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RFC 7962

Alternative Network Deployments: Taxonomy, Characterization, Technologies, and Architectures

Pages: 43
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Internet Research Task Force (IRTF)                      J. Saldana, Ed.
Request for Comments: 7962                        University of Zaragoza
Category: Informational                                   A. Arcia-Moret
ISSN: 2070-1721                                  University of Cambridge
                                                                B. Braem
                                                         E. Pietrosemoli
                                                    The Abdus Salam ICTP
                                                         A. Sathiaseelan
                                                 University of Cambridge
                                                              M. Zennaro
                                                    The Abdus Salam ICTP
                                                             August 2016

                    Alternative Network Deployments:
      Taxonomy, Characterization, Technologies, and Architectures


   This document presents a taxonomy of a set of "Alternative Network
   Deployments" that emerged in the last decade with the aim of bringing
   Internet connectivity to people or providing a local communication
   infrastructure to serve various complementary needs and objectives.
   They employ architectures and topologies different from those of
   mainstream networks and rely on alternative governance and business

   The document also surveys the technologies deployed in these
   networks, and their differing architectural characteristics,
   including a set of definitions and shared properties.

   The classification considers models such as Community Networks,
   Wireless Internet Service Providers (WISPs), networks owned by
   individuals but leased out to network operators who use them as a
   low-cost medium to reach the underserved population, networks that
   provide connectivity by sharing wireless resources of the users, and
   rural utility cooperatives.
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Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   This document is a product of the Internet Research Task Force
   (IRTF).  The IRTF publishes the results of Internet-related research
   and development activities.  These results might not be suitable for
   deployment.  This RFC represents the consensus of the Global Access
   to the Internet for All Research Group of the Internet Research Task
   Force (IRTF).  Documents approved for publication by the IRSG are not
   a candidate for any level of Internet Standard; see Section 2 of RFC

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at

Copyright Notice

   Copyright (c) 2016 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   ( in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   4
     1.1.  Mainstream Networks . . . . . . . . . . . . . . . . . . .   5
     1.2.  Alternative Networks  . . . . . . . . . . . . . . . . . .   5
   2.  Terms Used in This Document . . . . . . . . . . . . . . . . .   5
   3.  Scenarios Where Alternative Networks Are Deployed . . . . . .   7
     3.1.  Urban vs. Rural Areas . . . . . . . . . . . . . . . . . .   8
     3.2.  Topology Patterns Followed by Alternative Networks  . . .   9
   4.  Classification Criteria . . . . . . . . . . . . . . . . . . .  10
     4.1.  Entity behind the Network . . . . . . . . . . . . . . . .  10
     4.2.  Purpose . . . . . . . . . . . . . . . . . . . . . . . . .  10
     4.3.  Governance and Sustainability Model . . . . . . . . . . .  12
     4.4.  Technologies Employed . . . . . . . . . . . . . . . . . .  12
     4.5.  Typical Scenarios . . . . . . . . . . . . . . . . . . . .  13
   5.  Classification of Alternative Networks  . . . . . . . . . . .  13
     5.1.  Community Networks  . . . . . . . . . . . . . . . . . . .  14
     5.2.  Wireless Internet Service Providers (WISPs) . . . . . . .  16
     5.3.  Shared Infrastructure Model . . . . . . . . . . . . . . .  17
     5.4.  Crowdshared Approaches Led by the Users and Third-Party
           Stakeholders  . . . . . . . . . . . . . . . . . . . . . .  19
     5.5.  Rural Utility Cooperatives  . . . . . . . . . . . . . . .  21
     5.6.  Testbeds for Research Purposes  . . . . . . . . . . . . .  22
   6.  Technologies Employed . . . . . . . . . . . . . . . . . . . .  22
     6.1.  Wired . . . . . . . . . . . . . . . . . . . . . . . . . .  22
     6.2.  Wireless  . . . . . . . . . . . . . . . . . . . . . . . .  22
       6.2.1.  Media Access Control (MAC) Protocols for Wireless
               Links . . . . . . . . . . . . . . . . . . . . . . . .  23  802.11 (Wi-Fi)  . . . . . . . . . . . . . . . . .  23  Mobile Technologies . . . . . . . . . . . . . . .  24  Dynamic Spectrum  . . . . . . . . . . . . . . . .  24
   7.  Upper Layers  . . . . . . . . . . . . . . . . . . . . . . . .  26
     7.1.  Layer 3 . . . . . . . . . . . . . . . . . . . . . . . . .  26
       7.1.1.  IP Addressing . . . . . . . . . . . . . . . . . . . .  26
       7.1.2.  Routing Protocols . . . . . . . . . . . . . . . . . .  26  Traditional Routing Protocols . . . . . . . . . .  26  Mesh Routing Protocols  . . . . . . . . . . . . .  27
     7.2.  Transport Layer . . . . . . . . . . . . . . . . . . . . .  27
       7.2.1.  Traffic Management When Sharing Network Resources . .  27
     7.3.  Services Provided . . . . . . . . . . . . . . . . . . . .  28
       7.3.1.  Use of VPNs . . . . . . . . . . . . . . . . . . . . .  29
       7.3.2.  Other Facilities  . . . . . . . . . . . . . . . . . .  29
     7.4.  Security Considerations . . . . . . . . . . . . . . . . .  29
   8.  Informative References  . . . . . . . . . . . . . . . . . . .  30
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  40
   Contributors  . . . . . . . . . . . . . . . . . . . . . . . . . .  41
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  42
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1.  Introduction

