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This paper deals with the currently developing video encoding standard H.265/HEVC. The scope of this paper is to evaluate the encoding and compression efficiency of the new standard in comparison to its predecessor H.264/AVC and more specifically to validate if the main objective of the new codec is satisfied, which is to double the compression efficiency of the bit stream without deteriorating the quality level of the encoded signal. [ABSTRACT FROM PUBLISHER]

This paper builds on previous work [1] on IP off-loading over multi-granular photonic switching technologies to provide an in-depth techno-economic analysis for a real metro scenario. The main contribution of the paper is that it demonstrates a 42% capital cost reduction in favour of the proposed IP-offloading architecture, when compared against currently used, typical all-IP architectures. This is achieved by performing packet transport, aggregation, switching and grooming in the optical layer within an IP off-loading architecture using the Optical Packet Switch and Transport (OPST) technology. Such results show that multi-granular optical technologies are a strong candidate for solving the bottleneck problem caused by video streaming, cloud services and mobility in metropolitan area networks. Finally, the paper also discusses other, cumulative benefit aspects of multi-granular technologies, such as video and next-generation cloud services. [ABSTRACT FROM PUBLISHER]

In the ISM band multiple wireless technologies compete for a limited amount of spectrum, leading to interference and performance degradation. Reliable information on the spectrum occupation enables more optimal usage and can improve co-existence in the ISM band. In this paper, we study the robustness of the information obtained about the propagation environment when sensing with multiple, heterogeneous devices, at multiple diverse locations. More specifically, we look into the impact on the path loss estimation depending on the type, number and the location of the sensing devices. The analysis in this paper is done based on indoor measurements in the ISM band. Based on the presented measurements and analysis we conclude that analysis based on only one device type or in specific locations can lead to suboptimal or even incorrect estimation results. [ABSTRACT FROM PUBLISHER]

Relaying is undoubtedly a key technology for future wireless networks as it can be applied to provide coverage extension and capacity increase in a cost-effective manner. This paper presents an outline of the major advanced relaying concepts that will be part of future systems from the viewpoint of the ARTIST4G European project. These concepts can be divided into three categories, those pertinent to type-1 relays, type-2 relays and moving relays. The characteristics of each of these concepts are presented and the challenges related to their implementation are discussed. Furthermore the paper proposes a set of solutions to address the discussed challenges. For type-1 relays, the paper presents solutions for the allocation of resources to the backhaul and the access links, the inter-relay interference mitigation, and the multi-hop transmission mode. For type-2 relays, our focus is on the design of distributed hybrid automatic repeat request (HARQ) protocols. More specifically, we propose that the conventional HARQ schemes are adapted to exploit the potentially better channel conditions provided by the relays. Moreover distributed turbo coding solutions are introduced for increasing transmission reliability with the aid of relays. Finally, moving relays are presented as an efficient solution to the ever-growing demand for wireless broadband by users within public transportation vehicles. We show that moving relays can very effectively overcome the vehicle penetration loss and boost the achievable capacities of the vehicular users. Overall, we conclude that the presented advanced relaying concepts are very promising and can significantly enhance the user experience in future wireless networks. [ABSTRACT FROM PUBLISHER]

Although future radio access networks (RAN) will be empowered by Self-Organizing Network (SON) mechanisms, operator governance and coordination remain key requirements, in order to guarantee a robust, stable and desired network operation. This paper investigates the coordination of two promising SON mechanisms, namely Inter-Cell Interference Coordination (ICIC) and Capacity and Coverage Optimization (CCO), according to the operator policies in the context of a downlink LTE network. For this purpose, the paper intends to identify a methodology that can also be generalized beyond ICIC and CCO coordination. In this direction, the interactions between the two SON mechanisms are first modelled using a concept map methodology. Then, an appropriate mathematical formulation is designed to analytically describe the SON coordination as a weighted multi-objective optimization problem. The operator weights stand for the priority that the operator gives to each SON mechanism. Simulation results are presented in order to evaluate the coordination approach. They confirm that the operator can achieve a trade-off among even conflicting objectives by adjusting the weights in accordance to business goals. Moreover, the operator can offline elaborate on the best selection of weights in order to achieve a robust, stable and desired network operation. [ABSTRACT FROM PUBLISHER]

Acknowledging the shortcomings of traditional network management paradigms, many initiatives attempting to realize and foster the adoption of autonomic network management have taken place while others are still ongoing in the research community. The role of learning is undoubtedly of prime importance in autonomic network management since in principle, it allows for the introduced management and control functionality to exhibit “human”-like self-x attributes and behaviour and adapt to changing network and user conditions. This means that the human operator is offloaded from configuration and reconfiguration tasks that would otherwise require their constant attention and their very deep understanding of low-level network operations and dynamics. When so, human intervention is needed only when, despite the self-x efforts of the various management and control processes, the overall targets cannot be met. In this paper we present the approach of the ongoing UniverSelf project with respect to the role of learning. This paper presents how the learning framework fits in the overall management framework put forward by the project and what the requirements that the learning solutions must exhibit are. Finally, a specific case study corresponding to an instantiation of the learning framework to better illustrate these notions is also described. [ABSTRACT FROM PUBLISHER]

