Haut PDF Advances in Wireless and Mobile Communication Networks : A Multi-Layer Analysis

Advances in Wireless and Mobile Communication Networks : A Multi-Layer Analysis

Advances in Wireless and Mobile Communication Networks : A Multi-Layer Analysis

we have chosen for the scope of this research the femtocells as part of the indoor solution to offload the indoor traffic due to several of the reasons below. Femtocell can be defined as "a personal mobile network in a box". It is one of the constituents of the LTE-Advanced technology components. It is categorized under the heterogeneous network’s small cell concepts. It is designed to serve very small areas, such as a home or an office environment, providing radio coverage of a certain cellular network standard, e.g., Universal Mobile Telecommunications System (UMTS), World- wide Interoperability for Microwave Access (WiMAX), LTE. Femtocells are connected to the service provider via broadband connection, e.g., DSL or optical fiber. Femtocell uses the licensed spectrum owned by a mobile operator. It uses a low power Femto base station (or Femto Access Point) that utilizes fixed broadband connections to route Femtocell traffic to cellular networks. Moreover, it is a part of self organizing network (SON) with zero touch installation. Femtocells can support indoor users with high sig- nal strength and thus can offload these users from outdoor base stations with the main driver to improve the coverage and capacity. This offers better quality of service, not only to indoor users but also to outdoor users by offloading. Consequently, femtocells are beneficial for both operator and user. For the operator, femtocells increases the net- work capacity, permits the lower backhaul costs (less macrocell traffic) and sometimes expandes the revenue opportunities. As well, for the user, femtocells gives a better in- door coverage, a full speed data transfer at home and an ubiquitous mobility between home cell and overlaying macrocell [ 80 , 9 ].
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Multi Group Key Agreement Mechanism for Mobile P2P Wireless Networks

Multi Group Key Agreement Mechanism for Mobile P2P Wireless Networks

IV. P ERFORMANCE EVALUATION Several evaluation metrics that are used to evaluate the performance of group key agreements protocols are discussed in the literature [4]. Performance of the contributory key agreement can be divided into two categories: computation cost and communication cost. Communication costs include the total number of rounds, and total number of messages (both unicast and broadcast messages). Computation costs consist of the total number of cryptographic signatures, total sequential exponentiations, and total number of verifications. Unlike Clique I, Our proposed model uses only a few set of nodes for key agreement. Then, it converges rapidly with low cost communication.
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Multi-User Video Streaming over Multiple Heterogeneous Wireless Networks: A Distributed, Cross-Layer Design Paradigm

Multi-User Video Streaming over Multiple Heterogeneous Wireless Networks: A Distributed, Cross-Layer Design Paradigm

I. I NTRODUCTION As multimedia is expected to be the major traffic source on the next-generation wireless networks, QoS (Quality of Service) provisioning for wireless video transmission has become a critically important issue. In addition, recent years have also witnessed the increasing efforts towards standardization of architectures for convergence of heterogeneous access networks, and moreover, the integration of heterogeneous networks has fully become part of the 4G network design [1]. IEEE 802.21 [2] is delineating a framework to enable handovers and interoperability between heterogeneous wireless and wireline networks. Therefore, supporting multimedia appli- cations over heterogeneous networks has been one of the main fields of research in the networking and video coding communities. For example, the IMS (IP Multimedia Subsystems) platform [3] has defined an overlay architecture for providing multimedia services on top of heterogeneous wireless networks. Note that, the problem of video streaming over heterogeneous networks is further complicated by the heterogeneity of both the video contents and the network conditions. Up to now, providing a satisfactory communication quality in a heterogeneous wireless system is still a challenging problem because the end-to-end QoS guarantee is difficult to be provided [19].
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Dependable Wireless Industrial IoT Networks: Recent Advances and Open Challenges