   One of the aims of the Global Access to the Internet for All (GAIA)
   IRTF Research Group is "to document and share deployment experiences
   and research results to the wider community through scholarly
   publications, white papers, Informational and Experimental RFCs,
   etc."  [GAIA].  In line with this objective, this document proposes a
   classification of "Alternative Network Deployments".  This term
   includes a set of network access models that have emerged in the last
   decade with the aim of providing Internet connections, following
   topological, architectural, governance, and business models that
   differ from the so-called "mainstream" ones, where a company deploys
   the infrastructure connecting the users, who pay a subscription fee
   to be connected and make use of it.

   Several initiatives throughout the world have built these large-scale
   networks, using predominantly wireless technologies (including long
   distance links) due to the reduced cost of using unlicensed spectrum.
   Wired technologies such as fiber are also used in some of these

   The classification considers several types of alternate deployments:
   Community Networks are self-organized networks wholly owned by the
   community; networks acting as Wireless Internet Service Providers
   (WISPs); networks owned by individuals but leased out to network
   operators who use such networks as a low-cost medium to reach the
   underserved population; networks that provide connectivity by sharing
   wireless resources of the users; and finally there are some rural
   utility cooperatives also connecting their members to the Internet.

   The emergence of these networks has been motivated by a variety of
   factors such as the lack of wired and cellular infrastructures in
   rural/remote areas [Pietrosemoli].  In some cases, Alternative
   Networks may provide more localized communication services as well as
   Internet backhaul support through peering agreements with mainstream
   network operators.  In other cases, they are built as a complement or
   an alternative to commercial Internet access provided by mainstream
   network operators.

   The present document is intended to provide a broad overview of
   initiatives, technologies, and approaches employed in these networks,
   including some real examples.  References describing each kind of
   network are also provided.
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1.1.  Mainstream Networks

   In this document, we will use the term "mainstream networks" to
   denote those networks sharing these characteristics:

   o  Regarding scale, they are usually large networks spanning entire

   o  Top-down control of the network and centralized approach.

   o  They require a substantial investment in infrastructure.

   o  Users in mainstream networks do not participate in the network
      design, deployment, operation, governance, and maintenance.

   o  Ownership of the network is never vested in the users themselves.

1.2.  Alternative Networks

   The term "Alternative Network" proposed in this document refers to
   the networks that do not share the characteristics of "mainstream
   network deployments".  Therefore, they may share some of the
   following characteristics:

   o  Relatively small scale (i.e., not spanning entire regions).

   o  Administration may not follow a centralized approach.

   o  They may require a reduced investment in infrastructure, which may
      be shared by the users and commercial and non-commercial entities.

   o  Users in Alternative Networks may participate in the network
      design, deployment, operation, and maintenance.

   o  Ownership of the network is often vested in the users.