Improving energy efficiency in Internet equipments is becoming an increasingly important research topic. In this paper, we discuss the lesson gained by experimenting a power management mechanism aimed at reducing the power consumption while guaranteeing the Quality of Service (QoS). To this purpose, we drive the clock frequency of an open flexible and high-performance router, the NetFPGA, according to the measured input bit rate. An evaluation of the proposed power management policy is provided. [ABSTRACT FROM PUBLISHER]

The coexistence of OFDM-based cognitive radios (CRs) with licensed wireless systems puts strong attention on protection of primary links. In this paper, we have shown how environment-aware CR can calculate protection requirements for Out-of-Band (OOB) radiation attenuation on the basis of licensed users' receivers characteristic. In dynamically changing environment this approach can provide significant advantage over classical static spectrum masks. In the second part of this paper we have investigated how the calculated OOB attenuation requirement can be obeyed by OFDM system employing combination of windowing and cancellation carriers (CCs) shaping methods. We have shown how the transmitter can estimate a spectrum shape before any OFDM symbol being sent. On this basis the CR will not operate until spectrum shaping mechanisms fulfil the requirements. The calculations and simulations were carried for a wireless microphone being licensed system as the application of the CR in the UHF band is the most probable. [ABSTRACT FROM PUBLISHER]

While BitTorrent was originally conceived as a Peer-to-Peer file exchange protocol, it has proved extremely successful for asynchronous content distribution, allowing content sources to support huge numbers of users with a modest amount of bandwidth. This has prompted many researchers to study the possibility of using BitTorrent to support real-time media streaming. In this paper we present a comparison of three proposed adaptations to BitTorrent for media streaming, using our detailed packet-level BitTorrent simulator. Unlike previous evaluations which assumed that the streaming media player would drop data that did not arrive on time, in this paper we use a more realistic model where the player stalls when data are not available, thus placing emphasis on delays rather than losses. Our experiments indicate that under this, more realistic, evaluation model, user level performance can be quite reasonable. [ABSTRACT FROM PUBLISHER]

Distributed antenna systems (DASs) have been shown to considerably improve the physical-layer performance of cellular wireless networks. However, several issues in the design of radio resource management algorithms (RRM) for this type of system remain open today. This paper partially fills this gap by proposing a joint user scheduling, dynamic power control and beam-forming algorithm for the down-link of multi-cell DASs under the assumption of imperfect channel state information (CSI). The algorithm aims to schedule over the same frequency band a different user attached to a different distributed node within the cell. This goal is achieved by optimizing the power levels and beam-forming vectors of each node, thereby controlling the interference created between the simultaneous transmissions of the scheduled users while maximizing the sum-rate capacity of the cell. This optimization problem is solved by means of a gradient descent iterative technique, which provides the set of optimum node-user pairs to be scheduled, as well as their optimum transmit power levels and beam-forming vectors. Outer-cell interference is computed by reusing the results of previous iterations of the central cell in the transmission parameters of the outer-cells, thus mimicking more efficiently the behavior of the algorithm at the system-level. The algorithm is also evaluated in terms of fairness by means of the first-order moment of the spatial distribution of the capacity. Capacity and fairness properties of the algorithm are shown to considerably outperform previous solutions, particularly in scenarios with good line-of-sight, optimum node location, and relatively accurate CSI. [ABSTRACT FROM PUBLISHER]

Mobile data traffic is increasing dramatically, essentially due to the exploding use of wireless applications. To cope with this, one solution is the deployment of many small base station sites to cover the hot spots. With the deployment of more heterogeneous networks, the total energy expenditure will increase. Traditionally, the techniques to improve the energy efficiency of small base stations exploit the network load variation and the idle time. However, they do not consider that the resource scheduling can have an important impact on energy consumption when the network is not fully loaded. In fact, forcing the system to transmit a packet when the channel conditions are poor, results in low energy efficiency. In this paper we propose an adaptive scheduling algorithm for pico base stations that applies the optimal scheduling algorithm of “water-pouring” in time in a full LTE framework using consolidated pico base station power models from EARTH project. Our approach reduces the energy per information bit by transmitting at full load during good channel conditions and going into sleep mode the rest of the time. We quantify the achievable gains with realistic channel and network conditions and we show energy savings of up to 61% in the energy per information bit with a marginal impact on packet delay. [ABSTRACT FROM PUBLISHER]

In cooperative radio communication systems multiple relay nodes are used with receiver combining of the relayed and direct paths in order to combat fading outages. In this paper, different cooperative configurations are examined and novel analytical formulas and numerical results on the outage performance over correlated lognormal channels are presented. More specifically, the considered cooperative systems consist of a single relay forming a fundamental cooperative triangle-shaped configuration or two relays in arbitrary positions forming a diamond-shaped cooperative system. Moreover, the analysis covers both the Selection Combining (SC) and the Maximal Ratio Combining (MRC) at the receiver and the Fixed Relaying cooperative protocol. The performance of the proposed cooperative systems is compared with a direct link system, in order to investigate the benefits of cooperation over non-cooperation, as well as the benefits of utilizing an extra relay. The proposed expressions for the outage probability can be directly applied to various propagation scenarios where the lognormal distribution is used to describe the large scale fading effects such as, indoor, urban and on body propagation environments. Finally, the impact of the lognormal parameters (including correlation) on the cooperative system performance is investigated through extended numerical results. [ABSTRACT FROM PUBLISHER]