Dependable Wireless Industrial IoT Networks: Recent Advances and Open Challenges

• Real-time information delivery that each traffic flow shall be delivered with latency guarantee requirements. III. B ENCHMARKING II O T S YSTEMS AND P ROTOCOLS Over the last decade, an increasing number of low-power wireless technologies and communication protocols have been developed in order to satisfy the requirements of a wide range of IoT applications. These technologies are largely different in nature: devices making use of IEEE 802.15.4, Bluetooth Low Energy, and ANT+ radios, for example, enable short-range multi-hop communications, whilst devices embedding LoRa, NB-IoT, Sigfox, and Weightless transceivers can be used to build long-range wide area networks. All these technologies specify different signal management functions, modulation schemes, data rates, channel bandwidths and separations. This results in largely-diverse performance and makes it hard to quantify or compare (i) the suitability for a given IIoT appli- cation, as well as (ii) the achievable dependability in terms of reliability, timeliness, and availability (energy-efficiency). Indeed, several communication protocols have been proposed in conjunction with these technologies to sustain a dependable performance, e.g., in noisy RF environments. Such protocols range from multi-hop routing solutions making use of time- slotted channel hopping [11], [12], [13], to solutions based on synchronous transmissions and constructive interference [14], [15], [16]. With so many options available, choosing the best constellation for an IIoT application with stringent depend- ability requirements in terms of reliability, availability, and timeliness can be very complex. This is especially true, as the parametrization of a given protocol for a specific technology strongly affects the achievable performance. Moreover, the set of configurable parameters to be chosen can be quite large, which exacerbates the problem even further.
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Cross Layer Rate Control, Medium Access Control and Routing Design in Cooperative Multi-Hop Wireless Networks

Cross Layer Rate Control, Medium Access Control and Routing Design in Cooperative Multi-Hop Wireless Networks

I. INTRODUCTION In a wireless cooperative communication system, each user is assumed to transmit data and act as a cooperative agent for another user. That is to say, each user transmits both its own bits as well as some information for its partner [1]. The idea of cooperative network is first proposed to handle “flash crowds” on the Internet, where end-hosts cooperate in order to improve the overall network performance [2]. In recent years, some cooperative strategies for content delivery and sharing in wireless network have been proposed [3-5]. However, most of research in this area is to optimize physical layer performance without considering much detail about how cooperation interacts with higher layers and improves network performance. Specially, there is no specific solution describing how to solve the data flow movement problem over multiple hops in this architecture. In fact, since the cooperative network is a classic multi- source-multi-path system, one of the most challenge issues is the flow rate control: the Internet is based on an end-to-end paradigm, where the transport protocol (e.g. TCP) instances at the endpoints to detect overload conditions at intermediate nodes. When congestion occurs, the source reduces flow rate [6]. However, cooperative network is usually a distributed dynamic system and the congested nodes might not be adjusted at all when the sources react to the congestion.
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A Multi-Layer Architecture for Wireless Sensor Network Virtualization

A Multi-Layer Architecture for Wireless Sensor Network Virtualization

Keywords-Wireless Sensor Networks; Virtualization; Overlay Networks; Wireless Sensor Network Virtualization I. I NTRODUCTION Wireless Sensor Networks (WSNs) are amalgamations of micro-electro-mechanical systems, wireless communication systems and digital electronics nodes that sense, compute and communicate [1]. They are made up of sensors, sinks and gateway nodes. Virtualization is a technology that presents physical resources logically, and enables their efficient usage and sharing by multiple independent users [2]. The new generations of WSN nodes have more and more resources (e.g. storage, processing) [3]. It now makes sense to consider the efficient usage and sharing of these resources through virtualization. WSN virtualization enables the sharing of a WSN infrastructure by multiple applications [4]. There are two possible approaches to WSN virtualization. The first one is to allow a subset of sensor nodes to execute an application, while at the same time (preferably) another subset of sensor nodes executes a different application [5]. These subsets can vary in size and in number according to the application requirements. The second approach is to exploit the capabilities of the individual sensor nodes and execute multiple application tasks [4], [6] and [7]. Each application task is run by a logically distinct but identical physical sensor node.
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Pricing Strategies in Multi-Operator Heterogeneous Wireless Networks

