Marco Ajmone Marsan

Politecnico di Torino, Torino, Piedmont, Italy

Are you Marco Ajmone Marsan?

Claim your profile

Publications (287)105.74 Total impact

  • Marco Ajmone Marsan, Michela Meo
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper we exploit simple approximate queueing models to assess the effectiveness of the approaches that have been proposed to save energy in dense wireless local area networks (WLANs), based on the activation of access points (APs) according to the user demand. In particular, we look at a portion of a dense WLAN, where several APs are deployed to provide sufficient capacity to serve a large number of active users during peak traffic hours. To increase capacity, some APs are colocated and provide identical coverage; we say that these APs belong to the same group, and they serve users in the same area. The areas covered by different AP groups only partially overlap, so that some active users can only be served by a group of APs, but a fraction of active users can be served by more groups. Due to daily variations of the number of active users accessing the WLAN, some APs can be switched off to save energy when not all the capacity is needed. A real example of this setting is provided by a floor of one building of Politecnico di Torino in Italy, where a student library is located. The approximate analytical models indicate that the energy saving achievable with the proposed approaches is quite substantial, over 40% if at least one AP for each group is always kept on, even with no traffic, to be ready to accept incoming users, and it grows to almost 60% if all APs can be switched off at night, using a separate technology to activate an AP when the first user requests association in the morning.
    Computer Networks. 01/2014; 66:82–93.
  • Source
  • [Show abstract] [Hide abstract]
    ABSTRACT: Optimizing the tradeoff between power saving and Quality of Service (QoS) in the current Internet is a challenging research objective, whose difficulty stems also from the dominant presence of TCP traffic, and its elastic nature. In a previous work we have shown that an intertwining exists between capacity scaling approaches and TCP congestion control. In this paper we investigate the reasons of such intertwining, and we evaluate how and how much the dynamics of the two algorithms affect each other's performance. More specifically, we will show that such an interaction is essentially due to the overlap of the two closed loop controls, with different time constants.
    Energy Efficient and Green Networking (SSEEGN), 2013 22nd ITC Specialist Seminar on; 01/2013
  • S. Ali, G. Rizzo, B. Rengarajan, M. Ajmone Marsan
    [Show abstract] [Hide abstract]
    ABSTRACT: Context-awareness is a peculiar characteristic of an ever expanding set of applications that make use of a combination of restricted spatio-temporal locality and mobile communications, to deliver a variety of services to the end user. It is expected that by 2014 more than 1.5 billion people would be using applications based on local search (search restricted on the basis of spatio-temporal locality), and that mobile location based services will drive revenues of more than $15 billion worldwide. A common feature of such context-aware applications is the fact that their communication requirements significantly differ from ordinary applications. For most of them, the scope of generated content itself is local. This locally relevant content may be of little concern to the rest of the world, therefore moving this content from the user device to store it in a well-accessible centralized location and/or making this information available beyond its scope represents a clear waste of resources (connectivity, storage). Due to these specific requirements, opportunistic communication can play a special role when coupled with context-awareness. The benefit of opportunistic communications is that it naturally incorporates context as spatial proximity is closely associated with connectivity.
    Computer Communications Workshops (INFOCOM WKSHPS), 2013 IEEE Conference on; 01/2013
  • B. Rengarajan, G. Rizzo, M. Ajmone Marsan, B. Furletti
    [Show abstract] [Hide abstract]
    ABSTRACT: We consider the problem of minimizing the energy consumed in a cellular access network, under loads that slowly vary over space and time, while guaranteeing quality of service (QoS). In particular, we formalize the problem of jointly optimizing the base stations (BS) power levels and the association of users to BSs, while guaranteeing a minimum throughput to each user, and a target value of blocking probability. We propose abstractions that enable tracking of long-term spatial load distributions, and a practical algorithm for energy efficient user association and base station power allocation. Our algorithm is applicable to arbitrary (planar) BS layouts, to settings with interference, to different BS energy models, and to arbitrary user distributions over the service area. Through extensive simulations using measured data, and realistic BS deployments, we show that our algorithm leads to substantial energy savings both with traditional BS designs and with energy-proportional equipment, and we demonstrate the potential of BS sleep modes to achieve network-level energy proportionality.
    World of Wireless, Mobile and Multimedia Networks (WoWMoM), 2013 IEEE 14th International Symposium and Workshops on a; 01/2013
  • Marco Ajmone Marsan, Luca Chiaraviglio, Delia Ciullo, Michela Meo
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper we study base station sleep modes that, by reducing power consumption in periods of low traffic, improve the energy efficiency of cellular access networks. We assume that when some base stations enter sleep mode, radio coverage and service provisioning are provided by the base stations that remain active, so as to guarantee that service is available over the whole area at all times. This may be an optimistic assumption in the case of the sparse base station layouts typical of rural areas, but is, on the contrary, a realistic hypothesis for the dense layouts of urban areas, which consume most of the network energy. We consider the possibility of either just one sleep mode scheme per day (bringing the network from a high-power, fully-operational configuration, to a low-power reduced configuration), or several sleep mode schemes per day, with progressively fewer active base stations. For both contexts, we develop a simple analytical framework to identify optimal base station sleep times as a function of the daily traffic pattern. We start by considering homogeneous networks, in which all cells carry the same amount of traffic and cover areas of equal size. Considering both synthetic traffic patterns and real traffic traces, collected from cells of an operational network, we show that the energy saving achieved with base station sleep modes can be quite significant, the actual value strongly depending on the traffic pattern. Our results also show that most of the energy saving is already achieved with one sleep mode scheme per day. Some additional saving can be achieved with multiple sleep mode schemes, at the price of a significant increase in complexity. We then consider heterogeneous networks in which cells with different coverage areas and different amounts of traffic coexist. In particular, we focus on the common case in which some micro-cells provide additional capacity in a region covered by an umbrella macro-cell, and we prove that the optimal scheduling of micro-cell sleep times is in increasing order of load, from the least loaded to the most loaded. This provides a valuable guideline for the scheduling of sleep modes (i.e., of low-power configurations) in complex heterogeneous networks.
