Pub Date : 2009-06-23DOI: 10.1109/WIOPT.2009.5291640
Chul-Ho Lee, Do Young Eun
In this paper we focus on how the heterogeneous contact dynamics of mobile nodes impact the performance of forwarding/routing algorithms in delay/disruption-tolerant networks (DTNs). To this end, we consider two representative heterogeneous network models, each of which captures heterogeneity among node pairs (individual) and heterogeneity in underlying environment (spatial), respectively, and examine the full extent of difference in delay performances they cause on forwarding/routing algorithms through formal stochastic comparisons. We first show that these heterogeneous models correctly capture non-Poisson contact dynamics observed in real traces. Then, we consider direct forwarding and multicopy two-hop relay protocol and rigorously establish stochastic/convex ordering relationships on their delay performances under these heterogeneous models and the corresponding homogeneous model, all of which have the same average inter-contact time over all node pairs. We show that heterogeneous models predict an entirely opposite ordering relationship in the delay performances depending on which of the two heterogeneities is captured. This suggests that merely capturing non-Poisson contact dynamics - even if the entire distribution of aggregated inter-contact time is precisely matched, is not enough and that one should carefully evaluate the performance of forwarding/routing algorithms under a properly chosen heterogeneous network setting. Our results will also be useful in correctly exploiting the underlying heterogeneity structure so as to achieve better performance in DTNs.
{"title":"Heterogeneity in contact dynamics: Helpful or harmful to forwarding algorithms in DTNs?","authors":"Chul-Ho Lee, Do Young Eun","doi":"10.1109/WIOPT.2009.5291640","DOIUrl":"https://doi.org/10.1109/WIOPT.2009.5291640","url":null,"abstract":"In this paper we focus on how the heterogeneous contact dynamics of mobile nodes impact the performance of forwarding/routing algorithms in delay/disruption-tolerant networks (DTNs). To this end, we consider two representative heterogeneous network models, each of which captures heterogeneity among node pairs (individual) and heterogeneity in underlying environment (spatial), respectively, and examine the full extent of difference in delay performances they cause on forwarding/routing algorithms through formal stochastic comparisons. We first show that these heterogeneous models correctly capture non-Poisson contact dynamics observed in real traces. Then, we consider direct forwarding and multicopy two-hop relay protocol and rigorously establish stochastic/convex ordering relationships on their delay performances under these heterogeneous models and the corresponding homogeneous model, all of which have the same average inter-contact time over all node pairs. We show that heterogeneous models predict an entirely opposite ordering relationship in the delay performances depending on which of the two heterogeneities is captured. This suggests that merely capturing non-Poisson contact dynamics - even if the entire distribution of aggregated inter-contact time is precisely matched, is not enough and that one should carefully evaluate the performance of forwarding/routing algorithms under a properly chosen heterogeneous network setting. Our results will also be useful in correctly exploiting the underlying heterogeneity structure so as to achieve better performance in DTNs.","PeriodicalId":143632,"journal":{"name":"2009 7th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks","volume":"317 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115938277","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 : 2009-06-23DOI: 10.1109/WIOPT.2009.5291623
Chi-Kin Chau, M. H. Wahab, Fei Qin, Yunsheng Wang, Yang Yang
Many applications of sensor networks require batteries as the energy source, and hence critically rely on energy optimisation of sensor batteries. But as often neglected by the networking community, most batteries are non-ideal energy reservoirs and can exhibit battery recovery effect — the deliverable energy in batteries can be replenished per se, if left idling for sufficient duration. We made several contributions towards harnessing battery recovery effect in sensor networks. First, we empirically examine the gain of battery runtime due to battery recovery effect, and found this effect significant and duration-dependent. Second, based on our findings, we model the battery recovery effect in the presence of random sensing activities by a Markov chain model, and study the effect of duty cycling and buffering to harness battery recovery effect. Third, we propose a more energy-efficient duty cycling scheme that is aware of battery recovery effect, and analyse its performance with respect to the latency of data delivery.