In this paper, non-cooperative, energy-efficient resource allocation in a MIMO relay-assisted interference channel is considered. The energy efficiency of a given terminal is defined as the ratio between the throughput of that terminal and the consumed power. As far as the computation of the consumed power is concerned, not only the transmit power, but also the power dissipated in terminal's electronic circuitry to operate the device is considered. We consider both the cases of power control and of joint power control and linear receiver design; in the former case we are able to prove that a unique Nash equilibrium exists, and that the best-response-dynamics is guaranteed to converge to the unique equilibrium; in the latter scenario existence of the Nash equilibrium is shown, while the convergence of the best-response-dynamics is only conjectured, based on numerical evidence. Numerical results are provided to show the merits of the proposed algorithms. [ABSTRACT FROM PUBLISHER]

Implementing a flexible and modular architecture for scheduled systems will speed-up the deployment of novel and adjustable MACs for cellular systems. Such an architecture will be of great benefit for researchers, vendors and operators by enabling off-the-shelf devices to be used for testing modified MACs, by allowing fast upgrade of existing devices, and by drastically reducing the time-to-market of MAC products, which ultimately turns into enhanced services for the users. In this paper, we show how the architecture proposed in the FLAVIA project can enable the paradigm shift towards open, modular and flexible scheduled MAC architectures, thus allowing cellular operators to use up-to-date research results to augment and promptly update the capabilities of the cellular network by creating and instantiating MAC services. [ABSTRACT FROM PUBLISHER]

The new and emerging IT services require very high network capacities and specific IT resources that cannot be intrinsically delivered by the current Best Effort Internet. In response to this the European project GEYSERS (Generalised Architecture for Dynamic Infrastructure Services) is proposing a novel architecture that employs optical networking, capable of provisioning “Optical Network and IT resources” for end-to-end service delivery. GEYSERS adopts the Infrastructure as a Service framework and the Service-Oriented Networking paradigm and proposes an architecture that enables infrastructure operators to virtualize their infrastructures (optical network and IT resources) and offer them as a service based on the user/application requirements. This paper provides an overview of the GEYSERS approach regarding virtualization of infrastructures comprising optical network and IT resources. Special emphasis is given in the description of the Logical Composition Layer of the architecture that is responsible for both the creation and maintenance of virtual resources and the virtual infrastructures. An important function of the Logical Composition Layer is the virtual infrastructure planning process discussed in detail. An optimization scheme suitable to adaptively plan and re-plan virtual infrastructures employing evolutionary game theory is presented and compared to conventional centralized approaches. Our evolutionary game theory modelling results clearly indicate, that given sufficient time to learn the status of the underlying physical topology the virtual infrastructures planned have similar performance to those generated through traditional global optimization approaches such as integer linear programming. [ABSTRACT FROM PUBLISHER]

Over the past years, the deployment of sensor networks in industrial environments has attracted much attention in several business domains. An increasing number of applications have been developed, ranging from defence, public security, energy management, traffic control to health care. Integration of these sensor networks within domains relying on AAA (Authentication, Authorization and Accounting) infrastructures leads to the definition of novel services and profitable leveraging opportunities, while reinforcing the overall sensor networks security. This paper proposes architectures and solutions for wireless sensor networks in the field of sensor bootstrapping, (re-)authentication, secure routing and co-ownership. This work is carried out in the recently started “TWISNet: Trustworthy Wireless Industrial Sensor Networks” project1. [ABSTRACT FROM PUBLISHER]

In this paper, we propose a phase synchronization scheme for distributed beamforming in Wireless Sensor Networks. The scheme is decentralized, meaning that the Base Station (BS) is not required to coordinate the allocation of sensors to the corresponding training timeslots. The BS is only asked to perform an estimation and quantization of the signal phase in each timeslot, and send it as a feedback to the sensor nodes. In order to find the optimal number of training timeslots, we derive an upperbound of the resulting beamforming gain in this specific scenario. Computer simulation results are given in terms of achievable throughput for different number of sensors. [ABSTRACT FROM PUBLISHER]

This paper reports the results of the proof-of-concept developed to demonstrate the centralized full transmission impairment compensation between the central office and the user's premises in long-reach passive optical networks (LR-PONs). The impairment compensation technique uses the information from a broadband channel sounding performed by only nine extra RF-pilots. The transmission of OFDM-based quadruple-play services (GbE-OFDM, LTE, WiMAX and UWB) along LR-PONs with total reach of 100 km is demonstrated without inline optical dispersion compensation. This reach could not be obtained without the proposed centralized impairment compensation technique due to the distortion of UWB signals. The proposed compensation technique provides an EVM improvement of 5.2 dB in the higher UWB band after 100 km SMF transmission. Bi-directional communication of the OFDM-based bundle is achieved at 100 km. [ABSTRACT FROM PUBLISHER]

