Information-centric mobile caching network frameworks and caching optimization: a survey <s> Caching Framework based on Information-Centric Networking <s> The Internet has evolved greatly from its original incarnation. For instance, the vast majority of current Internet usage is data retrieval and service access, whereas the architecture was designed around host-to-host applications such as telnet and ftp. Moreover, the original Internet was a purely transparent carrier of packets, but now the various network stakeholders use middleboxes to improve security and accelerate applications. To adapt to these changes, we propose the Data-Oriented Network Architecture (DONA), which involves a clean-slate redesign of Internet naming and name resolution. <s> BIB001 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Caching Framework based on Information-Centric Networking <s> There have been many recent papers on data-oriented or content-centric network architectures. Despite the voluminous literature, surprisingly little clarity is emerging as most papers focus on what differentiates them from other proposals. We begin this paper by identifying the existing commonalities and important differences in these designs, and then discuss some remaining research issues. After our review, we emerge skeptical (but open-minded) about the value of this approach to networking. <s> BIB002 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Caching Framework based on Information-Centric Networking <s> Content-centric publish/subscribe networking is a flexible communication model that meets the requirements of the content distribution in the Internet, where information needs to be addressed by semantic attributes rather than origin and destination identities. In current implementations of publish/subscribe networks, messages are not stored and only active subscribers receive published messages. However, in a dynamic scenario, where users join the network at various instances, a user may be interested in content published before its subscription time. In this paper, we introduce a mechanism that enables storing in such networks, while maintaining the main principle of loose-coupled and asynchronous communication. Furthermore, we propose a new storage placement and replica assignment algorithm which differentiates classes of content based on their popularity and minimizes the clients response latency and the overall traffic of the network. We also present and compare two replica assignment alternatives and examine their performance when both the locality and the popularity of users request change. The performance of our proposed placement and replica assignment algorithm and the proposed storing mechanism is evaluated via simulations and insights are given for future work. The proposed mechanism is compared with mechanisms from the CDN (Content Delivery Networks) context and performs as close as 1-15% (depending on the conducted experiment) to a greedy (near optimal) approach installing up to 3 times less storage servers in the network and providing the necessary differentiation among the classes of the content. <s> BIB003 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Caching Framework based on Information-Centric Networking <s> The Internet is at a historic inflection point where mobile, wireless devices are becoming so dominant that core architectural changes are necessary to efficiently support them. This paper presents the high-level concepts and design decisions used to realize the key routing component of the MobilityFirst architecture, which is a clean-slate project being conducted as part of the NSF Future Internet Architecture program. In particular, we describe GSTAR, a mobilitycentric generalized storage-aware routing approach based on the following key design principles: separation of names from addresses, late binding of routable addresses, in-network storage, and conditional routing decision space. The GSTAR protocol described is based on hop-by-hop forwarding of large protocol data units (PDUs) between routers with storage. The packet header incorporates both name and address information enabling routers to execute a hybrid forwarding algorithm that uses topological addresses when available and refers back to names (i.e. global identifiers) to deal with dynamically changing points of attachment and disconnection. At a local level, GSTAR utilizes both fine-grain path quality information and DTN-style connectivity information to deal with the many challenges found in mobile environments. <s> BIB004 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Caching Framework based on Information-Centric Networking <s> The Internet is straining to meet demands that its design never anticipated, such as supporting billions of mobile devices and transporting huge amounts of multimedia content. The publish-subscribe Internet (PSI) architecture, a clean slate information-centric networking approach to the future Internet, was designed to satisfy the current and emerging user demands for pervasive content delivery, which the Internet can no longer handle. This article provides an overview of the PSI architecture, explaining its operation from bootstrapping to information delivery, focusing on its support for network layer caching and seamless mobility, which make PSI an excellent platform for ubiquitous information delivery. <s> BIB005 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Caching Framework based on Information-Centric Networking <s> The publish/subscribe communication paradigm has become an important architectural style for designing distributed systems and has recently been considered one of the most promising future network architectures that solves many challenges of content delivery in the current Internet. This work is concerned with scaling decentralized content-based publish/subscribe (CBPS) networks for large-scale content distribution. A fundamental step for CBPS networks to reach the large-scale is to move from the current exhaustive filtering service model, where a subscription selects every relevant publication, to a service model capturing the quantitative and qualitative heterogeneity of information consumers requirements. Moreover, the proposed work aims at leveraging caching for increasing the communication efficiency of CBPS operating at large-scale characterized by widely spread information consumers with heterogeneous requirements, large number of publications and scarcity of end-to-end bandwidth. We propose and design a service model for addressing the consumers' requirements for content-based