Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> Data caching on mobile clients is widely seen as an effective solution to improve system performance. In particular, cooperative caching, based on the idea of sharing and coordination of cache data among multiple users, can be particularly effective for information access in mobile ad hoc networks where mobile clients moving frequently and network topology changing dynamically. Most existing cache strategies perform replacement independently, and they seldom consider coordinated replacement and energy saving issues in the context of a mobile ad hoc network. This paper analysed the impact of energy on designing a cache replacement policy and formulate the energy-efficient coordinated cache replacement problem (ECORP) as a 0-1 knapsack problem. A heuristic algorithm called ECORP-greedy and an optimal solution called ECORP-OPT are presented to solve the problem. Simulations show that the proposed policies can significantly reduce energy consumption and access latency when compared to other replacement policies. <s> BIB001 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> This paper presents the design, implementation, and evaluation of Ditto, a system that opportunistically caches overheard data to improve subsequent transfer throughput in wireless mesh networks. While mesh networks have been proposed as a way to provide cheap, easily deployable Internet access, they must maintain high transfer throughput to be able to compete with other last-mile technologies. Unfortunately, doing so is difficult because multi-hop wireless transmissions interfere with each other, reducing the available capacity on the network. This problem is particularly severe in common gateway-based scenarios in which nearly all transmissions go through one or a few gateways from the mesh network to the Internet. Ditto exploits on-path as well as opportunistic caching based on overhearing to improve the throughput of data transfers and to reduce load on the gateways. It uses content-based naming to provide application independent caching at the granularity of small chunks, a feature that is key to being able to cache partially overheard data transfers. Our evaluation of Ditto shows that it can achieve significant performance gains for cached data, increasing throughput by up to 7x over simpler on-path caching schemes, and by up to an order of magnitude over no caching. <s> BIB002 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> As delivering contents has become the dominant usage of Internet, the efficient content distribution is being one of the hottest research areas in network community. In future network, it is anticipated that network entities such as routers will be equipped with in-network storage due to the trend of ever-decreasing storage cost. In this paper, we propose a novel content delivery architecture called Internet Service Provider (ISP) centric Content Delivery (iCODE) by which an ISP can provide content delivery services as well. iCODE can provide efficient content delivery services since an ISP can cache the contents in routers with storage modules considering traffic engineering and the locality of the content requests. Compared with CDN and P2P systems, iCODE can offer reduced delivery latency by placing the contents closer to end hosts, and incentives to ISPs by reducing inter-ISP traffic and allowing traffic engineering. We also discuss the technical and business issues to realize the iCODE architecture. <s> BIB003 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> In content-centric networking (CCN), the in-network caching feature provides several attractive advantages such as low dissemination latency and network transport load reduction. Thus, CCN requires less transport energy but additional energy to provide a caching capability at every content router. In this paper, we investigate the minimum energy consumption that CCN can achieve with optimal cache locations by considering different caching hardware technologies, number of downloads per hour, and content popularity. We first set up an energy consumption model for CCN and then formulate linear and nonlinear programming problems to minimize total energy consumption of CCN. Also, a genetic algorithm (GA) approach is proposed to find energy-efficient cache locations. Using reported energy efficiency of computational hardware and network equipment, we show CCN yield greater energy savings for very popular content and small-sized catalog, compared to conventional CDN. Our results also indicate that two aspects of the memory technology, energy-proportional caching and sufficient memory capacity, are critical to the overall energy efficiency gain of CCN. <s> BIB004 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> In content-oriented networking, content files are typically cached in network nodes, and hence how to cache content files is crucial for the efficient content delivery and cache storage utilization. In this paper, we propose a content caching scheme, WAVE, in which the number of chunks to be cached is adjusted based on the popularity of the content. In WAVE, an upstream node recommends the number of chunks to be cached at its downstream node, which is exponentially increased as the request count increases. Simulation results reveal that the average hop count of content delivery of WAVE is lower than other schemes, and the inter-ISP traffic volume of WAVE is the second lowest (CDN is the lowest). Also, WAVE achieves higher cache hit ratio and fewer frequent cache replacements than other on-demand caching strategies. <s> BIB005 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> Content-centric is an emerging networking paradigm conceived for the future