Pricing Strategies in Multi-Operator Heterogeneous Wireless Networks

The mobile broadband traffic is growing in a rapid manner, facing network operators with the challenge of expanding capacity and enhancing the Quality of Service (QoS) of their communication networks. In addition, operators are worried about the decrease of revenues especially from voice services, and they sense the need of new technical and network solutions that can generate new sources of revenues. Business solutions introduced in [1]show that mobile operators cooperate with other competitors and customers; some proposed partners can be providers of a non-telecom service like financial institutes, public transportation or third parties taking intermediary roles. Multi-operators cooperation in the form of open access and always best connected, has been proposed in a number of large research projects likeAmbient Networks[2], SPICE[3]… etc. and several types of cooperation between networks and business entities are made. The cooperation of wireless network operators in a sharing environment is also introduced in [3] as a cost effective network solution to expand capacity and improve operators’ profitability. Indeed, many works has showed that in a heterogeneous wireless environment, operators’ cooperation is unavoidable and inter-operator agreements can bring benefits in terms of both network performance and operators’ revenues [5][6]. In addition, new mobile
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Bottleneck Analysis for Routing and Call Scheduling in Multi-hop Wireless Networks

Bottleneck Analysis for Routing and Call Scheduling in Multi-hop Wireless Networks

I. I NTRODUCTION In wireless networks, the communication channels are shared among the terminals. Thus, one of the major problems faced is the reduction of capacity due to interferences caused by simultaneous transmissions [1]. In this work, we call a round a collection of links that can be simultaneously activated in the network. We address the problem called Round Weight- ing Problem (RWP) [2] that consider joint routing and schedul- ing. We present a cross-layer formulation of the problem. We have to find a minimum-length schedule of selected links in a TDMA (Time Division Multiple Access) based wireless network. As we deal with multi-hop networks, these selected links represent a routing solution (paths) providing enough capacity to achieve the routers requirements of bandwidth. Scheduling methods such TDMA can guarantee achieving higher capacities by allowing time slots to be shared by simultaneous transmissions.
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Resource Management in Wireless Access Networks: A layer-based classification - Version 1.0

Resource Management in Wireless Access Networks: A layer-based classification - Version 1.0

3.2.2.5 Multiple objectives resource management solutions In fact, a better resource management strategy can be achieved when multiple problems are taken into account simul- taneously. A novel resource manage scheme for single-network services that considers both resource allocation and user association in heterogeneous cellular networks (HeteNets) was proposed in [23]. A HeteNet consists of several pico-cells coexisting in the same region of a macro-cell as described in Fig. 3. Each pico-cell is managed by a pico-BS while a macro- cell is managed by a macro-BS. Three channel allocation schemes in HeteNets were discussed: co-channel deployment (CCD), orthogonal deployment (OD), and partially shared deployment (PSD). In OD, all pico-BSs share K sub-channels while other sub-channels are utilized by the macro BS. Meanwhile, in the CCD, all BSs in the region (both pico BSs and the macro BS) share all sub-channels. The last one is PSD in which all BSs share K sub-channels and the macro BS use others. The main objective is to assign throughput fairly to all users in the networks. In case of multimedia services, because the throughput is not well correlated to user’ experience, it can be replaced by MOS. Recently, thanks to development in integrated circuit, mobile devices can be equipped with two or more radio interfaces. As a result, the selection of an appropriate radio interface or a set of radio interfaces for a service is necessary. A radio interface and channel selection scheme was mentioned in [18]. An optimal solution for parallel multi-radio access (MRA) scheme to maximize system capacity was introduced. The results provided useful and insightful information in designing efficient MRA systems. However, the high complexity of algorithm can lead to obstacles in practical implementation.
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A Spatial Reuse Aloha MAC Protocol for Multihop Wireless Mobile Networks

