Pub Date : 2017-05-15DOI: 10.23919/WIOPT.2017.7959900
Marija Stojanova, Thomas Begin, A. Busson
WLANs (Wireless Local Area Networks) have become ubiquitous in our everyday life, and are mostly based on IEEE 802.11 standards. In this paper, we consider the performance evaluation of an arbitrary-topology unsaturated network based on the IEEE 802.11 DCF. We present a conflict graph-based modeling approach to discover the attainable throughput of each node. Our model consists of a single Markov chain which aims at describing, at a high-level of abstraction, the current state of the entire wireless network. Owing to its low complexity, our approach is simple to implement, can cope with medium sized networks, and its execution speed is fast. We validate its accuracy against a discrete-event simulator. Results show that our approach is typically accurate, with associated relative errors generally less than 15%, and that it captures complex phenomena such as node starvation. We investigate two potential applications of our proposed approach in which, starting with a given network, we improve its performance in terms of overall throughput or fairness by throttling the throughput demand of a node, or by turning a node off altogether.
{"title":"Conflict graph-based Markovian model to estimate throughput in unsaturated IEEE 802.11 networks","authors":"Marija Stojanova, Thomas Begin, A. Busson","doi":"10.23919/WIOPT.2017.7959900","DOIUrl":"https://doi.org/10.23919/WIOPT.2017.7959900","url":null,"abstract":"WLANs (Wireless Local Area Networks) have become ubiquitous in our everyday life, and are mostly based on IEEE 802.11 standards. In this paper, we consider the performance evaluation of an arbitrary-topology unsaturated network based on the IEEE 802.11 DCF. We present a conflict graph-based modeling approach to discover the attainable throughput of each node. Our model consists of a single Markov chain which aims at describing, at a high-level of abstraction, the current state of the entire wireless network. Owing to its low complexity, our approach is simple to implement, can cope with medium sized networks, and its execution speed is fast. We validate its accuracy against a discrete-event simulator. Results show that our approach is typically accurate, with associated relative errors generally less than 15%, and that it captures complex phenomena such as node starvation. We investigate two potential applications of our proposed approach in which, starting with a given network, we improve its performance in terms of overall throughput or fairness by throttling the throughput demand of a node, or by turning a node off altogether.","PeriodicalId":6630,"journal":{"name":"2017 15th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83837467","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 : 2017-05-15DOI: 10.23919/WIOPT.2017.7959941
Zheng Chang, Zhongyu Wang, Xijuan Guo, Zhu Han, T. Ristaniemi
In this paper, we investigate the energy efficient resource allocation problem for the wireless powered OFDMA multi-cell networks. In the considered system, the users who have data to transmit in the uplink are empowered by the wireless power obtained from multiple base stations (BSs) with a large scale of multiple antennas in the downlink. A time division protocol is considered to divide the time of wireless power transfer (WPT) in the downlink and wireless information transfer (WIT) in the uplink into separate time slot. With the objective to improve the energy efficiency (EE) of the system, we propose the antenna selection, time allocation, subcarrier and power allocation schemes. Due to the non-convexity of the formulated optimization problem, we first apply the nonlinear programming scheme to convert it to a convex optimization problem and then address it through an efficient alternating direction method of multipliers based distributed resource allocation algorithm. Extensive simulations are conducted to show the effectiveness of proposed schemes.
