{"title":"Decentralized energy-efficient base station operation for green cellular networks","authors":"Wei-Te Wong, Ya-Ju Yu, Ai-Chun Pang","doi":"10.1109/GLOCOM.2012.6503945","DOIUrl":"https://doi.org/10.1109/GLOCOM.2012.6503945","url":null,"abstract":"Given the explosive growth of mobile subscribers, network operators have to densely deploy base stations to serve the exponentially increasing access demands. Nevertheless, recent researches have pointed out that base station operation has been identified as a significant portion of total system energy consumption and 90% of the traffic is carried by only 40% of base stations even under peak traffic demand. Therefore, switching off underutilized base stations for saving power is an important issue with the increasing awareness of environmental responsibility and economical concerns of network operators. This paper targets the problem of dynamic base station operation, with an objective to minimize total power consumption of all base stations. We prove this problem is NP-hard and cannot be approximated in polynomial time with a ratio better than 3 over 2. Then, we propose a distributed algorithm to tackle it. The simulation results show that our proposed algorithm can significantly reduce the network power consumption.","PeriodicalId":72021,"journal":{"name":"... IEEE Global Communications Conference. IEEE Global Communications Conference","volume":"30 1","pages":"5194-5200"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88327830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yanming Cao, Qi Shi, Xinbing Wang, Xiaohua Tian, Y. Cheng
{"title":"Two-dimensional contract theory in Cognitive Radio networks","authors":"Yanming Cao, Qi Shi, Xinbing Wang, Xiaohua Tian, Y. Cheng","doi":"10.1109/GLOCOM.2012.6503269","DOIUrl":"https://doi.org/10.1109/GLOCOM.2012.6503269","url":null,"abstract":"While the spectrum resource of modern society is more and more insufficient, Cognitive Radio, which allows the Secondary Users (unlicensed users, SU) to access the licensed spectrum, is a promising solution to make the utilization of spectrum resource more efficient. Among many different paradigms of cognitive radio, market-driven spectrum trading has been proved to be an efficient way to deal with Cognitive Radio problems. In this paper, we consider the problem of spectrum trading with single primary user (PU) who has multiple spectra selling his idle spectra to multiple SUs in multiple types. Since there is only one PU, so it is a monopoly market, in which the PU sets the prices, powers and time for the spectrum he sells, just as a monopolist. SUs as customers choose the spectrum with exact price, power and time to buy. We model it as a two-dimensional power-time-price contract which is much different from the usual contract because the time could either be a strategy that an SU could decide to choose itself or a type which is not decided by SUs. We first discuss the situation in which the time is set as the strategy and we will prove that it can derive a feasible contract with some conditions. Then we will discuss the second situation in which the time is set as a type. In this situation, because the SU has two kinds of types, so it's difficult to make it become a feasible contract, however we will provide a solution to deal with this problem.","PeriodicalId":72021,"journal":{"name":"... IEEE Global Communications Conference. IEEE Global Communications Conference","volume":"16 1","pages":"1156-1161"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73783380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Zhang, Qiang Ye, Jie Cheng, Hongbo Jiang, Yake Wang, Rui Zhou, Peng Zhao
{"title":"Fault-tolerant scheduling for data collection in wireless sensor networks","authors":"L. Zhang, Qiang Ye, Jie Cheng, Hongbo Jiang, Yake Wang, Rui Zhou, Peng Zhao","doi":"10.1109/GLOCOM.2012.6503970","DOIUrl":"https://doi.org/10.1109/GLOCOM.2012.6503970","url":null,"abstract":"Wireless sensor networks are expected to be used in many different applications such as disaster relief, environmental control, and intelligent buildings. In this paper, we focus on a sensor network that collects environment data from all sensor nodes periodically. To gather the sensing data quickly and reliably, the scheduling algorithm should be able to coordinate the data transmissions in the network and react to node/link failures effectively. In this paper, we present an innovative scheduling algorithm, Fault-Tolerant Scheduling for data collection (FTS), that leads to short data collection time and high fault tolerance. Our experimental results show that FTS outperforms the DCSB algorithm and exhibits strong fault-tolerant capabilities.","PeriodicalId":72021,"journal":{"name":"... IEEE Global Communications Conference. IEEE Global Communications Conference","volume":"8 1","pages":"5345-5349"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75247255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A high quality event capture scheme for WSN-based