2.  Terms Used in This Document

   Considering the role that the Internet currently plays in everyday
   life, this document touches on complex social, political, and
   economic issues.  Some of the concepts and terminology used have been
   the subject of study of various disciplines outside the field of
   networking and are responsible for long debates whose resolution is
   out of the scope of this document.
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   o  "Global north" and "global south".  Although there is no consensus
      on the terms to be used when talking about the different
      development level of countries, we will employ the term "global
      south" to refer to nations with a relatively lower standard of
      living.  This distinction is normally intended to reflect basic
      economic country conditions.  In common practice, Japan in Asia,
      Canada and the United States in northern America, Australia and
      New Zealand in Oceania, and Europe are considered "developed"
      regions or areas [UN], so we will employ the term "global north"
      when talking about them.

   o  The "Digital Divide".  The following dimensions are considered to
      be meaningful when measuring the digital development state of a
      country: infrastructures (availability and affordability), the
      Information and Communications Technology (ICT) sector (human
      capital and technological industry), digital literacy, legal and
      regulatory framework, and content and services.  A lack of digital
      development in one or more of these dimensions is what has been
      referred as the "Digital Divide" [Norris].  It should be noted
      that this "Divide" is not only present between different countries
      but between zones of the same country, despite its degree of

   o  "Urban" and "rural" zones.  There is no single definition of
      "rural" or "urban", as each country and various international
      organizations define these terms differently, mainly based on the
      number of inhabitants, the population density, and the distance
      between houses [UNStats].  For networking purposes, the primary
      distinction is likely the average distance between customers,
      typically measured by population density, as well as the distance
      to the nearest Internet point-of-presence, i.e., the distance to
      be covered by "middle mile" or backhaul connectivity.  Some
      regions with low average population density may cluster almost all
      inhabitants into a small number of relatively dense small towns,
      for example, while residents may be dispersed more evenly in

   o  Demand.  In economics, it describes a consumer's desire and
      willingness to pay a price for a specific good or service.

   o  Provision is the act of making an asset available for sale.  In
      this document, we will mainly use it as the act of making a
      network service available to the inhabitants of a zone.

   o  Underserved area.  Area in which the telecommunication market
      permanently fails to provide the information and communications
      services demanded by the population.
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   o  Free, open, and neutral networks.  Their principles have been
      summarized this way [Baig]:

      *  You have the freedom to use the network for any purpose as long
         as you do not harm the operation of the network itself, the
         rights of other users, or the principles of neutrality that
         allow contents and services to flow without deliberate

      *  You have the right to understand the network, to know its
         components, and to spread knowledge of its mechanisms and

      *  You have the right to offer services and content to the network
         on your own terms.

      *  You have the right to join the network, and the responsibility
         to extend this set of rights to anyone according to these same

3.  Scenarios Where Alternative Networks Are Deployed

   Different studies have reported that as much as 60% of the people on
   the planet do not have Internet connectivity [Sprague]
   [InternetStats].  In addition, those unconnected are unevenly
   distributed: only 31% of the population in "global south" countries
   had access in 2014, against 80% in "global north" countries
   [WorldBank2016].  This is one of the reasons behind the inclusion of
   the objective to "significantly increase access to information and
   communications technology and strive to provide universal and
   affordable access to the Internet in least developed countries by
   2020," as one of the targets in the Sustainable Development Goals
   (SDGs) [SDG], considered as a part of "Goal 9.  Build resilient
   infrastructure, promote inclusive and sustainable industrialization
   and foster innovation."

   For the purpose of this document, a distinction between "global
   north" and "global south" zones is made, highlighting the factors
   related to ICT, which can be quantified in terms of:

   o  The availability of both national and international bandwidth, as
      well as equipment.

   o  The difficulty in paying for the services and the devices required
      to access the ICTs.

   o  The instability and/or lack of power supply.
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   o  The scarcity of qualified staff.

   o  The existence of a policy and regulatory framework that hinders
      the development of these models in favor of state monopolies or

   In this context, the World Summit of the Information Society [WSIS]
   aimed at achieving "a people-centred, inclusive and development-
   oriented Information Society, where everyone can create, access,
   utilize and share information and knowledge.  Therefore, enabling
   individuals, communities and people to achieve their full potential
   in promoting their sustainable development and improving their
   quality of life".  It also called upon "governments, private sector,
   civil society and international organizations" to actively engage to
   work towards the bridging of the digital divide.