{"title":"Energy efficient and distributed resource allocation for wireless powered OFDMA multi-cell networks","authors":"Zheng Chang, Zhongyu Wang, Xijuan Guo, Zhu Han, T. Ristaniemi","doi":"10.23919/WIOPT.2017.7959941","DOIUrl":"https://doi.org/10.23919/WIOPT.2017.7959941","url":null,"abstract":"In this paper, we investigate the energy efficient resource allocation problem for the wireless powered OFDMA multi-cell networks. In the considered system, the users who have data to transmit in the uplink are empowered by the wireless power obtained from multiple base stations (BSs) with a large scale of multiple antennas in the downlink. A time division protocol is considered to divide the time of wireless power transfer (WPT) in the downlink and wireless information transfer (WIT) in the uplink into separate time slot. With the objective to improve the energy efficiency (EE) of the system, we propose the antenna selection, time allocation, subcarrier and power allocation schemes. Due to the non-convexity of the formulated optimization problem, we first apply the nonlinear programming scheme to convert it to a convex optimization problem and then address it through an efficient alternating direction method of multipliers based distributed resource allocation algorithm. Extensive simulations are conducted to show the effectiveness of proposed schemes.","PeriodicalId":6630,"journal":{"name":"2017 15th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72907770","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 : 2017-05-15DOI: 10.23919/WIOPT.2017.7959867
M. N. Soorki, Mohammad J. Abdel-Rahman, A. B. Mackenzie, W. Saad
Millimeter wave (mmWave) communication is a promising solution for providing high capacity wireless access to regions with high traffic demands. The main challenge of mmWave communications is the availability of directional line of sight links between access points and mobile devices which stochastically change due to high attenuation in mmWave propagation and severe blockage of mmWave links with obstacles such as human bodies. In this paper, a novel framework for optimizing the deployment of mmW access points, while being cognizant of the mobile devices orientation, is proposed. In the studied model, the locations of potential access points and users are assumed as predefined parameters while the orientation of the users is changing stochastically. To minimize the number of access points while satisfying the line of sight coverage of mobile devices, first, a joint access point placement and mobile device assignment problem is proposed, assuming that the orientation of each user is deterministically known. This formulation is then extended to the case in which the orientation of the user is stochastic. Finally, the proposed deterministic and stochastic joint access point placement and mobile device assignment schemes are evaluated under various system parameters. Simulation results demonstrate the advantage of the proposed stochastic scheme to the deterministic scheme, in terms of reducing the load on access points. Moreover, on average, the proposed stochastic scheme can increase the probability of user satisfaction up to 24% for 0.95 requested coverage probability compared to the deterministic case.
{"title":"Joint access point deployment and assignment in mmWave networks with stochastic user orientation","authors":"M. N. Soorki, Mohammad J. Abdel-Rahman, A. B. Mackenzie, W. Saad","doi":"10.23919/WIOPT.2017.7959867","DOIUrl":"https://doi.org/10.23919/WIOPT.2017.7959867","url":null,"abstract":"Millimeter wave (mmWave) communication is a promising solution for providing high capacity wireless access to regions with high traffic demands. The main challenge of mmWave communications is the availability of directional line of sight links between access points and mobile devices which stochastically change due to high attenuation in mmWave propagation and severe blockage of mmWave links with obstacles such as human bodies. In this paper, a novel framework for optimizing the deployment of mmW access points, while being cognizant of the mobile devices orientation, is proposed. In the studied model, the locations of potential access points and users are assumed as predefined parameters while the orientation of the users is changing stochastically. To minimize the number of access points while satisfying the line of sight coverage of mobile devices, first, a joint access point placement and mobile device assignment problem is proposed, assuming that the orientation of each user is deterministically known. This formulation is then extended to the case in which the orientation of the user is stochastic. Finally, the proposed deterministic and stochastic joint access point placement and mobile device assignment schemes are evaluated under various system parameters. Simulation results demonstrate the advantage of the proposed stochastic scheme to the deterministic scheme, in terms of reducing the load on access points. Moreover, on average, the proposed stochastic scheme can increase the probability of user satisfaction up to 24% for 0.95 requested coverage probability compared to the deterministic case.","PeriodicalId":6630,"journal":{"name":"2017 15th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72625294","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 : 2017-05-15DOI: 10.23919/WIOPT.2017.7959936
J. Gorce, Yasser Fadlallah, J. Kélif, H. V. Poor, A. Gati
The envisioned Internet of Things (IoT) will involve a massive deployment of objects connected through wireless cells. While commercial solutions are already available, the fundamental limits of such networks in terms of node density, achievable rates or reliability are not known. To address this question, this paper uses a large scale Multiple Access Channel (MAC) to model IoT nodes randomly distributed over the coverage area of a unique base station. The traffic is represented by an information rate spatial density ρ(x). This model, referred to as the Spatial Continuum Multiple Access Channel, is defined as the asymptotic limit of a sequence of discrete MACs. The access capacity region of this channel is defined as the set of achievable information rate spatial densities achievable with vanishing transmission errors and under a sum-power constraint. Simulation results validate the model and show that this fundamental limit theoretically achievable when all nodes transmit simultaneously over an infinite time, may be reached even with a relatively small number of simultaneous transmitters (typically around 20 nodes) which gives credibility to the model. The results also highlight the potential interest of non-orthogonal transmissions for IoT uplink transmissions when compared to an ideal time sharing strategy.