The convergence between IT and optical network services is a fundamental step to support new emerging applications, typically distributed and with strict requirements in terms of performance and service reliability. The FP7 GEYSERS project has designed a new network architecture capable of joint and on-demand provisioning of ‘Optical Network + Any-IT’ resources for end-to-end service delivery. This service, referred to as Network + IT Provisioning Service (NIPS), is enabled through the cross-layer cooperation between the Service Middleware Layer (SML) and an enhanced Network Control Plane (NCP+) along the overall service lifecycle. This paper describes the GEYSERS NCP+ architecture that extends standard ASON/GMPLS and PCE solutions to operate over a virtual optical network infrastructure and offer on-demand provisioning of enhanced network transport services between virtual IT resources connected to the network edges. In the proposed architecture, some of the functionalities traditionally provided by the SML, like the selection of the IT end-points, are moved to the NCP+ side, allowing global optimization of the utilization of network and IT resources and of energy consumption. Simulation results are provided to evaluate the benefits of the combined computation of IT end-points and network paths, both in terms of reduced service blocking probability and utilization of the infrastructure resources. [ABSTRACT FROM PUBLISHER]

Multi-standard mobile devices are allowing users to enjoy higher data rates and ubiquitous connectivity. These advances are achieved on the expense of higher energy consumption requirements due to the continuous connectivity and the multiple active wireless interfaces. In this paper, we use one advantage of the multiple interfaces, namely short range communications. Mobile terminals use short range cooperative network to take advantage of the good channel quality of short range links to save energy in multi-standard mobile terminals. In this cooperative network, the combined energy of all MTs is treated as a pool of resources, which is used by all MTs in the network. Toward this end, we propose cooperation between mobile terminals using short-range technology to achieve energy savings. We conduct a quantitative numerical analysis to show the energy saving gains that can be achieved. We derive the energy gains in different use cases, considering the combination of WiFi and WiMedia in different channel conditions. We show that up to 80% energy savings can be achieved when using a combination compared to using WiFi without cooperation. We also show that short range cooperation can be used to extend the lifetime of the whole network. In such scenario, terminals, which are running out of battery or low in energy, can still relay their data through other mobile terminals, even with slight increase in the total energy consumption. The increase in the energy consumption of the relays can hence be compensated by some kind of payment, which opens opportunities for new business models. [ABSTRACT FROM PUBLISHER]

This paper explores the trade-off between cooperation and secrecy in cognitive radio networks. We consider a scenario consisting of a primary and a secondary system. In the simplest case, each system is represented by a pair of transmitter and receiver. We assume a secrecy constraint on the transmission in the sense that the message of the primary transmitter has to be concealed from the secondary user. Both situations where the secondary transmitter is aware and unaware of the primary message are investigated and compared. Furthermore, we extend our results to the scenario where the secondary system comprises multiple users. For each case we sketch the derivation of the rates that are achievable from an information theoretic perspective. We then investigate the findings by numerical simulations. Our main result is that, in spite of the secrecy constraint, cooperation is beneficial in terms of the achievable rates. The secondary transmitter has the two contradicting tasks of helping the primary system and transmitting its own message. Our results show that both tasks can be accomplished simultaneously, improving both systems' performance. In particular, the secondary system can achieve a significant rate without decreasing the primary rate below the benchmark rate achievable without the help of the secondary transmitter. In the case of multiple secondary users, the rate region reduces, which results in a lower individual rate. However, the linear increase in sumrate counterbalances this effect. [ABSTRACT FROM PUBLISHER]

A new concept for Machine-to-Machine (M2M) communications infrastructure via airliners is presented. The main principles and resulting challenges are described. A first study on possible coverage within Europe and North America using airliners endorses the concept's feasibility. Furthermore, system dimension aspects are investigated in a proof-of-principle manner to understand its feasibility. All commercial flights during 24 hours were considered on the basis of real global flight data. Paper's goal is stimulating further research activities and ideas in this area. [ABSTRACT FROM PUBLISHER]

The move towards broadband converged networks and applications is increasing the need for advanced network monitoring. As the EPC will completely overhaul the classic GPRS architecture by replacing it with a much flatter all-IP network; it will become a single converged core handling all applications including the existing telephony services. In this context, application performance monitoring will be essential in order to measure the user experience and to get more insight into the traffic trends and applications usage. In this paper, we will discuss the challenges facing network monitoring in EPC and provide recommendations in this regard. [ABSTRACT FROM PUBLISHER]