{"title":"Battery recovery aware sensor networks","authors":"Chi-Kin Chau, M. H. Wahab, Fei Qin, Yunsheng Wang, Yang Yang","doi":"10.1109/WIOPT.2009.5291623","DOIUrl":"https://doi.org/10.1109/WIOPT.2009.5291623","url":null,"abstract":"Many applications of sensor networks require batteries as the energy source, and hence critically rely on energy optimisation of sensor batteries. But as often neglected by the networking community, most batteries are non-ideal energy reservoirs and can exhibit battery recovery effect — the deliverable energy in batteries can be replenished per se, if left idling for sufficient duration. We made several contributions towards harnessing battery recovery effect in sensor networks. First, we empirically examine the gain of battery runtime due to battery recovery effect, and found this effect significant and duration-dependent. Second, based on our findings, we model the battery recovery effect in the presence of random sensing activities by a Markov chain model, and study the effect of duty cycling and buffering to harness battery recovery effect. Third, we propose a more energy-efficient duty cycling scheme that is aware of battery recovery effect, and analyse its performance with respect to the latency of data delivery.","PeriodicalId":143632,"journal":{"name":"2009 7th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115322203","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 : 2009-06-23DOI: 10.1109/WIOPT.2009.5291643
E. Anderson, Gary V. Yee, Caleb T. Phillips, D. Sicker, D. Grunwald
Increasingly, directional antennas are being used in wireless networks. Such antennas can improve the quality of individual links and decrease overall interference. However, the interaction of environmental effects with signal directionality is not well understood. We observe that state of the art simulators make simplifying assumptions which are often unrealistic and can give a misleading picture of application layer performance. Because simulators are often used for prototyping and validating new ideas, their realism and accuracy are of primary importance. In this paper, we apply a new empirical simulation method for directional antennas and study how well this models reality. We show that not only is our model easy to implement, but is also more accurate and thus better able to predict the performance of propagation-sensitive applications.
{"title":"The impact of directional antenna models on simulation accuracy","authors":"E. Anderson, Gary V. Yee, Caleb T. Phillips, D. Sicker, D. Grunwald","doi":"10.1109/WIOPT.2009.5291643","DOIUrl":"https://doi.org/10.1109/WIOPT.2009.5291643","url":null,"abstract":"Increasingly, directional antennas are being used in wireless networks. Such antennas can improve the quality of individual links and decrease overall interference. However, the interaction of environmental effects with signal directionality is not well understood. We observe that state of the art simulators make simplifying assumptions which are often unrealistic and can give a misleading picture of application layer performance. Because simulators are often used for prototyping and validating new ideas, their realism and accuracy are of primary importance. In this paper, we apply a new empirical simulation method for directional antennas and study how well this models reality. We show that not only is our model easy to implement, but is also more accurate and thus better able to predict the performance of propagation-sensitive applications.","PeriodicalId":143632,"journal":{"name":"2009 7th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129444667","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 : 2009-06-23DOI: 10.1109/WIOPT.2009.5291633
V. Simon, M. Bérces, E. Varga, L. Bacsardi
The need for self-managing Multihop MANETs (Mobile Ad Hoc Networks) arose recently, where the network rapidly adapts to the changes of the environment without any central control. One of the challenges is how to spread the information fast and resource-effectively in the network. This paper presents a novel adaptive framework, which utilizes natural selection for choosing the adequate message forwarding algorithms for changing environments. The survival of the competing algorithms depends on their efficiency, while the fitness evaluation is made locally without overhead generating performance feedback. Performance evaluations were carried out in our simulation platform tailored to a self-managing MANET environment, to analyze the performance measures of different message forwarding algorithms.
