Information-centric mobile caching network frameworks and caching optimization: a survey <s> Modeling behavior and performance analysis of caching system <s> ABSTP~CT. A formal model is presented for paging algorithms under /-order nonstationary assumptions about program behavior. When processing a program under paging in a given memory, a given paging policy generates a certain (expected) number of page calls, i.e., its "cost." Under usual assumptions about memory system organization, minimum cost is always achieved by a demand paging algorithm. The minimum cost for /-order program behavior assumptions is expressed as a dynamic programming problem whose solution yields an optimal replacement algorithm. Solutions are exhibited in several 0-order cases of interest. Paging algorithms that implement and approximate the minimum cost are discussed. <s> BIB001 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Modeling behavior and performance analysis of caching system <s> This paper aims at finding fundamental design principles for hierarchical Web caching. An analytical modeling technique is developed to characterize an uncooperative two-level hierarchical caching system where the least recently used (LRU) algorithm is locally run at each cache. With this modeling technique, we are able to identify a characteristic time for each cache, which plays a fundamental role in understanding the caching processes. In particular, a cache can be viewed roughly as a low-pass filter with its cutoff frequency equal to the inverse of the characteristic time. Documents with access frequencies lower than this cutoff frequency have good chances to pass through the cache without cache hits. This viewpoint enables us to take any branch of the cache tree as a tandem of low-pass filters at different cutoff frequencies, which further results in the finding of two fundamental design principles. Finally, to demonstrate how to use the principles to guide the caching algorithm design, we propose a cooperative hierarchical Web caching architecture based on these principles. Both model-based and real trace simulation studies show that the proposed cooperative architecture results in more than 50% memory saving and substantial central processing unit (CPU) power saving for the management and update of cache entries compared with the traditional uncooperative hierarchical caching architecture. <s> BIB002 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Modeling behavior and performance analysis of caching system <s> This paper addresses two unresolved issues about Web caching. The first issue is whether Web requests from a fixed user community are distributed according to Zipf's (1929) law. The second issue relates to a number of studies on the characteristics of Web proxy traces, which have shown that the hit-ratios and temporal locality of the traces exhibit certain asymptotic properties that are uniform across the different sets of the traces. In particular, the question is whether these properties are inherent to Web accesses or whether they are simply an artifact of the traces. An answer to these unresolved issues will facilitate both Web cache resource planning and cache hierarchy design. We show that the answers to the two questions are related. We first investigate the page request distribution seen by Web proxy caches using traces from a variety of sources. We find that the distribution does not follow Zipf's law precisely, but instead follows a Zipf-like distribution with the exponent varying from trace to trace. Furthermore, we find that there is only (i) a weak correlation between the access frequency of a Web page and its size and (ii) a weak correlation between access frequency and its rate of change. We then consider a simple model where the Web accesses are independent and the reference probability of the documents follows a Zipf-like distribution. We find that the model yields asymptotic behaviour that are consistent with the experimental observations, suggesting that the various observed properties of hit-ratios and temporal locality are indeed inherent to Web accesses observed by proxies. Finally, we revisit Web cache replacement algorithms and show that the algorithm that is suggested by this simple model performs best on real trace data. The results indicate that while page requests do indeed reveal short-term correlations and other structures, a simple model for an independent request stream following a Zipf-like distribution is sufficient to capture certain asymptotic properties observed at Web proxies. <s> BIB003 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Modeling behavior and performance analysis of caching system <s> Cache cooperation improves the performance of isolated caches, especially for caches with small cache populations. To make caches cooperate on a large scale and effectively increase the cache population, several caches are usually federated in caching architectures. In this paper, we discuss and compare the performance of different caching architectures. In particular, we consider hierarchical and distributed caching. We derive analytical models to study important performance parameters of hierarchical and distributed caching, i.e., client's perceived latency, bandwidth usage, load in the caches, and disk space usage. Additionally, we consider a hybrid caching architecture that combines hierarchical caching with distributed caching at every level of a caching hierarchy. We evaluate the performance of a hybrid scheme and determine the optimal number of caches that should cooperate at each caching level to minimize client's retrieval latency. <s> BIB004 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Modeling behavior and performance analysis of caching system <s> Renewed interest in caching systems stems from their wide-spread use for reducing the