A Spatial Reuse Aloha MAC Protocol for Multihop Wireless Mobile Networks

d(λ, p ∗ ) = κ/ √ λ for some κ (see 4.19), we conclude that under the assumptions made above, this average stationary origin to destination delay ought to be proportional to L √ λ. 6 Implementation Issues This section contains a list of questions that have to be addressed for the design of a complete MSR- Aloha MAC protocol based on the notion of progress. First MSR-Aloha being a random access MAC protocol, we have to cope with collisions. Of course MAC collisions can be handled above the MAC layer but it can be easily shown that this leads to inefficient communication systems. This is why a good implementation of MSR-Aloha should use MAC acknowledgments for point to point packets as it is done in MAC protocols used for WLANs standards [15, 16]. We have assumed that MSR-Aloha is slotted, the slot can be divided in two parts: a data part (the main part) used by the emitter to send the packet and an acknowledgment part used by the receiver to indicate that it has correctly received the packet. In case a packet is not acknowledged, MSR-Aloha will just have to
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Access Selection and Joint Pricing in Multi-Operator Wireless Networks: A Stackelberg Game

Access Selection and Joint Pricing in Multi-Operator Wireless Networks: A Stackelberg Game

The mobile traffic broadband is growing in a fast manner, facing network operators with the challenge of expanding capacity and enhancing the Quality of Service (QoS) of their communication networks. Multi-operators cooperation in the form of open access has been proposed in a number of large research projects like ANWIRE, SPICE, Ambient Networks, etc. [1]. The cooperation of wireless network operators in a sharing environment is also introduced in [2] as a cost effective network solution to expand capacity and improve operators’ profitability. In fact, network sharing is widely used in WLAN systems where local access providers offer wireless access to service providers. A similar structure exists in cellular networks where Mobile Virtual Network Operator (MVNO) provides mobile services without having a mobile network of their own. Multi-operator solutions are introduced for shared small cells as for macro cellular networks, within different business models including inter-connection provider or a third party local operator [3] [4].
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Content replication in mobile wireless networks

Content replication in mobile wireless networks

3.3.3 The power-law of human mobility in virtual world traces In [72], we also conduct a measurement study of user mobility but in a virtual en- vironment. We present a novel methodology to capture spatio-temporal dynamics of user mobility that overcomes most of the limitations of previous attempts : it is cheap, it re- quires no logistic organization, it is not bound to a specific wireless technology and can potentially scale up to a very large number of participants. Our measurement approach exploits the tremendous raise in popularity of Networked Virtual Environments (NVEs), wherein thousands of users connect daily to interact, play, do business and follow university courses just to name a few potential applications. Here we focus on the SecondLife (SL) “metaverse” [3] which has recently gained momentum in the on-line community. Tempted by the question whether our methodology could provide similar results to those obtained in real-world experiments, we study the statistical distribution of user contacts and show that from a qualitative point of view user mobility in Second Life presents similar traits to those of real humans. We further push our analysis to the network topology that emerge from user interaction and show that they are highly clustered. We focus on the spatial properties of user movements and observe that users in Second Life revolve around seve- ral points of interest traveling in general short distances. Besides our findings, the traces collected in this work can be very useful for trace-driven simulations of communication schemes in mobile networks and their performance evaluation.
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A Protocol for Content-Based Communication in Disconnected Mobile Ad Hoc Networks

A Protocol for Content-Based Communication in Disconnected Mobile Ad Hoc Networks

profile. Yet this possibility has not been used in the simulation runs whose results have been presented so far. Let us now observe how the global performance of document dis- semination is affected when hosts are allowed to behave altruistically. In Fig. 21 we observe how the satisfaction ratio of document delivery evolves over time, depending on whether the mobile hosts adopt either an altruistic or a selfish be- haviour. A host is said to behave selfishly when it only accepts to store, carry, and for- ward only documents it is itself interested in. This corresponds to the behaviour we have actually considered in al lthe results presented so far. A host is said to behave altruistically when it accepts to receive and store in its cache documents it overhears on the wireless medium, even though these documents present no interest to him. The results presented in Fig. 21 were obtained during a simulation where the capacity of each host's cache was set to 300 documents, which in that particular case is slightly larger than the capacity required for carrying only interesting documents, and therefore allows that the remaining space be used for carrying non-interesting ones. Each document was given a 75 minute lifetime, and the scope of multi-hop forwarding was set to 2 hops.
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2019 — Wireless networks physical layer security : modeling and performance characterization

2019 — Wireless networks physical layer security : modeling and performance characterization

