Pub Date : 2012-04-01DOI: 10.1109/WCNC.2012.6214358
A. Bazzi, B. Masini, G. Pasolini
Considering vehicles as sensors for traffic and pollution information is a new paradigm to monitor the environment and to open the way to an efficient smart navigation. In this work we focus on the uplink acquisition of traffic information from vehicles toward a remote control center. With the increase in the number of vehicles equipped with on board units (OBUs) enabling cellular transmissions, this service is leading to higher loads for the cellular network itself and, consequently, to higher costs. In this paper we discuss the opportunity to take advantage of vehicle-to-vehicle (V2V) and vehicle-to-roadside communications in addition to vehicle-to-infrastructure cellular transmissions. The objective is twofold: to investigate the potential reduction of data transmitted over the cellular networks and to verify the potential transmission delay reduction, by sharing and aggregating information through V2V communications. Results are obtained through an integrated simulation platform jointly taking into account both realistic vehicular environments and wireless network communication aspects.
{"title":"V2V and V2R for cellular resources saving in vehicular applications","authors":"A. Bazzi, B. Masini, G. Pasolini","doi":"10.1109/WCNC.2012.6214358","DOIUrl":"https://doi.org/10.1109/WCNC.2012.6214358","url":null,"abstract":"Considering vehicles as sensors for traffic and pollution information is a new paradigm to monitor the environment and to open the way to an efficient smart navigation. In this work we focus on the uplink acquisition of traffic information from vehicles toward a remote control center. With the increase in the number of vehicles equipped with on board units (OBUs) enabling cellular transmissions, this service is leading to higher loads for the cellular network itself and, consequently, to higher costs. In this paper we discuss the opportunity to take advantage of vehicle-to-vehicle (V2V) and vehicle-to-roadside communications in addition to vehicle-to-infrastructure cellular transmissions. The objective is twofold: to investigate the potential reduction of data transmitted over the cellular networks and to verify the potential transmission delay reduction, by sharing and aggregating information through V2V communications. Results are obtained through an integrated simulation platform jointly taking into account both realistic vehicular environments and wireless network communication aspects.","PeriodicalId":329194,"journal":{"name":"2012 IEEE Wireless Communications and Networking Conference (WCNC)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128064491","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}
Pub Date : 2012-04-01DOI: 10.1109/WCNC.2012.6214047
Jawad Manssour
A low-complexity user pairing algorithm for the broadcast phase of the XOR-based network coding is presented. The proposed scheme achieves the same spectral efficiency as an exhaustive search approach based on maximizing the sum-rate when network coding is utilized for all transmissions. The proposed scheme is further complemented with an adaptive switch, per user pair, between network coding and conventional relaying to maximize the achievable sum-rate based on the instantaneous link conditions. The proposed user pairing and its extension are based on measurements readily available in today's networks, thus not requiring any signaling overhead. System-level simulations based on adaptive coding and modulation are utilized to quantify the gains from the proposed user pairing and adaptive transmission scheme switch. The obtained results show significant throughput gains especially in the low signal-to-noise ratio region. The gains are due to alleviating the link asymmetry problem in bidirectional relaying with network coding by exploiting multi-user diversity. This improved performance is obtained without any notable increase in complexity, thus rendering the proposed approach a good candidate for practical implementation purposes.
{"title":"Practical user pairing and selective network coding for multi-user bidirectional relaying","authors":"Jawad Manssour","doi":"10.1109/WCNC.2012.6214047","DOIUrl":"https://doi.org/10.1109/WCNC.2012.6214047","url":null,"abstract":"A low-complexity user pairing algorithm for the broadcast phase of the XOR-based network coding is presented. The proposed scheme achieves the same spectral efficiency as an exhaustive search approach based on maximizing the sum-rate when network coding is utilized for all transmissions. The proposed scheme is further complemented with an adaptive switch, per user pair, between network coding and conventional relaying to maximize the achievable sum-rate based on the instantaneous link conditions. The proposed user pairing and its extension are based on measurements readily available in today's networks, thus not requiring any signaling overhead. System-level simulations based on adaptive coding and modulation are utilized to quantify the gains from the proposed user pairing and adaptive transmission scheme switch. The obtained results show significant throughput gains especially in the low signal-to-noise ratio region. The gains are due to alleviating the link asymmetry problem in bidirectional relaying with network coding by exploiting multi-user diversity. This improved performance is obtained without any notable increase in complexity, thus rendering the proposed approach a good candidate for practical implementation purposes.","PeriodicalId":329194,"journal":{"name":"2012 IEEE Wireless Communications and Networking Conference (WCNC)","volume":"2016 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128068681","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}
Pub Date : 2012-04-01DOI: 10.1109/WCNC.2012.6214419
Zhenning Shi, Daqing Gu
In this paper, we investigate efficient beamforming schemes for downlink broadcast channels of MIMO systems. Optimal solution to this problem is known to be infeasible due to the prohibitive complexity and recent research focuses on suboptimal approaches with reduced complexity. We first present a progressive beamforming method that maximizes the net gain in sum throughput for newly added users and achieves high sum throughput in MU-MIMO channels. Nevertheless, there is severe asymmetry in the performance between data streams: data streams scheduled at an earlier stage are better protected compared to their counterparts configured in later stages. We then show that inter-stream asymmetry can be substantially alleviated by updating beamforming vectors over iterations. An adaptive algorithm is developed to enhance the efficiency of iterative processing and is shown to substantially improve the system performance with manageable complexity.
