Pub Date : 2007-09-01DOI: 10.1093/ietcom/e90-b.9.2513
Y. Fukuda, Y. Oie
Wireless LANs have been widely deployed, and multiple access points (APs) are likely to become much more available for wireless stations (STAs) which can roam from one AP to another by some rule. We focus on an efficient and fair way to use the wireless access resources provided by multiple APs. In particular, our major concern is to develop a decentralized way to enable each STA to select an appropriate available AP independently. A straightforward way is to select the AP with the strongest signal; however, this is shown to need further improvement. Hence, we propose decentralized AP selection strategies to achieve an efficient and fair share of wireless access resources, and evaluate them by simulations. The results show that the proposed strategies can attain an excellent throughput performance by use of the number of active STAs sharing each AP, even if STAs employ the strategies only when entering the wireless LAN. In addition, if STAs roam from one AP to another, the total throughput and fairness can be further improved very much.
{"title":"Decentralized access point selection architecture for wireless LANs","authors":"Y. Fukuda, Y. Oie","doi":"10.1093/ietcom/e90-b.9.2513","DOIUrl":"https://doi.org/10.1093/ietcom/e90-b.9.2513","url":null,"abstract":"Wireless LANs have been widely deployed, and multiple access points (APs) are likely to become much more available for wireless stations (STAs) which can roam from one AP to another by some rule. We focus on an efficient and fair way to use the wireless access resources provided by multiple APs. In particular, our major concern is to develop a decentralized way to enable each STA to select an appropriate available AP independently. A straightforward way is to select the AP with the strongest signal; however, this is shown to need further improvement. Hence, we propose decentralized AP selection strategies to achieve an efficient and fair share of wireless access resources, and evaluate them by simulations. The results show that the proposed strategies can attain an excellent throughput performance by use of the number of active STAs sharing each AP, even if STAs employ the strategies only when entering the wireless LAN. In addition, if STAs roam from one AP to another, the total throughput and fairness can be further improved very much.","PeriodicalId":242981,"journal":{"name":"2004 Symposium on Wireless Telecommunications","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124612352","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 : 2004-05-14DOI: 10.1109/WTS.2004.1319584
Jun Li, Yan Du, Wei Zhang, Yongsheng Zhang
We present new carrier frequency acquisition and channel estimation algorithms for OFDM systems. Both new algorithms utilize only one training frame to carry out carrier frequency acquisition and channel estimation at the same time. The simulation results show that both algorithms are immune from timing error with a high precision and low computational complexity.
{"title":"Joint carrier frequency acquisition and channel estimation algorithms for OFDM systems","authors":"Jun Li, Yan Du, Wei Zhang, Yongsheng Zhang","doi":"10.1109/WTS.2004.1319584","DOIUrl":"https://doi.org/10.1109/WTS.2004.1319584","url":null,"abstract":"We present new carrier frequency acquisition and channel estimation algorithms for OFDM systems. Both new algorithms utilize only one training frame to carry out carrier frequency acquisition and channel estimation at the same time. The simulation results show that both algorithms are immune from timing error with a high precision and low computational complexity.","PeriodicalId":242981,"journal":{"name":"2004 Symposium on Wireless Telecommunications","volume":"21 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120984993","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 : 2004-05-14DOI: 10.1109/WTS.2004.1319563
P. Maruthi, G. Sridhar, V. Sridhar
We consider a campus environment connected using multiple WLANs and WLAN routers providing interconnection between the WLAN networks. The servers part of WLANs in a campus network provide various services to users across the network. We have extended our earlier work related to service- and session-specific labeling, path, and switching. The extension is to support service-specific QoS and this is achieved by identifying an SSP (service-specific path) tree (a collection of SSPs) rooted at the WLAN router connected to the server hosting the service. Further, the service QoS parameters are distributed across the SSP tree for network resource reservation purposes. This reserved SSP tree is used to set up bidirectional QoS supported session-specific paths.