information retrieval and describe the relevant protocols necessary to implement such a service. We evaluate the proposed approach, by using realistic workload scenarios and comparing different content and interest forwarding strategies as well as caching policies in terms of resource efficiency and user perceived QoS metrics. <s> BIB006 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Caching Framework based on Information-Centric Networking <s> For more than a decade, the inherent drawbacks of current Internet have been calling for its revolutionary designs. The end-to-end model, which was designed for special data transmission in the early age of Internet, is causing troubles everywhere in nowadays content based web services. Consequently, Information Centric Network (ICN) is proposed to solve these problems. As the most permanent clean-slate approach for next generation Internet, ICN has attracted much attention from network researchers in the passed few years. This survey focuses on the current progress of the research work in ICN. It investigates various key aspects such as naming and routing schemes, in-network caching policies, etc., and highlights the benefit of implementing ICN, open research issues and new interests in this domain. <s> BIB007 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Caching Framework based on Information-Centric Networking <s> We present testbed experiments of multi-source mobile video streaming that jointly exploits mobility and throughput prediction to prefetch video data in caches located at hotspots that the mobile will encounter and device-to-device (D2D) communication to opportunistically obtain parts of a video from neighboring mobile devices. A contribution of this paper includes a procedure to efficiently utilize multirate Wi-Fi links, which can be legacy Wi-Fi hotspot links and device-to-device links using Wi-Fi direct. <s> BIB008 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Caching Framework based on Information-Centric Networking <s> In recent years large attention is being devoted to a new networking trend focused on data centricity. The major motivation has been the development of a framework able to mitigate the mismatch between the current Internet architecture - host based - and the way most users use the network - agnostic of content location. The first proposals were focus on fix infrastructures in an attempt to devise a data-centric solution for the global Internet. On the other hand, the number of available wireless Internet access points and wireless mobile devices is growing significantly. Hence, it is very important to have in mind scenarios where networked pervasive systems need to communicate independently of the networking conditions. In such pervasive networks, it is important to support the development of communication services aware of users? context: the goal would be to increase data usefulness and delivery probability, as well as to reduce cost and latency. This article presents an information and context oriented networking framework (ICON) able to support the deployment of pervasive networks by combining two networking paradigms that are highly correlated to the efficiency of data sharing: data-centric networking and opportunistic networking. <s> BIB009 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Caching Framework based on Information-Centric Networking <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> BIB010 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Caching Framework based on Information-Centric Networking <s> Hash-routing is a well-known technique used in server-cluster environments to direct content requests to the responsible servers hosting the requested content. In this work, we look at hash-routing from a different angle and apply the technique to Information-Centric Networking (ICN) environments, where in-network content caches serve as temporary storage for content. In particular, edge-domain routers re-direct requests to in-network caches, more often than not off the shortest path, according to the hash-assignment function. Although the benefits of this off-path in-network caching scheme are significant (e.g., high cache hit rate with minimal co-ordination overhead), the basic scheme comes with disadvantages. That is, in case of very large domains the off-path detour of requests might increase latency to prohibitive levels. In order to deal with extensive detour delays, we investigate nodal/domain clustering techniques, according to which large domains are split in clusters, which in turn apply hash-routing in the subset of nodes of each cluster. We model and evaluate the behaviour of nodal clustering and report significant improvement in delivery latency, which comes at the cost of a slight decrease in cache hit rates (i.e., up to 50% improvement in delivery latency for less than 10% decrease in cache hit rate compared to the original hash-routing scheme applied in the whole domain). <s> BIB011
The networking paradigm of current Internet is host based, and the information exchanges are realized by network address based routing. The host-centric Internet can hardly meet the increasing demands of content based services supported by mobile end users since smart end devices and various multimedia applications are deployed. ICN has shifted the current complex Internet model to a simple one based on named contents and it enables named content routing through publishersubscriber driven communication. In ICN, end-users express their interests for a given content by sending content requests, and the entire network is responsible for routing the requests based only on the content name towards the best content caches and delivering the content through the reverse paths to the end-users BIB007 . The key technologies of ICN include information naming, namebased routing, in-networking caching and related caching strategies, native multicast, self-secured content as well as mobility management of consumers and publishers. The main elements in ICN are content publishers, end users (content subscribers) and cacheenabled content routers (CRs). For information naming in ICN, the content name is the only identifier for content objects, which permits either the end-user or the intermediate networking unit to locate the best content holder. Besides the fundamental property of identifying the different content, information naming is globally unique, location independent, selfdefined and security intergraded. Hierarchical naming and flat naming are two categories of ICN naming structures which are mainly