{"title":"Enhanced beamforming over multiple iterations for downlink broadcast channels","authors":"Zhenning Shi, Daqing Gu","doi":"10.1109/WCNC.2012.6214419","DOIUrl":"https://doi.org/10.1109/WCNC.2012.6214419","url":null,"abstract":"In this paper, we investigate efficient beamforming schemes for downlink broadcast channels of MIMO systems. Optimal solution to this problem is known to be infeasible due to the prohibitive complexity and recent research focuses on suboptimal approaches with reduced complexity. We first present a progressive beamforming method that maximizes the net gain in sum throughput for newly added users and achieves high sum throughput in MU-MIMO channels. Nevertheless, there is severe asymmetry in the performance between data streams: data streams scheduled at an earlier stage are better protected compared to their counterparts configured in later stages. We then show that inter-stream asymmetry can be substantially alleviated by updating beamforming vectors over iterations. An adaptive algorithm is developed to enhance the efficiency of iterative processing and is shown to substantially improve the system performance with manageable complexity.","PeriodicalId":329194,"journal":{"name":"2012 IEEE Wireless Communications and Networking Conference (WCNC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121693833","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}
Pub Date : 2012-04-01DOI: 10.1109/WCNC.2012.6214212
S. Kahraman, M. Çelebi
In this paper we introduce an efficient decoding method which is based on the dimensionality reduction of the search tree in the sphere decoder for the golden code in a low SNR regime. A codeword of the golden code has four independent m-QAM data symbols, hence, the required complexity of the exhaustive-search decoder is m4. An efficient implementation of the maximum-likelihood decoder for the golden code with a worst-case complexity is known to be proportional to m2.5. Additionally, in low range of SNR, sphere decoding has significantly high expected decoding complexity. Our motivation is for an efficient decoder with a worst-case complexity of no more than m2 for a low SNR regime. In this purpose, we show that our proposed method has m1.5 complexity in the worst-case with a loss of only 1 dB with respect to optimal decoding.
{"title":"Dimensionality reduced decoding for the golden code with the worst-case complexity of O(m1.5) for low range of SNR","authors":"S. Kahraman, M. Çelebi","doi":"10.1109/WCNC.2012.6214212","DOIUrl":"https://doi.org/10.1109/WCNC.2012.6214212","url":null,"abstract":"In this paper we introduce an efficient decoding method which is based on the dimensionality reduction of the search tree in the sphere decoder for the golden code in a low SNR regime. A codeword of the golden code has four independent m-QAM data symbols, hence, the required complexity of the exhaustive-search decoder is m4. An efficient implementation of the maximum-likelihood decoder for the golden code with a worst-case complexity is known to be proportional to m2.5. Additionally, in low range of SNR, sphere decoding has significantly high expected decoding complexity. Our motivation is for an efficient decoder with a worst-case complexity of no more than m2 for a low SNR regime. In this purpose, we show that our proposed method has m1.5 complexity in the worst-case with a loss of only 1 dB with respect to optimal decoding.","PeriodicalId":329194,"journal":{"name":"2012 IEEE Wireless Communications and Networking Conference (WCNC)","volume":"129 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121775506","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}
Pub Date : 2012-04-01DOI: 10.1109/WCNC.2012.6214341
B. Hao, Zan Li, Yunmei Ren, W. Yin
Passive source localization has been the focus of considerable research efforts due to its usefulness in various applications. This paper performs a fundamental investigation of whether the gain ratios of arrival (GROAs) can be utilized in conjunction with the range differences of arrival (RDOAs) to improve the multiple sources localization accuracy in the presence of sensor location uncertainties. In this paper, we derive the Cramer-Rao lower bound (CRLB) of multiple source location estimate using both RDOAs and GROAs when sensor positions have errors. Simulations show that the localization accuracy improvements contributed by GROA measurements are significant for two far-field sources, two near-field sources and two enclosed sources as the SNR, jamming signal bandwidth factor C/ωo or sensor position error power σs2 increases. The CRLB will provide reasonable reference for localization algorithm research in the future.