{"title":"QoS management in service specific label switched wireless networks","authors":"P. Maruthi, G. Sridhar, V. Sridhar","doi":"10.1109/WTS.2004.1319563","DOIUrl":"https://doi.org/10.1109/WTS.2004.1319563","url":null,"abstract":"We consider a campus environment connected using multiple WLANs and WLAN routers providing interconnection between the WLAN networks. The servers part of WLANs in a campus network provide various services to users across the network. We have extended our earlier work related to service- and session-specific labeling, path, and switching. The extension is to support service-specific QoS and this is achieved by identifying an SSP (service-specific path) tree (a collection of SSPs) rooted at the WLAN router connected to the server hosting the service. Further, the service QoS parameters are distributed across the SSP tree for network resource reservation purposes. This reserved SSP tree is used to set up bidirectional QoS supported session-specific paths.","PeriodicalId":242981,"journal":{"name":"2004 Symposium on Wireless Telecommunications","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125558272","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 : 2004-05-14DOI: 10.1109/WTS.2004.1319545
Chi-Chen Lee, Jul-Hung Yeh, Jyh-cheng Chen
The paper provides the comparison between WCDMA and cdma2000 of the impact of an inactivity timer on the energy consumption of a mobile station. Both simulation and analysis are utilized to investigate the impact of the inactivity timer and the performance comparison between WCDMA and cdma2000. The novel and practical models proposed analyze and quantify the energy consumption in the case of bursty and streaming traffic. The analytic models are verified extensively by simulation.
{"title":"Impact of inactivity timer on energy consumption in WCDMA and cdma2000","authors":"Chi-Chen Lee, Jul-Hung Yeh, Jyh-cheng Chen","doi":"10.1109/WTS.2004.1319545","DOIUrl":"https://doi.org/10.1109/WTS.2004.1319545","url":null,"abstract":"The paper provides the comparison between WCDMA and cdma2000 of the impact of an inactivity timer on the energy consumption of a mobile station. Both simulation and analysis are utilized to investigate the impact of the inactivity timer and the performance comparison between WCDMA and cdma2000. The novel and practical models proposed analyze and quantify the energy consumption in the case of bursty and streaming traffic. The analytic models are verified extensively by simulation.","PeriodicalId":242981,"journal":{"name":"2004 Symposium on Wireless Telecommunications","volume":"217 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115986824","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 : 2004-05-14DOI: 10.1109/WTS.2004.1319562
J. Holub, J. Beerends, R. Smid
The paper deals with the estimation of the relation between speech transmission quality and average call duration for a given network and portfolio of customers. It uses non-intrusive speech quality measurements on live speech calls. The basic idea behind this analysis is an expectation that the average call duration is higher for calls of a good quality since users are less disturbed during their conversation by transmission impairments. Both traditional and state of the art methods for non-intrusive speech transmission quality measurements and also for call duration monitoring are briefly described and two basic dependency analysis methods are shown. The relations for result uncertainty estimation are derived. A numerical example is given based on a limited training database that is constructed on the basis of real network data. Finally, potential applications are presented and discussed The first results indicate that, in the low to medium quality range (mean opinion scores between 1 and 3), the call duration increases with increasing speech quality.
{"title":"A dependence between average call duration and voice transmission quality: measurement and applications","authors":"J. Holub, J. Beerends, R. Smid","doi":"10.1109/WTS.2004.1319562","DOIUrl":"https://doi.org/10.1109/WTS.2004.1319562","url":null,"abstract":"The paper deals with the estimation of the relation between speech transmission quality and average call duration for a given network and portfolio of customers. It uses non-intrusive speech quality measurements on live speech calls. The basic idea behind this analysis is an expectation that the average call duration is higher for calls of a good quality since users are less disturbed during their conversation by transmission impairments. Both traditional and state of the art methods for non-intrusive speech transmission quality measurements and also for call duration monitoring are briefly described and two basic dependency analysis methods are shown. The relations for result uncertainty estimation are derived. A numerical example is given based on a limited training database that is constructed on the basis of real network data. Finally, potential applications are presented and discussed The first results indicate that, in the low to medium quality range (mean opinion scores between 1 and 3), the call duration increases with increasing speech quality.","PeriodicalId":242981,"journal":{"name":"2004 Symposium on Wireless Telecommunications","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114827580","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 : 2004-05-14DOI: 10.1109/WTS.2004.1319548
Chen Chen, Jiandong Li, Linjing Zhao, Jun Niu
A novel estimator for integer frequency offset estimation of OFDM systems is derived, which is based on the maximum likelihood (ML) technique and exploits the differential information between two consecutive blocks of OFDM data symbols in the frequency domain. The reason why the ML estimator has better performance than the conventional method is analyzed. How to select the differential sequence is also studied. By computer simulations, the performance of the ML estimator is compared with that of the conventional method for the additive white Gaussian noise (AWGN) channel and the multipath fading channel. The simulation results are in good agreement with the analytical study.