structural health monitoring","authors":"Chao Yang, Jiannong Cao, Xuefeng Liu, Lijun Chen, Daoxu Chen","doi":"10.1109/GLOCOM.2012.6503182","DOIUrl":"https://doi.org/10.1109/GLOCOM.2012.6503182","url":null,"abstract":"In recent years, there has been an increasing interest in the adoption of wireless sensor networks (WSNs) for structural health monitoring (SHM). However, considering the large amount of sampled data, limited power supply and wireless bandwidth of WSNs, it is generally not possible for sensor nodes to monitor structural condition continuously especially for long-term SHM. From SHM perspective, it is highly desirable to collect data during the occurrence of some certain kinds of events such as earthquakes, large wind, etc, since data collected during these periods are more informative for damage detection purpose. However, these events in SHM occur infrequently and if happen, only last for a very short period of time. To effectively capture these short events using energy-limited wireless sensor nodes is a challenging task that has not been addressed in literature. In this paper, we propose a fast and reliable scheme to capture these short-term events. In terms of hardware, the radio-triggered unit and the vibration-triggered unit are designed in our motes. From software perspective, we develop the event capture scheme to realize fast, reliable and energy-efficient event detection under noisy environment. We mainly study the very first problem of the scheme: sentry selection. The optimization problem is formulated and we show that the problem is a general case of the classical k-center problem. Then we propose a greedy algorithm to solve this problem, and conduct simulation to test the effectiveness of the proposed algorithm.","PeriodicalId":72021,"journal":{"name":"... IEEE Global Communications Conference. IEEE Global Communications Conference","volume":"37 1","pages":"622-627"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76954460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tradeoff of spectral and energy efficiencies: Impact of power amplifier on OFDM systems","authors":"Jingon Joung, Chin Keong Ho, Sumei Sun","doi":"10.1109/GLOCOM.2012.6503619","DOIUrl":"https://doi.org/10.1109/GLOCOM.2012.6503619","url":null,"abstract":"Spectral efficiency (SE) and energy efficiency (EE) are key measures for wireless communication systems. In OFDM systems, the non-linear effects and inefficiencies of power amplifiers (PAs) have posed practical challenges for system design. In this paper, we analyze the impact of the PA on the SE and EE tradeoff of OFDM systems. We also propose a PA switching technique which achieves a better SE-EE tradeoff, e.g., the EE can be improved by 323% with 15% SE reduction.","PeriodicalId":72021,"journal":{"name":"... IEEE Global Communications Conference. IEEE Global Communications Conference","volume":"71 1","pages":"3274-3279"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77225304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Optimizing content retrieval delay for LT-based distributed cloud storage systems","authors":"Haifeng Lu, C. Foh, Yonggang Wen, Jianfei Cai","doi":"10.1109/GLOCOM.2012.6503396","DOIUrl":"https://doi.org/10.1109/GLOCOM.2012.6503396","url":null,"abstract":"Among different setups of cloud storage systems, fountain-codes based distributed cloud storage system provides reliable online storage solution through placing coded content fragments into multiple storage nodes. Luby Transform (LT) code is one of the popular fountain codes for storage systems due to its efficient recovery. However, to ensure high success decoding of fountain codes based storage, retrieval of additional fragments is required, and this requirement introduces additional delay, which is critical for content retrieval or downloading applications. In this paper, we show that multiple-stage retrieval of fragments is effective to reduce the content-retrieval delay. We first develop a delay model for various multiple-stage retrieval schemes applicable to our considered system. With the developed model, we study optimal retrieval schemes given the success decodability requirement. Our numerical results demonstrate that the content-retrieval delay can be significantly reduced by optimally scheduling packet requests in a multi-stage fashion.","PeriodicalId":72021,"journal":{"name":"... IEEE Global Communications Conference. IEEE Global Communications Conference","volume":"67 1","pages":"1920-1925"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76232520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Joint optimization for MIMO AF multiple-relay systems with correlated channel uncertainties","authors":"Chia-Chang Hu, Yi-Shiang Chiu, Sheng-Shang Lin","doi":"10.1109/GLOCOM.2012.6503690","DOIUrl":"https://doi.org/10.1109/GLOCOM.2012.6503690","url":null,"abstract":"In the paper, the source/relays-precoders and destination-equalizer combined optimization is proposed in a dual-hop multiple-input multiple-output (MIMO) amplify-and-forward (AF) multiple-relay system with correlated channel uncertainties in both hops. By taking correlated channel uncertainties into account, a robust transceiver joint design is developed based on the minimum mean-squared error (MMSE) criterion under individual power constraints at the source and relays. Simulation results illustrate that the robust transceiver design architecture for an AF-MIMO system equipped with multiple relays outperforms substantially the non-robust transceiver design.","PeriodicalId":72021,"journal":{"name":"... IEEE Global Communications Conference. IEEE Global Communications Conference","volume":"12 1","pages":"3690-3695"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80502666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuanping Zhu, Jing Xu, Yang Yang, Xin Yang, Ze-ping Hu
{"title":"Inter-cell interference statistics of uplink OFDM systems with Soft Frequency Reuse","authors":"Yuanping Zhu, Jing Xu, Yang Yang, Xin Yang, Ze-ping Hu","doi":"10.1109/GLOCOM.2012.6503872","DOIUrl":"https://doi.org/10.1109/GLOCOM.2012.6503872","url":null,"abstract":"Soft Frequency Reuse (SFR) has been widely used to deal with the severe ICI (Inter-Cell Interference) especially for cell edge users. This paper presents an analytical method to investigate the statistics of inter-cell interference in uplink when SFR scheme is adopted in OFDM (Orthogonal Frequency Division Multiplexing) systems. PDF (Probability Density Function) of ICI from one adjacent interfering cell is derived and then used to deduce the expectation and variance of ICI from multiple interfering cells. The derived results are validated through comparison with Monte Carlo simulations. In addition, the relationships between system parameters and statistics of ICI in different frequency bands are investigated. These contributions will give inspect into important guidelines to system optimization.","PeriodicalId":72021,"journal":{"name":"... IEEE Global Communications Conference. IEEE Global Communications Conference","volume":"15 1","pages":"4764-4769"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78871794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Asymptotically Optimal Likelihood detector for cyclostationary signature induced by Cyclic Delay Diversity","authors":"Yonglei Jiang, Huaxia Chen, Honglin Hu","doi":"10.1109/GLOCOM.2012.6503301","DOIUrl":"https://doi.org/10.1109/GLOCOM.2012.6503301","url":null,"abstract":"The Cyclic Delay Diversity (CDD)-induced cyclostationary signature is considered to be a robust and cost-efficient scheme for self-coordination of Cognitive Radio Network (CRN). However, the performance of network coordination relies on the reliable detection of such cyclostationary signatures. In this paper, we deduce an exact covariance matrix to characterize the statistics of cyclostationary signature. Based on the covariance matrix, we propose an Asymptotically Optimal Likelihood (AOL) detector for the test of the CDD-induced cyclostationary signature. In addition, an Asymptotically Maximum Likelihood Probability (AMLP) criterion is provided to solve the multiple signatures identification issue. Comprehensive simulations verify that the proposed detector provides superior performance in detection probability and observation duration, compared with the existing Constant False Alarm Rate (CFAR) detector.","PeriodicalId":72021,"journal":{"name":"... IEEE Global Communications Conference. IEEE Global Communications Conference","volume":"8 1","pages":"1351-1355"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81841895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Precoding design for cognitive two-way relay networks","authors":"Rui Wang, M. Tao","doi":"10.1109/GLOCOM.2012.6503681","DOIUrl":"https://doi.org/10.1109/GLOCOM.2012.6503681","url":null,"abstract":"We study precoding design for cognitive two-way relay networks (C-TWRNs). In C-TWRN, the multi-antenna secondary transmitter not only transmits its own signal to the secondary receiver, it also acts as relay to help forwarding signals of two primary users via two-way relaying in the licensed frequency band. Our objective is to design linear relay transceiver or precoder such that the achievable rate of the secondary user is maximized while maintaining rate requirements of the primary users. To achieve this goal, different relay strategies, i.e., amplify-and-forward (AF), bit level XOR based decode-and-forward (DF-XOR) and symbol level superposition coding based decode-and-forward (DF-SUP), are considered. By transforming these non-convex design problems into suitable forms, efficient optimization tools are used to find the optimal solutions of all the schemes. Closed-form solutions are also obtained under certain conditions.","PeriodicalId":72021,"journal":{"name":"... IEEE Global Communications Conference. IEEE Global Communications Conference","volume":"91 1","pages":"3638-3643"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78692919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}