Internet. Data retrieval and distribution are based on content names instead of host addresses. In this paper we propose a content-centric architecture for energy-efficient multihop communications in a wireless mesh network and compare its performances against a legacy IP-based approach. <s> BIB006 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> This work studies on the issue of energy efficient caching for Content-centric Networking (CCN) architecture. We first build the energy consumption model for content distribution in an Internet Service Provider (ISP) and find that the objective of energy optimization can translate into that of minimizing average response hops. We then develop an aging popularity-based in-network caching scheme (APC), where each router implements caching policy using its local information but relying little on coordination. Simulation results show that APC has significant advantage over the widely used Leaving Copies Everywhere (LCE) in terms of the saved energy consumption, cache hit rate and the average number of response hops, so it helps improve user access experience and reduce network traffic other than the energy optimization. Encouragingly, APC can save up to 70% energy. <s> BIB007 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> Information Centric Networks (ICNs) is a new architecture for the Future Internet to deliver content at large-scale. It relies on named data and caching features, which consists of storing content across the delivery path to serve forthcoming requests. In this paper, we study the problem of finding the optimal assignment of the objects in the available caches in ICN. The optimization problem is to cache objects in order to minimize overall network overhead. We formulate this problem as a combinatorial optimization problem. We show that this optimization problem is NP complete. Metaheuristic methods are considered as effective methods for solving this problem, Genetic Algorithm (GA) is one of those algorithms that can solve this problem efficiently. We will adapt cache management system based on GA for solving the considered problem. In contrast to traditional locally caching systems this algorithm consider both global and local search and make caching decisions about where and which item will be cached in order to minimize overall network overhead. <s> BIB008 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> We investigate on the sustainability of multihop wireless communications in the context of Information-Centric Networks, when content is replicated in caches over the network. The problem is cast in a flat wireless network for a given content popularity distribution and sized by three parameters, (i) the network size N, (ii) the content volume M and (iii) the cache capacity K per node. The objective is to select a joint replication and delivery scheme that minimizes the link traffic. Assuming the Zipf distribution about the content popularity, a law well established in the research on Internet traffic, we compute an order optimal solution, let the three size parameters jointly scale to infinity, and find the scaling laws about the link rates, ranging from ON down to o(1). Analyzing the derived laws, we determine the regimes that the network becomes sustainable subject to the scaling of the three network size parameters and the Zipf rank exponent, characterize the relative merit of network resources and identify the induced trade-offs about network expansion. <s> BIB009 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> The demand for rich multimedia services over mobile networks has been soaring at a tremendous pace over recent years. However, due to the centralized architecture of current cellular networks, the wireless link capacity as well as the bandwidth of the radio access networks and the backhaul network cannot practically cope with the explosive growth in mobile traffic. Recently, we have observed the emergence of promising mobile content caching and delivery techniques, by which popular contents are cached in the intermediate servers (or middleboxes, gateways, or routers) so that demands from users for the same content can be accommodated easily without duplicate transmissions from remote servers; hence, redundant traffic can be significantly eliminated. In this article, we first study techniques related to caching in current mobile networks, and discuss potential techniques for caching in 5G mobile networks, including evolved packet core network caching and radio access network caching. A novel edge caching scheme based on the concept of content-centric networking or information-centric networking is proposed. Using trace-driven simulations, we evaluate the performance of the proposed scheme and validate the various advantages of the utilization of caching content in 5G mobile networks. Furthermore, we conclude the article by exploring new relevant opportunities and challenges. <s> BIB010 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> This article introduces the idea of ICN-enabled IEEE 802.11 wireless access points (APs) as nano data centers. After elaborating its design, we evaluate the performance with trace-based simulation and prototype-based experiment. The evaluation shows that even a small size cache, e.g. 1Gbyte nearby mobile users can reduce traffic load by 15%, which enables mobile operators to reduce operational cost in the mobile back-haul areas. Moreover, a mobile user can download content files with less delay and interruption, especially when the performance of network becomes degraded or unstable. The synergy between ICN supporting mobility as the norm and widely deployed broadband IEEE 802.11 wireless access points makes this proposal attractive as a potential