{"title":"Fundamental limits of a dense IoT cell in the uplink","authors":"J. Gorce, Yasser Fadlallah, J. Kélif, H. V. Poor, A. Gati","doi":"10.23919/WIOPT.2017.7959936","DOIUrl":"https://doi.org/10.23919/WIOPT.2017.7959936","url":null,"abstract":"The envisioned Internet of Things (IoT) will involve a massive deployment of objects connected through wireless cells. While commercial solutions are already available, the fundamental limits of such networks in terms of node density, achievable rates or reliability are not known. To address this question, this paper uses a large scale Multiple Access Channel (MAC) to model IoT nodes randomly distributed over the coverage area of a unique base station. The traffic is represented by an information rate spatial density ρ(x). This model, referred to as the Spatial Continuum Multiple Access Channel, is defined as the asymptotic limit of a sequence of discrete MACs. The access capacity region of this channel is defined as the set of achievable information rate spatial densities achievable with vanishing transmission errors and under a sum-power constraint. Simulation results validate the model and show that this fundamental limit theoretically achievable when all nodes transmit simultaneously over an infinite time, may be reached even with a relatively small number of simultaneous transmitters (typically around 20 nodes) which gives credibility to the model. The results also highlight the potential interest of non-orthogonal transmissions for IoT uplink transmissions when compared to an ideal time sharing strategy.","PeriodicalId":6630,"journal":{"name":"2017 15th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80744185","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 : 2017-05-15DOI: 10.23919/WIOPT.2017.7959896
Foad Hajiaghajani, R. Davoudi, M. Rasti
In this paper, we investigate the joint admission control and resource allocation problem for collaborative computation under fading channels. We develop an Internet-of-Things (IoT) framework in which establishing Device-to-Device (D2D) communications, resource-poor wearable Source Mobile Terminals (SMTs) may offload their computations to resource-rich Processing Mobile Terminals (PMTs), or execute them locally, so as to save energy. Considering the offloading scenario, first, a probabilistic admission control algorithm is proposed for Mobile Terminals (MTs) taking both the deadline and energy harvesting constraints into account. Then, the joint CPU clock frequency/transmit power allocation and collaborative pair selection problem for MTs is addressed mathematically. For local execution scenario, optimal CPU clock frequencies are obtained for SMTs. Finally, based on energy consumption and outage imposed by each scenario, SMTs decide whether to offload their computations or execute them locally. Simulation results demonstrate that the proposed D2D-aided Collaborative Mobile Cloud (DCMC) approach attains a near-optimal energy expenditure in a semi-feasible system while effectively mitigating outage ratio of MTs.
{"title":"Energy efficient resource allocation and admission control for D2D-aided collaborative mobile clouds","authors":"Foad Hajiaghajani, R. Davoudi, M. Rasti","doi":"10.23919/WIOPT.2017.7959896","DOIUrl":"https://doi.org/10.23919/WIOPT.2017.7959896","url":null,"abstract":"In this paper, we investigate the joint admission control and resource allocation problem for collaborative computation under fading channels. We develop an Internet-of-Things (IoT) framework in which establishing Device-to-Device (D2D) communications, resource-poor wearable Source Mobile Terminals (SMTs) may offload their computations to resource-rich Processing Mobile Terminals (PMTs), or execute them locally, so as to save energy. Considering the offloading scenario, first, a probabilistic admission control algorithm is proposed for Mobile Terminals (MTs) taking both the deadline and energy harvesting constraints into account. Then, the joint CPU clock frequency/transmit power allocation and collaborative pair selection problem for MTs is addressed mathematically. For local execution scenario, optimal CPU clock frequencies are obtained for SMTs. Finally, based on energy consumption and outage imposed by each scenario, SMTs decide whether to offload their computations or execute them locally. Simulation results demonstrate that the proposed D2D-aided Collaborative Mobile Cloud (DCMC) approach attains a near-optimal energy expenditure in a semi-feasible system while effectively mitigating outage ratio of MTs.","PeriodicalId":6630,"journal":{"name":"2017 15th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80870769","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 : 2017-05-15DOI: 10.23919/WIOPT.2017.7959879
M. Hanawal, Y. Hayel, Quanyan Zhu
Throughput of a mobile ad hoc network (MANET) operating on an unlicensed spectrum can increase if nodes can also transmit on a (shared) licensed spectrum. However, the transmissions on the licensed spectrum has to be limited to avoid degradation of quality of service (QoS) to primary users (PUs). We address the problem of how the nodes of a MANET or secondary users (SUs) should spread their transmissions on both licensed and unlicensed spectra to maximize network throughput, and characterize ‘throughput gain’ achieved in such spectrum sharing systems. We show that the gain can be significant and is increasing in the density of the SUs. The primary and secondary users are modeled as two independent Poisson point processes and their performance is evaluated using techniques from stochastic geometry.