document download latency over the Internet. Since caches are usually organized in a hierarchical manner, it is important to study the performance properties of tandem caches. The first step in understanding this problem is to characterize the miss stream from one single cache since it represents the input to the next level cache. In this regard, we discover that the miss stream from one single cache is approximated well by the superposition of a number of asymptotically independent renewal processes. Interestingly, when this weakly correlated miss sequence is fed into another cache, this barely observable correlation can lead to measurably different caching performance when compared to the independent reference model. This result is likely to enable the development of a rigorous analysis of the tandem cache performance. <s> BIB005 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Modeling behavior and performance analysis of caching system <s> Content-centric networking proposals, as Parc's CCN, have recently emerged to define new network architectures where content, and not its location, becomes the core of the communication model. These new paradigms push data storage and delivery at network layer and are designed to better deal with current Internet usage, mainly centered around content dissemination and retrieval. In this paper, we develop an analytical model of CCN in-network storage and receiver-driven transport, that more generally applies to a class of content ori ented networks identified by chunk-based communication. We derive a closed-form expression for the mean stationary throughput as a function of hit/miss probabilities at the caches along the path, of content popularity and of content/cache size. Our analytical results, supported by chunk level simulations, can be used to analyze fundamental trade-offs in current CCN architecture, and provide an essential building block for the design and evaluation of enhanced CCN protocols. <s> BIB006 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Modeling behavior and performance analysis of caching system <s> Networking Named Content (NNC) was recently proposed as a new networking paradigm to realise Content Centric Networks (CCNs). The new paradigm changes much about the current Internet, from security and content naming and resolution, to caching at routers, and new flow models. In this paper, we study the caching part of the proposed networking paradigm in isolation from the rest of the suggested features. In CCNs, every router caches packets of content and reuses those that are still in the cache, when subsequently requested. It is this caching feature of CCNs that we model and evaluate in this paper. ::: ::: Our modelling proceeds both analytically and by simulation. Initially, we develop a mathematical model for a single router, based on continuous time Markov-chains, which assesses the proportion of time a given piece of content is cached. This model is extended to multiple routers with some simple approximations. The mathematical model is complemented by simulations which look at the caching dynamics, at the packet-level, in isolation from the rest of the flow. <s> BIB007 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Modeling behavior and performance analysis of caching system <s> Information-Centric Networking (ICN) focuses on content retrieval by replacing host-based addressing with content-based addressing. However, in MANETs, content retrieval is faced with significant challenges for nodes' high mobility. Information-Centric MANETs (ICMs) are expected to provide benefits, and there are great significance and challenges for realistically modeling content retrieval in ICMs. In this paper, we design an analytical model of content retrieval for ICMs in 1-dimensional case, which considers the nodes mobility, natures of wireless environment and caching in-networking features in ICN. Our model extracts many considerations in a pervasive methodology composed of three basic objects: locations, nodes, and contents. And closed-form expressions for throughput and delay are derived based on the hit/miss probabilities at the mobile nodes. Several simulation experiments are conducted to check the reliability of proposed model. Overall, the results show that this model can be chosen to guide further research and evaluation of optimized ICMs in the future. <s> BIB008 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Modeling behavior and performance analysis of caching system <s> Information Centric Network (ICN) proposals, have recently emerged to define new network architectures where content, and not its location, becomes the core of the communication model. Such new paradigms push data storage and delivery at network layer and are designed to cope with current Internet usage, mainly centered around content dissemination and retrieval.In this paper, we develop an analytical model of ICN storage and bandwidth sharing under fairly general assumptions on total demand, topology, content popularity and limited network resources. Our study applies to a class of content oriented networks identified by receiver-driven packet-based communication with in-network storage. We derive a closed-form expression for expected stationary delivery time as a function of hit/miss probabilities at network caches, content popularity and cache sizes. Our analytical results, supported by packet level simulations, can be used to analyze fundamental trade-offs of ICN architectures. They also provide an essential building block for the design and evaluation of ICN protocols. <s> BIB009 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Modeling behavior and performance analysis of caching system <s> This paper introduces a novel analytical model for estimating the cache hit ratio as a function of time. The cache may not reach the