The Internet is kept together by means of a set of complex business interconnection agreements among multiple networks. However, existing peering and transit interconnection agreements do not provide any type of QoS assurance and pertain to interdomain traffic aggregates of multiple services (both elastic and inelastic). Thus, the current technological and business landscape is not appropriate for the provision of the emerging QoS-sensitive services. These and other economic inefficiencies of the current interconnection regime motivate the increasing research and business interest in providing solutions for enabling sustainable ecosystems, where these emerging services can be efficiently provisioned. In this paper we study the impact of the ETICS Assured Service Quality (ASQ) services on the strategies of the Internet interconnection market stakeholders. We investigate whether ASQ products can mitigate some undesirable strategic phenomena arising from players' conflicting interests. The relation of ASQ traffic with existing interconnection agreements and its potential to isolate traffic and/or regions of a network enables carriers to better control the business management of their infrastructure, and results in better investment incentives and services for the end-users. In fact, this applies to both best-effort and ASQ traffic. Thus, the ETICS ASQ products constitute a powerful tool for both meeting the needs of the ASQ services' customers and improving the quality of the best-effort Internet services as well, leading to a win-win outcome for all the market stakeholders. [ABSTRACT FROM PUBLISHER]

Opportunistic Networks (ONs) can be defined as temporary, operator-governed, coordinated extension of the infrastructure. These opportunistic networks can be used for extending the coverage of cellular networks, for offloading traffic from cellular networks by using direct connections between the devices or for opportunistic capacity extensions. While work has already been made or is ongoing on how to create and maintain such opportunistic networks, this paper analyses the probabilities that such opportunistic networks can be established and maintained in the different scenarios. [ABSTRACT FROM PUBLISHER]

Excessive energy consumption in nowadays wireless mobile devices inevitably leads to reduction of those devices operational time, which may jeopardize mobile traffic growth and limit user mobility. One of the possible ways to break the reduction in operational time of mobile devices is to utilize low-power short-range cooperative communication, as short-range cooperative communication offers data relaying between peer mobile devices. As we show in the paper, short-range cooperative data relaying may lead to significant energy saving gains spanning between 14% and 33%. However, still 3GPP has not standardized a way to exploit short-range technologies by introducing mobile relay services, and consequently mobile devices connected to 3GPP networks cannot benefit from the reduced energy consumption provided by the data relaying. Herein, we propose a solution where data exchange between a mobile device and a 3GPP network is performed via another mobile device, and is handled as an untrusted non-3GPP IP access standardized in Release 8. The proposed solution shall promote utilization of short-range technologies on a broader scale and thus, provisioning of energy efficient cooperative communications. Additionally, it shall create an opportunity for new business and pricing models based on short-range cooperative communication. [ABSTRACT FROM PUBLISHER]

Internet environment is rapidly being migrated towards ‘mobile’, but the current Internet was historically designed for ‘static’ environment and thus it is inevitably subject to architectural limitations in the mobile-oriented Internet environment. In this paper, we propose a new inter-networking architecture for the mobile-oriented Internet environment. For this, we first identify a set of requirements by analyzing the problems of the current Internet in the viewpoint of mobile-oriented Internet environments. Based on the requirements, we describe the proposed architecture with the three functional building blocks: Host ID and Local Locator (HILL), Dynamic and Distributed Mapping System (DDMS) and Query-First Data Delivery (QFDD). Finally, the proposed architecture is compared with the existing ones in various aspects. [ABSTRACT FROM PUBLISHER]

There are many projects in the search for Future Internet (FI), supported by many countries and with different fundamental targets. This paper is centered around the HIMALIS architecture proposed as part of the AKARI project by the NICT of Japan. We describe this architecture and discuss its research and experimentation capabilities, finally showing its behavior in a scenario with heterogeneous underlying networks and handover events (mobility). [ABSTRACT FROM PUBLISHER]

This paper presents a framework for including cognitive management functionalities in the spectrum selection process for Opportunistic Networks (ONs).The framework is based on a decision making functionality interacting with a knowledge management block that stores and processes information about the spectrum use. Different approaches for spectrum selection are discussed covering specific cases including the capability to aggregate different bands and the possibility to jointly select the spectrum and the network interface. Illustrative results of the proposed framework are presented. [ABSTRACT FROM PUBLISHER]

The exponential increase in the requests of demanding services has lead current networks to their limits. As a result there is need to handle the increased traffic. This work focuses on the solution of Opportunistic Networks (ONs) which are operator-governed, coordinated extensions of the infrastructure. More specifically a macro base station (BS) is considered that faces congestion issues. A proportion of the macro-terminals will be redirected to nearby femtocells forming an ON. Femtocells are low-power BSs that exploit the backhaul network of the end-user, e.g. an ADSL line, to communicate with the operator. This paper aims at solving the complex optimization problem of resource allocation to femtocells. Thus, an innovative greedy algorithm is proposed, namely the Dynamic Resource Allocation (DRA) algorithm. The algorithm allocates power levels to femtocells in order to cover the most terminals possible but with the minimum transmission power possible. In addition, it utilizes an assignment algorithm to distribute terminals to femtocells and QoS to terminals. Finally, the algorithm is validated through a Java-based platform and is compared with the well-known Simulated Annealing and Tabu Search algorithms. [ABSTRACT FROM PUBLISHER]