supported in existing ICN solutions BIB007 . The name-based ICN routing can be realized by the undirected naming resolution service and the direct name based routing. The naming resolution requires one or several centralized servers (e.g. RendezVous points, register servers, trigger points, etc.) in the networking topology. The content publications are collected in these servers, which have a global view of all the published content objects and the networking topology. When an ICN router wants to forward a request message, the routing path is calculated in the centralized server by existing routing protocol. The name based routing is directly performed in the ICN routers. Each router has a local forwarding information base which is filled by the content publication messages. The request forwarding paths are calculated in the local routers by their own forwarding strategies BIB007 . Mobility and caching are realized by information naming, name resolution and data routing in ICN. In ICN, caching is ubiquitous. On-path and off-path caching are supported by name resolution request process. In onpath caching, the network places information cached along the path taken by a name resolution request, while in off-path caching, the network exploits information cached outside that path. For mobility support, subscriber mobility and publisher mobility are distinguished. Subscriber mobility is intrinsically supported in ICN architectures, since mobile subscribers can just send new subscriptions for information after a handoff. Publisher mobility is more difficult to support compared to subscriber mobility, because the name resolution system (in the coupled approach) or the routing tables (in the decoupled approach) need to be updated  . Figure 1 gives the abstract architecture of caching framework based on ICN, in which caches are usually placed at every CR. Some ICN architectures are constructed since 2007   including DONA, 4WARD, PSIRP, COMET, CON-VERGENCE, NDN/CCN, PURSUIT, SAIL, MobilityFirst, ANR Connect, CBMEN, NDN-NP, MobilityFirst-NP, Green-ICN, I-CAN, COMIT, POINT, UMOBILE, RIFE, BONVOYAGE, etc. BIB008  [10] [11] [12] [13] [14] . From the perspective of relevant projects, most of the projects which have launched from 2007 to 2012 focus on theoretical research such as architecture, naming, routing, forwarding and security. While the majority of the projects launched since 2013 are concentrated on specific application scenarios to enhance the architectures, such as Internet access, opportunistic communications as well as multimodal transport. The business models for ICN and the migration strategies are also concentrated which are compatible with TCP/IP, such as IP over ICN. Consequently, the study on ICN has been shifted from theoretical research to some specific applications practice  . Since the main topic of this paper is on mobile caching framework and caching optimization, and information centric caching and its mobility support mechanisms are distinct depending on various ICN architectures, in this section, caching and mobility support are surveyed based on several typical ICN architectures. DONA  BIB001 is one of the first complete ICN architectures with flat names proposed by UC Berkeley. DONA supports on-path caching by Resolution Handler (RH) infrastructure. A RH which decides to cache a requested data object can replace the source IP address of an incoming FIND request with its own IP address before it forwards the message to the next RH. Once the response traverses the current RH, the data returned would be cached. If path-labels are used, the data always return via the intermediate RHs, which can make a caching decision or not. If a subsequent FIND message requesting the same object reaches a caching RH, the RH can directly return the data to the subscriber. Information may also be replicated off-path if the information through its local RH is registered. A RH receiving multiple REGISTER messages for the same information maintains (and propagates upwards) only the pointers to the best available copy. Mobile subscribers can simply send new FIND messages from their current location relying on the RH infrastructure to provide them with the closest copy of the information. Mobile publishers can also unregister and re-register their information when changing their network location  . CCN  BIB002 architecture is the other fully-fledged ICN architecture presented by PARC. NDN  project funded by the US Future Internet Architecture project develops the CCN architecture. NDN supports on-path caching, since each CR first consults its Content Store (CS) whenever it receives an INTEREST message and caches all information objects carried by DATA messages. A CS just caches every incoming Data packets   temporarily in order to avoid packet losses and satisfy requests for the same data subsequently. NDN supports Off-path caching by delivering an INTEREST to any data source that may be hosting the requested information object. Subscriber mobility is implemented by sending new INTEREST messages from its current location for the information objects it has not received yet. Publisher mobility is enabled by Forwarding Information Base which requires advertising the name prefixes for the information it is hosting via the routing protocol again  . As one of the important architectures proposed by EU Framework 7 Programme, PURSUIT constructs architecture with a publisher-subscriber protocol stack. PURSUIT supports both on-path and off-path caching. In the onpath caching, forwarded packets are cached at Forwarding Nodes to serve subsequent requests. However, on-path caching may not be very effective because name resolution is decoupled from data routing. In the off-path caching, caches act as publishers by advertising the available information to the Rendezvous Network. Mobility is facilitated by multicast and caching BIB005 . Four types of mobility cases are considered. Local subscriber mobility can be handled via multicast and caching, while Publisher mobility is harder to support since the publisher's new position information in the network need to be notified to the topology management function. In PURSUIT, Publish-Subscribe systems are organized as a collection of autonomous components BIB003 , so clients act either as publishers who publish new events in the network or as subscribers who subscribe events they are interested in. The SAIL architecture supports on-path caching at the CRs. In SAIL, the caches are regarded as publishers by envisaging the deployment of large scale information object caching and replication mechanisms