steady-state hit ratio when the number of Web objects, object popularity, and/or caching resources themselves are subject to change. Hence, the only way to quantify the hit ratio experienced by Web users is to calculate the instantaneous hit ratio. The proposed analysis considers a single Web cache with infinite or finite capacity. For a cache with finite capacity, two replacement policies are considered: Least Recently Used (LRU) and First-In-First-Out (FIFO). Based on the insights from the proposed analytical model, we propose a new replacement policy, called Frequency-Based-FIFO (FB-FIFO). The results show that FB-FIFO outperforms both LRU and FIFO, assuming that the number of Web objects is fixed. Assuming that new popular objects are generated periodically, the results show that FB-FIFO adapts faster than LRU and FIFO to the changes in the popularity of the cached objects when the cache capacity is large relative to the number of newly generated objects. <s> BIB010 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Modeling behavior and performance analysis of caching system <s> Information-Centric Networking (ICN) is a cleanslate networking architecture that puts information in focus instead of addressed hosts. Construction of content retrieval model to estimate the delivery performance is challenging in this ICN-based Mobile Ad hoc Networks (MANETs). In this paper, we propose a novel content retrieval model (PRCRM) for Information-Centric MANETs (ICMs) in 2-dimensional case. By investigating the distribution of content popularity, receiverdriven mechanism, content caching and replacement mechanism and generalized mobility model in 2-dimensional space, PRCRM constructs a novel content retrieval model based on the content hit/miss probability to estimate the content retrieval-related performance. We evaluate PRCRM by comparing its performance with another state of the art solution in terms of RTT and throughput. Simulation results demonstrate PRCRM's rationality and validity and it is shown that PRCRM is available to analyze content retrieval in ICMs. <s> BIB011 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Modeling behavior and performance analysis of caching system <s> To reduce network redundancy, in-network caching is considered in many future Internet architectures, such as Information Centric Networking. In in-network caching system, the item sojourn time of LRU (Least Recently Used) replacement policy is an important issue for two reasons: firstly, LRU is one of the most common used cache policy; secondly, item sojourn time is positively correlated to the hit probability, so this metric parameter could be useful to design the caching system. However, to the best of our knowledge, the sojourn time hasn't been studied theoretically so far. In this paper, we first model the LRU cache policy by Markov chain. Then an approximate closed-form expression of the item expectation sojourn time is provided through the theory of stochastic service system, which is a function of the item request rates and cache size. Finally, extensive simulation results are illustrated to show that the expression is a good approximation of the item sojourn time. <s> BIB012 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Modeling behavior and performance analysis of caching system <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> BIB013 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Modeling behavior and performance analysis of caching system <s> Collapsed forwarding has been used in cache systems to reduce the load on servers by aggregating requests for the same content. This technique has made its way into design proposals for the future Internet architecture through a data structure called Pending Interest Table (PIT). A PIT keeps track of interest packets that are received at a cache-router until they are responded to. PITs are considered useful for a variety of reasons e.g., communicating without the knowledge of source and destination, reducing bandwidth usage, better security, etc. Due to the high access frequency to the PIT, it is essential to understand its behavior, and the effect it has on cache performance. In this paper, we consider a TTL-based cache with a Pending Interest Table, and analyze the cache hit probability, mean response time perceived by the users, and size of the PIT, among other metrics of interest. In our analysis, we account for the time it takes for the cache to download a file from the server defined as a random variable. We apply our model to analyze traditional caching policies LRU, FIFO, and RANDOM, and verify the accuracy of our model through numerical simulations. <s> BIB014 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Modeling behavior and performance analysis of caching system <s> Abstract Mobile Ad-hoc NETworks (MANETs) connect mobile wireless devices without an underlying communication infrastructure. Communications occur in a multi-hop fashion, using mobile devices as routers. Several MANET distributed applications require to exchange data (GPS position, messages, pictures, etc.) by using a topic-based publish–subscribe interaction. Participants of these applications can publish information items on a given topic (identified by a name) and can subscribe to a topic to receive the related published information. An efficient dissemination of publish–subscribe data in MANET environments demands for robust systems, able to face radio resource scarcity, network partitioning, frequent topology changes. Many MANET publish–subscribe systems have been proposed so far in the literature assuming an underlying TCP/IP network. In this paper, we discuss the benefits of building a MANET publish–subscribe system exploiting Content Centric Networking (CCN) technology, rather than TCP/IP. We show how CCN functionality, such as in-network