Pub Date : 2010-12-01DOI: 10.1109/GLOCOM.2010.5684138
R. Chang, W. Fok, Weichao Li, Edmond W. W. Chan, Xiapu Luo
In the current Internet landscape, a stub autonomous system (AS) could choose from a number of providers and peers to advertise its routes. However, the route selection may not always result in a best choice in terms of end-to-end path performance. Instead of having an AS to monitor all possible paths, we argue that it is much more effective and beneficial for a number of neighboring ASes to cooperate in the path measurement. In this paper, we present a neighbor-cooperative measurement system in which each participating AS conducts measurement using their current routes for the same set of remote endpoints. A collation of the measurement results can help identify and correct poor routes, compare different providers' network services, and diagnose network performance problems. We report measurement results from an actual deployment involving eight neighboring universities for over a year.
{"title":"Neighbor-Cooperative Measurement of Network Path Quality","authors":"R. Chang, W. Fok, Weichao Li, Edmond W. W. Chan, Xiapu Luo","doi":"10.1109/GLOCOM.2010.5684138","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5684138","url":null,"abstract":"In the current Internet landscape, a stub autonomous system (AS) could choose from a number of providers and peers to advertise its routes. However, the route selection may not always result in a best choice in terms of end-to-end path performance. Instead of having an AS to monitor all possible paths, we argue that it is much more effective and beneficial for a number of neighboring ASes to cooperate in the path measurement. In this paper, we present a neighbor-cooperative measurement system in which each participating AS conducts measurement using their current routes for the same set of remote endpoints. A collation of the measurement results can help identify and correct poor routes, compare different providers' network services, and diagnose network performance problems. We report measurement results from an actual deployment involving eight neighboring universities for over a year.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"84 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83868846","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 : 2010-12-01DOI: 10.1109/GLOCOM.2010.5683847
Yong Cheng, V. Lau
In this paper, we investigate the convergence behavior of the primal-dual scaled gradient algorithm (PDSGA) for solving distributed network utility maximization problems under time-varying fading channels. Our analysis shows that the proposed PDSGA converges to a limit region rather than a point under FSMC channels. We also show that the asymptotic tracking errors are given by $mathcal{O}left(overline{T}big/ overline{N}right)$, where $overline{T}$ and $overline{N}$ are the update interval and the average sojourn time of the FSMC, respectively. Based on these analysis, we derive a distributive solution for determining the scaling matrices based on local CSI at each node. The numerical results show the superior performance of the proposed PDSGA over several baseline schemes.
{"title":"Iterative Primal-Dual Scaled Gradient Algorithm with Dynamic Scaling Matrices for Solving Distributive NUM over Time-Varying Fading Channels","authors":"Yong Cheng, V. Lau","doi":"10.1109/GLOCOM.2010.5683847","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5683847","url":null,"abstract":"In this paper, we investigate the convergence behavior of the primal-dual scaled gradient algorithm (PDSGA) for solving distributed network utility maximization problems under time-varying fading channels. Our analysis shows that the proposed PDSGA converges to a limit region rather than a point under FSMC channels. We also show that the asymptotic tracking errors are given by $mathcal{O}left(overline{T}big/ overline{N}right)$, where $overline{T}$ and $overline{N}$ are the update interval and the average sojourn time of the FSMC, respectively. Based on these analysis, we derive a distributive solution for determining the scaling matrices based on local CSI at each node. The numerical results show the superior performance of the proposed PDSGA over several baseline schemes.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"85 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83894424","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 : 2010-12-01DOI: 10.1109/GLOCOM.2010.5683485
R. Prabhu, B. Daneshrad
In this paper we formulate a power loading problem for the spatial subchannels (parallel channels) of a single-carrier MIMO-SVD system. The power loading solution is designed to minimize the energy-per-goodbit (EPG) of the MIMO-SVD system. The optimum power loading obtained by solving a nonlinear fractional program, has a closed-form expression and is found by applying a water-filling procedure. It is observed that the optimum total transmit power (water level) depends not only on the MIMO channel realization, but also on the ratio of circuit power cost (which depends on the number of antennas) to transmit power cost (which depends on path loss and other factors). We study the statistical performance (using simulation) of the solution in Rayleigh and Rician flat-fading channels. Using outage EPG as a measure of performance, we determine the MIMO configuration (from a set of allowed configurations) that yields the minimum outage EPG. It is observed that the average number of spatial subchannels utilized (which indicates preference for diversity or multiplexing) depends on the ratio of circuit power cost to transmit power cost and fading type (Rayleigh or Rician). For both cases, the results show that both multiplexing and diversity obtained by MIMO systems are critical for energy efficiency.