application scenario for ICN. <s> BIB011 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> Information-Centric Networking (ICN) has a great potential to better support the content distribution over the future Internet. Meanwhile, users with mobile devices will also access ICN, introducing a new challenge to ICN providers to handle such mobile content requests. In this paper, a mobility and popularity-based caching strategy is proposed to increase the cache hit rate through WiFi while people are moving from one WiFi hotspot to another. It thus lowers the network traffic from the local ICN to the outside Internet. Specifically, a precise derivation on the content request rate is provided based on the content popularity and user mobility. A novel caching strategy is further developed based on this derivation for both the mobility-oblivious and mobility-aware scenarios. We evaluate different caching strategies with a trace-driven simulation and our new approach can achieve a 33.84% reduction on the network traffic when compared with the caching strategies only considering the content popularity. <s> BIB012 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> In this paper, we investigate content-centric data transmission in the context of short opportunistic contacts and base our work on an existing content-centric networking architecture. In case of short interconnection times, file transfers may not be completed and the received information is discarded. Caches in content-centric networks are used for short-term storage and do not guarantee persistence. We implemented a mechanism to extend caching on persistent storage enabling the completion of disrupted content transfers. The mechanisms have been implemented in the CCNx framework and have been evaluated on wireless mesh nodes. Our evaluations using multicast and unicast communication show that the implementation can support content transfers in opportunistic environments without significant processing and storing overhead. <s> BIB013 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> The current Internet trends show that what is exchanged is becoming more important than who are exchanging it. As a result, the Internet is effectively moving from interconnecting machines to interconnecting information. Information-Centric Networking (ICN) has been proposed as a paradigm shift from the host-to-host Internet to a host-to-content one, or in other words from an end-to-end communication system to a native distribution network. The added value of the ICN architecture is that it allows Network Service Providers (NSPs) to participate in the actual content delivery, instead of simply being data-agnostic connectivity providers. This paper investigates an intra-domain traffic engineering (TE) approach for ICNs by leveraging the caching/replication of information items at the nodes of the network. Particularly, we present two variations of a distributed, on-line gradient descent type cache management algorithm, designed for ICNs, which re-assigns the information items between the nodes of the network with the aim, either to minimize the average link stress of the network, or to minimize the link stress (min-max) of the most congested link. Both approaches enhance the service capability of the network (high throughput and low latency) and minimizes congestion. Our extensive simulations, using realistic network topologies and synthetic workload generators, show that the proposed algorithms can significantly reduce information items' transfer time and link utilization. <s> BIB014 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> Pushing and caching the popular multimedia data can effectively reduce the redundant content transmission and cope with the explosive traffic growth. In this paper, we contribute to analyzing the push-based and cache-based content delivery in the heterogeneous network (HetNet). When the network load is off-peak, the most popular contents can be pushed to the relays and the cache-enabled users via broadcasting, and then be cached down to be reused for frequent access. The locations of the base stations, relays and device-to-device pairs are first modeled as mutually independent Poisson Point Processes (PPPs). Then the energy consumption is derived based on the access protocol and the tier association priority. The impacts of network characteristics such as the heterogeneity of multimedia contents, node densities and the limited caching capacity are further elaborated. Besides, the node densities allocation strategy is discussed for full use of the caching resources, which provides valuable insights on the wireless intelligent network planning. <s> BIB015 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> The network densification of small cells (SCs) is a promising way to cope with the explosive growth of future traffic demands in 5G networks. However, the overall power consumption and the backhaul limitation of the network have become the key factors affecting the network performance and users’ quality-of-experience, which have great importance in 5G wireless networks. Due to the complexity of 5G networks and the variety of user behaviors, the combination of software-defined networks and content delivery strategy could be a more efficient way to manage such networks. In this paper, a cache-enabled wireless heterogeneous network with the control-plane ( $C$ -plane) and user-plane ( $U$ -plane) split is proposed, where the macro cell and SCs with different cache abilities are overlaid and cooperated together in the backhaul scenario. Using an evaluation tool composed of stochastic processes and classical power consumption model, key performance indicators, e.g., the coverage probability, throughput, and energy