{"title":"On the Cramer-Rao bound of multiple sources localization using RDOAs and GROAs in the presence of sensor location uncertainties","authors":"B. Hao, Zan Li, Yunmei Ren, W. Yin","doi":"10.1109/WCNC.2012.6214341","DOIUrl":"https://doi.org/10.1109/WCNC.2012.6214341","url":null,"abstract":"Passive source localization has been the focus of considerable research efforts due to its usefulness in various applications. This paper performs a fundamental investigation of whether the gain ratios of arrival (GROAs) can be utilized in conjunction with the range differences of arrival (RDOAs) to improve the multiple sources localization accuracy in the presence of sensor location uncertainties. In this paper, we derive the Cramer-Rao lower bound (CRLB) of multiple source location estimate using both RDOAs and GROAs when sensor positions have errors. Simulations show that the localization accuracy improvements contributed by GROA measurements are significant for two far-field sources, two near-field sources and two enclosed sources as the SNR, jamming signal bandwidth factor C/ωo or sensor position error power σs2 increases. The CRLB will provide reasonable reference for localization algorithm research in the future.","PeriodicalId":329194,"journal":{"name":"2012 IEEE Wireless Communications and Networking Conference (WCNC)","volume":" 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132076112","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}
Pub Date : 2012-04-01DOI: 10.1109/WCNC.2012.6214311
Kun-Chan Lan, Chen-Yuan Li
Previously, a multi-homed NEMO architecture has been proposed to improve the reliability and aggregate the bandwidth of MR by simultaneously using multiple wireless links. In this work, we propose a novel protocol called ETOM (Enhancements for TCP On a Multi-homed mobile router) to improve the performance of sending a single TCP connection over multiple wireless links on a MR. ETOM consists of three components. First, we use a reordering buffer to eliminate unnecessary retransmission caused by out-of-order packets. Second, we develop a Multi-homed Split Connection mechanism to enable the TCP connection to quickly adapt to the conditions of multiple links when packet loss occurs. Finally, a Scheduled Window-based Transmission Control algorithm is proposed to mitigate the negative effects of out-of-order packets in the case of using heterogeneous links in a multi-homed environment. We evaluate the performance of ETOM by comparing it with the Concurrent Multi-path Transfer SCTP (CMT-SCTP). ETOM resolves several performance issues that could hinder the development and practical application of multi-homed mobile router technology.
以前，已经提出了一种多归属NEMO架构，通过同时使用多个无线链路来提高可靠性和聚合MR带宽。在这项工作中，我们提出了一种新的协议ETOM(增强TCP On a multi -home mobile router)，以提高在MR.上的多个无线链路上发送单个TCP连接的性能。首先，我们使用重排序缓冲区来消除由无序数据包引起的不必要的重传。其次，我们开发了一种多主分离连接机制，使TCP连接能够快速适应多链路发生丢包时的情况。最后，提出了一种基于调度窗口的传输控制算法，以减轻在多宿主环境中使用异构链路时无序数据包的负面影响。我们通过将ETOM与并发多路径传输SCTP (CMT-SCTP)进行比较来评估其性能。ETOM解决了几个性能问题，这些问题可能会阻碍多家庭移动路由器技术的发展和实际应用。
{"title":"Improving TCP performance over an on-board multi-homed network","authors":"Kun-Chan Lan, Chen-Yuan Li","doi":"10.1109/WCNC.2012.6214311","DOIUrl":"https://doi.org/10.1109/WCNC.2012.6214311","url":null,"abstract":"Previously, a multi-homed NEMO architecture has been proposed to improve the reliability and aggregate the bandwidth of MR by simultaneously using multiple wireless links. In this work, we propose a novel protocol called ETOM (Enhancements for TCP On a Multi-homed mobile router) to improve the performance of sending a single TCP connection over multiple wireless links on a MR. ETOM consists of three components. First, we use a reordering buffer to eliminate unnecessary retransmission caused by out-of-order packets. Second, we develop a Multi-homed Split Connection mechanism to enable the TCP connection to quickly adapt to the conditions of multiple links when packet loss occurs. Finally, a Scheduled Window-based Transmission Control algorithm is proposed to mitigate the negative effects of out-of-order packets in the case of using heterogeneous links in a multi-homed environment. We evaluate the performance of ETOM by comparing it with the Concurrent Multi-path Transfer SCTP (CMT-SCTP). ETOM resolves several performance issues that could hinder the development and practical application of multi-homed mobile router technology.","PeriodicalId":329194,"journal":{"name":"2012 IEEE Wireless Communications and Networking Conference (WCNC)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130190603","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}
Pub Date : 2012-04-01DOI: 10.1109/WCNC.2012.6214102
J. Xue, Md. Zahurul I. Sarkar, C. Zhong, T. Ratnarajah
In this paper, we study the error exponent of generalized-K fading multiple-input multiple-output (MIMO) channels over Orthogonal Space-Time Block Codes (OSTBC). Error exponent sets ultimate bounds on the performance of communication systems employing codes of finite complexity and has been seen as one of the most significant information theoretic measures of reliability. In this paper, closed-form expressions of Gallager's random coding and expurgated error exponents for generalized-K fading MIMO channels over OSTBC are derived, assuming that there is no channel-state information (CSI) at the transmitter and perfect CSI at the receiver. Based on which, we gain valuable insight into the fundamental tradeoff between the communication reliability and information rate of the channel. The necessary codeword length to achieve predefined error probability at a given rate below the capacity of channel is identified. Moreover, we derive closed-form expressions for the cutoff rate, critical rate and expurgation rate.