{"title":"Energy-Efficient Power Loading for a MIMO-SVD System and Its Performance in Flat Fading","authors":"R. Prabhu, B. Daneshrad","doi":"10.1109/GLOCOM.2010.5683485","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5683485","url":null,"abstract":"In this paper we formulate a power loading problem for the spatial subchannels (parallel channels) of a single-carrier MIMO-SVD system. The power loading solution is designed to minimize the energy-per-goodbit (EPG) of the MIMO-SVD system. The optimum power loading obtained by solving a nonlinear fractional program, has a closed-form expression and is found by applying a water-filling procedure. It is observed that the optimum total transmit power (water level) depends not only on the MIMO channel realization, but also on the ratio of circuit power cost (which depends on the number of antennas) to transmit power cost (which depends on path loss and other factors). We study the statistical performance (using simulation) of the solution in Rayleigh and Rician flat-fading channels. Using outage EPG as a measure of performance, we determine the MIMO configuration (from a set of allowed configurations) that yields the minimum outage EPG. It is observed that the average number of spatial subchannels utilized (which indicates preference for diversity or multiplexing) depends on the ratio of circuit power cost to transmit power cost and fading type (Rayleigh or Rician). For both cases, the results show that both multiplexing and diversity obtained by MIMO systems are critical for energy efficiency.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"2 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83950077","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 : 2010-12-01DOI: 10.1109/GLOCOM.2010.5683364
Qin Huang, Shu Lin, K. Abdel-Ghaffar
Flash memory is a non-volatile computer storage device which consists of blocks of cells. While increasing the voltage level of a single cell is fast and simple, reducing the level of a cell requires the erasing of the entire block containing the cell. Since block erasures are costly, traditional flash coding schemes have been developed to maximize the number of writes before a block erasure is needed. A novel coding scheme based on error-correcting codes allows the cell levels to increase as evenly as possibly and as a result, increases the number of writes before a block erasure. The scheme is also capable of combating noise in flash memories in order to enhance data reliability.
{"title":"Flash Coding Scheme Based on Error-Correcting Codes","authors":"Qin Huang, Shu Lin, K. Abdel-Ghaffar","doi":"10.1109/GLOCOM.2010.5683364","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5683364","url":null,"abstract":"Flash memory is a non-volatile computer storage device which consists of blocks of cells. While increasing the voltage level of a single cell is fast and simple, reducing the level of a cell requires the erasing of the entire block containing the cell. Since block erasures are costly, traditional flash coding schemes have been developed to maximize the number of writes before a block erasure is needed. A novel coding scheme based on error-correcting codes allows the cell levels to increase as evenly as possibly and as a result, increases the number of writes before a block erasure. The scheme is also capable of combating noise in flash memories in order to enhance data reliability.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"10 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83991292","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 : 2010-12-01DOI: 10.1109/GLOCOM.2010.5684246
Dijiang Huang
This paper describes Anonymous Communication Service (ACS), an PKI certificate service based system that permits the end user to access services offered by the service provider (SP) on the world-wide-web anonymously. ACS achieves end user anonymity by using pseudonym certificates issued to the user for the real certificates. The user can obtain multiple pseudonym certificates and use them for different transactions. Web servers or SP's are unable to determine the user's real identity or profile the user based upon the transactions. However, a user performing an illegal transaction can be revoked.