efficiency (EE), are derived as closed-form expressions or the functions of the signal-to-interference-plus-noise ratio threshold, path loss exponent, transmission power and density of macro and SCs, cache ability, file popularity, and backhaul capacity. Fundamental trade-offs are illustrated between EE and transmission power, EE and SC density, as well as the throughput and density of SCs. Numerical results show that the proposed cache-enabled software-defined networks have much higher throughput and improved EE than current LTE networks, which shows a promising solution for future cellular networks. <s> BIB016 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> The Internet is currently mostly exploited as a means to perform massive digital content distribution. Such a usage profile was not specifically taken into account while initially designing the architecture of the network: as a matter of fact, the Internet was instead conceived around the concept of host-to-host communications between two remote machines. To solve this problem, Content-Delivery Networks?(CDNs) are currently used as a well-established technology to serve content-driven demands through an infrastructure that is not tailored for that purpose. On the other hand, the novel paradigm of Content-Centric Networking?(CCN) aims at filling the gap of this misalignment by changing the network-layer protocols, solving the content-distribution problem at its root. In this paper, we formulate novel optimization models to analyze the performance gains that CDN and CCN can achieve, by reducing the total amount of traffic exchanged through the network. We tackle this problem by adopting a time-varying content popularity evolution model that accurately represents the dynamic behavior of users. We discover that, in most of the cases, CDN reduces the overall traffic exchanged between network nodes, leading to better performance, whereas?CCN should instead be preferred in those scenarios where?CDN cannot quickly react to popularity evolution. On top of that, we show that very limited benefits can be obtained by changing the cache replacement algorithms. Finally, all our key findings are confirmed by simulation campaigns that further complement this work. <s> BIB017 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> Recently there has been a new emerging trend in integrating Information Centric Networking (ICN) and Software Defined Networking (SDN) together in the future Internet research area. Software defined information centric networking (SD-ICN) may face more serious scalability problem in control plane compared with traditional SDN environment due to new features about in-network caching and content-based communication. In this paper, we propose a scalable area-based hierarchical architecture (SAHA) for intra-domain communication to address the control plane scalability problem in SD-ICN. The SAHA supports scalable awareness of network resources and content resources, as well as guarantees efficient interest matching and resource adaptation. Simulation experiments under OMNET++ show that the proposed SAHA can achieve outstanding scalability in resource awareness and content-based communication. An area-based hierarchical architecture (SAHA) for intra-domain communication in SD-ICN is proposed.The SAHA supports interest matching and resource adaptation.The detailed scalable resource awareness process and content-based communication process are designed.The compatible solution for inter-domain communication is also discussed. <s> BIB018 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Network centric optimization based on caching networks <s> We develop an analytical framework for distribution of popular content in an Information Centric Network (ICN) that comprises of Access ICNs, a Transit ICN and a Content Provider. Using a generalized Zipf distribution to model content popularity, we devise a game theoretic approach to jointly determine caching and pricing strategies in such an ICN. Under the assumption that the caching cost of the access and transit ICNs is inversely proportional to popularity, we show that the Nash caching strategies in the ICN are 0-1 (all or nothing) strategies. Further, for the case of symmetric Access ICNs, we show that the Nash equilibrium is unique and the caching policy (0 or 1) is determined by a threshold on the popularity of the content (reflected by the Zipf probability metric), i.e., all content more popular than the threshold value is cached. We also show that the resulting threshold of the Access and Transit ICNs, as well as all prices can be obtained by a decomposition of the joint caching and pricing problem into two independent caching only and pricing only problems. <s> BIB019
In this section, research issues on network centric optimization in mobile caching networks are investigated. Mathematic methods mainly include optimization theory and game theory. Some optimization on caching schemes and caching architectures are evaluated by simulation. Optimization theory is applied in BIB015 BIB007 BIB004 BIB001 BIB008  BIB009 BIB016 BIB017 ] to obtain network performance improvement, while game theory is considered in   BIB019 . In BIB015 , the three-tier heterogeneous wireless caching network is modeled in order to analyze the energy saving of the system. Caching storages are available in both the relays and some of the users. The impacts of network characteristics such as the heterogeneity of multimedia contents, node density and the limited caching capacity are elaborated. The locations of the base stations, relays and device-to-device pairs are modeled as mutually independent Poisson point processes (PPPs), and four content access cases in the three-tier network model are