Pub Date : 2008-12-30DOI: 10.1109/ISWCS.2008.4726051
Manuj Sharma, A. Sahoo, K. Nayak
Cognitive radio based dynamic spectrum access network is emerging as a technology to address spectrum scarcity. In this study, we assume that the channel is licensed to some primary (licensed) operator. We consider a sensor network with cognitive radio capability that acts as a secondary (unlicensed) network and uses the channel in underlay mode. The secondary network uses interference temperature model to ensure that the interference to the primary devices remain below a predefined threshold. We use hidden Markov model (HMM) to model the interference temperature dynamics of a primary channel. The HMM is trained using Baum-Welch procedure. The trained HMM is shown to be statistically stable. Secondary nodes use this trained HMM to predict the interference temperature of the channel in future time slots and computes the value of channel availability metric (CAM) for the channel. CAM is used by secondary nodes to select a primary channel for transmission. Results of application of such trained HMMs in channel selection in multi-channel wireless network are presented.
{"title":"Channel modeling based on interference temperature in underlay cognitive wireless networks","authors":"Manuj Sharma, A. Sahoo, K. Nayak","doi":"10.1109/ISWCS.2008.4726051","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726051","url":null,"abstract":"Cognitive radio based dynamic spectrum access network is emerging as a technology to address spectrum scarcity. In this study, we assume that the channel is licensed to some primary (licensed) operator. We consider a sensor network with cognitive radio capability that acts as a secondary (unlicensed) network and uses the channel in underlay mode. The secondary network uses interference temperature model to ensure that the interference to the primary devices remain below a predefined threshold. We use hidden Markov model (HMM) to model the interference temperature dynamics of a primary channel. The HMM is trained using Baum-Welch procedure. The trained HMM is shown to be statistically stable. Secondary nodes use this trained HMM to predict the interference temperature of the channel in future time slots and computes the value of channel availability metric (CAM) for the channel. CAM is used by secondary nodes to select a primary channel for transmission. Results of application of such trained HMMs in channel selection in multi-channel wireless network are presented.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127526387","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 : 2008-12-30DOI: 10.1109/ISWCS.2008.4726154
Jinglong Zhou, A. Lo, Ziyuan Liu, I. Niemegeers
Next generation communication networks will comprise third-generation (3G) cellular and multi-hop ad hoc networks. The paper has evaluated the end-to-end performance of TCP over a multi-hop cellular network that comprises the enhanced universal mobile telecommunications system (UMTS), namely, HSDPA and the IEEE 802.11 ad hoc networks for bulk data transfers under different HSDPA radio channel quality as well as number of hops. The throughput simulation results show that bottleneck of the multi-hop cellular network shifted between the UMTS/HSDPA network and the ad hoc network based on the different channel quality and number of hops. Ad hoc network can increase the service range of cellular network, and also improve the performance for the end-user who experiences bad channel conditions. Moreover, the relation between HSDPA radio channel usage and end-to-end user experience under different network configurations and channel conditions is also revealed. Our result can be used to select optimal routes and system performance optimization.
{"title":"TCP performance evaluation over multi-hop cellular network: HSDPA and IEEE 802.11","authors":"Jinglong Zhou, A. Lo, Ziyuan Liu, I. Niemegeers","doi":"10.1109/ISWCS.2008.4726154","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726154","url":null,"abstract":"Next generation communication networks will comprise third-generation (3G) cellular and multi-hop ad hoc networks. The paper has evaluated the end-to-end performance of TCP over a multi-hop cellular network that comprises the enhanced universal mobile telecommunications system (UMTS), namely, HSDPA and the IEEE 802.11 ad hoc networks for bulk data transfers under different HSDPA radio channel quality as well as number of hops. The throughput simulation results show that bottleneck of the multi-hop cellular network shifted between the UMTS/HSDPA network and the ad hoc network based on the different channel quality and number of hops. Ad hoc network can increase the service range of cellular network, and also improve the performance for the end-user who experiences bad channel conditions. Moreover, the relation between HSDPA radio channel usage and end-to-end user experience under different network configurations and channel conditions is also revealed. Our result can be used to select optimal routes and system performance optimization.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124878770","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 : 2008-12-30DOI: 10.1109/ISWCS.2008.4726132
S. MacLean, S. Datta
Wireless sensor networks have been used in proposed solutions to many important practical problems. A very important problem in many wireless sensor networks is localization, or the determination of geographical locations of the sensor nodes. In this work, we study the problem of range-free localization-or computing locations based only on the neighborhood information of nodes. These algorithms typically assume that a fraction of the sensor nodes (called seeds) know their location at all times, by using GPS or other means. Other nodes compute their locations by exchanging information with their neighbors. A lower bound on the expected maximum achievable accuracy of range-free localization algorithms was presented in Nagpal et al., 2003. This bound has been widely quoted in the literature and has been extended by Hu and Evans, 2004. In this paper, we show that the previous argument used is incorrect and prove a correct lower bound. We compare our analytical results with measurements from simulation experiments. Finally, we discuss why bounds obtained using this argument may not be tight and how better bounds may be proved.