Keywords: Cascaded α − μ fading channels, Fox’s H-function, reliability, secrecy analysis. 7.2 Introduction The ever-increasing demand for highly reliable wireless communication systems has led to the prosperous of various accurate channel modeling in system design and evaluation. A com- prehensive summary of all existing fading models includes (i) short-term fading: Rayleigh, Rician, Nakagami-m, and Weibull; (ii) long-term fading: Lognormal; (iii) composite fading: Rayleigh-lognormal; and (iv) cascaded fading Boulogeorgos, A. A. A., Sofotasios, P. C., Selim, B., Muhaidat, S., Karagiannidis, G. K. & Valkama, M. (2016); Hajri, N., Youssef, N., Kawa- bata, T., Patzold, M. & Dahech, W. (2018); Karagiannidis et al. (2007); Peppas, K., Lazarakis, F., Alexandridis, A. & Dangakis, K. (2010); Sagias, N. C. & Tombras, G. S. (2007); Trigui, I., Laourine, A., Affes, S. & Stephenne, A. (2009); Yilmaz, F. & Alouini, M. S. (2009); Zheng, Z. (2015). In particular, the cascaded fading channel is mathematically based on the multiplicative modeling approach and happens over wireless communication links when 1) transmitter-and- receiver pairs experience rich scattering, but the existence of some keyholes or pinholes makes it still possible to keep the transmission; 2) the received signals are engendered by the product of a bunch of rays reflected via N statistically independent scatters.
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Broadcast in Self-Organizing Multi-hop Wireless Networks

Broadcast in Self-Organizing Multi-hop Wireless Networks

9.1.2 Gateways nodes selection Still according to the self-stabilization (see [12]), in an expected bounded time, each tree root r can be aware of the identity of all its neighboring clusters, the sets of the frontier nodes in C(r) for every neighboring cluster as well as the kind of the mirror (leaf or internal node) chosen by each of them. The gateway selection we propose is distributed, so, a selection is performed at every step in the tree. Frontier nodes send their parent the following information: their ID, whether they are leaves and whether they have a leaf as mirror. Each parent selects the best candidate among its children and sends the same information to its own parent and so on, up to reach the cluster-head. Thus, the selection is semi-distributed as every internal node eliminate some candidates. This way, only small packets are forwarded from the frontier nodes to the cluster-head and this one does not have too many data to compute.
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Interference Modeling in CSMA Multi-Hop Wireless Networks

Interference Modeling in CSMA Multi-Hop Wireless Networks

+04 1.00e +04 2.15e +05 1.41e +04 1.25e +03 1.25e +03 log-normal 1.28e +03 1.32e +03 9.10e +03 1.14e +03 1.60e +03 1.49e +03 Table 2: Value of the χ 2 statistics. In this Section we study the interference level probability density function (pdf). We use the parameters of the IEEE 802.15.4 standard at the 868 MHz frequency. These parameters are summarized in Table 1. We compare two scenarios. For both scenario, an emitter is located at (0, r 2 ), where r is the inhibition ball radius, and a receiver is located at the origin. In scenario 1, we suppose that there is an inhibition ball centered at the emitter. This ball models the CCA operation done by this node before emitting. In scenario 2, we add an inhibition ball centered at the receiver. This scenario models the use of a RTS/CTS handshake. Other network nodes are distributed in the observation window B according to one of the three point processes, Poisson, Mat`ern and SSI, addressed so far. We consider three different density of nodes : n = 0.2 R r 2 2 , n = 0.7
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Performance of CSMA in multi-channel wireless networks

Performance of CSMA in multi-channel wireless networks

It turns out that, while CSMA is always efficient in ad-hoc mode, in the sense that the network is stable whenever possible, it is generally inefficient in infrastructure mode, when all data flows originate from or are destined to some finite set of access points. This is due to the inherent bias of CSMA against downlink traffic, from the access points to the stations: each access point attempts to access the radio channels with the same rate, independently of the number of active downlink flows at this access point. We prove that a slight modification of CSMA, which consists in running one instance of CSMA per flow at each access point, corrects this bias and makes the algorithm optimal. We refer to this algorithm, introduced in [6], as flow-aware CSMA.
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Overview on Multi-Channel Communications in Wireless Sensor Networks