{"title":"ML-based estimator for integer frequency offset estimation of OFDM systems","authors":"Chen Chen, Jiandong Li, Linjing Zhao, Jun Niu","doi":"10.1109/WTS.2004.1319548","DOIUrl":"https://doi.org/10.1109/WTS.2004.1319548","url":null,"abstract":"A novel estimator for integer frequency offset estimation of OFDM systems is derived, which is based on the maximum likelihood (ML) technique and exploits the differential information between two consecutive blocks of OFDM data symbols in the frequency domain. The reason why the ML estimator has better performance than the conventional method is analyzed. How to select the differential sequence is also studied. By computer simulations, the performance of the ML estimator is compared with that of the conventional method for the additive white Gaussian noise (AWGN) channel and the multipath fading channel. The simulation results are in good agreement with the analytical study.","PeriodicalId":242981,"journal":{"name":"2004 Symposium on Wireless Telecommunications","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122747727","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 : 2004-05-14DOI: 10.1109/WTS.2004.1319570
Xiaoyong Su, B. Prabhu, C. Chu, R. Gadh
Although various collaborative systems have successfully improved enterprise work efficiency, mobile collaborative systems, which allow collaboration via wireless networks and mobile devices, still lack robust functionality and content representation support. The paper proposes a novel mobile collaboration framework for multimedia content generation, representation and delivery. A unified file format and a message queue management middleware, designed for, and employed in, a heterogeneous computing environment, are also discussed.
{"title":"Middleware for multimedia mobile collaborative system","authors":"Xiaoyong Su, B. Prabhu, C. Chu, R. Gadh","doi":"10.1109/WTS.2004.1319570","DOIUrl":"https://doi.org/10.1109/WTS.2004.1319570","url":null,"abstract":"Although various collaborative systems have successfully improved enterprise work efficiency, mobile collaborative systems, which allow collaboration via wireless networks and mobile devices, still lack robust functionality and content representation support. The paper proposes a novel mobile collaboration framework for multimedia content generation, representation and delivery. A unified file format and a message queue management middleware, designed for, and employed in, a heterogeneous computing environment, are also discussed.","PeriodicalId":242981,"journal":{"name":"2004 Symposium on Wireless Telecommunications","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132249727","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 : 2004-05-14DOI: 10.1109/WTS.2004.1319568
Wei Li, Hang-Li Chen, D. Agrawal
We propose and analyze a handoff scheme with channel borrowing in integrated wireless mobile networks. Channels in each cell are divided into two parts and pre-allocated to real-time and non-real-time services. Each type of service is allowed to borrow channels from the other under certain conditions. A non-real-time service call can borrow an unused channel assigned to real-time service but it can be preempted by a real-time service call. A real-time service call borrows a channel from non-real-time service with a certain probability which depends on the number of available idle non-real-time service channels. We model the system by a six-dimensional Markov chain and compute the system performance in terms of blocking probability of originating calls, forced termination probability of real-time service calls, and average transmission delay of non-real-time service calls. The proposed scheme maximizes the resource utilization and keeps a certain quality of service (QoS) for each service at the time of congestion.