无线传感器网络已被用于解决许多重要的实际问题。在许多无线传感器网络中，一个非常重要的问题是定位，或确定传感器节点的地理位置。在这项工作中，我们研究了无距离定位问题-或仅基于节点的邻域信息计算位置。这些算法通常假设一小部分传感器节点(称为种子)通过使用GPS或其他手段随时知道它们的位置。其他节点通过与邻居交换信息来计算它们的位置。Nagpal et al.， 2003提出了无距离定位算法期望最大可实现精度的下界。这一界限在文献中被广泛引用，并由Hu和Evans(2004)扩展。在本文中，我们证明了先前使用的论点是不正确的，并证明了一个正确的下界。我们将分析结果与模拟实验的测量结果进行了比较。最后，我们讨论了为什么用这个论证得到的界可能不是紧的，以及如何证明更好的界。
{"title":"A lower bound on range-free node localization algorithms","authors":"S. MacLean, S. Datta","doi":"10.1109/ISWCS.2008.4726132","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726132","url":null,"abstract":"Wireless sensor networks have been used in proposed solutions to many important practical problems. A very important problem in many wireless sensor networks is localization, or the determination of geographical locations of the sensor nodes. In this work, we study the problem of range-free localization-or computing locations based only on the neighborhood information of nodes. These algorithms typically assume that a fraction of the sensor nodes (called seeds) know their location at all times, by using GPS or other means. Other nodes compute their locations by exchanging information with their neighbors. A lower bound on the expected maximum achievable accuracy of range-free localization algorithms was presented in Nagpal et al., 2003. This bound has been widely quoted in the literature and has been extended by Hu and Evans, 2004. In this paper, we show that the previous argument used is incorrect and prove a correct lower bound. We compare our analytical results with measurements from simulation experiments. Finally, we discuss why bounds obtained using this argument may not be tight and how better bounds may be proved.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116488369","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 : 2008-12-30DOI: 10.1109/ISWCS.2008.4726092
L. Thiele, M. Schellmann, T. Wirth, V. Jungnickel
Cellular radio systems are often limited due to the presence of cochannel interference. Basically, radio systems may be operated by utilizing asynchronous or synchronous downlink transmission from all base stations in the system, where synchronization between terminals and their serving base station is mandatory in both concepts. We provide a comparison between the theoretical achievable spectral efficiency in an orthogonal frequency division multiple access systems using different linear equalizers and their resulting performance taking estimation errors into account. It is shown, that the choice of the appropriate receiver depends on the degree of synchronization in the system. We demonstrate that a 3G long term evolution radio system may achieve higher spectral efficiency thanks to interference suppression if fully synchronized data transmission from all base stations is introduced.
