Publications
Please find below the papers submitted by COMBO partners to Conferences and Journals accross the world:
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ICTON 2015, 5-9 July 2015, Budapest, Hungary
- Fixed-mobile convergence and virtualization in 5G optical transport networks
Authors: J. Montalvo, M. Arroyo, J.A. Torrijos, J. Lorca, I. Berberana, Telefónica Investigación y Desarrollo, Madrid, Spain
Abstract: In this paper, we analyse promising network architectures with the potential to support the transport of 5G services. The main challenges of functional and architectural convergence between fixed and mobile networks are analysed. The potential technical and economic benefits of virtualization of mobile network functions are also discussed.
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ONDM 2015, 11-14 May, 2015, Pisa, Italy
- The Frontiers of Optical Access Networks
Authors: S. Pachnicke, M. Eiselt, K. Grobe J.-P. Elberns
Abstract: We report on the state-of-the-art and future prospects and challenges of optical access networks. These networks can be used for various different applications such as fiber-to-the-home (FTTH) but also for backhauling data communications as well as for mobile back- and fronthauling purposes. While currently different, physically separated networks are used for these applications, in the future convergence to a unified network is envisioned. We will describe the challenges associated with such a network. We will also give a short overview on current standardization activities and an outlook to next-generation optical access networks.
(pdf version will be available after presentation at ONDM 2015)
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Networks 2014, 17-19 September 2014, Madeira, Portugal
- Dynamic Bandwidth and Wavelength Allocation with Coexistence of Transmission Technologies in TWDM PONs
Authors: Anna Buttaboni, Marilet De Andrade, Massimo Tornatore
Abstract: In a Passive Optical Network (PON), the possibility of smooth upgrading the network infrastructure is an important requirement for network providers as it allows to minimize initial investments for networks deployment. During the upgrade process, it is expected a coexistence of new and old end-users, i.e., Optical Network Units (ONU), with diverse transceiver technologies. Our work focuses on the scenario where the network is upgraded from a TDM PON to a hybrid WDM/TDM PON (both short-reach and long-reach), and where the transceivers used in the old TDM PON can coexist with the new transceivers adopted in the hybrid WDM/TDM PON. In this work, we extend two existing Dynamic Bandwidth and Wavelength Allocation (DBWA) algorithms to make them able to manage the traffic originated by transceivers of the end-user. To investigate the importance of a DBWA which can specifically manage the traffic originated by transceivers with different characteristics (e.g., different tuning time), we also compare them to a DBWA which is not aware that different transmission technologies with different requirements coexist in the network. Then, we compare the performances of these DBWAs to understand which policies are better to allocate the ONU transmissions in a network scenario where several transmission technologies coexist. Finally, we test these DBWAs in different network scenarios, with both short-reach (PON) and long-reach (LR-PON), to study what are the network parameters that affect the performance of such algorithms.
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ICC2014, 10-14 June 2014, Sydney, Australia
- Using Replicated Video Servers for VoD Traffic Offloading in Integrated Metro/Access Networks
Authors: Giacomo Verticale, Massimo Tornatore
Abstract: Internet traffic is increasingly becoming a mediastreaming traffic. Especially, Video-on-Demand (VoD) services are pushing the demand for broadband connectivity to the Internet, and optical fiber technology is being deployed in the access network to keep up with such increasing demand. To provide a more scalable network architecture for video/content delivery, network operators are currently considering novel integrated metro/access networks which accommodate replicated video servers directly in their infrastructure. In such way, servers for VoD delivery are placed nearer to the end users, the core segment of the network is partially traffic offloaded, and the end users experience better performance in terms of QoS. In our work, we will evaluate the performance improvement of an integrated metro/access architecture for VoD delivery with replicated video servers considering different configurations in terms of number of replicated servers, meshing degree and adopted network technologies. We develop a network simulator in which replicas of video servers (called Metro Servers, or MSs) are deployed to meet the demand of VoD traffic. In the result section we compare the performance of the various configurations and discuss which are the minimum requirements to minimize blocking of the VoD requests.