{"title":"Error exponents for Orthogonal STBC in generalized-K fading MIMO channels","authors":"J. Xue, Md. Zahurul I. Sarkar, C. Zhong, T. Ratnarajah","doi":"10.1109/WCNC.2012.6214102","DOIUrl":"https://doi.org/10.1109/WCNC.2012.6214102","url":null,"abstract":"In this paper, we study the error exponent of generalized-K fading multiple-input multiple-output (MIMO) channels over Orthogonal Space-Time Block Codes (OSTBC). Error exponent sets ultimate bounds on the performance of communication systems employing codes of finite complexity and has been seen as one of the most significant information theoretic measures of reliability. In this paper, closed-form expressions of Gallager's random coding and expurgated error exponents for generalized-K fading MIMO channels over OSTBC are derived, assuming that there is no channel-state information (CSI) at the transmitter and perfect CSI at the receiver. Based on which, we gain valuable insight into the fundamental tradeoff between the communication reliability and information rate of the channel. The necessary codeword length to achieve predefined error probability at a given rate below the capacity of channel is identified. Moreover, we derive closed-form expressions for the cutoff rate, critical rate and expurgation rate.","PeriodicalId":329194,"journal":{"name":"2012 IEEE Wireless Communications and Networking Conference (WCNC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130232021","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}
Pub Date : 2012-04-01DOI: 10.1109/WCNC.2012.6214198
Y. Kawamoto, Hiroki Nishiyama, N. Kato, N. Yoshimura, N. Kadowaki
Recently, Non-Geostationary Earth Orbit (NGEO) satellite networks have gained research attention. Since they offer many features, e.g., extensive coverage, disaster-resistance, and efficient power consumption, they are considered as a good candidate for providing global communication services. Moreover, Multi-Layered Satellite Networks (MLSNs), which consist of layered NGEO satellite networks, have attracted much attention since they achieve excellent load distribution through bypassing traffic from the lower layer to upper layer. However, there is a possibility that traffic congestion may exist at a satellite on the upper layer because each satellite on the upper layer usually covers more than one satellite on lower layers in MLSNs. In this paper, we focus on traffic control in two-layered networks, especially on distributing the packet flow between the two layers in order to minimize the transfer delay of the network. Simulation results demonstrate the correctness of our analyses about delay in the network.