{"title":"Throughput maximization of large-scale secondary networks over licensed and unlicensed spectra","authors":"M. Hanawal, Y. Hayel, Quanyan Zhu","doi":"10.23919/WIOPT.2017.7959879","DOIUrl":"https://doi.org/10.23919/WIOPT.2017.7959879","url":null,"abstract":"Throughput of a mobile ad hoc network (MANET) operating on an unlicensed spectrum can increase if nodes can also transmit on a (shared) licensed spectrum. However, the transmissions on the licensed spectrum has to be limited to avoid degradation of quality of service (QoS) to primary users (PUs). We address the problem of how the nodes of a MANET or secondary users (SUs) should spread their transmissions on both licensed and unlicensed spectra to maximize network throughput, and characterize ‘throughput gain’ achieved in such spectrum sharing systems. We show that the gain can be significant and is increasing in the density of the SUs. The primary and secondary users are modeled as two independent Poisson point processes and their performance is evaluated using techniques from stochastic geometry.","PeriodicalId":6630,"journal":{"name":"2017 15th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78808668","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 : 2017-05-15DOI: 10.23919/WIOPT.2017.7959931
Dor Shaviv, Ayfer Özgür
We consider a general class of stochastic optimization problems, in which the state represents a certain level or amount which can be partly used and depleted, and subsequently filled by a random amount. This is motivated by energy harvesting applications, in which one manages the amount of energy in a battery, but is also related to inventory models and queuing models. We propose a simple policy that requires minimal knowledge of the distribution of the stochastic process involved, and show that it is a close approximation to the optimal solution with bounded guarantees. Specifically, under natural assumptions on the reward function, we provide constant multiplicative and additive gaps to optimality, which do not depend on the problem parameters. This allows us to obtain a simple formula for approximating the long-term expected average reward, which gives some insight on its qualitative behavior as a function of the maximal state and the distribution of the disturbance.
{"title":"Approximately optimal policies for a class of Markov decision problems with applications to energy harvesting","authors":"Dor Shaviv, Ayfer Özgür","doi":"10.23919/WIOPT.2017.7959931","DOIUrl":"https://doi.org/10.23919/WIOPT.2017.7959931","url":null,"abstract":"We consider a general class of stochastic optimization problems, in which the state represents a certain level or amount which can be partly used and depleted, and subsequently filled by a random amount. This is motivated by energy harvesting applications, in which one manages the amount of energy in a battery, but is also related to inventory models and queuing models. We propose a simple policy that requires minimal knowledge of the distribution of the stochastic process involved, and show that it is a close approximation to the optimal solution with bounded guarantees. Specifically, under natural assumptions on the reward function, we provide constant multiplicative and additive gaps to optimality, which do not depend on the problem parameters. This allows us to obtain a simple formula for approximating the long-term expected average reward, which gives some insight on its qualitative behavior as a function of the maximal state and the distribution of the disturbance.","PeriodicalId":6630,"journal":{"name":"2017 15th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89072848","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 : 2017-05-15DOI: 10.23919/WIOPT.2017.7959949
Helena Rocha, Tiago Cacoilo, Pedro Rodrigues, S. Kandasamy, R. Campos
Enterprise Wi-Fi networks have been increasingly considering energy efficiency. In this paper, we present the Wi-Green project wherein we are investigating new techniques and innovative solutions that will allow the minimization of the energy consumption in Wi-Fi networks. In Wi-Green we will consider an enterprise network, in which there is equipment from different vendors, with different ages and different consumption profiles.
{"title":"Wi-Green: Optimization of the power consumption of Wi-Fi networks sensitive to traffic patterns invited paper","authors":"Helena Rocha, Tiago Cacoilo, Pedro Rodrigues, S. Kandasamy, R. Campos","doi":"10.23919/WIOPT.2017.7959949","DOIUrl":"https://doi.org/10.23919/WIOPT.2017.7959949","url":null,"abstract":"Enterprise Wi-Fi networks have been increasingly considering energy efficiency. In this paper, we present the Wi-Green project wherein we are investigating new techniques and innovative solutions that will allow the minimization of the energy consumption in Wi-Fi networks. In Wi-Green we will consider an enterprise network, in which there is equipment from different vendors, with different ages and different consumption profiles.","PeriodicalId":6630,"journal":{"name":"2017 15th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88485059","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 : 2017-05-15DOI: 10.23919/WIOPT.2017.7959872
Alessandro Lieto, Ilaria Malanchini, V. Suryaprakash, A. Capone
Active sharing of wireless infrastructure can be an effective approach to reduce costs and improve network profitability. However, schemes proposed so far neither guarantee network operators the autonomy to compete and differentiate themselves in various market segments, nor give infrastructure providers the economic resources to keep the network updated in terms of technology and capacity. In this work, we propose a techno-economic model that allows network operators to compete and dynamically select the quality target to deliver to their customers, while simultaneously seeking to maximize their profits. In order to understand the willingness of network operators to participate in such a scenario, we develop a non-cooperative game wherein the Nash Equilibria show the propensity of operators to meet the customers' requirements. This work also points out the importance of retaining independent regulatory bodies, within the new business ecosystem, charged with proposing pricing policies capable of incentivizing investments towards infrastructure upgrades.