自管理多跳移动自组织网络(Multihop manet, Mobile Ad Hoc network)是一种无需中央控制就能快速适应环境变化的网络。如何在网络中快速有效地传播信息是一个挑战。本文提出了一种新的自适应框架，利用自然选择来选择适合变化环境的消息转发算法。竞争算法的生存取决于它们的效率，而适应度评估是在局部进行的，没有开销产生性能反馈。性能评估是在我们为自管理MANET环境量身定制的仿真平台上进行的，以分析不同消息转发算法的性能指标。
{"title":"Natural selection of message forwarding algorithms in Multihop wireless networks","authors":"V. Simon, M. Bérces, E. Varga, L. Bacsardi","doi":"10.1109/WIOPT.2009.5291633","DOIUrl":"https://doi.org/10.1109/WIOPT.2009.5291633","url":null,"abstract":"The need for self-managing Multihop MANETs (Mobile Ad Hoc Networks) arose recently, where the network rapidly adapts to the changes of the environment without any central control. One of the challenges is how to spread the information fast and resource-effectively in the network. This paper presents a novel adaptive framework, which utilizes natural selection for choosing the adequate message forwarding algorithms for changing environments. The survival of the competing algorithms depends on their efficiency, while the fitness evaluation is made locally without overhead generating performance feedback. Performance evaluations were carried out in our simulation platform tailored to a self-managing MANET environment, to analyze the performance measures of different message forwarding algorithms.","PeriodicalId":143632,"journal":{"name":"2009 7th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130245789","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 : 2009-06-23DOI: 10.1109/WIOPT.2009.5291629
A. C. Chan
Finding an optimal key assignment (subject to given constraints) for a key predistribution scheme in wireless sensor networks is a difficult task. Hence, most of the practical schemes are based on probabilistic key assignment, which leads to sub-optimal schemes requiring key storage linear in the total number of nodes. A graph theoretic framework is introduced to study the fundamental tradeoffs between key storage, average key path length (directly related to the battery consumption) and resilience (to compromised nodes) of key predistribution schemes for wireless sensor networks. Based on the proposed framework, a lower bound on key storage is derived for a given average key path length. An upper bound on the compromising probability is also given. This framework also leads to the design of key assignment schemes with a storage complexity of the same order as the lower bound.
{"title":"A graph theoretic approach for optimizing key pre-distribution in wireless sensor networks","authors":"A. C. Chan","doi":"10.1109/WIOPT.2009.5291629","DOIUrl":"https://doi.org/10.1109/WIOPT.2009.5291629","url":null,"abstract":"Finding an optimal key assignment (subject to given constraints) for a key predistribution scheme in wireless sensor networks is a difficult task. Hence, most of the practical schemes are based on probabilistic key assignment, which leads to sub-optimal schemes requiring key storage linear in the total number of nodes. A graph theoretic framework is introduced to study the fundamental tradeoffs between key storage, average key path length (directly related to the battery consumption) and resilience (to compromised nodes) of key predistribution schemes for wireless sensor networks. Based on the proposed framework, a lower bound on key storage is derived for a given average key path length. An upper bound on the compromising probability is also given. This framework also leads to the design of key assignment schemes with a storage complexity of the same order as the lower bound.","PeriodicalId":143632,"journal":{"name":"2009 7th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130651170","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 : 2009-06-23DOI: 10.1109/WIOPT.2009.5291617
B. Rong, A. Ephremides
We study the impact of user cooperation in wireless networks on improving the stable throughput and delay performance. Specifically, we consider a multiaccess system in which a set of source users generate packets to deliver to a common destination. A cooperation strategy is proposed at the protocol level, where users with a better channel to the destination have the option to relay packets from users that are farther afield. For the case of erasure channels with single-packet reception, we derive the stable throughput regions under different multiple access policies based on such cooperation strategy. Then we prove that the stable throughput region of the cooperative system strictly contains the stable throughput region achieved without cooperation. We also assess the delay performance, and show that cooperation significantly reduces the delay of all users. Finally, we characterize the effect of inter-user channel quality on performance, and show that the gain in performance through cooperation increases as the channel quality improves. Our work offers an innovative perspective by implementing cooperation at the network protocol level, while taking into consideration of fading and attenuation at the physical layer as well as the nature of traffic burstiness in a network.
{"title":"Protocol-level cooperation in wireless networks: Stable throughput and delay analysis","authors":"B. Rong, A. Ephremides","doi":"10.1109/WIOPT.2009.5291617","DOIUrl":"https://doi.org/10.1109/WIOPT.2009.5291617","url":null,"abstract":"We study the impact of user cooperation in wireless networks on improving the stable throughput and delay performance. Specifically, we consider a multiaccess system in which a set of source users generate packets to deliver to a common destination. A cooperation strategy is proposed at the protocol level, where users with a better channel to the destination have the option to relay packets from users that are farther afield. For the case of erasure channels with single-packet reception, we derive the stable throughput regions under different multiple access policies based on such cooperation strategy. Then we prove that the stable throughput region of the cooperative system strictly contains the stable throughput region achieved without cooperation. We also assess the delay performance, and show that cooperation significantly reduces the delay of all users. Finally, we characterize the effect of inter-user channel quality on performance, and show that the gain in performance through cooperation increases as the channel quality improves. Our work offers an innovative perspective by implementing cooperation at the network protocol level, while taking into consideration of fading and attenuation at the physical layer as well as the nature of traffic burstiness in a network.","PeriodicalId":143632,"journal":{"name":"2009 7th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122473821","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 : 2009-06-23DOI: 10.1109/WIOPT.2009.5291628
K. Son, Yung Yi, S. Chong
Achieving sufficient spatial capacity gain by having small cells requires careful treatment of inter-cell interference (ICI) management via BS power coordination coupled with user scheduling inside cells. Optimal algorithms have been known to be hard to implement due to high computation and signaling overheads. We propose joint pattern-based ICI management and user scheduling algorithms that are practically implementable. The basic idea is to decompose the original problem into two sub-problems, where we run ICI management at a slower time scale than user scheduling. We empirically show that even with such a slow tracking of system dynamics at the ICI management part, the decomposed approach achieves high performance increase, compared to a conventional universal reuse scheme.