{"title":"Anonymous Certification Services","authors":"Dijiang Huang","doi":"10.1109/GLOCOM.2010.5684246","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5684246","url":null,"abstract":"This paper describes Anonymous Communication Service (ACS), an PKI certificate service based system that permits the end user to access services offered by the service provider (SP) on the world-wide-web anonymously. ACS achieves end user anonymity by using pseudonym certificates issued to the user for the real certificates. The user can obtain multiple pseudonym certificates and use them for different transactions. Web servers or SP's are unable to determine the user's real identity or profile the user based upon the transactions. However, a user performing an illegal transaction can be revoked.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"32 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84003012","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 : 2010-12-01DOI: 10.1109/GLOCOM.2010.5684170
Ming Zhang, S. Alam, Shigang Chen, Jianwei Liu
Contention among multiple nearby WLANs in urban areas may cause severe TCP unfairness, where some TCP flows can achieve very high throughput at the expense of starving others. This unfairness results from the fact that different physical nodes conveying TCP flows at a wireless bottleneck may have different channel observations and consequently they may provide inconsistent feedbacks to the TCP sources. Existing solutions to this problem try to synchronize channel observations of contending nodes by exchanging control messages among them. They rely on the assumption that these nodes are within each other''s transmission range, which however may not always hold. In this paper, we propose a new approach, called Wireless Probabilistic Drop (WPD), to improve TCP fairness without requiring direct communication among nodes. In WPD, when a node detects congestion, it probabilistically chooses to either drop some packets to resolve the congestion, or aggressively spread the congestion signal to other contending nodes. Each node makes the choice with a probability that is proportional to its flow rate. Henceforth, high-rate flows tend to perform rate reduction more often, and low-rate flows are more likely to increase their flow rates. Eventually, all flows passing the bottleneck are expected to get a fair share of the channel bandwidth. Extensive simulations in ns-2 demonstrate that WPD can significantly improve fairness among TCP flows across multiple contending WLANs.
{"title":"A Probabilistic Approach for Improving TCP Fairness across Multiple Contending WLANs","authors":"Ming Zhang, S. Alam, Shigang Chen, Jianwei Liu","doi":"10.1109/GLOCOM.2010.5684170","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5684170","url":null,"abstract":"Contention among multiple nearby WLANs in urban areas may cause severe TCP unfairness, where some TCP flows can achieve very high throughput at the expense of starving others. This unfairness results from the fact that different physical nodes conveying TCP flows at a wireless bottleneck may have different channel observations and consequently they may provide inconsistent feedbacks to the TCP sources. Existing solutions to this problem try to synchronize channel observations of contending nodes by exchanging control messages among them. They rely on the assumption that these nodes are within each other''s transmission range, which however may not always hold. In this paper, we propose a new approach, called Wireless Probabilistic Drop (WPD), to improve TCP fairness without requiring direct communication among nodes. In WPD, when a node detects congestion, it probabilistically chooses to either drop some packets to resolve the congestion, or aggressively spread the congestion signal to other contending nodes. Each node makes the choice with a probability that is proportional to its flow rate. Henceforth, high-rate flows tend to perform rate reduction more often, and low-rate flows are more likely to increase their flow rates. Eventually, all flows passing the bottleneck are expected to get a fair share of the channel bandwidth. Extensive simulations in ns-2 demonstrate that WPD can significantly improve fairness among TCP flows across multiple contending WLANs.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"21 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82866990","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 : 2010-12-01DOI: 10.1109/GLOCOM.2010.5683455
K. Law, Barnabas C. Okeke
Sensors in wireless sensor network (WSN) usually spatially spread across geographical locations. They may be placed randomly or in an initially organized manner to cooperatively monitor certain physical or environmental phenomena. They have limited transmission powers due to their small sizes and battery constraints. Some sensors may not be able to send data directly to the sink for processing and analysis. This has led to, for example, the design of tree-based structure for delivering data over multiple hops to reach the sink. In this paper, a novel lifetime extending heuristic (MLC-X) is proposed for tree-based multi-level clustered wireless sensor network. Duties of nodes at bottlenecks in tree are modified for sustaining longer network lifetime. And the simulation results indicate that the heuristic can successfully extend life spans of sensor networks.