   Some Alternative Networks have been deployed in underserved areas,
   where citizens may be compelled to take a more active part in the
   design and implementation of ICT solutions.  However, Alternative
   Networks (e.g., [Baig]) are also present in some "global north"
   countries, being built as an alternative to commercial ones managed
   by mainstream network operators.

   The consolidation of a number of mature Alternative Networks (e.g.,
   Community Networks) sets a precedent for civil society members to
   become more active in the search for alternatives to provide
   themselves with affordable access.  Furthermore, Alternative Networks
   could contribute to bridge the digital divide by increasing human
   capital and promoting the creation of localized content and services.

3.1.  Urban vs. Rural Areas

   The differences presented in the previous section are not only
   present between countries, but within them too.  This is especially
   the case for rural inhabitants, who represent approximately 55% of
   the world's population [IFAD2011], with 78% of them in "global south"
   countries [ITU2011].  According to the World Bank, adoption gaps
   "between rural and urban populations are falling for mobile phones
   but increasing for the internet" [WorldBank2016].

   Although it is impossible to generalize among them, there exist some
   common features in rural areas that have prevented incumbent
   operators from providing access and that, at the same time, challenge
   the deployment of alternative infrastructures [Brewer] [Nungu]
   [Simo_c].  For example, a high network latency was reported in
   [Johnson_b], which could be in the order of seconds during some
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   These challenges include:

   o  Low per capita income, as the local economy is mainly based on
      subsistence agriculture, farming, and fishing.

   o  Scarcity or absence of basic infrastructures, such as electricity,
      water, and access roads.

   o  Low population density and distance (spatial or effective) between
      population clusters.

   o  Underdeveloped social services, such as healthcare and education.

   o  Lack of adequately educated and trained technicians, and high
      potential for those (few) trained to leave the community
      incentivized by better opportunities, higher salaries, or the
      possibility of starting their own companies [McMahon].

   o  High cost of Internet access [Mathee].

   o  Harsh environments leading to failure in electronic communication
      devices [Johnson_a], which reduces the reliability of the network.

   Some of these factors challenge the stability of Alternative Networks
   and the services they provide: scarcity of spectrum, scale, and
   heterogeneity of devices.  However, the proliferation of Alternative
   Networks [Baig] together with the raising of low-cost, low-
   consumption, low-complexity off-the-shelf wireless devices have
   allowed and simplified the deployment and maintenance of alternative
   infrastructures in rural areas.

3.2.  Topology Patterns Followed by Alternative Networks

   Alternative Networks, considered self-managed and self-sustained,
   follow different topology patterns [Vega_a].  Generally, these
   networks grow spontaneously and organically, that is, the network
   grows without specific planning and deployment strategy and the
   routing core of the network tends to fit a power law distribution.
   Moreover, these networks are composed of a high number of
   heterogeneous devices with the common objective of freely connecting
   and increasing the network coverage and the reliability.  Although
   these characteristics increase the entropy (e.g., by increasing the
   number of routing protocols), they have resulted in an inexpensive
   solution to effectively increase the network size.  One such example
   is [Vega_a], which has had an exponential growth rate in
   the number of operating nodes during the last decade.
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   Regularly, rural areas in these networks are connected through long-
   distance links and/or wireless mesh networks, which in turn convey
   the Internet connection to relevant organizations or institutions.
   In contrast, in urban areas, users tend to share and require mobile
   access.  Since these areas are also likely to be covered by
   commercial ISPs, the provision of wireless access by virtual
   operators like [Fon] may constitute a way to extend the user capacity
   to the network.  Other proposals like "Virtual Public Networks"
   [Sathiaseelan_a] can also extend the service.

4.  Classification Criteria

   The classification of Alternative Network Deployments, presented in
   this document, is based on the following criteria:

4.1.  Entity behind the Network

   The entity (or entities) or individuals behind an Alternative Network
   can be:

   o  A community of users.

   o  A public stakeholder.

   o  A private company.

   o  Supporters of a crowdshared approach.

   o  A community that already owns the infrastructure and shares it
      with an operator, who, in turn, may also use it for backhauling

   o  A research or academic entity.