caching and multicasting can be used to achieve an efficient and reliable data dissemination in MANET environments, including the support of delay tolerant delivery. We present different design approaches, describe our topic-based publish–subscribe CCN system, and report the results of a performance evaluation study carried out with real software in an emulated environment. The emulation environment is based on Linux virtual machines. The performance evaluation required also a CCN MANET routing engine, which we developed as a plug-in of the OLSR Linux daemon. <s> BIB015 </s> Information-centric mobile caching network frameworks and caching optimization: a survey <s> Modeling behavior and performance analysis of caching system <s> We study the performance of a family of cache replacement algorithms. The cache is decomposed into lists. Some of these lists can be virtual in the sense that only meta-data are stored in those lists. An item enters the cache via the first list and jumps to the next list whenever a hit on it occurs. The classical policies FIFO, RANDOM, CLIMB, and its hybrids are obtained as special cases. We present explicit expressions for the cache content distribution and miss probability under the IRM model. We develop an algorithm with a time complexity that is polynomial in the cache size and linear in the number of items to compute the exact miss probability. We introduce lower and upper bounds on the latter that can be computed in a time that is linear in the cache size times the number of items. We introduce a mean-field model to approximate the transient behavior of the miss probability and prove that this model becomes exact as the cache size and number of items go to infinity. We show that the set of ODEs associated to the mean-field model has a unique fixed point that can be used to approximate the miss probability in case the exact computation is too time consuming. Using this approximation, we provide guidelines on how to select a replacement algorithm within the family considered such that a good trade-off is achieved between the cache reactivity and its steady-state hit probability. We simulate these cache replacement algorithms on traces of real data and show that they can outperform LRU. Finally, we also disprove the well-known conjecture that the CLIMB algorithm is the optimal finite-memory replacement algorithm under the IRM model. <s> BIB016
When a caching system is working, the content objects are inserted and evicted by the system, and the contents are required by users. Since the contents may be stored in any of the caching locations in the network, the contents are retrieved in the whole caching network and can be found at a low cost. According to the behavior of the caching system during the time when it is working, the performance of a caching system is related to its caching architecture, caching behavior, content request pattern and content features. Figure 6 illustrates a typical caching system based on caching behavior. Caching architecture depends on the caching network topology. The typical topology includes hierarchy BIB002 BIB004 , tandem BIB005 and arbitrary topology  . Caching behavior is often defined as the caching state concerning cache node, cache space, the total number of contents and content location in the cache, caching content insertion policy and content eviction policy. The content which is inserted or evicted from one of the cache nodes would cause the state transition of the caching system. Caching behavior involves steady state behavior and transient behavior. For content request pattern, content requests are usually assumed to arrive in the network exogenously and the content request arrival process usually follows the Poisson process. The independent reference model (IRM) is often used to capture the notion of page reference frequencies BIB001 . Under IRM, requests received at different times are stochastically independent when modeling content request pattern. The Zipf discrete distribution is often used in the literature to represent the popularity of Internet contents since it is shown that it is an adequate model BIB003 . Content requests for different content follows Zipf-distribution BIB003 with X R r¼1 C=r α ¼ 1 , where the probability of a request for the r-th popular content is C/r α with α being the popularity factor, where R is the total number of content units. The caching insertion and eviction policy can be selected according to the popularity of contents. When a cache store is full, the selected content will be evicted according to the caching eviction policy in the event of an arrival of a new uncached content, and the new content is inserted into the cache according to the content insertion policy. In order to evaluate the efficiency of finding the contents in the caching system, cache hit is used to record for a request finding a matching content along the content delivery path. Otherwise, a cache miss is recorded. In the event of a cache miss, the content request traverses the full content delivery path to the content nodes with the content or to the server. The analysis of modeling behavior and performance of caching system relates to the architecture of caching system. The performance is also different depending on whether the caches are cooperative. Some works study Che et al. analyze the performance of two-level web hierarchy caches which a single cache is deployed at the root level and a set of caches are set at the leaf level. LRU algorithm is used at each cache locally BIB002 BIB004 . A stochastic model is proposed to characterize the uncooperative hierarchical caching system. An approximation technique is employed and the miss ratio is obtained to match the exact results accurately, which is called Che's approximation. A characteristic time for a given cache is identified as a function