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European Wireless 2014, 14-16 May 2014, Barcelona, Spain
- Fixed and Mobile Convergence: Needs and Solutions
Authors: S. Gosselin, J. De Biasio, M. Feknous, T. Mamouni, J. Torrijos, L. Cucala, D. Breuer, E. Weis, F. Geilhardt, D. v. Hugo, E. Bogenfeld, A. Hamidian, N. Fonseca, Y. Liu, S. Kuehrer, A. Gravey, A. Mitcsenkov, J.V. Galán, E. Masgrau, L. Gómez, L. Alonso, S. Höst, A. Magee
Abstract: The drivers of Fixed and Mobile Convergence (FMC) are discussed. A reference framework for FMC proposed by European project COMBO is then presented. Some use cases of FMC are described, showing the needs for mutualization and convergence of fixed and mobile broadband networks. Five network scenarios providing technical solutions to FMC use cases are proposed. They target an optimal and seamless quality of experience for the end user together with an optimized network infrastructure ensuring increased performance, flexibility, reduced cost and reduced energy consumption.
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ITG-Fachtagung "Photonische Netze" 2014, 5-6 May 2014, Leipzig, Germany
- FMC traffic model for aggregation networks
Authors: Carsten Behrens, Ralf Hülsermann, Dirk Breuer
Abstract: Increased convergence of fixed and mobile networks necessitates a combined network modelling approach to identify optimum locations for core network functions and potentially leverage synergies. The fixed-mobile convergence (FMC) traffic modeling approach documented in this paper is based on the CISCO Visual Networking Index and focuses on the network of a big German incumbent. As a first step, fixed traffic is distributed across Germany according to the number of potential xDSL customers, while mobile network traffic is dispersed with the help of mobile traffic measurements. Emerging traffic is then assigned to more than 7000 access areas, aggregated via a metro network with more than 800 regio points of presence (PoPs) and directed towards the backbone network with 18 core PoPs. Under these assumptions, the busiest regio PoP will experience traffic of 15.2Gb/s in the year 2017, with 14.4Gb/s accounting for fixed network traffic and only 0.7Gb/s for mobile network traffic. The busiest core PoP will have to deal with a throughput of 390Gb/s, with 370Gb/s originating in the fixed network and 20Gb/s in the mobile network.
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WCNC 2014, 6-9 April 2014, Istanbul, Turkey
- Very Tight Coupling between LTE and Wi-Fi for Advanced Offloading Procedures
Authors: X. Lagrange
Abtract: Wi-Fi access points are now widely deployed by customers or by the operators. This represents an interesting solution to offload the LTE networks. In this paper we propose a very-tight coupling solution between LTE and Wi-Fi, which can be used to enhance the offloading procedures. In this architecture PDCP (Packet Data Convergence Protocol) is used as the common layer between LTE andWi-Fi and the security procedures defined for LTE are reused for Wi-Fi transmission. It is thus possible to use Wi-Fi transmissions even when a terminal is covered by a Wi-Fi access point for a short period. We describe the entities of this architecture, the protocol stack and describe how user packets are transmitted.
Relevance to COMBO: This paper proposes an architecture where the aggregation network is used to connect Wi-Fi Access Point to LTE base stations. It is a one-author paper because the idea is personal. However, the idea was stimulated by the COMBO project and discussions on convergence.
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NMTS2014, 30 March - 2 April, 2014, Dubau, UAE
- On the Tradeoff between Performance and User Privacy in Information Centric Networking
Authors: Giacomo Verticale,
Abstract: Widespread use of caching provides advantages for users and providers, such as reduced network latency, higher content availability, bandwidth reduction and server load balancing. In Information Centric Networking, the attention is shifted from users to content, which is addressed by its name and not by its location. Moreover, the content objects are stored as close as possible to the customers. Therefore, the cache has a central role for the improvement of the network performance but this is strictly related to the caching policy used. However, this comes at the price of increased tracing of users communication and users behavior to define an optimal caching policy. A malicious node could exploit such information to compromise the privacy of users. In this work, we compare different caching policies and we take the first steps for defining the tradeoff between caching performance and user privacy guarantee. In particular, we provide a way to implement prefetching and we define some bounds for the users’ privacy in this context.