   The above actors may play different roles in the design, financing,
   deployment, governance, and promotion of an Alternative Network.  For
   example, each of the members of a Community Network maintains the
   ownership over the equipment they have contributed, whereas in others
   there is a single entity, e.g., a private company who owns the
   equipment, or at least a part of it.

4.2.  Purpose

   Alternative Networks can be classified according to their purpose and
   the benefits they bring compared to mainstream solutions, regarding
   economic, technological, social, or political objectives.  These
   benefits could be enjoyed mostly by the actors involved (e.g.,
   lowering costs or gaining technical expertise) or by the local
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   community (e.g., Internet access in underserved areas) or by the
   society as a whole (e.g., network neutrality).

   The benefits provided by Alternative Networks include, but are not
   limited to:

   o  Extending coverage to underserved areas (users and communities).

   o  Providing affordable Internet access for all.

   o  Reducing initial capital expenditures (for the network and the end
      user, or both).

   o  Providing additional sources of capital (beyond the traditional
      carrier-based financing).

   o  Reducing ongoing operational costs (such as backhaul or network

   o  Leveraging expertise and having a place for experimentation and

   o  Reducing hurdles to adoption (e.g., digital literacy, literacy in
      general, and relevance).

   o  Providing an alternative service in case of natural disasters and
      other extreme situations.

   o  Community building, social cohesion, and quality of life

   o  Experimentation with alternative governance and ownership models
      for treating network infrastructures as a commons.

   o  Raising awareness of political debates around issues like network
      neutrality, knowledge sharing, access to resources, and more.

   Note that the different purposes of Alternative Networks can be more
   or less explicitly stated and they could also evolve over time based
   on the internal dynamics and external events.  For example, the Red
   Hook WIFI network in Brooklyn [Redhook] started as a Community
   Network focusing more on local applications and community building
   [TidePools], but it became widely known when it played a key role as
   an alternative service available during the Sandy storm [Tech]
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   Moreover, especially for those networks with more open and horizontal
   governance models, the underlying motivations of those involved may
   be very diverse, ranging from altruistic ones related to the desire
   of free sharing of Internet connectivity and various forms of
   activism to personal benefits from the experience and expertise
   through the active participation in the deployment and management of
   a real and operational network.

4.3.  Governance and Sustainability Model

   Different governance models are present in Alternative Networks.
   They may range from some open and horizontal models, with an active
   participation of the users (e.g., Community Networks) to a more
   centralized model, where a single authority (e.g., a company or a
   public stakeholder) plans and manages the network, even if it is
   (total or partially) owned by a community.

   Regarding sustainability, some networks grow "organically" as a
   result of the new users who join and extend the network, contributing
   their own hardware.  In some other cases, the existence of previous
   infrastructure (owned by the community or the users) may lower the
   capital expenditures of an operator, who can therefore provide the
   service with better economic conditions.

4.4.  Technologies Employed

   o  Standard Wi-Fi.  Many Alternative Networks are based on the
      standard IEEE 802.11 [IEEE.802.11] using the Distributed
      Coordination Function.

   o  Wi-Fi-based Long Distance (WiLD) networks.  These can work with
      either Carrier Sense Multiple Access with Collision Avoidance
      (CSMA/CA) or an alternative Time Division Multiple Access (TDMA)
      Media Access Control (MAC) [Simo_b].

   o  TDMA.  It can be combined with a Wi-Fi protocol, in a non-standard
      way [airMAX].  This configuration allows each client to send and
      receive data using pre-designated timeslots.

   o  802.16-compliant (Worldwide Interoperability for Microwave Access
      (WiMax)) [IEEE.802.16] systems over non-licensed bands.

   o  Dynamic Spectrum Solutions (e.g., based on the use of TV White
      Spaces).  A set of television frequencies that can be utilized by
      secondary users in locations where they are unused, e.g., IEEE
      802.11af [IEEE.802.11AF] or 802.22 [IEEE.802.22].
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   o  Satellite solutions can also be employed to give coverage to wide
      areas, as proposed in the RIFE project (

   o  Low-cost optical fiber systems are also used to connect households
      in different places.

4.5.  Typical Scenarios

   The scenarios where Alternative Networks are usually deployed can be
   classified as:

   o  Urban/rural areas.

   o  "Global north" / "global south" countries.