    Computer Networks. 01/2013; 57(17):3276–3290.
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this paper we study cellular access networks which solely rely on renewable energy. We consider a cellular network in which a mesh of base stations (BSs) that are powered with renewable sources, and interconnected with wireless backhaul links, cover the service area, and provide connection to few, typically remote, wired network accesses to the national and international backbone. In particular, we study how to dimension BS power generators and energy storage. We start by discussing the BS energy need, that depends on both the BS consumption model and the BS traffic profiles. Focusing then on some specific locations, we consider the use of photovoltaic (PV) panels, and dimension them based on the daily energy need of the BS and on typical radiative power of sun in the considered locations. Once the PV system has been dimensioned, we also evaluate the energy storage capacity that is needed to absorb energy production variability due to both daily and seasonal radiative power variations. Finally, we investigate the effectiveness of integrating the PV system with wind turbines, as well as the benefit induced on the system by base station sleep modes.
    Communications Workshops (ICC), 2013 IEEE International Conference on; 01/2013
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cellular networks have been traditionally dimensioned to fulfill the desired quality of service (QoS) requirements at all times, and consequently their deployment has been planned to meet the expected peak of the user demand. However, with the user demand recently increasing at exponential pace, concerns about the cellular networks energy consumption have been raised. In response, energy-efficient resource management schemes have been proposed, which take into account energy consumption, and control how much of the network infrastructure is actually needed at different times, and how much can be temporarily powered off to cut energy consumption. Since most of the energy consumed in cellular networks is used by base stations (BSs), algorithms for managing BSs seem to be the most urgent development to achieve energy-efficient operation. This paper provides a quick overview of the BS management techniques that were recently proposed for cellular networks. In addition, an outlook on real implementation aspects, including current commercial products, and trends in the development of energy-efficient hardware is also given.
    Digital Communications - Green ICT (TIWDC), 2013 24th Tyrrhenian International Workshop on; 01/2013
  • S. Ali, G. Rizzo, B. Rengarajan, M. Ajmone Marsan
    [Show abstract] [Hide abstract]
    ABSTRACT: Context-awareness is a peculiar characteristic of an ever expanding set of applications that make use of a combination of restricted spatio-temporal locality and mobile communications, to deliver a variety of services to the end user. It is expected that by 2014 more than 1.5 billion people would be using applications based on local search (search restricted on the basis of spatio-temporal locality), and that mobile location based services will drive revenues of more than $15 billion worldwide. A common feature of such context-aware applications is the fact that their communication requirements significantly differ from ordinary applications. For most of them, the scope of generated content itself is local. This locally relevant content may be of little concern to the rest of the world, therefore moving this content from the user device to store it in a well-accessible centralized location and/or making this information available beyond its scope represents a clear waste of resources (connectivity, storage). Due to these specific requirements, opportunistic communication can play a special role when coupled with context-awareness. The benefit of opportunistic communications is that it naturally incorporates context as spatial proximity is closely associated with connectivity.
    INFOCOM, 2013 Proceedings IEEE; 01/2013
  • Thorsten Herfet, Marco Ajmone Marsan
    [Show abstract] [Hide abstract]
    ABSTRACT: Data aggregation has been the focus of many researchers as one of the most important applications in Wireless Sensor Networks. A main issue of data aggregation is how to construct efficient schedules by which data can be aggregated without any interference. ...
    Computer Communications. 11/2012; 35(18):2236.
  • Marco Ajmone Marsan
    European Conference and Exhibition on Optical Communication; 09/2012
  • Ana Paula Couto da Silva, Michela Meo, Marco Ajmone Marsan
    [Show abstract] [Hide abstract]
    ABSTRACT: The increasing concern about the energy consumption of communication networks is driving the research community to identify approaches to save energy in the networks of today. For instance, considering wireless local area networks (WLANs), the activation of network resources can be driven by the user demand, avoiding having to always power on all Access Points (APs). In this paper, we consider a portion of a dense WLAN system, where many APs are deployed to provide sufficient capacity to serve a large number of active users during peak traffic hours. To provide large capacity, a number of APs are colocated in the same position and provide identical coverage; we say that these APs belong to the same group, and they serve users in the same area. The areas covered by different groups only partially overlap, so that some active users can only be served by a group of APs, but a fraction of active users can be served by several groups. Due to daily variations of the number of active users accessing the WLAN, some APs can be switched off to save energy when not all the capacity is needed. The main focus of our study is the investigation of the type of algorithm that should be used for the association of active users with APs in order to increase the amount of saved energy in dense WLANs. Results show that when some system state information is available, such as the number of users associated with each AP, the energy consumption can decrease up to 20%. Furthermore, our study gives comprehensive insights on the trade-off between the opposite needs to save energy and provide quality of service to the users.