of the request processes, the cache size and the request pattern. Additionally, a cache can be viewed roughly as a lowpass filter with its cutoff frequency which is the inverse of the characteristic time, so contents with access frequencies lower than the cutoff frequency will have good chances to pass through the cache with the result of cache misses. According to the above idea, the cache tree can be considered as a tandem of lowpass filters at different cutoff frequencies. Based on the concept of filtering defined by the characteristic time, the hierarchical caching principles are then presented to guide the design of a cooperative hierarchical caching architecture. Since caches are usually organized in a hierarchical manner, the cache of each level needs to serve the miss sequence from the preceding level cache, it is important to study the performance properties of tandem caches. BIB005 analyzes the miss stream from one single cache since it represents the input to the next level cache, and miss stream from one single cache is approximated by the superposition of a number of asymptotically independent renewal processes. Approximation of a renewal sequence is provided for predicting the fault probability in the second cache, which proves to be more accurate than IRM by experiments. The analysis can be used to rigorously characterize the performance of tandem caches. However, from a practical perspective, experiments indicate that the difference in fault probabilities in the second cache obtained by comparing the independent reference model approximation and the actual miss stream is not large, although measurable. Hence, using the IRM approximation for dimensioning networks of caches may be acceptable. In BIB014 , the behavior of a Time-To-Live (TTL) based caches is analyzed with a Pending Interest Table ( PIT) in NDN, in which each content is associated with a timer assuming that the request arrivals can be described as renewal processes which generalizes the classical IRM. The PIT keeps track of all the Interests that a router has forwarded but are not satisfied yet, a content is evicted from the cache when its timer expires. Replacementbased caching policies are mapped to TTL-based caching policies, and then expressions for cache hit probability, response time perceived by the users, and the size of the Pending Interest Table are derived. Applying the model proposed in BIB014 , the traditional caching policies such as LRU, FIFO, and RANDOM can also be analyzed. In BIB016 , the performance of two families of replacement algorithms FIFO(m) and RANDOM(m) under the IRM model is studied by decomposing caches into lists. Explicit expressions for miss probability are presented by analyzing the steady state probabilities. Furthermore, the authors develop an algorithm with a time complexity that is polynomial in the cache size and linear in the number of items to compute the overall and per content item miss probabilities of the FIFO (m) and RANDOM (m) algorithm. Lower and upper bounds on the overall miss probability of RAN-DOM (m) are presented. An analytical model of ICN storage and bandwidth sharing is proposed under fairly general assumptions on total demand, topology, content popularity and limited network resources in  BIB006 BIB009 . Given the assumptions that the caching network topology is a linear and binary tree, each user implements a receiver-driven flow control protocol yielding fair and efficient bandwidth utilization along the path to the content repository, and caches are managed by LRU per-packet replacement policy. A closed-form expression for expected stationary delivery time is derived as a function of hit/miss probabilities on network caches, content popularity and cache sizes. The research results can be applied to a class of content oriented receiver-driven packet-based communication networks with in-network storage. The analytical results supported by packet level simulations can be used to analyze fundamental trade-offs of ICN architectures. An essential building block for the design and evaluation of ICN protocols is also provided. In ICN, since caching becomes a ubiquitous functionality available at each router, it is of paramount importance to develop efficient tools for the performance analysis of large-scale interconnected caches for content distribution. However, the complexity of evaluating the performance of cache networks grows exponentially with increase of the cache size and the number of contents, especially in constructing exact models of a specific multi-cache system. The authors of  propose a unified methodology to analyze the hit probability of caches (both isolated and interconnected) for caching eviction policies (e.g. LRU, q-LRU, K-LRU, RANDOM, FIFO) and caching insertion policies (e.g. LCE, LCD). In  , a simple closed-form expression of cache hit probability is obtained by extending Che's approximation under the small cache regime, which reveals superiority of the k-LRU policy by considering traffic model as renewal traffic and the effects of temporal locality (e.g. if a content is requested at a given point in time, then the content will be requested again with great probability in the near future). In  , an algorithm called a-NET is proposed to approximate the behavior of multi-cache networks by leveraging existing approximation algorithms for isolated LRU caches. Graph is used to denote the network of caches with arbitrary topology. The average rate of requests for a content at a cache consists of a Poisson stream of exogenous requests and miss streams of the cache's neighbors. The miss probability of each cache and the average number of response hops are used to evaluate the accuracy of a-NET. The behavior of caches can be modeled by Markov chains or Markov Process. Several works characterize the content dynamics in a single