The Experts below are selected from a list of 1878 Experts worldwide ranked by ideXlab platform

Dario Pompili - One of the best experts on this subject based on the ideXlab platform.

  • cooperative Hierarchical Caching and request scheduling in a cloud radio access network
    IEEE Transactions on Mobile Computing, 2018
    Co-Authors: Tuyen X Tran, Guosen Yue, Dario Pompili
    Abstract:

    In this article, we propose a novel cooperative Hierarchical Caching framework in a Cloud Radio Access Network (C-RAN), in which a new cloud-cache at Cloud Processing Unit (CPU) is envisioned to bridge the storage-capacity/delay-performance gap between the traditional edge-based and core-based Caching paradigms. A delay-cost model is introduced and the cache placement problem is formulated that aims at minimizing the average delay-cost of content delivery in the network. Given the NP-completeness of the cache placement problem, we propose a low-complexity heuristic cache-management strategy comprising of a proactive cache-distribution algorithm and a reactive cache-replacement algorithm. Furthermore, a Cache-Aware Request Scheduling (CARS) algorithm is devised in order to optimize online the tradeoff between content download rate and content access delay. Via extensive numerical simulations—carried out using both real-world YouTube video requests and synthetic content requests—it is demonstrated that the proposed cache-management strategy outperforms traditional Caching strategies in terms of cache hit ratio, average content access delay, and backhaul traffic load. Additionally, it is shown that the proposed CARS algorithm achieves superior tradeoff performance over traditional approaches that optimize either users’ rate or access delay alone.

  • cooperative Hierarchical Caching in 5g cloud radio access networks
    IEEE Network, 2017
    Co-Authors: Tuyen X Tran, Abolfazl Hajisami, Dario Pompili
    Abstract:

    Over the last few years, C-RAN is proposed as a transformative architecture for 5G cellular networks that brings the flexibility and agility of cloud computing to wireless communications. At the same time, content Caching in wireless networks has become an essential solution to lower the content- access latency and backhaul traffic loading, leading to user QoE improvement and network cost reduction. In this article, a novel cooperative Hierarchical Caching (CHC) framework in C-RAN is introduced where contents are jointly cached at the BBU and at the RRHs. Unlike in traditional approaches, the cache at the BBU, cloud cache, presents a new layer in the cache hierarchy, bridging the latency/capacity gap between the traditional edge-based and core-based Caching schemes. Trace-driven simulations reveal that CHC yields up to 51 percent improvement in cache hit ratio, 11 percent decrease in average content access latency, and 18 percent reduction in backhaul traffic load compared to the edge-only Caching scheme with the same total cache capacity. Before closing the article, we discuss the key challenges and promising opportunities for deploying content Caching in C-RAN in order to make it an enabler technology in 5G ultra-dense systems.

  • octopus a cooperative Hierarchical Caching strategy for cloud radio access networks
    Mobile Adhoc and Sensor Systems, 2016
    Co-Authors: Tuyen X Tran, Dario Pompili
    Abstract:

    Recently, implementing Radio Access Network (RAN) functionality on cloud-based computing platform has become an emerging solution that leverages the many advantages of cloud infrastructure, such as shared computing resources and storage capacity, while lowering the operational cost. In this paper, we propose a novel Caching framework aimed at fully exploiting the potential of such systems through cooperative Hierarchical Caching which minimizes the network costs of content delivery and improves users' Quality of Experience (QoE). In particular, the cloud-cache in the cloud processing unit (CPU) presents a new layer in the RAN cache hierarchy, bridging the capacity-performance gap between the traditional edge-based and core-based Caching schemes. A delay cost model is introduced to characterize and formulate the cache placement optimization problem, which is shown to be NP-complete. As such, a low complexity, heuristic cache management strategy is proposed, constituting of a proactive cache distribution algorithm and a reactive cache replacement algorithm. Extensive numerical simulations are carried out using both real-world YouTube video requests and synthetic content requests. It is demonstrated that our proposed Octopus Caching strategy significantly outperforms the traditional Caching strategies in terms of cache hit ratio, average content access delay and backhaul traffic load.