{"title":"Making the case for dynamic wireless infrastructure sharing: A techno-economic game","authors":"Alessandro Lieto, Ilaria Malanchini, V. Suryaprakash, A. Capone","doi":"10.23919/WIOPT.2017.7959872","DOIUrl":"https://doi.org/10.23919/WIOPT.2017.7959872","url":null,"abstract":"Active sharing of wireless infrastructure can be an effective approach to reduce costs and improve network profitability. However, schemes proposed so far neither guarantee network operators the autonomy to compete and differentiate themselves in various market segments, nor give infrastructure providers the economic resources to keep the network updated in terms of technology and capacity. In this work, we propose a techno-economic model that allows network operators to compete and dynamically select the quality target to deliver to their customers, while simultaneously seeking to maximize their profits. In order to understand the willingness of network operators to participate in such a scenario, we develop a non-cooperative game wherein the Nash Equilibria show the propensity of operators to meet the customers' requirements. This work also points out the importance of retaining independent regulatory bodies, within the new business ecosystem, charged with proposing pricing policies capable of incentivizing investments towards infrastructure upgrades.","PeriodicalId":6630,"journal":{"name":"2017 15th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78649095","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 : 2017-05-15DOI: 10.23919/WIOPT.2017.7959914
S. Somuyiwa, A. György, Deniz Gündüz
We study the problem of proactively pushing contents into a finite capacity cache memory of a user equipment in order to reduce the long-term average energy consumption in a wireless network. We consider an online social network (OSN) framework, in which new contents are generated over time and each content remains relevant to the user for a random time period, called the lifetime of the content. The user accesses the OSN through a wireless network at random time instants to download and consume all the relevant contents. Downloading contents has an energy cost that depends on the channel state and the number of downloaded contents. Our aim is to reduce the long-term average energy consumption by proactively caching contents at favorable channel conditions. In previous work, it was shown that the optimal caching policy is infeasible to compute (even with the complete knowledge of a stochastic model describing the system), and a simple family of threshold policies was introduced and optimised using the finite difference method. In this paper we improve upon both components of this approach: we use linear function approximation (LFA) to better approximate the considered family of caching policies, and apply the REINFORCE algorithm to optimise its parameters. Numerical simulations show that the new approach provides reduction in both the average energy cost and the running time for policy optimisation.
{"title":"Improved policy representation and policy search for proactive content caching in wireless networks","authors":"S. Somuyiwa, A. György, Deniz Gündüz","doi":"10.23919/WIOPT.2017.7959914","DOIUrl":"https://doi.org/10.23919/WIOPT.2017.7959914","url":null,"abstract":"We study the problem of proactively pushing contents into a finite capacity cache memory of a user equipment in order to reduce the long-term average energy consumption in a wireless network. We consider an online social network (OSN) framework, in which new contents are generated over time and each content remains relevant to the user for a random time period, called the lifetime of the content. The user accesses the OSN through a wireless network at random time instants to download and consume all the relevant contents. Downloading contents has an energy cost that depends on the channel state and the number of downloaded contents. Our aim is to reduce the long-term average energy consumption by proactively caching contents at favorable channel conditions. In previous work, it was shown that the optimal caching policy is infeasible to compute (even with the complete knowledge of a stochastic model describing the system), and a simple family of threshold policies was introduced and optimised using the finite difference method. In this paper we improve upon both components of this approach: we use linear function approximation (LFA) to better approximate the considered family of caching policies, and apply the REINFORCE algorithm to optimise its parameters. Numerical simulations show that the new approach provides reduction in both the average energy cost and the running time for policy optimisation.","PeriodicalId":6630,"journal":{"name":"2017 15th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75089672","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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