provided. The average energy consumption of the network based on network architecture and the content access protocol is formulated. Numerical results show that the proposed mobile caching system has significant performance gain compared with the system in which neither users nor relays have caching ability considering the influence of the content size and popularity. By analyzing the influence of node density, the results reveal that there exists optimal node density arrangement to make full use of the caching resource through switching off or waking up some relays. In BIB016 , a cache-enabled wireless heterogeneous network framework based on software defined features is presented, in which content delivery strategy is combined with SDN to facilitate the management of the variety of user behaviors. Macro cells and small cells are modeled as independent homogeneous PPPs, and they are cooperative to cache contents based on the popularity ranking. The hit probability, the coverage probability, throughput, and energy efficiency are derived as closedform expressions or the functions of the SINR ratio threshold, path loss exponent, transmission power and density of macro and small cells, cache ability, content popularity, and backhaul capacity. Numerical results show that the proposed cache-enabled framework has much higher throughput and improved energy efficiency than that of current LTE networks. The energy efficient caching for CCN is studied in BIB007 . The energy consumption model is defined including energy consumption for transmission, caching and devices. The objective of energy optimization is transformed into the problem of minimizing average response hops. An energy-efficient aging popularity-based caching scheme is designed to improve energy efficiency and reduce network traffic. An energy consumption model for CCN is constructed to minimize the total energy consumption of CCN BIB004 . The energy consumption model consists of two major parts, namely the caching energy and the transport energy. An energy-proportional model is used to define the caching energy. The caching energy is proportional to Fig. 7 Performance metrics used in information centric mobile caching networks power efficiency of caching which depends on the caching hardware technology, and the transport energy includes the energy consumption in core and edge networks. Minimization of total energy consumption of CCN is then formulated as linear and nonlinear programming problems. A genetic algorithm approach is proposed to find energy-efficient cache locations. Numerical results indicate that energy-proportional caching with sufficient caching capacity is required for realizing green CCN. In BIB001 , the problem of energy-conscious cache placement in wireless ad hoc networks is addressed in order to get the trade-off performance between energy consumption and access latency. Considering limited amount of available energy of mobile devices and scarcity of communication bandwidth in wireless networks, caching strategy is designed to minimize the total cost considering both the access latency and the energy expenditure for the nodes to access the cache. A connected graph G = (V, E) is used to represent a multi-hop ad hoc network with V nodes connected by E links, a caching strategy is defined by a vector with length of E, where the value of element equals to '1' if a copy of content is transmitted on corresponding edge during the dissemination phase, and the value equals to '0' otherwise. The optimization problem is then formulated as an integer linear program, and the problem is the same as a special case of the connected facility location problem, which is known to be NP-hard. A polynomial time algorithm which provides a sub-optimal solution is derived. The performance of the algorithm outperforms comparing to that of three other caching schemes. The optimization problem is investigated in BIB008 to minimize overall network overhead by finding the optimal assignment of the objects in the available caches and satisfying the required constraint. By considering a network where the nodes are considered as Autonomous Systems in ICN, the Genetic Algorithm is used to support both local and global searching for finding best locations for caching contents. In BIB017 , an optimization model is formulated which focuses on reducing the total amount of traffic exchanged through the network in CCN and CDN. Based on a time varying content popularity evolution model that accurately represents the dynamic behavior of users and the most notable cache replacement policies, numerical results show that CDN reduces the overall traffic exchanged between network nodes in most of the cases, whereas CCN performs well in those scenarios where CDN can not quickly react to popularity evolution. Different cache replacement algorithms have very limited effects on the performance evaluation results. The optimization problem is investigated for minimizing traffic load in large wireless networks in  , in which the popularity of a single file varies with time. In addition, traffic in Information-Centric based multi-hop wireless network is studied in BIB009 . Some works present their own optimization objectives, such as the utility function illustrating the amount of bits delivered to users by a certain SBS in  , the utility function specifying the utility related to the prices, caching costs, demands and fraction of content stored in BIB019 . In BIB009 , the sustainability of multi-hop wireless communications in the context of Information-Centric Networks is addressed when content is replicated in caches over the network. In a flat wireless network for a given content popularity distribution with the network size N, the content volume M and the cache capacity K per node, the optimization objective is to select a joint replication and delivery scheme that minimizes the link traffic. By letting the three size parameters jointly scale to infinity, the scaling laws is found about the link rates ranging from O (N 1/2 ) down to O (1), and the regime that the network becomes sustainable subject to the scaling of the three network size parameters and the Zipf rank exponent is determined. The merit of network resources and the induced trade-offs about network expansion are analyzed. The SBSs are faced with some constrained backhaul bandwidth and limited storage capacity.  