{"title":"A handoff scheme with probability-based channel borrowing in integrated wireless mobile networks","authors":"Wei Li, Hang-Li Chen, D. Agrawal","doi":"10.1109/WTS.2004.1319568","DOIUrl":"https://doi.org/10.1109/WTS.2004.1319568","url":null,"abstract":"We propose and analyze a handoff scheme with channel borrowing in integrated wireless mobile networks. Channels in each cell are divided into two parts and pre-allocated to real-time and non-real-time services. Each type of service is allowed to borrow channels from the other under certain conditions. A non-real-time service call can borrow an unused channel assigned to real-time service but it can be preempted by a real-time service call. A real-time service call borrows a channel from non-real-time service with a certain probability which depends on the number of available idle non-real-time service channels. We model the system by a six-dimensional Markov chain and compute the system performance in terms of blocking probability of originating calls, forced termination probability of real-time service calls, and average transmission delay of non-real-time service calls. The proposed scheme maximizes the resource utilization and keeps a certain quality of service (QoS) for each service at the time of congestion.","PeriodicalId":242981,"journal":{"name":"2004 Symposium on Wireless Telecommunications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131064693","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 : 2004-05-14DOI: 10.1109/WTS.2004.1319581
Z. Taha, Xian Liu
An ad hoc network is a collection of wireless mobile hosts forming a temporary network without the aid of any centralized administration. In the absence of a centralized administration node, routing is a challenging issue. We focus on a particular source initiated on-demand protocol, called dynamic source routing (DSR), and show how use of multipath techniques can reduce the frequency of route discovery. The frequency of route discovery in DSR is one of the main performance metrics in mobile ad hoc networks. This performance metric was studied using an exponential model, which might be an appropriate model for voice traffic, but is not a suitable model for data traffic. Studies have shown that data traffic is more precisely characterized by heavy-tailed distributions. We present an approach to characterize data traffic through the compound log-normal distribution. Reliability archetypes of series and parallel connections have been used in developing these models.
{"title":"A model for evaluating multi-route routing in ad hoc networks","authors":"Z. Taha, Xian Liu","doi":"10.1109/WTS.2004.1319581","DOIUrl":"https://doi.org/10.1109/WTS.2004.1319581","url":null,"abstract":"An ad hoc network is a collection of wireless mobile hosts forming a temporary network without the aid of any centralized administration. In the absence of a centralized administration node, routing is a challenging issue. We focus on a particular source initiated on-demand protocol, called dynamic source routing (DSR), and show how use of multipath techniques can reduce the frequency of route discovery. The frequency of route discovery in DSR is one of the main performance metrics in mobile ad hoc networks. This performance metric was studied using an exponential model, which might be an appropriate model for voice traffic, but is not a suitable model for data traffic. Studies have shown that data traffic is more precisely characterized by heavy-tailed distributions. We present an approach to characterize data traffic through the compound log-normal distribution. Reliability archetypes of series and parallel connections have been used in developing these models.","PeriodicalId":242981,"journal":{"name":"2004 Symposium on Wireless Telecommunications","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133334273","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 : 2004-05-14DOI: 10.1109/WTS.2004.1319582
Xiaolong Li, D. Agrawal, Qing-An Zeng
In ad hoc networks, the mobility of nodes affects the system performance. Considerable attention has been paid to mobility models. However, most work is confined to simulation. A novel method is proposed to analyze the performance of mobile ad hoc networks (MANETs) considering the node's mobility. In the proposed method, of each communicating pair, one is considered to be stationary while the second is moving with a velocity relative to the first one. Using this method, system performance parameters, such as the average radio range dwell time of mobile nodes, link holding time, link breaking probability, and throughput of CSMA/CA protocols, are obtained by a theoretical framework. The results obtained from the proposed analytical model are observed to match well with simulation results.
{"title":"Impact of mobility on the performance of mobile ad hoc networks","authors":"Xiaolong Li, D. Agrawal, Qing-An Zeng","doi":"10.1109/WTS.2004.1319582","DOIUrl":"https://doi.org/10.1109/WTS.2004.1319582","url":null,"abstract":"In ad hoc networks, the mobility of nodes affects the system performance. Considerable attention has been paid to mobility models. However, most work is confined to simulation. A novel method is proposed to analyze the performance of mobile ad hoc networks (MANETs) considering the node's mobility. In the proposed method, of each communicating pair, one is considered to be stationary while the second is moving with a velocity relative to the first one. Using this method, system performance parameters, such as the average radio range dwell time of mobile nodes, link holding time, link breaking probability, and throughput of CSMA/CA protocols, are obtained by a theoretical framework. The results obtained from the proposed analytical model are observed to match well with simulation results.","PeriodicalId":242981,"journal":{"name":"2004 Symposium on Wireless Telecommunications","volume":"183 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131610047","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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