5.  Classification of Alternative Networks

   This section classifies Alternative Networks according to the
   criteria explained previously.  Each of them has different incentive
   structures, maybe common technological challenges, but most
   importantly interesting usage challenges that feed into the
   incentives as well as the technological challenges.

   At the beginning of each subsection, a table is presented including a
   classification of each network according to the criteria listed in
   the "Classification Criteria" subsection.  Real examples of each kind
   of Alternative Network are cited.
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5.1.  Community Networks

   | Entity behind  | community                                        |
   | the network    |                                                  |
   | Purpose        | all the goals listed in Section 4.2 may be       |
   |                | present                                          |
   | Governance and | participatory administration model: non-         |
   | sustainability | centralized and open building and maintenance;   |
   | model          | users may contribute their own hardware          |
   | Technologies   | Wi-Fi [IEEE.802.11] (standard and non-standard   |
   | employed       | versions) and optical fiber                      |
   | Typical        | urban and rural                                  |
   | scenarios      |                                                  |

          Table 1: Characteristics Summary for Community Networks

   Community Networks are non-centralized, self-managed networks sharing
   these characteristics:

   o  They start and grow organically, and they are open to
      participation from everyone, sharing an open participation
      agreement.  Community members directly contribute active (not just
      passive) network infrastructure.  The network grows as new hosts
      and links are added.

   o  Knowledge about building and maintaining the network and ownership
      of the network itself is non-centralized and open.  Different
      degrees of centralization can be found in Community Networks.  In
      some of them, a shared platform (e.g., a website) may exist where
      minimum coordination is performed.  Community members with the
      right permissions have an obvious and direct form of
      organizational control over the overall organization of the
      network (e.g., IP addresses, routing, etc.) in their community
      (not just their own participation in the network).

   o  The network can serve as a backhaul for providing a whole range of
      services and applications, from completely free to even commercial
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   Hardware and software used in Community Networks can be very diverse
   and customized, even inside one network.  A Community Network can
   have both wired and wireless links.  Multiple routing protocols or
   network topology management systems may coexist in the network.

   These networks grow organically, since they are formed by the
   aggregation of nodes belonging to different users.  A minimal
   governance infrastructure is required in order to coordinate IP
   addressing, routing, etc.  Several examples of Community Networks are
   described in [Braem].  A technological analysis of a Community
   Network is presented in [Vega_b], which focuses on technological
   network diversity, topology characteristics, the evolution of the
   network over time, robustness and reliability, and networking service

   These networks follow a participatory administration model, which has
   been shown to be effective in connecting geographically dispersed
   people, thus enhancing and extending digital Internet rights.

   Users adding new infrastructure (i.e., extensibility) can be used to
   formulate another definition: A Community Network is a network in
   which any participant in the system may add link segments to the
   network in such a way that the new segments can support multiple
   nodes and adopt the same overall characteristics as those of the
   joined network, including the capacity to further extend the network.
   Once these link segments are joined to the network, there is no
   longer a meaningful distinction between the previous and the new
   extent of the network.  The term "participant" refers to an
   individual, who may become the user, provider, and manager of the
   network at the same time.

   In Community Networks, profit can only be made by offering services
   and not simply by supplying the infrastructure, because the
   infrastructure is neutral, free, and open (mainstream Internet
   Service Providers base their business on the control of the
   infrastructure).  In Community Networks, everybody usually keeps the
   ownership of what he/she has contributed or leaves the stewardship of
   the equipment to the network as a whole (the commons), even loosing
   track of the ownership of a particular equipment itself, in favor of
   the community.

   The majority of Community Networks comply with the definition of Free
   Network, included in Section 2.
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5.2.  Wireless Internet Service Providers (WISPs)

   | Entity behind  | company                                          |
   | the network    |                                                  |
   | Purpose        | to serve underserved areas; to reduce capital    |
   |                | expenditures in Internet access; and to provide  |
   |                | additional sources of capital                    |
   | Governance and | operated by a company that provides the          |
   | sustainability | equipment; centralized administration            |
   | model          |                                                  |
   | Technologies   | wireless, e.g., [IEEE.802.11] and [IEEE.802.16]  |
   | employed       | and unlicensed frequencies                       |
   | Typical        | rural (urban deployments also exist)             |
   | scenarios      |                                                  |

                Table 2: Characteristics Summary for WISPs

   WISPs are commercially operated wireless Internet networks that
   provide Internet and/or Voice over Internet (VoIP) services.  They
   are most common in areas not covered by mainstream telecommunications
   companies or ISPs.  WISPs mostly use wireless point-to-multipoint
   links using unlicensed spectrum but often must resort to licensed
   frequencies.  Use of licensed frequencies is common in regions where
   unlicensed spectrum is either perceived to be crowded or too
   unreliable to offer commercial services, or where unlicensed spectrum
   faces regulatory barriers impeding its use.