exploits caching capabilities in SBSs to overcome the backhaul capacity limitations and enhance the QoS of users. A network deployed with M mobile UEs and N SBSs is considered based on Manhattan mobility model. Each SBS experiences unique network conditions due to the number of UEs currently serviced and the existing traffic load on the backhaul, therefore the SBSs individually decide which UEs to serve, which is then transformed into the problem of UE-SBS association. A utility function is defined as the amount of bits that SBS i (i ∈ N) deliver to UE m (m ∈ M) during the service time in order to formulate the UE-SBS association problem, and the problem is modeled as a one-to-many matching game for a SBS and many UEs. To solve the problem in a decentralized approach, the aim of each SBS is to maximize its own utility. An algorithm based on the deferred acceptance scheme is proposed to identify a UE-SBS matching. The results show that the proposed cell association scheme yields significant performance improvement comparing to a cell association technique without caching considerations. In  , an energy-efficient distributed in-network caching scheme for CCN is proposed. In the proposed scheme, each CR only needs make caching decisions locally considering both caching energy consumption and transport energy consumption. The energy-efficient distributed in-network caching problem is then formulated as a non-cooperative game, and the optimization objective is energy cost and energy saving rate. Pure strategy Nash equilibria is proved to exist in the distributed solution, and it always has a strategy profile that implements the socially optimal configuration, even if the routers are self-interested in nature. Simulation results indicate that the proposed scheme is competitive to the centralized scheme, and has superior performance compared to other schemes widely used in CCN. Besides, it exhibits a fast convergence speed when the capacity of CRs varies. In BIB019 , joint caching and pricing strategies based on content popularity are investigated among access ICNs, a transit ICN and a CP. Each of the ICNs (players) has its own pricing strategy for charging others by providing service and the caching cost of access and transit ICNs is inversely proportional to the content popularity, while CP has constant cost for caching all types of content. The utility function for each player is defined as the utility obtained by providing the services for others, which is related to the prices, caching costs with respect to content popularity, demands and fraction of content stored. A non-cooperative joint caching and pricing strategies game among players is formulated, where each player tries to maximize its own utility. A unique Nash equilibrium exists for the problem of joint caching and pricing strategies for the case of symmetric Access ICNs, and the 0-1 caching strategy is determined by a threshold value which can be obtained by decomposing the joint problem into two independent caching only and pricing only problems, then contents rank based on popularity before the threshold are cached. Numerical results show that as the Zipf 's factor increases, only those requests for less popular contents are forwarded by the transit ICN to the CP, since requests for the more popular contents are locally served by access ICN. In addition to mathematic methods, simulation can also be used to evaluate the optimization of the mobile caching system, which include discrete event-driven simulators, test beds and trace-based simulation. In BIB018 , an architecture called SAHA is proposed to address the control plane scalability problem in SD-ICN for intra-domain communication. The SAHA supports scalable awareness of network resources and content resources as well as guarantees efficient interest matching and resource adaptation. The effects on scalability performance of resource awareness on the control plane are analyzed. Relations of number of routers, number of areas and number of interests, number of resources and average cache hit rate at area controllers are investigated respectively. Simulation experiments under OMNET++ show that the proposed SAHA can achieve outstanding scalability in resource awareness and content-based communication. In BIB010 , techniques for caching in current mobile networks and potential techniques for caching in 5G mobile networks are surveyed including evolved packet core (EPC) network caching, RAN caching and CCN-based caching. Using trace-driven simulations, the performance of different caching techniques is compared with respect to traffic load. Besides, the Internet inter-ISP cost, eternal cost and total network OPEX are compared with the No cache, EPC cache and EPC + RAN cache policy. In  , Breadcrumbs is evaluated in wireless multihop networks by using QualNet, and simulation results show that Breadcrumbs improves not only popular content throughput but also unpopular content throughput. In BIB011 , a new ICN use case is presented which ICNenabled IEEE 802.11 APs are designed as nano data centers at the edge of the network, especially at multiple standalone