This paper proposes a new approach which enables cognitive radio systems to perform parallel sensing. Thanks to the spatial rejection capabilities of antenna processing and to the a priori knowledge of the cyclostationarity properties of the incumbent Radio Access Technology (RAT), an opportunistic user can perform periodic in-band sensing to detect a potential incumbent system without having to insert quiet periods on its waveform. [ABSTRACT FROM PUBLISHER]

Indoor localization is an important research challenge for context aware computing. Although various solutions and products are developed based on Wi-Fi received signal strength indicator (RSSI) fingerprinting-based indoor localization, the construction of a complete and high quality database of fingerprints is a challenge, because in particular human involvement is usually required in such methods. We have developed the unsupervised Density-based Clustering Combined Localization Algorithm (DCCLA) to address this problem. The fingerprints of meaningful locations in people's daily lives can be automatically learned without requiring explicit data labelling from users. In this paper an extensive experimental investigation of the performance of DCCLA is presented. These experiments focus on Wi-Fi signal propagation conditions, including the distance to an Access Point (AP), the damping of the signal, and Fast Fading. The parameters used in DCCLA are determined based on these performance analysis and evaluation. [ABSTRACT FROM PUBLISHER]

Cognitive Radio has been one of the key research topics in the wireless community for about 10 years. The digital switch-over in the TV bands provides opportunities for Cognitive Radio Systems (CRS) to operate in the UHF spectrum under incumbent protection restrictions. Regulation bodies, in particular the FCC and OFCOM in the UK, have specified parameters under which CRS shall operate. Amongst the key protection measures, adjacent channel leakage ratio (ACLR) has been forced to very low levels by the FCC and the OFCOM. In this paper we present multi-carrier techniques which aim at very low ACLR. Key parameters for these air interfaces are provided based on the scenario constraints from the literature. [ABSTRACT FROM PUBLISHER]

One of the most fundamental forms of cooperation in any network is the cooperation between network nodes for routing and the subsequent context dissemination. To do so each node runs an instance of a routing process relying, in many cases, only on partial network information rather than network-wide information. This can lead to instabilities and problematic situations, such as deadlocks or livelocks. Deadlock is a condition where a process stalls; meaning it reaches a state from which there is no exit action. When it comes to routing this would mean the condition where a packet reaches a node and is not forwarded any further because the routing process has reached a state which was not taken into account in its behavioural specification. Livelock is a condition from where a process can exit; however every exit action will eventually lead the process back to the same condition. With respect to routing this would refer to the existence of loops. In this paper we show how formal verification, and in particular model checking, can be applied in this context; to find such problems and also assess the performance and quantify properties of the overall routing process. As an example case study we use a routing protocol designed for wireless sensor networks named Adaptive Load Balanced Algorithm Rainbow version, suitable for context dissemination in Wireless Sensor Network environments, where energy efficient operations are also important. [ABSTRACT FROM PUBLISHER]

We discuss physical layer options for next generation optical Ethernet transport systems with interface rates beyond 100 Gb/s. In particular, we focus on the benefits and drawbacks of employing higher order modulation formats such as quadrature amplitude modulation (QAM) or advanced four-dimensional modulation formats such as polarization-switched quadrature phase-shift keying (PS-QPSK). Furthermore, we discuss promising multiplexing methods such as Nyquist wavelength-division multiplexing (WDM). Such multiplexing can be used for the generation of multi-carrier super-channels with bit rates, which by far exceed those of single-carrier signals. In this contribution we report on an experimental investigation of single-carrier 448-Gb/s polarization-division multiplexing (PDM) 16QAM signals in a WDM transmission experiment over 250 km of ultra-large-effective-area fiber (ULAF). Furthermore, we discuss recent experimental results of Nyquist WDM super-channel generation and transmission of an 8×112-Gb/s PS-QPSK Nyquist WDM signal over up to 9000 km ULAF. [ABSTRACT FROM PUBLISHER]

Due to the rise of the energy efficiency (EE) as a system performance evaluation criterion, the EE-spectral efficiency (SE) trade-off is becoming a key tool for getting insight on how to efficiently design future communication system. As far as the single-input single-output (SISO) Rayleigh fading channel is concerned, the EE-SE trade-off has been accurately approximated in the past but only at low-SE. In this paper, we propose a novel and more generic closed-form approximation (CFA) of this EE-SE trade-off which is very accurate for any SE values. We compare our CFA with two existing CFAs and show the great accuracy of the former for a wider range of SE in comparison with the latter. As an application, we use our CFA to study the variation of EE-SE trade-off when a realistic power model is assumed and to compare the energy consumption of SISO against a 2×2 multi-input multi-output (MIMO) system over the Rayleigh fading channel. [ABSTRACT FROM PUBLISHER]