cooperative with the Name Resolution System (NRS). SAIL considers a hierarchy of caches in which local caches are part of a tree which includes a small number of caching servers at the root. The caches which are in the higher level of the hierarchy have larger storage space in order to store popular objects, which would have been evicted by local caches because of their limited storage size. Cache replacement policies are also investigated on which popular objects are dynamically moved to caches that are closer to the consumers. Host mobility is enabled by maintaining topological information for each registered host by the NRS. Upon a change of location, the moving host updates the topological information in the NRS where it is registered and a notification is issued to the nodes which are communicating with the mobile host   . COMET supports on-path and off-path caching. Onpath caching originates from name resolution. Registering cached copies with the Content Resolution System is required in Off-path caching. In COMET, two novel schemes are proposed which are different from NDN's "cache everything" on-path caching, one is the ProbCache, which is a probabilistic caching scheme  , the other is the Centrality scheme based on the observation that Content-aware Routers (CaRs) locating on shortest paths are more likely to obtain a cache hit, thus an information object should only be cached by the CaR with the highest centrality in its path. Mobility-aware CaRs are deployed at the edge of the access networks to support user mobility, and track the mobility of users and context information and can predict their future locations  . In CONVERGENCE, on-path caching is supported in a manner similar to NDN. Off-path caching and replication are facilitated by registering additional copies of an information object stored at Internal Nodes to the NRS. CONVERGENCE supports subscriber mobility via new requests as in NDN, and Publisher mobility relies on unspecified name resolution system  23] . MobilityFirst supports on-path caching passing messages at intermediate CRs opportunistically, and allows subsequent requests for the same Globally Unique Identifier (GUID) to be replied with the locally cached copy. In addition, once an information object is cached off-path or replicated, the Global Name Resolution Service (GNRS) is notified of the change in order to update the corresponding GUID entry with the additional network addresses. Despite of the "slow-path" operation which the GNRS can be repeatedly consulted as a message traverses the network, each CR can adopt its own policy and decide when to consult with the GNRS for additional cached copies. Addressing host, information, and entire network mobility is another important objective in MobilityFirst. Host mobility is primarily handled by GNRS when a network attached object changes its point of attachment. Network mobility is also supported. Mobility causes disconnections and variable link conditions in networks, which can be solved by a storage-aware routing mechanism exploited at the intra-domain level by deploying local storage as in delay-tolerant networking  BIB004 . The method of information centric caching and mobility support of the typical ICN architectures are summarized. Besides, some performances of the architectures are investigated based on the ICN architectures surveyed above in the aspect of scalability of control plane, content based caching protocol, information centric context networking and domain clustering based networking. In the following, some improved architectures and mechanisms are presented based on the aforementioned ICN architectures. A scalable area-based hierarchical architecture (SAHA) for intra-domain communication is proposed to address the control plane scalability problem in Software defined information centric networking (SD-ICN) in BIB010 . The SAHA supports scalable awareness of network resources and content resources, and it also guarantees efficient interest matching and resource adaptation. A decentralized content-based publish/subscribe (CBPS) network for large-scale content distribution is proposed in BIB006 . The fundamental idea for CBPS networks to reach the large-scale is to convert the current exhaustive filtering service model into a service model capturing the quantitative and qualitative heterogeneity of information consumer requirements, where a subscription has to select every relevant publication. A service model is designed addressing the consumers' requirements for content-based information retrieval and the relevant protocols are provided. The proposed approach is evaluated, and different content and interest forwarding strategies as well as caching policies are compared in terms of resource efficiency and QoS metrics in realistic workload scenarios. In BIB009 , an information and context oriented networking framework (ICON) is presented to support the deployment of pervasive networks by combining two networking paradigms that are highly correlated to the efficiency of data sharing: namely data-centric networking and opportunistic networking. ICON incorporates four components, namely Decision Engine, Data Engine, Context Engine and Network Engine. In ICON, data is shared taking into account users' social affinities instead of the capability of devices by using a data-centric forwarding algorithm, which is based on a utility function that reflects the probability of encountering nodes with a certain interest among the ones that have similar daily social habits. The reason to use social proximity with content knowledge is that nodes with similar daily habits have higher probability of having similar content interests; and social proximity metrics allow a faster dissemination of data by taking advantage of more frequent and longer contacts between socially closer nodes. However, ICON lacks of evaluation considering node mobility and traffic models. In order to deal with extensive delivery latency, an ICN based networking method integrated with hashrouting and domain clustering techniques is presented in BIB011 . The network is represented as a graph which consists of the sets of routers and communication links and each node of the graph enables to cache and forward a request to corresponding caching nodes. Domain clustering technique is used to partition the set of routers of the large domain into clusters containing the subset of routers, and a hash function is implemented at the nodes of each cluster to determine both the content placement and the request-to-cache routing process, thus reducing the retrieval delay.