{"title":"Lifetime Extending Heuristic for Clustered Wireless Sensor Networks","authors":"K. Law, Barnabas C. Okeke","doi":"10.1109/GLOCOM.2010.5683455","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5683455","url":null,"abstract":"Sensors in wireless sensor network (WSN) usually spatially spread across geographical locations. They may be placed randomly or in an initially organized manner to cooperatively monitor certain physical or environmental phenomena. They have limited transmission powers due to their small sizes and battery constraints. Some sensors may not be able to send data directly to the sink for processing and analysis. This has led to, for example, the design of tree-based structure for delivering data over multiple hops to reach the sink. In this paper, a novel lifetime extending heuristic (MLC-X) is proposed for tree-based multi-level clustered wireless sensor network. Duties of nodes at bottlenecks in tree are modified for sustaining longer network lifetime. And the simulation results indicate that the heuristic can successfully extend life spans of sensor networks.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"54 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82886776","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 : 2010-12-01DOI: 10.1109/GLOCOM.2010.5683107
Hanlin Sun, Yuehui Jin, Yidong Cui, Shiduan Cheng
End-to-end delay is an important QoS metric and has received much research attention. Recently, the multifractal detrended fluctuation analysis (MFDFA) is widely used as a robust tool to investigate the scale behavior of non-stationary time series. In this paper, we use MFDFA to analyze the scale behavior of end-to-end delay series. Based on ping series of both home and international paths, we find the 2-order correlation of delay series is analysis scale, path, and (collection) time dependent: may be biscaling or even multiscaling, persistent or anti-persistent. In addition, we observe that delay series may be multifractal at both fine and coarse scales. We also examine the source of multifractality for delay series and find the source is much complex.
{"title":"Investigating Scaling Behavior of End-to-End Delay","authors":"Hanlin Sun, Yuehui Jin, Yidong Cui, Shiduan Cheng","doi":"10.1109/GLOCOM.2010.5683107","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5683107","url":null,"abstract":"End-to-end delay is an important QoS metric and has received much research attention. Recently, the multifractal detrended fluctuation analysis (MFDFA) is widely used as a robust tool to investigate the scale behavior of non-stationary time series. In this paper, we use MFDFA to analyze the scale behavior of end-to-end delay series. Based on ping series of both home and international paths, we find the 2-order correlation of delay series is analysis scale, path, and (collection) time dependent: may be biscaling or even multiscaling, persistent or anti-persistent. In addition, we observe that delay series may be multifractal at both fine and coarse scales. We also examine the source of multifractality for delay series and find the source is much complex.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"55 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82760421","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 : 2010-12-01DOI: 10.1109/GLOCOM.2010.5683673
J. Kao, S. Berber, V. Kecman
In this paper, we propose a support vector machine receiver for a multi-code Chaos-based CDMA (MC-CB-CDMA) system. Unlike the conventional multi-code CDMA, the main aim for the assigning multiple spreading codes for each user is to provide unequal error protection on the transmitted data without using further error correction coding (ECC). In addition, the proposed SVM receiver is further simplified by the recursive feature elimination algorithm so that it has a less complexity than the conventional correlator receiver. The modified receiver is also very flexible in controlling the level of error protection in the system. Simulation results are compared with correlator receiver and huge performance gain is achieved due to the multi-user detection capability from the SVM receiver. Theoretical probability of error for both the correlator and the SVM receiver have been derived and confirmed with the simulation results.