{"title":"Adaptive multi-pattern reuse in multi-cell networks","authors":"K. Son, Yung Yi, S. Chong","doi":"10.1109/WIOPT.2009.5291628","DOIUrl":"https://doi.org/10.1109/WIOPT.2009.5291628","url":null,"abstract":"Achieving sufficient spatial capacity gain by having small cells requires careful treatment of inter-cell interference (ICI) management via BS power coordination coupled with user scheduling inside cells. Optimal algorithms have been known to be hard to implement due to high computation and signaling overheads. We propose joint pattern-based ICI management and user scheduling algorithms that are practically implementable. The basic idea is to decompose the original problem into two sub-problems, where we run ICI management at a slower time scale than user scheduling. We empirically show that even with such a slow tracking of system dynamics at the ICI management part, the decomposed approach achieves high performance increase, compared to a conventional universal reuse scheme.","PeriodicalId":143632,"journal":{"name":"2009 7th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122545031","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 : 2009-06-23DOI: 10.1109/WIOPT.2009.5291612
J. Yoon, Hyoungshick Kim
A mobile ad hoc network (MANET) is a decentralized network of mobile nodes. Due to the broadcast nature of radio transmissions, communication in MANETs is more susceptible to malicious traffic analysis. An interesting problem is how to thwart malicious traffic analysis. Most anonymous communication protocols are based on the pseudonyms of mobile nodes. However, conventional pseudonym schemes have some limitations such as collisions of pseudonyms and high computational complexity due to the use of cryptographic hash functions. Collisions of identities are not desirable since they are the main causes for reduced effective bandwidth, increased energy consumption and non-deterministic data delivery. In this paper, we propose a new collision-free pseudonym scheme to enable anonymous communication. In our approach, each node generates pseudonyms by using a permutation matrix without collisions. The challenging issue is how to store the overall permutation matrix. It is practically hard to assume that mobile nodes maintain the permutation matrix due to the limitation of resources. Therefore we design the online computation of each node's own pseudonym without loading the overall matrix.
{"title":"A new collision-free pseudonym scheme in mobile ad hoc networks","authors":"J. Yoon, Hyoungshick Kim","doi":"10.1109/WIOPT.2009.5291612","DOIUrl":"https://doi.org/10.1109/WIOPT.2009.5291612","url":null,"abstract":"A mobile ad hoc network (MANET) is a decentralized network of mobile nodes. Due to the broadcast nature of radio transmissions, communication in MANETs is more susceptible to malicious traffic analysis. An interesting problem is how to thwart malicious traffic analysis. Most anonymous communication protocols are based on the pseudonyms of mobile nodes. However, conventional pseudonym schemes have some limitations such as collisions of pseudonyms and high computational complexity due to the use of cryptographic hash functions. Collisions of identities are not desirable since they are the main causes for reduced effective bandwidth, increased energy consumption and non-deterministic data delivery. In this paper, we propose a new collision-free pseudonym scheme to enable anonymous communication. In our approach, each node generates pseudonyms by using a permutation matrix without collisions. The challenging issue is how to store the overall permutation matrix. It is practically hard to assume that mobile nodes maintain the permutation matrix due to the limitation of resources. Therefore we design the online computation of each node's own pseudonym without loading the overall matrix.","PeriodicalId":143632,"journal":{"name":"2009 7th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127323965","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 : 2009-06-23DOI: 10.1109/WIOPT.2009.5291622
A. Sridharan, B. Krishnamachari
The receiver capacity model is a simple model to capture flow dynamics in a multi-hop wireless network, by presenting linear constraints to define the feasible rate region of the network, taking into account interference. The model associates with each receiver in the network a notion of constant receiver capacity. Receiver capacity is defined as the maximum possible sum rate of all flows that the receiver can send, receive, and overhear. As has been shown in prior work by the authors, the linear constraints presented by this model make it particularly useful in approximating the true rate region, and designing distributed protocols for multi-hop wireless networks. It is well known that if we use only local constraints to define the rate region, the constraints have to be bounded by some fraction of the interference free link rate, in order to ensure that the rate satisfying these constraints can be feasibly scheduled in any graph. The key challenge in using this model is therefore to estimate the fraction of the link rate that the receiver capacity should be set to, in order to present a feasible rate vector. In this work we answer this question from a theoretical standpoint, and show that as long as the receiver capacity is set to ⅓ the interference free link rate, all rate vectors that satisfy the constraints of the receiver capacity model can be feasibly scheduled.