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OFC/NFOEC 2014, 9-13 March 2014 San Francisco, California, USA
- QoS of Optical Packet Metro networks
Authors: Annie Gravey, Philippe Gravey, Michel Morvan, Bogdan Uscumlic, Lida Sadeghioon
Abstract: Metro networks support increasing traffic volumes and evolving traffic profiles. Revisiting metro networks architecture, this paper shows that both optical transparency and sub-wavelength granularity can be achieved, while still ensuring transport network QoS levels.
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Optical Switching and Networking Journal, 2014
- Optimization of Long-Reach TDM/WDM Passive Optical Networks
Authors: Marilet De Andrade, Anna Buttaboni, Massimo Tornatore, Pierpaolo Boffi, Paolo Martelli, Achille Pattavina
Abstract: Long-Reach Passive Optical Network (LR-PON) using hybrid TDM/WDM techniques is one of the candidates for the future optical access that can solve the expected increase in terms of traffic demand and area coverage. One of its advantages is the possibility to share the capacity of any wavelength among more than one user, through TDM/WDM hybrid multiplexing. However, it is still an open issue which transmission technology (DWDM transmitters, colorless transmitters, coherent detection, direct detection) can more effectively satisfy the requirements and characteristics of the future long-reach access network. In this paper we propose a new optimization model based on Mixed Integer Linear Programming (MILP) that formalizes the problem of selecting the most cost-effective transmission technology in LR TDM/WDM PONs while also assigning the wavelength-channels line rate and the splitting ratio of the remote nodes at different levels, under bandwidth and power budget constraints. Using this proposed MILP formulation we can identify the optimal transmission technology for a wide set of possible LR-PON scenarios of interest. In this work we provide an evaluation of the optimal transmission technologies under several PON scenarios with varying traffic loads and area coverage. We also analyze the cost sensitivity of the optimization process for coherent-detection technology since it is still under research and development.
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IEEE ANTS 2013, 15-18 December 2013, Chennai, Tamil Nadu, India
- LTE core network testing using generated traffic based on models from real-life data
Authors: Pál Varga, Péter Olaszi
Abstract: The aim of this paper is to describe a general methodology for testing the mobile network core with traffic generated from a simulated access-segment. A main element of this methodology is to derive load models and mobility models from real-life traffic patterns, and use these – as well as prerecorded protocol messages – in the process. The Evolved Packet Core (EPC) of Long Term Evolution (LTE) provides a good base for presenting practical elements of this methodology. This paper demonstrates the workflow of this methodology through a practical example of EPC load testing. This demonstration covers issues related to nodes and interfaces covered during such tests; dialogs used for session and mobility control; and crosscorrelating message flows that effect various elements across the architecture."
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CogInfoCom 2013, 2-5 December 2013, Budapest, Hungary
- Energy-Availability-QoS Trade-off for Future Converged Fixed-Mobile Networks
Authors: T. Cinkler, A. Ladanyi, R. Beres, A. Mitcsenkov, G. Paksy, B. Molnar, R. Ando
Abstract: In the access part of the Future Internet the fixed and mobile access is expected to converge not only to better utilize the resources, but also to decrease the power consumption, to increase the availability and also to improve the QoS/QoE of users. We present architectures and algorithms to show what Energy-Availability-QoS tradeoffs can be reached. We support our approach by intensive simulations. The electric energy consumption [kWh] grows from year to year. The share of InfoCommunications Technologies (ICT) grows even faster. In this paper we focus primarily onto reducing energy consumption of the access part of modern heterogeneous mobile networks that leads to “greening” of this part of the network. The idea of our “greening” algorithm is based on selective switch-off and on consolidation of resources, employed jointly with both, the vertical and the horisontal handover (handoff). We show by simulations the energy saving benefits of our approach.