{"title":"Adaptive Multi-Code Chaos-Based CDMA with Unequal Error Protection Using Reduced Support Vector Machine","authors":"J. Kao, S. Berber, V. Kecman","doi":"10.1109/GLOCOM.2010.5683673","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5683673","url":null,"abstract":"In this paper, we propose a support vector machine receiver for a multi-code Chaos-based CDMA (MC-CB-CDMA) system. Unlike the conventional multi-code CDMA, the main aim for the assigning multiple spreading codes for each user is to provide unequal error protection on the transmitted data without using further error correction coding (ECC). In addition, the proposed SVM receiver is further simplified by the recursive feature elimination algorithm so that it has a less complexity than the conventional correlator receiver. The modified receiver is also very flexible in controlling the level of error protection in the system. Simulation results are compared with correlator receiver and huge performance gain is achieved due to the multi-user detection capability from the SVM receiver. Theoretical probability of error for both the correlator and the SVM receiver have been derived and confirmed with the simulation results.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"5 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86749685","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 : 2010-12-01DOI: 10.1109/GLOCOM.2010.5683133
Ruben P. Murillo-Perez, C. B. Rodríguez-Estrello, F. A. Cruz-Pérez
In this paper, two analytical approaches to approximately calculate the access (at connection level) waiting time distribution for an OFDMA-based wireless cellular system with finite buffering under First-Come, First-Served (FCFS) discipline and Adaptive Modulation and Coding (AMC) are proposed. It has been demonstrated in previous published works that access waiting time is a random sum of random variables with the same distribution but random mean. Therefore, the computational complexity for the numerical evaluation of the access waiting time probability distribution increases exponentially with the size of the buffer and the number of coverage regions. In order to reduce the computational complexity, the use of negative exponential distribution is proposed to approximate the whole access waiting time distribution for certain conditions of traffic load. Moreover, an efficient way to calculate its parameter through the Little's theorem is proposed. A more general approach is based on the central limit theorem (CLT). In particular, it considers that the conditional access waiting time of a service request queued in the a given position can be adequately approximated by a Gaussian distribution. The proposed approximation approaches are numerically evaluated and compared against the exact mathematical analysis in terms of the cumulative distribution function. Numerical results show that the maximum percentage error between the both approximated CDFs is smaller than 10% relative to the exact analysis under certain conditions.
{"title":"Approximated Calculations of Connection Level Access Waiting Time Distribution in OFDMA-Based Wireless Cellular Systems with AMC","authors":"Ruben P. Murillo-Perez, C. B. Rodríguez-Estrello, F. A. Cruz-Pérez","doi":"10.1109/GLOCOM.2010.5683133","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5683133","url":null,"abstract":"In this paper, two analytical approaches to approximately calculate the access (at connection level) waiting time distribution for an OFDMA-based wireless cellular system with finite buffering under First-Come, First-Served (FCFS) discipline and Adaptive Modulation and Coding (AMC) are proposed. It has been demonstrated in previous published works that access waiting time is a random sum of random variables with the same distribution but random mean. Therefore, the computational complexity for the numerical evaluation of the access waiting time probability distribution increases exponentially with the size of the buffer and the number of coverage regions. In order to reduce the computational complexity, the use of negative exponential distribution is proposed to approximate the whole access waiting time distribution for certain conditions of traffic load. Moreover, an efficient way to calculate its parameter through the Little's theorem is proposed. A more general approach is based on the central limit theorem (CLT). In particular, it considers that the conditional access waiting time of a service request queued in the a given position can be adequately approximated by a Gaussian distribution. The proposed approximation approaches are numerically evaluated and compared against the exact mathematical analysis in terms of the cumulative distribution function. Numerical results show that the maximum percentage error between the both approximated CDFs is smaller than 10% relative to the exact analysis under certain conditions.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"13 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86791640","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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