    Computer Networks (1976) 07/2012; 56(10):2522–2537.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Recent works advocate the possibility of improving energy efficiency of network devices by modulating switching and transmission capacity according to traffic load. However, addressing the trade-off between energy saving and Quality of Service (QoS) under these approaches is not a trivial task, specially because most of the traffic in the Internet of today is carried by TCP, and is hence adaptive to the available resources. In this paper we present a preliminary investigation of the possible intertwining between capacity scaling approaches and TCP congestion control, and we show how this interaction can affect performance in terms of both energy saving and QoS.
    01/2012;
  • [Show abstract] [Hide abstract]
    ABSTRACT: We discuss how to save energy in IP-over-WDM networks, presenting the vision of TREND, the FP7 NoE, and the saving that can be obtained with an adaptive routing solution that puts network interfaces of various granularities to sleep in periods of low traffic. Results refer to two operator networks, considering power and traffic forecasts for 2020.
    ECOC 2012-European Conference and Exhibition on Optical Communication; 01/2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper briefly describes the objectives of the TREND (Toward Real Energy-efficient Network Design) Network of Excellence of the European Commission 7th Framework Programme, and outlines some of the main results obtained so far within the project, looking at wireless access networks, core networks, and content distribution issues.
    Sustainable Internet and ICT for Sustainability (SustainIT), 2012; 01/2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this paper we study base station sleep modes, which are today considered a viable approach to improve the energy efficiency of cellular access networks, by reducing power consumption in periods of low traffic. When some base stations are switched off, radio coverage and service provisioning are taken care of by the base stations that remain active, so as to guarantee that service is available over the whole area at all times. This is a realistic assumption in the case of the dense base station layouts of urban areas, which consume most of the network energy. We develop simple analytical models that allow optimal base station switch-off times to be identified as a function of the daily traffic pattern, in the cases in which either just one switch-off per day is possible (bringing the network from a high-power, fully-operational configuration, to a low-power reduced configuration), or several switch-offs per day are permitted (progressively reducing the number of active base stations and the network power). We first assume that any fraction of base stations can be switched off, then we consider a realistic case. We quantify the percentage of energy which can be saved with base station sleep modes, proving that it can be close to 50% of the total network energy consumption.
    Communications and Electronics (ICCE), 2012 Fourth International Conference on; 01/2012
  • Source
    M.A. Marsan, M. Meo
    [Show abstract] [Hide abstract]
    ABSTRACT: In this short note we briefly discuss three issues related to the relevance and the possible impact of research in the field of green networking, with special attention to the wireless case, since this is the context where energy efficiency is needed most.
    Ad Hoc Networking Workshop (Med-Hoc-Net), 2011 The 10th IFIP Annual Mediterranean; 07/2011
  • Source
    Balaji Rengarajan, Gianluca Rizzo, Marco Ajmone Marsan
    [Show abstract] [Hide abstract]
    ABSTRACT: Sleep modes are emerging as a promising technique for energy-efficient networking: by adequately putting to sleep and waking up network resources according to traffic demands, a proportionality between energy consumption and network uti-lization can be approached, with important reductions in energy consumption. Previous studies have investigated and evaluated sleep modes for wireless access networks, computing variable percentages of energy savings. In this paper we characterize the maximum energy saving that can be achieved in a cellular wireless access network under a given performance constraint. In partic-ular, our approach allows the derivation of realistic estimates of the energy-optimal density of base stations corresponding to a given user density, under a fixed performance constraint. Our results allow different proposals to be measured against the maximum theoretically achievable improvement. We show, through numerical evaluation and simulation, the possible energy savings in today's networks, and we further demonstrate that even with the development of highly energy-efficient hardware, a holistic approach incorporating system level techniques is essential to achieving maximum energy efficiency.
    01/2011;
  • Source
    Marco Ajmone Marsan, Luca Chiaraviglio, Delia Ciullo, Michela Meo
    [Show abstract] [Hide abstract]
    ABSTRACT: The introduction of sleep modes in the operations of base stations is today considered one of the most promising approaches to reduce the energy consumption of cellular access networks. Several papers have considered this option, assuming that the switch-on and switch-off transients are of negligible duration. In this paper we study the switch-off transients for one cell, investigating the amount of time necessary to implement the switch-off, while allowing terminals to handover to a new BS without overloading the signaling channels, and we show that the switch-off durations have a marginal impact on the energy savings achievable with the sleep mode scheme. I. INTRODUCTION
    01/2011;
  • Source
    Marco Ajmone Marsan, Michela Meo
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper we study the energy-aware cooperative management of the cellular access networks of the operators that offer service over the same area. In particular, we evaluate the amount of energy that can be saved by using all networks in high traffic conditions, but progressively switching off networks during the periods when traffic decreases, and eventually becomes so low that the desired quality of service can be obtained with just one network. When a network is switched off, its customers are allowed to roam over those networks that remain powered on. Several alternatives are studied, as regards the traffic profile, the switch-off pattern, the energy cost model, and the roaming policy. Numerical results indicate that a huge amount of energy can be saved with an energy-aware cooperative management of the networks, and suggest that, to reduce energy consumption, and thus the cost to operate the networks, new cooperative attitudes of the operators should be encouraged with appropriate incentives, or even enforced by regulation authorities.
    Computer Networks. 01/2011; 55:386-398.