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ECOC 2013, 22-26 September 2013, London, UK
- Experimental evaluation of delay-sensitive traffic routing in multi-layer (packet-optical) aggregation networks for fixed mobile convergence
Authors: R. Martinez, R. Casellas, R, Muñoz, R. Vilalta
Abstract: We report the implementation and performance evaluation of an active stateful PCE that relies on a GMPLS control plane for the actual provisioning of elastic connections in a flexi-grid DWDM network. It is based on experimental extensions to the PCEP protocol and enables more advanced and concurrent path computations.
(link to pdf)
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IEEE GreenCom 2013, 20-23 August 2013 Beijing, China
- Model to Analyze the Energy Savings of Base Station Sleep Mode in LTE HetNets
Authors: P. Dini, M.Miozzo, N.Bui,N.Baldo
Abstract: In this paper we study the base station (BS) sleep mode as an approach to decrease the energy consumption of LTE HetNets. We present an energy model which takes into account that (i) macro, micro and pico BSs have different power consumption profiles, (ii) macro BS power consumption is varying with the load, and (iii) communication through a macro, micro or pico cell has different radio resource utilization. Furthermore, we introduce two sleep algorithms, namely single sleep and multiple sleep, to determine the time instant to enable micro or pico BSs sleep mode. Finally, we analyze the two proposed algorithms in different HetNet topologies and with different traffic requirements to evaluate the network energy consumption and the savings that the sleep mode can achieve"
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FuNeMS 2013, 3-5 July 2013 Lisbon, Portugal
- Converged fixed and mobile broadband networks based on Next Generation Point of Presence
Authors: S. Gosselin, T. Mamouni, P. Bertin, J. Torrijos, D. Breuer, E. Weis, J.-C. Point
Absract: To achieve a joint optimization of fixed and mobile networks, we propose a new broadband network architecture organized around the innovative concept of Next Generation Point of Presence (NG-POP). NG-POP targets a disruptive evolution of the first aggregation node, also called Central Office (CO), or Local POP by opposition to more centralized POPs. It will allow both a better distribution of all essential functions of fixed and mobile networks (functional convergence) and a better mutualisation of fixed and mobile equipment and infrastructures (structural convergence). This paper presents the main ideas related to functional and structural convergence and illustrates the benefits expected from the underlying NG-POP concept for future converged fixed and mobile networks. The architectural concepts presented in this paper will be assessed in details in European large scale integrating project COMBO (COnvergence of fixed and Mobile BrOadband access/aggregation networks).
- Optical fiber solution for mobile fronthaul to achieve Cloud Radio Access Network
Authors: Philippe CHANCLOU, Anna PIZZINAT, Fabien LE CLECH, To-Linh REEDEKER, Yannick LAGADEC, Fabienne SALIOU, Bertrand LE GUYADER, Laurent GUILLO, Qian DENIEL, Stéphane GOSSELIN, Sy Dat LE, Thierno DIALLO, Romain BRENOT, Francois LELARGE, Lucia MARAZZI, Paola PAROLARI, Mario MARTINELLI, Sean O’DULL, Simon Arega GEBREWOLD, David HILLERKUSS, Juerg LEUTHOLD, Giancarlo GAVIOLI, Paola GALLI
Abstract: This paper describes the technical aspects of optical access solutions for mobile fronthaul application. The mobile context and main constraints of fronthaul signals are presented. The need for a demarcation point between the Mobile operator and the Fiber provider is introduced. The optical solution to achieve such a network is discussed. A WDM network with passive monitoring at the antenna site and automatic wavelength assignment is proposed based on self-seeded solution.