  • octopus a cooperative Hierarchical Caching strategy for cloud radio access networks
    arXiv: Networking and Internet Architecture, 2016
    Co-Authors: Tuyen X Tran, Dario Pompili
    Abstract:

    Recently, implementing Radio Access Network (RAN) functionalities on cloud-based computing platform has become an emerging solution that leverages the many advantages of cloud infrastructure, such as shared computing resources and storage capacity, while lowering the operational cost. In this paper, we propose a novel Caching framework aimed at fully exploiting the potential of such Cloud-based RAN (C-RAN) systems through cooperative Hierarchical Caching which minimizes the network costs of content delivery and improves users' Quality of Experience (QoE). In particular, we consider the cloud-cache in the cloud processing unit (CPU) as a new layer in the RAN cache hierarchy, bridging the capacity-performance gap between the traditional edge-based and core-based Caching schemes. A delay cost model is introduced to characterize and formulate the cache placement optimization problem, which is shown to be NP-complete. As such, a low complexity, heuristic cache management strategy is proposed, constituting of a proactive cache distribution algorithm and a reactive cache replacement algorithm. Extensive numerical simulations are carried out using both real-world YouTube video requests and synthetic content requests. It is demonstrated that our proposed Octopus Caching strategy significantly outperforms the traditional Caching strategies in terms of cache hit ratio, average content access delay and backhaul traffic load.

  • cooperative Hierarchical Caching in 5g cloud radio access networks c rans
    arXiv: Information Theory, 2016
    Co-Authors: Tuyen X Tran, Abolfazl Hajisami, Dario Pompili
    Abstract:

    Over the last few years, Cloud Radio Access Network (C-RAN) has arisen as a transformative architecture for 5G cellular networks that brings the flexibility and agility of cloud computing to wireless communications. At the same time, content Caching in wireless networks has become an essential solution to lower the content-access latency and backhaul traffic loading, which translate into user Quality of Experience (QoE) improvement and network cost reduction. In this article, a novel Cooperative Hierarchical Caching (CHC) framework in C-RAN is introduced where contents are jointly cached at the BaseBand Unit (BBU) and at the Radio Remote Heads (RRHs). Unlike in traditional approaches, the cache at the BBU, cloud cache, presents a new layer in the cache hierarchy, bridging the latency/capacity gap between the traditional edge-based and core-based Caching schemes. Trace-driven simulations reveal that CHC yields up to 80% improvement in cache hit ratio, 21% decrease in average content-access latency, and 20% reduction in backhaul traffic load compared to the edge-only Caching scheme with the same total cache capacity. Before closing the article, several challenges and promising opportunities for deploying content Caching in C-RAN are highlighted towards a content-centric mobile wireless network.

Wang Miao - One of the best experts on this subject based on the ideXlab platform.

  • privacy preserving federated deep learning for cooperative Hierarchical Caching in fog computing
    IEEE Internet of Things Journal, 2021
    Co-Authors: Geyong Min, Zi Wang, Wang Miao
    Abstract:

    Over the past few years, Fog Radio Access Networks (F-RANs) have become a promising paradigm to support the tremendously increasing demands of multimedia services, by pushing computation and storage functionalities towards the edge of networks, closer to users. In F-RANs, distributed edge Caching among Fog Access Points (F-APs) can effectively reduce network traffic and service latency as it places popular contents at local caches of F-APs rather than the remote cloud. Due to the limited Caching resources of F-APs and spatio-temporally fluctuant content demands from users, many cooperative Caching schemes were designed to decide which contents are popular and how to cache them. However, these approaches often collect and analyse the data from Internet-of-Things (IoT) devices at a central server to predict the content popularity for Caching, which raises serious privacy issues. To tackle this challenge, we propose a Federated Learning based Cooperative Hierarchical Caching scheme (FLCH), which keeps data locally and employs IoT devices to train a shared learning model for content popularity prediction. FLCH exploits horizontal cooperation between neighbour F-APs and vertical cooperation between the BaseBand Unit (BBU) pool and F-APs to cache contents with different degrees of popularity. Moreover, FLCH integrates a differential privacy mechanism to achieve a strict privacy guarantee. Experimental results demonstrate that FLCH outperforms five important baseline schemes in terms of the cache hit ratio, while preserving data privacy. Moreover, the results show the effectiveness of the proposed cooperative Hierarchical Caching mechanism for FLCH.