{"title":"On the value of synchronous downlink MIMO-OFDMA systems with linear equalizers","authors":"L. Thiele, M. Schellmann, T. Wirth, V. Jungnickel","doi":"10.1109/ISWCS.2008.4726092","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726092","url":null,"abstract":"Cellular radio systems are often limited due to the presence of cochannel interference. Basically, radio systems may be operated by utilizing asynchronous or synchronous downlink transmission from all base stations in the system, where synchronization between terminals and their serving base station is mandatory in both concepts. We provide a comparison between the theoretical achievable spectral efficiency in an orthogonal frequency division multiple access systems using different linear equalizers and their resulting performance taking estimation errors into account. It is shown, that the choice of the appropriate receiver depends on the degree of synchronization in the system. We demonstrate that a 3G long term evolution radio system may achieve higher spectral efficiency thanks to interference suppression if fully synchronized data transmission from all base stations is introduced.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"778 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125946636","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 : 2008-12-30DOI: 10.1109/ISWCS.2008.4726064
A. Enayati, A. Salahi
In this paper, we propose a low rate bandwidth efficient channel coding scheme for MC-CDMA system so that by using it, the coded system without any extra bandwidth, significantly improves the performance of an un-coded system over fading channels. Moreover, we investigate the performance of multiple antennas array aided coded MC-CDMA system by employing different smart antennas techniques at the receiver and in order to reduce the search space and computational complexity of Maximum Likelihood (ML) post-FFT Multiuser Detection (MUD) technique, we propose a ML algorithm based on Sensitive Bits Algorithm (SBA) and Less Complex Norm Approximation (LCNA) based Euclidean distance. The performance and complexity of the proposed MUD algorithms are compared with nonlinear MMSE-SIC and ML MUD algorithms. It is shown that with a minimal penalty in performance compared to ML algorithm, the SBA-LCNA-based proposed two-step schemes for multiple antennas array aided coded MC-CDMA system have significant reduction in the complexity.
{"title":"A novel channel coding scheme for smart antenna based MC-CDMA systems mid two-step reduced complexity Multiuser Detection algorithm","authors":"A. Enayati, A. Salahi","doi":"10.1109/ISWCS.2008.4726064","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726064","url":null,"abstract":"In this paper, we propose a low rate bandwidth efficient channel coding scheme for MC-CDMA system so that by using it, the coded system without any extra bandwidth, significantly improves the performance of an un-coded system over fading channels. Moreover, we investigate the performance of multiple antennas array aided coded MC-CDMA system by employing different smart antennas techniques at the receiver and in order to reduce the search space and computational complexity of Maximum Likelihood (ML) post-FFT Multiuser Detection (MUD) technique, we propose a ML algorithm based on Sensitive Bits Algorithm (SBA) and Less Complex Norm Approximation (LCNA) based Euclidean distance. The performance and complexity of the proposed MUD algorithms are compared with nonlinear MMSE-SIC and ML MUD algorithms. It is shown that with a minimal penalty in performance compared to ML algorithm, the SBA-LCNA-based proposed two-step schemes for multiple antennas array aided coded MC-CDMA system have significant reduction in the complexity.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127411235","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 : 2008-12-30DOI: 10.1109/ISWCS.2008.4726049
S. Mekki, J. Danger, B. Miscopein, J. Boutros
The Expectation-Maximization (EM) algorithm is studied to perform channel estimation in a low cost and high data rate impulse radio UWB receiver. The system under consideration uses a pulse position modulation with a simple analog energy detector. In order to overcome the problems inherent to high data rates, such as inter-symbol interferences, a probabilistic equalizer is used. The EM algorithm and the equalizer are embedded into the loop of an iterative channel decoder. This permits to refine both the channel parameters and the signal probability at each iteration. We present numerical results performed on the channel models from the IEEE 802.15.3 a task group. These results show that the EM algorithm contributes to achieve data rate greater than 100 Mb/s with a simple impulse radio UWB receiver.
{"title":"EM channel estimation in a low-cost UWB receiver based on energy detection","authors":"S. Mekki, J. Danger, B. Miscopein, J. Boutros","doi":"10.1109/ISWCS.2008.4726049","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726049","url":null,"abstract":"The Expectation-Maximization (EM) algorithm is studied to perform channel estimation in a low cost and high data rate impulse radio UWB receiver. The system under consideration uses a pulse position modulation with a simple analog energy detector. In order to overcome the problems inherent to high data rates, such as inter-symbol interferences, a probabilistic equalizer is used. The EM algorithm and the equalizer are embedded into the loop of an iterative channel decoder. This permits to refine both the channel parameters and the signal probability at each iteration. We present numerical results performed on the channel models from the IEEE 802.15.3 a task group. These results show that the EM algorithm contributes to achieve data rate greater than 100 Mb/s with a simple impulse radio UWB receiver.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128272510","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 : 2008-12-30DOI: 10.1109/ISWCS.2008.4726043
S. Michaelis, A. Lewandowski, K. Daniel, C. Wietfeld
Efficient management of mobile network resources is a critical task for successful operation. Giving higher priority and quality of service to applications with a high return on invest value, demands for intelligent distribution of bit rates and radio access. The research approach proposed here is based on the fact, that users cannot move freely, but are restricted to streets or rails in position, direction and speed. Following the geographical topology while in motion some locations generate a unique signature by forcing the user to traverse similar sequences of base stations. The signatures can be revealed by applying pattern detection methods on the historical user movements, allowing to predict future positions of the user on a large time scale, especially to reserve resources for rescue workers. In this paper we discuss the effect of different attributes about the user's movement for the prediction quality on different pattern detection algorithms in order to improve and accelerate the process of rescue missions. Further the availability of these attributes will be discussed for different scenarios and validated by traces from an actual large scale HSDPA/GSM network.