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ICC2013, 9-13 June, 2013 Budapest, Hungary
- Energy Efficient Content Distribution
Authors: Julio Araujo, Frederic Giroire, Yaning Liu
Abstract: To optimize energy efficiency in network, operators try to switch off as many network devices as possible. Recently, there is a trend to introduce content caches as an inherent capacity of network equipment, with the objective of improving the efficiency of content distribution and reducing network congestion. In this work, we study the impact of using in-network caches and content delivery network (CDN) cooperation on an energy-efficient routing. We formulate this problem as Energy Efficient Content Distribution. The objective is to find a feasible routing, so that the total energy consumption of the network is minimized subject to satisfying all the demands and link capacity. We exhibit the range of parameters (size of caches, popularity of content, demand intensity, etc.) for which caches are useful. Experimental results show that by placing a cache on each backbone router to store the most popular content, along with well choosing the best content provider server for each demand to a CDN, we can save a total up to 23% of power in the backbone, while 16% can be gained solely thanks to caches.
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ICC2013, 9-13 June, 2013 Budapest, Hungary
- Dynamic Adaptive Streaming over CCN: A Caching and Overhead Analysis
Authors: Yaning Liu, Joost Geurts
Abstact: In this paper, we present our implementation and evaluation of Dynamic Adaptive Streaming over Content centric networking (DASC) which implements MPEG Dynamic Adaptive Streaming over HTTP (DASH) utilizing a Content Centric Networking (CCN) naming scheme to identify content segments in a CCN network. In particular, video segments formatted according to MPEG-DASH are available in different quality levels but instead of HTTP, CCN is used for referencing and delivery. Based on the conditions of the network, the DASC client issues interests for segments achieving the best throughput. Due to segment caching within the network, subsequent requests for the same content can be served quicker. As a result, the quality of the video a user receives progressively improves, effectively overcoming bottlenecks in the network. We present two sets of experiments to evaluate the performance of DASC showing that throughput indeed improves. However, the generated overhead is relatively large and the adaptation strategy used for DASH that assumes an end-to-end connection could be revised for the hop-by-hop architecture of CCN.
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ONDM 2013, 16-19 April 2013, Brest, France
- Placement of Base-Band Units (BBUs) over Fixed/Mobile Converged Multi-Stage WDM-PONs
Authors: N. Carapellese, M. Tornatore, A. Pattavina
Abstract: The convergence between fixed access networks and mobile backhauling networks is the basis of the evolution towards future Next-Generation Access Networks. Multi-Stage WDMPONs are the ideal converged infrastructures for carrying both fixed access and mobile backhauling, because they inherit some features of WDM core/metro networks, e.g., large capacity and high transparency. Moreover, they provide support for the “BBU Hotelling” backhauling solution, which consists in separating base stations’ Base-Band Units (BBU) from their Remote Radio Heads (RRH), and grouping them into consolidated “Hotels”, with reduced costs and energy consumption. In this work, we propose and model by an ILP formulation the novel “BBU Placement” network optimization problem, on a converged Multi- Stage WDM-PON. The aim is to decide in which nodes to place BBUs, together with the routing and wavelength assignment of traffic demands, such that the number of Hotels is minimized. We capture the importance of the maximum latency of Digitized Radio-over-Fiber (D-RoF) flows exchanged between each BBU and its RRH, which becomes a constraint on the maximum propagation delay of corresponding routes. Simulation results are obtained by generating some random multi-stage tree instances and solving them via CPLEX. The analysis of the number of Hotels versus network sizes and maximum D-RoF delay validates the proposed model and highlights the strong impact of such parameters on the achievable BBU consolidation.
(link to pdf)
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OFC/NFOEC 2013, 17-21 March 2013, Anaheim, USA
- Unified Access and Aggregation Network Allowing Fixed and Mobile Networks to Converge
Authors: D. Breuer, E. Weis, S. Gosselin, T. Mamouni, J. Torrijos
Abstract: A new concept for unified access and aggregation network architecture allowing fixed and mobile networks to converge is proposed based on the concepts of Next Generation POP combining structural and functional convergence.
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