Tuyen X Tran - One of the best experts on this subject based on the ideXlab platform.

  • cooperative Hierarchical Caching and request scheduling in a cloud radio access network
    IEEE Transactions on Mobile Computing, 2018
    Co-Authors: Tuyen X Tran, Guosen Yue, Dario Pompili
    Abstract:

    In this article, we propose a novel cooperative Hierarchical Caching framework in a Cloud Radio Access Network (C-RAN), in which a new cloud-cache at Cloud Processing Unit (CPU) is envisioned to bridge the storage-capacity/delay-performance gap between the traditional edge-based and core-based Caching paradigms. A delay-cost model is introduced and the cache placement problem is formulated that aims at minimizing the average delay-cost of content delivery in the network. Given the NP-completeness of the cache placement problem, we propose a low-complexity heuristic cache-management strategy comprising of a proactive cache-distribution algorithm and a reactive cache-replacement algorithm. Furthermore, a Cache-Aware Request Scheduling (CARS) algorithm is devised in order to optimize online the tradeoff between content download rate and content access delay. Via extensive numerical simulations—carried out using both real-world YouTube video requests and synthetic content requests—it is demonstrated that the proposed cache-management strategy outperforms traditional Caching strategies in terms of cache hit ratio, average content access delay, and backhaul traffic load. Additionally, it is shown that the proposed CARS algorithm achieves superior tradeoff performance over traditional approaches that optimize either users’ rate or access delay alone.

  • cooperative Hierarchical Caching in 5g cloud radio access networks
    IEEE Network, 2017
    Co-Authors: Tuyen X Tran, Abolfazl Hajisami, Dario Pompili
    Abstract:

    Over the last few years, C-RAN is proposed as a transformative architecture for 5G cellular networks that brings the flexibility and agility of cloud computing to wireless communications. At the same time, content Caching in wireless networks has become an essential solution to lower the content- access latency and backhaul traffic loading, leading to user QoE improvement and network cost reduction. In this article, a novel cooperative Hierarchical Caching (CHC) framework in C-RAN is introduced where contents are jointly cached at the BBU and at the RRHs. Unlike in traditional approaches, the cache at the BBU, cloud cache, presents a new layer in the cache hierarchy, bridging the latency/capacity gap between the traditional edge-based and core-based Caching schemes. Trace-driven simulations reveal that CHC yields up to 51 percent improvement in cache hit ratio, 11 percent decrease in average content access latency, and 18 percent reduction in backhaul traffic load compared to the edge-only Caching scheme with the same total cache capacity. Before closing the article, we discuss the key challenges and promising opportunities for deploying content Caching in C-RAN in order to make it an enabler technology in 5G ultra-dense systems.

  • octopus a cooperative Hierarchical Caching strategy for cloud radio access networks
    Mobile Adhoc and Sensor Systems, 2016
    Co-Authors: Tuyen X Tran, Dario Pompili
    Abstract:

    Recently, implementing Radio Access Network (RAN) functionality on cloud-based computing platform has become an emerging solution that leverages the many advantages of cloud infrastructure, such as shared computing resources and storage capacity, while lowering the operational cost. In this paper, we propose a novel Caching framework aimed at fully exploiting the potential of such systems through cooperative Hierarchical Caching which minimizes the network costs of content delivery and improves users' Quality of Experience (QoE). In particular, the cloud-cache in the cloud processing unit (CPU) presents a new layer in the RAN cache hierarchy, bridging the capacity-performance gap between the traditional edge-based and core-based Caching schemes. A delay cost model is introduced to characterize and formulate the cache placement optimization problem, which is shown to be NP-complete. As such, a low complexity, heuristic cache management strategy is proposed, constituting of a proactive cache distribution algorithm and a reactive cache replacement algorithm. Extensive numerical simulations are carried out using both real-world YouTube video requests and synthetic content requests. It is demonstrated that our proposed Octopus Caching strategy significantly outperforms the traditional Caching strategies in terms of cache hit ratio, average content access delay and backhaul traffic load.