cache or caching network by Markov chain BIB012 BIB010   BIB007 . The authors in  also use a discrete Markov chain to model the behavior of a tagged content k at a generic cache with size N. Markov chain consists of states (i, j), i represents the number of cache misses for contents except tagged content k, since k entered the cache, j represents the state of k, when i is not greater than N, k is in the i-th location of the cache. Otherwise k might experience eviction state, miss state and absorbing state. The Markov Model is used to measure distribution of the number of requests between two requests for content k. In  , a cache network is modeled as a discrete-time Markov chain with state space Ω 0 , in which the content inserted or evicted from one of the cache nodes would cause the state transition of the system. Supposing that the network has m cache nodes, each cache space is N and the total number of contents is n. The system state is s, s = (s  In BIB012 , the work process of LRU replacement policy is modeled as a homogeneous Markov chain. The state of the chain represents the corresponding content position in the cache. Supposing that each content has the same size and the cache space is N. The Markov chain states of content f i is Ω = {0, 1, … , N}, where state 0 denotes the content f i is not in the cache, and state j denotes content f i is at the j-th position of the cache. According to LRU policy, the transfer rate matrix can be obtained. Then the steady-state probability of each state is derived by the balance equation. The closed-form expression of content sojourn time at a cache employing LRU policy is got, and content expectation sojourn time is provided to get the expression of hit probability. In BIB010 , an analytical model is presented for estimating the instantaneous hit ratio of a single cache for both LRU and FIFO. Markov chain is used to model each object in the cache. The state representation is obtained, and the instantaneous hit ratio of object is presented. In BIB007 , CCN is modeled using Markov chains. For a single router, the state of the chain represents the exact slot that the packet currently occupies in the cache, and the Packet of Interest (PoI) arrives as a Poisson process with rate λ. State i (1 ≤ i ≤ N) denotes the PoI is in the i th position of router, and state N + 1 denotes the packet is not in the cache. The requests for packets in cache, but further down than the PoI or not in cache are assumed to arrive as a Poisson process with rate μ. All states (except state 1) have a transition to state 1 with rate λ. All states i (1 ≤ i ≤ N) have a transition to state i + 1 with rate μ. The chain can be trivially shown to be ergodic, and the equilibrium probability of PoI in every state is obtained, and the modeling can be extended to the multiple router system. The system of two routers is analyzed as a use case. Some works analyze the caching behavior considering user mobility BIB013 BIB008 BIB011 BIB015 . In BIB013 , user mobility is characterized by a stationary Markov model. The transition matrix is calculated based on the real trace data of mobile users. The statistics from the trace-based data indicates that it is a finite, irreducible and ergodic Markov chain. For a mobile user, staying on each site represents a state. Let T i,j denotes the probability of transition from site i to site j. The request rate R k,j for content k at site j is derived, and a threshold ε is set to stop the iteration process if the variance of R k,j is small enough. [85] provides an analytical modeling on InformationCentric MANETs supporting mobility. The model of content retrieval for ICMANETs in 1-dimensional case is presented, which extracts locations, nodes, and contents as three basic objects. The nodes' location distribution on the generalized mobility model is analyzed and the close-form expression for the location distribution model is derived under a stationary moving process. Then, the process of content retrieval in ICMANETs is analyzed and the expression of the miss probability at a location is obtained. The closed-form expressions for accurately estimating the throughput and delay of content retrieval are derived which are used to evaluate the performance of content retrieval in ICMANETs. However, the analytical model only covers 1-dimensional case which is meaningful in the actual scene in the paper. In BIB011 , the model is extended from 1-dimensional case in BIB008 to 2-dimensional case by constructing an analytical model of content retrieval for ICMANETs based on the content hit/miss probability called PRCRM in BIB008 . The model is divided into node space, content space and session space. By investigating the distribution of content popularity, receiver-driven mechanism, content insertion and eviction mechanism and generalized mobility model in 2-dimensional space, PRCRM can be used to estimate the content retrieval-related performance. In BIB015 , a publish-subscribe system exploiting CCN system in MANET is investigated including CCN functionality, data dissemination, in-network caching, multicasting and delay tolerant delivery. Different design approaches are provided. The topic based publishsubscribe CCN system is evaluated in an emulated environment based on Linux virtual machines. The results show that Pull and Push are the two dissemination models on which publish-subscribe CCN systems may be based. Pull approach can be developed by using the CCN architecture without modifying, but requires polling, which in general leads to an undesirable overhead. However, in case of MANETs, polling is also used to refresh the topology of the dispatching multicast tree, which otherwise should be done with other means. The evaluation also reveals that the effectiveness of the CCN functionality increases with the area side and the number of subscribers.