Publication Stats

6k Citations
105.74 Total Impact Points

Institutions

  • 1982–2013
    • Politecnico di Torino
      • • DET - Department of Electronics and Telecommunications
      • • DAUIN - Department of Control and Computer Engineering
      Torino, Piedmont, Italy
  • 2012
    • The Optical Society
      Society Hill, New Jersey, United States
  • 2009
    • Federal Technological University of Parana
      Curityba, Paraná, Brazil
  • 2007
    • University of Massachusetts Amherst
      • School of Computer Science
      Amherst Center, MA, United States
  • 1988–2006
    • University of Milan
      • Department of Computer Science
      Milano, Lombardy, Italy
  • 2004–2005
    • Università degli Studi di Trento
      Trient, Trentino-Alto Adige, Italy
    • University of Bradford
      • Department of Computing
      Bradford, ENG, United Kingdom
  • 1996–2001
    • Federal University of Rio de Janeiro
      Rio de Janeiro, Rio de Janeiro, Brazil
  • 1986–2001
    • Università degli Studi di Torino
      • Dipartimento di Informatica
      Torino, Piedmont, Italy
    • Politecnico di Bari
      Bari, Apulia, Italy
  • 2000
    • Università della Calabria
      Rende, Calabria, Italy
  • 1989–1995
    • Budapest University of Technology and Economics
      Budapeŝto, Budapest, Hungary