{"title":"Macromobility prediction for high-priority resource reservation in wireless networks","authors":"S. Michaelis, A. Lewandowski, K. Daniel, C. Wietfeld","doi":"10.1109/ISWCS.2008.4726043","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726043","url":null,"abstract":"Efficient management of mobile network resources is a critical task for successful operation. Giving higher priority and quality of service to applications with a high return on invest value, demands for intelligent distribution of bit rates and radio access. The research approach proposed here is based on the fact, that users cannot move freely, but are restricted to streets or rails in position, direction and speed. Following the geographical topology while in motion some locations generate a unique signature by forcing the user to traverse similar sequences of base stations. The signatures can be revealed by applying pattern detection methods on the historical user movements, allowing to predict future positions of the user on a large time scale, especially to reserve resources for rescue workers. In this paper we discuss the effect of different attributes about the user's movement for the prediction quality on different pattern detection algorithms in order to improve and accelerate the process of rescue missions. Further the availability of these attributes will be discussed for different scenarios and validated by traces from an actual large scale HSDPA/GSM network.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131766945","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 : 2008-12-30DOI: 10.1109/ISWCS.2008.4726030
U. Bandara, Priyantha Bandara
Tagciti is a novel location-aware and socially-relevant information creating and discovering service for mobile users. Instead of depending on commercially created location related information, Tagciti provides users the necessary means to become part of the information creation process. It enables the creation of dynamic, up to date, and socially-relevant shared information. Also, it provides an effective mechanism to discover created information in a socially-relevant and location-aware manner utilizing users¿ social network and location information. We recognize the following as the key requirements for Tagciti: expressive, extensible and well defined data structure, correlation of information, self governing of the service, organic growth of the system with the community, and integration with existing technology. The initial system has been implemented based on the above requirements. Moreover, the mobile terminal implementation of the system is conducted using two separate platforms: Android platform of Open Handset Alliance and Japans¿ Mobile-Internet. Based on user tests and feasibility evaluations, the effectiveness and relevance of such a service in a mobile environment is evaluated and also the improvements needed to be done in the next stage of system implementation is recognized.
{"title":"Tagciti: A practical approach for location-aware and socially-relevant information creation and discovery for mobile users","authors":"U. Bandara, Priyantha Bandara","doi":"10.1109/ISWCS.2008.4726030","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726030","url":null,"abstract":"Tagciti is a novel location-aware and socially-relevant information creating and discovering service for mobile users. Instead of depending on commercially created location related information, Tagciti provides users the necessary means to become part of the information creation process. It enables the creation of dynamic, up to date, and socially-relevant shared information. Also, it provides an effective mechanism to discover created information in a socially-relevant and location-aware manner utilizing users¿ social network and location information. We recognize the following as the key requirements for Tagciti: expressive, extensible and well defined data structure, correlation of information, self governing of the service, organic growth of the system with the community, and integration with existing technology. The initial system has been implemented based on the above requirements. Moreover, the mobile terminal implementation of the system is conducted using two separate platforms: Android platform of Open Handset Alliance and Japans¿ Mobile-Internet. Based on user tests and feasibility evaluations, the effectiveness and relevance of such a service in a mobile environment is evaluated and also the improvements needed to be done in the next stage of system implementation is recognized.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133600075","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 : 2008-12-30DOI: 10.1587/TRANSCOM.E92.B.1627
Daisuke Nishikawa, Y. Kishiyama, K. Higuchi, M. Sawahashi
This paper presents the optimum control interval for intra-cell fractional transmission power control (TPC) for a shared data channel employing frequency domain channel-dependent scheduling and adaptive modulation and coding (AMC) in the evolved UTRA uplink using single-carrier (SC)-FDMA radio access. The simulation results show that the best attenuation factor in the fractional TPC is approximately 0.6 for achieving the maximum user throughput when the maximum target received signal power, P0 is -60 dBm. Then, we show that the optimum averaging interval for the desired signal level, which corresponds to a substantial control interval for the fractional TPC, is approximately 100 - 200 msec regardless of the maximum Doppler frequency up to 222 Hz and the distance at the shadowing correlation of 0.5. Throughout the simulation results, we verify that slow intra-cell fractional TPC associated with fast AMC is effective in achieving the maximum cell throughput and cell-edge user throughput.