IEEE802.11 APs. LRU is used as the cache replacement scheme. The prototype over the virtualization platform of JGN-X (Japan Gigabit Network eXtreme) and youtube trace files collected from the university of Massachusetts Amherst campus are used to evaluate the performance of network resource saving. The results show that network resource saving is a function of cache size at the edge of the network. Mobile operators can reduce operational cost in the mobile backhaul areas. Even a small cache size, e.g., 1Gbyte can achieve around 0.15 cache hit rate, which implies that 15% of total requests from mobile users for youtube video clips could be served from wireless access points directly. In BIB005 , a popularity-based and collaborative caching scheme is presented in content-oriented networks called WAVE, in which an upstream node suggests its downstream node to cache the number of chunks adapting to request count. A discrete event-driven simulator GT-ITM is used. The results show WAVE outperforms other on-demand caching schemes in terms of network performance such as link stress and Inter-ISP traffic. In BIB012 , a Mobility-aware caching policy is presented which takes user mobility into account. The proposed policy is evaluated compared with other caching strategies using trace-driven simulation. The results show that the proposed approach can achieve a 33.84% reduction on the network traffic compared with caching strategies only considering the content popularity. In BIB013 , a mechanism is presented to extend caching on persistent storage enabling the completion of disrupted content transfers in the context of short opportunistic contacts based on CCNx networking architecture in wireless mesh network. Evaluations are performed on PCEngines ALIX 3D2 system boards running with ADAM, and the results show that the proposed mechanism can support content transfers in opportunistic environments without significant processing and storing overhead. In  , existing content dissemination architectures and energy efficiency of various networking devices used for content delivery are surveyed and compared, including networking devices such as DSL, OLT, GPON, DSLAM and core network devices etc., and the energy consumption performance of different deployment scenarios of CCN nodes are compared with nano data center and the case without using CCN. The results show that even with 20 percent deployment of CCN routers in the core, CCN can effectively reduce the hop length, thereby significantly reducing energy consumption. Also, it is more effective to deploy CCN nodes at the edge because requests travel across a shorter distance. The energy efficiency comparison using simple trace-based simulations reveals that a change from a host-oriented to a content-centric networking model can substantially improve energy efficiency of content dissemination. The design, implementation, and evaluation of Ditto is presented in BIB002 , which is a system that opportunistically caches overheard data to improve subsequent transfer throughput in wireless mesh networks. Ditto exploits on-path as well as opportunistic caching based on overhearing to improve the throughput of data transfers and to reduce load on the gateways. The authors use the MAP testbed at Purdue University and Emulab's indoor wireless testbed to evaluate the performance of the system, and the results show that Ditto outperforms simpler caching schemes which only cache along the actual data transfer path in terms of throughput. In  , AMVS-NDN (Adaptive Mobile Video Streaming and Sharing in Wireless Named Data Networking) is designed and implemented as a framework of adaptive mobile video streaming and sharing in the NDN architecture to address the video traffic problem. In AMVS-NDN, once a mobile station (MS) obtained video segments from the video server via the BS, other MSs nearby can opportunistically receive the video segment from the MS who holds the segments. In general, a MS always requests a segment over local Wi-Fi connectivity. If no MS that holds the segment is available, it will request the segment via 3G/4G. The framework is evaluated by a testbed consisting of a WiMAX base station and some Android phones. It achieves higher video quality and less cellular traffic than that of other solutions. An intra-domain traffic engineering approach for ICNs is investigated in BIB014  to reduce the link stress of network. To minimize the average link stress of the network, or to minimize the link stress (min-max) of the most congested link, two variations of a distributed, on-line gradient descent type cache management algorithm are presented. By using realistic network topologies and synthetic workload generators, the evaluation results show that the proposed algorithms can extremely decrease link utilization. In BIB003 , a content delivery architecture called ISPcentric content delivery (iCODE) is developed, and it provides efficient content delivery services since an ISP can cache contents in content router. GT-ITM is used to generate topologies for evaluating the performance of iCODE, the results indicate that iCODE can offer incentives to ISPs by reducing inter-ISP traffic and link stress comparing to CDN and P2P systems. In BIB006 , a content-centric MANET architecture called CHANET is proposed which is built on a connectionless layer designed on top of legacy IEEE 802.11 to provide content-based routing and transport functionality. In CHANET, nodes only cache the content matching with a pending Interest and apply LFU policy. The CHANET has been simulated in Network Simulator 2. Simulation results show the great benefits offered by CHANET in terms of high throughput and network multiplication factor compared to traditional TCP/IP-based MANETs.