{"title":"A delay-based traffic distribution technique for Multi-Layered Satellite Networks","authors":"Y. Kawamoto, Hiroki Nishiyama, N. Kato, N. Yoshimura, N. Kadowaki","doi":"10.1109/WCNC.2012.6214198","DOIUrl":"https://doi.org/10.1109/WCNC.2012.6214198","url":null,"abstract":"Recently, Non-Geostationary Earth Orbit (NGEO) satellite networks have gained research attention. Since they offer many features, e.g., extensive coverage, disaster-resistance, and efficient power consumption, they are considered as a good candidate for providing global communication services. Moreover, Multi-Layered Satellite Networks (MLSNs), which consist of layered NGEO satellite networks, have attracted much attention since they achieve excellent load distribution through bypassing traffic from the lower layer to upper layer. However, there is a possibility that traffic congestion may exist at a satellite on the upper layer because each satellite on the upper layer usually covers more than one satellite on lower layers in MLSNs. In this paper, we focus on traffic control in two-layered networks, especially on distributing the packet flow between the two layers in order to minimize the transfer delay of the network. Simulation results demonstrate the correctness of our analyses about delay in the network.","PeriodicalId":329194,"journal":{"name":"2012 IEEE Wireless Communications and Networking Conference (WCNC)","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134271652","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}
Pub Date : 2012-04-01DOI: 10.1109/WCNC.2012.6214520
I. Stefan, H. Elgala, H. Haas
In this paper, the performance of an asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) indoor wireless system is investigated. In particular, the illuminance distribution inside a room (5m×5 m×3m) under different brightness conditions, i.e. dimming levels, and the electrical signal-to-noise ratio (SNR) at the receiver are considered. The system performance is also assessed in terms of bit-error-ratio (BER) as a function of average transmitted optical power. Brightness control is achieved using the continuous current reduction (CCR) technique to assure higher luminous efficacy compared to the pulse-width modulation (PWM) dimming technique. In addition, the impact of the induced distortions due to the nonlinear behavior of the light-emitting diode (LED) as a light source is included in the simulation model. For a circular area of about 1m radius located directly below one of the four LED illumination modules utilized in the room, having illuminance values above 300 lx (10% brightness), a 9 dB average electrical SNR is achieved at the receiver located on a desktop.
{"title":"Study of dimming and LED nonlinearity for ACO-OFDM based VLC systems","authors":"I. Stefan, H. Elgala, H. Haas","doi":"10.1109/WCNC.2012.6214520","DOIUrl":"https://doi.org/10.1109/WCNC.2012.6214520","url":null,"abstract":"In this paper, the performance of an asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) indoor wireless system is investigated. In particular, the illuminance distribution inside a room (5m×5 m×3m) under different brightness conditions, i.e. dimming levels, and the electrical signal-to-noise ratio (SNR) at the receiver are considered. The system performance is also assessed in terms of bit-error-ratio (BER) as a function of average transmitted optical power. Brightness control is achieved using the continuous current reduction (CCR) technique to assure higher luminous efficacy compared to the pulse-width modulation (PWM) dimming technique. In addition, the impact of the induced distortions due to the nonlinear behavior of the light-emitting diode (LED) as a light source is included in the simulation model. For a circular area of about 1m radius located directly below one of the four LED illumination modules utilized in the room, having illuminance values above 300 lx (10% brightness), a 9 dB average electrical SNR is achieved at the receiver located on a desktop.","PeriodicalId":329194,"journal":{"name":"2012 IEEE Wireless Communications and Networking Conference (WCNC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131555024","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}
Pub Date : 2012-04-01DOI: 10.1109/WCNC.2012.6214313
R. Badra, H. Abdulla
Provision of voice services over 3G W-CDMA radio access networks is generally designed as a function of the air interface requirements of circuit-switched (CS) connections. On the other hand, packetized VoIP speech services such as Skype, which is becoming increasingly popular among 3G users, impose a more demanding set of requirements on the radio interface, carrying a penalty in terms of coverage. This work quantifies such penalty as a function of key parameters of the radio uplink. Results show that Skype coverage is always a fraction of conventional CS speech connections, and that such fraction is mainly a function of the vocoder type selected by Skype and the uplink Block Error Rate. It is found that Skype cell coverage probability ranges from 67% to 98% of the CS voice service coverage. As a result of this analysis, a set of recommendations aimed at closing the gap between CS voice and Skype coverage is formulated.
{"title":"Coverage analysis of Skype VoIP services over 3G cellular networks","authors":"R. Badra, H. Abdulla","doi":"10.1109/WCNC.2012.6214313","DOIUrl":"https://doi.org/10.1109/WCNC.2012.6214313","url":null,"abstract":"Provision of voice services over 3G W-CDMA radio access networks is generally designed as a function of the air interface requirements of circuit-switched (CS) connections. On the other hand, packetized VoIP speech services such as Skype, which is becoming increasingly popular among 3G users, impose a more demanding set of requirements on the radio interface, carrying a penalty in terms of coverage. This work quantifies such penalty as a function of key parameters of the radio uplink. Results show that Skype coverage is always a fraction of conventional CS speech connections, and that such fraction is mainly a function of the vocoder type selected by Skype and the uplink Block Error Rate. It is found that Skype cell coverage probability ranges from 67% to 98% of the CS voice service coverage. As a result of this analysis, a set of recommendations aimed at closing the gap between CS voice and Skype coverage is formulated.","PeriodicalId":329194,"journal":{"name":"2012 IEEE Wireless Communications and Networking Conference (WCNC)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131758207","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}
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