  • octopus a cooperative Hierarchical Caching strategy for cloud radio access networks
    arXiv: Networking and Internet Architecture, 2016
    Co-Authors: Tuyen X Tran, Dario Pompili
    Abstract:

    Recently, implementing Radio Access Network (RAN) functionalities on cloud-based computing platform has become an emerging solution that leverages the many advantages of cloud infrastructure, such as shared computing resources and storage capacity, while lowering the operational cost. In this paper, we propose a novel Caching framework aimed at fully exploiting the potential of such Cloud-based RAN (C-RAN) systems through cooperative Hierarchical Caching which minimizes the network costs of content delivery and improves users' Quality of Experience (QoE). In particular, we consider the cloud-cache in the cloud processing unit (CPU) as a new layer in the RAN cache hierarchy, bridging the capacity-performance gap between the traditional edge-based and core-based Caching schemes. A delay cost model is introduced to characterize and formulate the cache placement optimization problem, which is shown to be NP-complete. As such, a low complexity, heuristic cache management strategy is proposed, constituting of a proactive cache distribution algorithm and a reactive cache replacement algorithm. Extensive numerical simulations are carried out using both real-world YouTube video requests and synthetic content requests. It is demonstrated that our proposed Octopus Caching strategy significantly outperforms the traditional Caching strategies in terms of cache hit ratio, average content access delay and backhaul traffic load.

  • cooperative Hierarchical Caching in 5g cloud radio access networks c rans
    arXiv: Information Theory, 2016
    Co-Authors: Tuyen X Tran, Abolfazl Hajisami, Dario Pompili
    Abstract:

    Over the last few years, Cloud Radio Access Network (C-RAN) has arisen as a transformative architecture for 5G cellular networks that brings the flexibility and agility of cloud computing to wireless communications. At the same time, content Caching in wireless networks has become an essential solution to lower the content-access latency and backhaul traffic loading, which translate into user Quality of Experience (QoE) improvement and network cost reduction. In this article, a novel Cooperative Hierarchical Caching (CHC) framework in C-RAN is introduced where contents are jointly cached at the BaseBand Unit (BBU) and at the Radio Remote Heads (RRHs). Unlike in traditional approaches, the cache at the BBU, cloud cache, presents a new layer in the cache hierarchy, bridging the latency/capacity gap between the traditional edge-based and core-based Caching schemes. Trace-driven simulations reveal that CHC yields up to 80% improvement in cache hit ratio, 21% decrease in average content-access latency, and 20% reduction in backhaul traffic load compared to the edge-only Caching scheme with the same total cache capacity. Before closing the article, several challenges and promising opportunities for deploying content Caching in C-RAN are highlighted towards a content-centric mobile wireless network.

Shivendra S Panwar - One of the best experts on this subject based on the ideXlab platform.

  • on expiration based Hierarchical Caching systems
    IEEE Journal on Selected Areas in Communications, 2004
    Co-Authors: Y T Hou, Jianping Pan, Shivendra S Panwar
    Abstract:

    Caching is an important means to scale up the growth of the Internet. Weak consistency is a major approach used in Web Caching and has been deployed in various forms. The paper investigates some fundamental properties and performance issues associated with an expiration-based Caching system. We focus on a Hierarchical Caching system based on the time-to-live expiration mechanism and present a basic model for such system. By analyzing the intrinsic timing behavior of the basic model, we derive important performance metrics from the perspectives of the Caching system and end users, respectively. Based on the results for the basic model, we introduce threshold-based and randomization-based techniques to enhance and generalize the basic model further. Our results offer some important insights into a Hierarchical Caching system based on the weak consistency paradigm.