{"title":"Investigation on optimum control interval for intra-cell fractional TPC using AMC for shared channel in Evolved UTRA uplink","authors":"Daisuke Nishikawa, Y. Kishiyama, K. Higuchi, M. Sawahashi","doi":"10.1587/TRANSCOM.E92.B.1627","DOIUrl":"https://doi.org/10.1587/TRANSCOM.E92.B.1627","url":null,"abstract":"This paper presents the optimum control interval for intra-cell fractional transmission power control (TPC) for a shared data channel employing frequency domain channel-dependent scheduling and adaptive modulation and coding (AMC) in the evolved UTRA uplink using single-carrier (SC)-FDMA radio access. The simulation results show that the best attenuation factor in the fractional TPC is approximately 0.6 for achieving the maximum user throughput when the maximum target received signal power, P0 is -60 dBm. Then, we show that the optimum averaging interval for the desired signal level, which corresponds to a substantial control interval for the fractional TPC, is approximately 100 - 200 msec regardless of the maximum Doppler frequency up to 222 Hz and the distance at the shadowing correlation of 0.5. Throughout the simulation results, we verify that slow intra-cell fractional TPC associated with fast AMC is effective in achieving the maximum cell throughput and cell-edge user throughput.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134335048","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 : 2008-12-30DOI: 10.1109/ISWCS.2008.4726148
Stefan Alfredsson, A. Brunström, M. Sternad
The performance of applications in wireless networks is partly dependent upon the link configuration. Link characteristics varies with frame retransmission persistency, link frame retransmission delay, adaptive modulation strategies, coding, and more. The link configuration and channel conditions can lead to packet loss, delay and delay variations, which impact different applications in different ways. A bulk transfer application may tolerate delays to a large extent, while packet loss is undesirable. On the other hand, real-time interactive applications are sensitive to delay and delay variations, but may tolerate packet loss to a certain extent. This paper contributes a study of the effect of link frame retransmission persistency and delay on packet loss and latency for real-time interactive applications. The results indicate that a reliable retransmission mechanism with fast link retransmissions in the range of 2-8 ms is sufficient to provide an upper delay bound of 50 ms over the wireless link, which is well within the delay budget of voice over IP applications.
{"title":"Impact of 4G wireless link configurations on VoIP network performance","authors":"Stefan Alfredsson, A. Brunström, M. Sternad","doi":"10.1109/ISWCS.2008.4726148","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726148","url":null,"abstract":"The performance of applications in wireless networks is partly dependent upon the link configuration. Link characteristics varies with frame retransmission persistency, link frame retransmission delay, adaptive modulation strategies, coding, and more. The link configuration and channel conditions can lead to packet loss, delay and delay variations, which impact different applications in different ways. A bulk transfer application may tolerate delays to a large extent, while packet loss is undesirable. On the other hand, real-time interactive applications are sensitive to delay and delay variations, but may tolerate packet loss to a certain extent. This paper contributes a study of the effect of link frame retransmission persistency and delay on packet loss and latency for real-time interactive applications. The results indicate that a reliable retransmission mechanism with fast link retransmissions in the range of 2-8 ms is sufficient to provide an upper delay bound of 50 ms over the wireless link, which is well within the delay budget of voice over IP applications.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129344699","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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