Overview on Multi-Channel Communications in Wireless Sensor Networks

any 2-hop neighborhood are assigned different frequencies, but it induces high communication overhead due to the ID and frequency exchange between 2-hop neighbors using CSMA/CA. The even-selection strategy is more suitable for dense WSN where the number of frequencies is smaller than the number of nodes within two hops. It is similar to exclusive frequency strategy, but when all frequencies are already chosen in a 2-hop neighborhood, a node randomly chooses one of the least chosen frequencies. Hence, it does not ensure that nodes in any 2-hop neighborhood are assigned different frequencies. In the eavesdropping strategy, each node takes a random backoff during which it waits for its 1-hop neighbors to choose their frequencies. When its backoff expires, it randomly chooses one of the least chosen frequencies within one hop. This strategy has less communication overhead compared to the first two strategies, but it only collects frequencies information within 1-hop neighborhood and during a limited random time interval which results in more conflicts and more interferences. In the implicit-consensus strategy, nodes exchange their identities in their 2-hop neighborhood. For each frequency, each node calculates a random number for itself and a random number for each node in its 2-hop neighborhood using the same pseudo- random number generator. A node wins current frequency if its random number is the highest among all the other random numbers. It then broadcasts its frequency to the 2- hop neighbors. This strategy guarantees smaller overhead but assumes a high number of available frequencies. The performance of MMSN is evaluated through simulations using GloMoSim simulator and compared with CSMA/CA. In this evaluation, MMSN uses even selection for channel allocation. When the number of channel increases from 1 to 4, packet delivery ratio increases from 95.2% to 97.3%, aggregate MAC throughput increases by 119% from 239Kbps to 523Kbps and the channel access delay decreases to 0.021s, which is 37.5% of the delay when only 1 frequency is available. Results also show that when the system loads increases from 15 CBR streams to 50 CBR streams, CSMA/CA has a decreased packet delivery ratio from 98.3% to 95.4%, while MMSN does not have such an obvious packet loss.
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Enabling Roaming in Heterogeneous Multi-Operator Wireless Networks

Enabling Roaming in Heterogeneous Multi-Operator Wireless Networks

3.3.1.2 Seamless Service Mobility Service mobility allows users to maintain access to their services even while mov- ing or changing devices and network operators or service providers. One solu- tion for service mobility is to have the mobile user carry this information on his PDA or cellular phone (in a memory chip or the SIM card). Nevertheless, even with local storage, updates made on any of the user’s end systems still needs to propagate to the other devices, even if the device performing the update and the other devices are never in the same place. This requires network storage (Schulzrinne & Wedlund, 2000). The other issue refers to authorization, in this matter, even if the service profile is placed on the mobile device, the home net- work still has to validate such user profile before allowing any service to be used. Without the proper roaming agreements between network operators the remote validation of a user profile is not a trivial task. Furthermore, a concern of het- erogeneous wireless operators refers to efficient service provisioning to mobile users once they roam into a UWN. The SIP architecture is predicated on hav- ing a home server, that can be physically located in the cellular network, associ- ated with the user’s SIP address. Under this architecture, the home sever stores service-related information and this element is in charge of propagating service information among all domains (Schulzrinne & Wedlund, 2000). Although, this architecture assures an efficient update of user’s service profile it lacks of the se- curity mechanisms to verify the mobile user’s and rights to perform the services indicated in the service profile. In this connection, our research work provides efficient mechanisms for service authorization, a process that comprises the verifi- cation of the mobile user profile validity and the right of a subscriber to perform certain service. All this, without compromising the privacy of the user service profile. More details are available in the next chapter.
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Multi-Objective flow-interface mapping in heterogeneous and mobile networks

Multi-Objective flow-interface mapping in heterogeneous and mobile networks

•  Necessary an intelligent decision maker to flow-interface mapping:. –  Taking into account Applications’ requirements, Users preferences, Administrators’ policies and Networks chara[r]

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