  • modeling and analysis of an expiration based Hierarchical Caching system
    Global Communications Conference, 2002
    Co-Authors: Y T Hou, Jianping Pan, Xueyan Tang, Shivendra S Panwar
    Abstract:

    Caching is an important means to scale up the growth of the Internet. Weak consistency is a major approach used in Web Caching and has been deployed in various forms. The paper investigates some properties and performance issues of an expiration-based Caching system. We focus on a Hierarchical Caching system based on the time-to-live (TTL) expiration mechanism and present a basic model for such a system. By analyzing the intrinsic TTL timing behavior in the basic model, we derive several important performance metrics from the perspective of the Caching system and end users, respectively. Our results offer some basic understanding of a Hierarchical Caching system based on the weak consistency paradigm.

Y T Hou - One of the best experts on this subject based on the ideXlab platform.

  • coping miss synchronization in Hierarchical Caching systems with nonlinear ttl functions
    International Conference on Communications, 2004
    Co-Authors: Y T Hou, Jianping Pan, K Sohraby, S X Shen
    Abstract:

    Under the weak consistency paradigm, time-to-live (TTL)-based Hierarchical Caching systems are proposed to support Web content delivery. Within such systems, due to strictly Hierarchical Caching structure and linear TTL countdown function, a single user request may encounter consecutive cache miss events at cache servers of different levels in the hierarchy. This behavior, referred to as miss synchronization, is the main cause of a sudden increase in user-perceived response time. In this paper, we examine this undesirable behavior to gain a better understanding of its properties and characteristics. To mitigate this problem, we propose a family of nonlinear TTL countdown functions using a novel concept called extended lifetime. Performance analysis indicates that the proposed approach can effectively avoid miss synchronization in Hierarchical Caching systems. Further, a carefully-designed nonlinear countdown function can reduce cache miss ratio and user response time without any significant increase in outlived objects.

  • on expiration based Hierarchical Caching systems
    IEEE Journal on Selected Areas in Communications, 2004
    Co-Authors: Y T Hou, Jianping Pan, Shivendra S Panwar
    Abstract:

    Caching is an important means to scale up the growth of the Internet. Weak consistency is a major approach used in Web Caching and has been deployed in various forms. The paper investigates some fundamental properties and performance issues associated with an expiration-based Caching system. We focus on a Hierarchical Caching system based on the time-to-live expiration mechanism and present a basic model for such system. By analyzing the intrinsic timing behavior of the basic model, we derive important performance metrics from the perspectives of the Caching system and end users, respectively. Based on the results for the basic model, we introduce threshold-based and randomization-based techniques to enhance and generalize the basic model further. Our results offer some important insights into a Hierarchical Caching system based on the weak consistency paradigm.

  • on prefetching in Hierarchical Caching systems
    International Conference on Communications, 2003
    Co-Authors: Y T Hou, Jianping Pan, Chonggang Wang
    Abstract:

    Hierarchical Caching is deployed to scale up the explosive Web growth, and the expiration-based mechanism is adopted as an economic means to support the weak consistency in this context. However, given a hierarchy, the user perceived performance heavily depends on its position. Normally, a user near the hierarchy leaf suffers higher miss rate and longer response time. Such an intrinsic property can discourage users from participating in any Hierarchical Caching systems. In this paper, we analyze the performance of a proposed approach, i.e., freshness and retrieval threshold based cache prefetching, to mitigate the bias against leaf users. We also use ns-2 to further substantiate our analysis. By adopting this approach with the appropriate parameters, the fairness among users within a Caching hierarchy can be considerably improved.

  • modeling and analysis of an expiration based Hierarchical Caching system
    Global Communications Conference, 2002
    Co-Authors: Y T Hou, Jianping Pan, Xueyan Tang, Shivendra S Panwar
    Abstract:

    Caching is an important means to scale up the growth of the Internet. Weak consistency is a major approach used in Web Caching and has been deployed in various forms. The paper investigates some properties and performance issues of an expiration-based Caching system. We focus on a Hierarchical Caching system based on the time-to-live (TTL) expiration mechanism and present a basic model for such a system. By analyzing the intrinsic TTL timing behavior in the basic model, we derive several important performance metrics from the perspective of the Caching system and end users, respectively. Our results offer some basic understanding of a Hierarchical Caching system based on the weak consistency paradigm.