End-to-end real-time optical orthogonal frequency division multiple access (OOFDMA) passive optical networks (PONs) with adaptive dynamic bandwidth allocation (DBA) and colorless optical network units (ONUs) are experimentally demonstrated, for the first time, at aggregated 10.375Gb/s over 26.4km standard single mode fibers (SSMFs) based on intensity-modulation and direct-detection. The colorless ONU operation across the entire C-band is successfully achieved by utilizing cost-effective reflective semiconductor optical amplifier (RSOA) intensity modulators, whose narrow signal modulation bandwidths are fully exploited through adaptability of the OOFDM transceivers and adaptive DBA. Taking into account the optical beat interference effect, the impact of wavelength spacing between adjacent ONUs on the upstream OOFDMA PON performance is experimentally investigated, based on which the minimum achievable ONU wavelength spacing is identified. [ABSTRACT FROM PUBLISHER]

This paper introduces a convergence capability maturity model of network, compute and storage management for virtual infrastructures across distributed locations. It additionally presents a service middleware layer that enhances convergence maturity, while enabling business objectives to be translated into technical resource demands. Architectural and application studies show the value of the model and application of the service middleware layer. [ABSTRACT FROM PUBLISHER]

Future generation networks are characterized by a high level of complexity and dynamicity due to a relevant level of heterogeneity in terms of nodes and devices as well as provided services. In this context, network operators face the challenge of managing this complexity, while lowering the operational expenses. Context awareness becomes a necessity for the efficient management of resources, dynamic deployment of value added services towards guaranteeing the end to end quality of services. This paper presents a novel framework for the context management of future networks, that is able to collect, transform and reason on context information. Embedded in this framework, mechanisms for the building of knowledge are also introduced, with special focus on autonomic context discovery, monitoring, diagnosis and prediction. [ABSTRACT FROM PUBLISHER]

This paper proposes an innovative metro mesh optical node and a two-fold control plane architectural solution composed of vertically interoperable sub-wavelength enabled GMPLS and TSON layers. Experimental results demonstrate very high throughput (8.68 Gbps) low latency (<160

Telecommunication satellites must follow the advances of terrestrial network capacities and increase their total throughputs in order to remain competitive. This paper shows how the terrestrial fibre technology at 1550-nm wavelength can be extended to support an optical feeder link between ground and a GEO satellite. With 100 Gb/s in a single direction, an optical uplink would outperform the near-term Ka-band systems. Mitigation techniques against clouds and turbulence are described. The impact of satellite transparency on the optical transmission system is discussed. To increase the profitability of the optical solution, cost and link availability associated with various ground station networks should be carefully assessed. [ABSTRACT FROM PUBLISHER]

Currently, there is enormous progress in the field of optical wireless communication. There is the well known IrDA organization approved 1 Gbps Giga- IR standard and established a new 10 Giga-IR WG recently. In addition there are many more players fostering that kind of wireless technology. There is the IEEE 802.15.7 task group founded in 2008 and focusing on visible light communication in combination with state of the art illumination. Data rates are available up to 100 Mbps with link distances up to some meters. Furthermore, there are other organizations like VLCC, ISO and the Li-Fi Consortium as well as various scientific approaches to make optical wireless usable in the public. Additionally optical wireless communication can be seen in a broader field meaning a complete optical eco-system comprising wireless communication, navigation, natural user interfaces and many more. This paper will introduce different cutting-edge technologies regarding optical wireless communication, research and standardization work as well as provide an overview of various applications where those technologies can be used advantageously. Current application scenarios are, for example, complete wireless terminal solutions for portable devices, Car2X communication or wireless indoor communication. It also explains Li-Fi and the idea of a new eco-system combining different optical wireless technologies. [ABSTRACT FROM PUBLISHER]

The European Union FP7 CHRON project addresses the challenge of controlling and managing the next generation of heterogeneous optical networks supporting the Future Internet. For that aim, the CHRON project proposes a Cognitive Heterogeneous Reconfigurable Optical Network, which observes, acts, learns and optimizes its performance. The core element of such network is the Cognitive Decision System, which makes decisions on how to deal with traffic demands and network events by using knowledge acquired from previous experience and considering the current network status. In this paper, we present the architecture of this Cognitive Decision System, and then show a set of methods developed for two of its building blocks: the Virtual Topology Design module and the Quality of Transmission (QoT) estimator module. Regarding the former module, we present two multiobjective genetic algorithms to solve the impairment-aware virtual topology design problem, and evaluate their performance under realistic traffic demands. Results show that one of the methods, which is enhanced with additional cognition, leads to better results. For the latter module, we present a cognitive QoT estimator, which achieves more than 99% successful classifications of optical connections into high or low QoT categories, and is much faster for on-line operation than an existing approach. [ABSTRACT FROM PUBLISHER]

This paper presents an End-to-End (E2E) Operations, Administration, and Maintenance (OAM) architecture for Telco networks including a Sub-wavelength domain. It addresses two main issues: compatibility between MPLS networks and different Sub-wavelength technologies, and scalability of the OAM flows across the whole network. The case for OPST Sub-wavelength technology in the data plane has been studied extensively, however this is the first study on a methodology to scale the number of OAM flows in an E2E scenario combing both subwavelength and MPLS switching domains. Finally the inter-carrier issue in E2E OAM is also explored. [ABSTRACT FROM PUBLISHER]

