/parameters show that the IU’s privacy increases with decreasing OUs’ utility given a fixed allowable interference for the IUs.