{"title":"Feasibility of the receiver capacity model for multi-hop wireless networks","authors":"A. Sridharan, B. Krishnamachari","doi":"10.1109/WIOPT.2009.5291622","DOIUrl":"https://doi.org/10.1109/WIOPT.2009.5291622","url":null,"abstract":"The receiver capacity model is a simple model to capture flow dynamics in a multi-hop wireless network, by presenting linear constraints to define the feasible rate region of the network, taking into account interference. The model associates with each receiver in the network a notion of constant receiver capacity. Receiver capacity is defined as the maximum possible sum rate of all flows that the receiver can send, receive, and overhear. As has been shown in prior work by the authors, the linear constraints presented by this model make it particularly useful in approximating the true rate region, and designing distributed protocols for multi-hop wireless networks. It is well known that if we use only local constraints to define the rate region, the constraints have to be bounded by some fraction of the interference free link rate, in order to ensure that the rate satisfying these constraints can be feasibly scheduled in any graph. The key challenge in using this model is therefore to estimate the fraction of the link rate that the receiver capacity should be set to, in order to present a feasible rate vector. In this work we answer this question from a theoretical standpoint, and show that as long as the receiver capacity is set to ⅓ the interference free link rate, all rate vectors that satisfy the constraints of the receiver capacity model can be feasibly scheduled.","PeriodicalId":143632,"journal":{"name":"2009 7th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126440113","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 : 2009-06-23DOI: 10.1109/WIOPT.2009.5291589
K. Hayashi, Takeshi Fujii, Megumi Kaneko, H. Sakai, Y. Okada
This paper considers a transmit beamforming and subcarrier power allocation method for orthogonal frequency division multiple access (OFDMA) systems. As the beamforming vector control criterion, we employ the maximization of so-called signal-to-leakage-plus-noise ratio (SLNR) at each base station, which enable us to obtain closed form beamforming vector by using only locally available information. We also discuss the local optimality of the SLNR based beamforming vector. As for the subcarrier power allocation, two different approaches are employed, namely, the equalization of signal-to-interference-plus-noise ratio (SINR) for subcarriers and the maximization of sum rate of subcarriers. Computer simulation results show the validity of the transmit beamforming and power allocation method with highlighting the difference between the two power allocation algorithms.
{"title":"Transmit beamforming and power allocation for downlink OFDMA systems","authors":"K. Hayashi, Takeshi Fujii, Megumi Kaneko, H. Sakai, Y. Okada","doi":"10.1109/WIOPT.2009.5291589","DOIUrl":"https://doi.org/10.1109/WIOPT.2009.5291589","url":null,"abstract":"This paper considers a transmit beamforming and subcarrier power allocation method for orthogonal frequency division multiple access (OFDMA) systems. As the beamforming vector control criterion, we employ the maximization of so-called signal-to-leakage-plus-noise ratio (SLNR) at each base station, which enable us to obtain closed form beamforming vector by using only locally available information. We also discuss the local optimality of the SLNR based beamforming vector. As for the subcarrier power allocation, two different approaches are employed, namely, the equalization of signal-to-interference-plus-noise ratio (SINR) for subcarriers and the maximization of sum rate of subcarriers. Computer simulation results show the validity of the transmit beamforming and power allocation method with highlighting the difference between the two power allocation algorithms.","PeriodicalId":143632,"journal":{"name":"2009 7th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132798417","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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