Future Internet (FI) constitutes a demanding environment that requires joint management of networks and services. It is also widely believed that autonomic/cognitive management systems offer a suitable and viable choice for confronting the problems of the complex FI. In this regard, Unified Management Framework (UMF), is an extensible management framework with the goal to unify and establish autonomics in the management of networks and services, it is developed within UniverSelf research project and appears to be a promising solution. UMF provides the processes, tools and methods for achieving unification of diverse autonomic solutions, governance of automatically managed infrastructures and services, and “plug and play” of autonomic solutions within existing and future management ecosystems. This paper describes the approach followed for the design of UMF, whereas it also details the set of functional blocks that comprise the first UMF functional view as a result of this design approach. Based on the elaboration and evolution of these functional blocks, three components namely, governance, knowledge, coordination are introduced as the so called UMF core that will monopolize the effort towards deriving the upcoming releases of UMF. [ABSTRACT FROM PUBLISHER]

Although having a multitude of practical applications, the control of large queueing networks is a notoriously difficult problem. It becomes especially challenging when, besides guaranteeing stability, a given cost metric shall be minimized. Recently, an interesting new policy design framework for the control problem, called h-MaxWeight, has been proposed which is a natural generalization of the famous MaxWeight policy. Stability of the policy is achieved through a perturbation technique, however, the stability crucially depends on the choice of parameters which has to be adapted in simulations. In this paper we use a different perturbation technique where the required properties are much easier to implement. This leads to a novel control framework, called μ-MaxWeight, which guarantees universal stability while still operating 'close' to the underlying cost criterion. To illustrate the approach we focus on the example of an in-flight entertainment system which has both wired and wireless components as well as queueing constraints, including buffer underflow constraints. We determine a suitable cost function for this scenario and perform simulations, which suggest that the new approach to policy synthesis can provide significantly higher gains irrespective of any further assumptions on the network model or parameter choice. [ABSTRACT FROM PUBLISHER]

To date implementations of Internet of Things (IoT) architectures are confined to particular application areas and tailored to meet only the limited requirements of their narrow applications. To overcome technology and sector boundaries this paper proposes a dynamic service creation environment that employs i) orchestration of business services based on re-usable IoT service components, ii) self-management capable components for automated configuration and testing of services for things, and iii) abstraction of the heterogeneity of underlying technologies to ensure interoperability. To ensure reliability and robustness the presented approach integrates self-testing and self-adaptation in all service life cycle phases. The service life cycle management distinguishes the IoT service creation phase (design-time) and the IoT service provision phase (run-time). For test-friendly service creation (1) semantic service descriptions are employed to derive semi-automatically services and related tests, (2) and testing is systematically integrated into a Service Creation Environment. For reliable and robust service provisioning the presented system (3) forces validation tests in a sandbox environment before deployment and (4) enables run-time monitoring for service adaptation. The system under test is modelled by finite state machines (FSM) that are semi-automatically composed of re-usable test components. Then path searching algorithms are applied to derive automatically tests from the FSM model. The resulting tests are specified in the test control notation TTCN-3 and compiled to run the validation tests. [ABSTRACT FROM PUBLISHER]

In this paper, the impact of cooperative mechanisms on medium access control protocol is evaluated in terms of end-users Quality of Service (QoS) and energy consumption. A dynamic and efficient management of cooperative strategies based on beacon reception information is proposed. The aim is to guarantee satisfying end-users QoS (low packet error rate, low latency) and to minimize the energy consumption. The performance analysis is based on measured time-variant BAN channels at 2.45 GHz. [ABSTRACT FROM PUBLISHER]

The continuing deployment of fiber in the local loop, presents an obvious opportunity to also provide backhauling to mobile base stations in the vicinity of Passive Optical Networks (PONs). To exploit this synergy, one must fully exploit the existing PON MAC tools and also ascertain that certain extreme performance requirements arising from the mobile traffic support can be met by the shared PON medium. This dual objective is addressed in this paper with performance simulations evaluating the most demanding scenario in terms of latency: i.e. that of the hard-handover exchange of messages via one PON over the core network. Also MAC fine-tuning techniques that can improve latency as well as system utilization in the presence of mobile traffic are presented and assessed. [ABSTRACT FROM PUBLISHER]

Virtualization has been a hot topic in computer science this last 10 years, and a key enabler to the recent advances. By technically enabling the Cloud paradigm, virtualization is becoming an inspiring source for the whole IT industry. At the same moment the virtualization of commodity PC was envisioned, Software Defined Radio started as a huge promise of efficient wireless transmission hardware. Unfortunately, the pace of innovation has still to reach the one of the PC virtualization. Yet, there is a another option. The current state of the art of hardware and software of wireless adapter in standard PC reveals interesting capabilities in terms of unused wireless capacity, processing power and in more general way, bringing new functionalities at no extra cost. The actual hardware can be used to provide hardware-assisted virtualization, in a manner very similar to PC virtualization. In this paper we review the current virtualization proposal and bring some insight of some extra capabilities provided by hardware. [ABSTRACT FROM PUBLISHER]