   Most WISPs are operated by local companies responding to a perceived
   market gap.  There is a small but growing number of WISPs, such as
   [Airjaldi] in India, that have expanded from local service into
   multiple locations.

   Since 2006, the deployment of cloud-managed WISPs has been possible
   with hardware from companies such as [Meraki] and later [OpenMesh]
   and others.  Until recently, however, most of these services have
   been aimed at "global north" markets.  In 2014, a cloud-managed WISP
   service aimed at "global south" markets was launched [Everylayer].
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5.3.  Shared Infrastructure Model

   | Entity behind  | shared: companies and users                      |
   | the network    |                                                  |
   | Purpose        | to eliminate a capital expenditures barrier (to  |
   |                | operators); lower the operating expenses         |
   |                | (supported by the community); and extend         |
   |                | coverage to underserved areas                    |
   | Governance and | the community rents the existing infrastructure  |
   | sustainability | to an operator                                   |
   | model          |                                                  |
   | Technologies   | wireless in non-licensed bands, mobile           |
   | employed       | femtocells, WiLD networks [WiLD], and/or low-    |
   |                | cost fiber                                       |
   | Typical        | rural areas, and more particularly rural areas   |
   | scenarios      | in "global south" regions                        |

        Table 3: Characteristics Summary for Shared Infrastructure

   In mainstream networks, the operator usually owns the
   telecommunications infrastructure required for the service or
   sometimes rents infrastructure to/from other companies.  The problem
   arises in large areas with low population density, in which neither
   the operator nor the other companies have deployed infrastructure and
   such deployments are not likely to happen due to the low potential
   return on investment.

   When users already own deployed infrastructure, either individually
   or as a community, sharing that infrastructure with an operator can
   benefit both parties and is a solution that has been deployed in some
   areas.  For the operator, this provides a significant reduction in
   the initial investment needed to provide services in small rural
   localities because capital expenditure is only associated with the
   access network.  Renting capacity in the users' network for
   backhauling only requires an increment in the operating expenditure.
   This approach also benefits the users in two ways: they obtain
   improved access to telecommunications services that would not be
   accessible otherwise, and they can derive some income from the
   operator that helps to offset the network's operating costs,
   particularly for network maintenance.
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   One clear example of the potential of the "shared infrastructure
   model" nowadays is the deployment of 3G services in rural areas in
   which there is a broadband rural Community Network.  Since the
   inception of femtocells (small, low-power cellular base stations),
   there are complete technical solutions for low-cost 3G coverage using
   the Internet as a backhaul.  If a user or community of users has an
   IP network connected to the Internet with some excess capacity,
   placing a femtocell in the user premises benefits both the user and
   the operator, as the user obtains better coverage and the operator
   does not have to support the cost of the backhaul infrastructure.
   Although this paradigm was conceived for improved indoor coverage,
   the solution is feasible for 3G coverage in underserved rural areas
   with low population density (i.e., villages), where the number of
   simultaneous users and the servicing area are small enough to use
   low-cost femtocells.  Also, the amount of traffic produced by these
   cells can be easily transported by most community broadband rural

   Some real examples can be referenced in the TUCAN3G project, which
   deployed demonstrator networks in two regions in the Amazon forest in
   Peru [Simo_d].  In these networks [Simo_a], the operator and several
   rural communities cooperated to provide services through rural
   networks built up with WiLD links [WiLD].  In these cases, the
   networks belonged to the public health authorities and were deployed
   with funds that came from international cooperation for telemedicine
   purposes.  Publications that justify the feasibility of this approach
   can also be found on that website.
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5.4.  Crowdshared Approaches Led by the Users and Third-Party

   | Entity behind  | community, public stakeholders, private          |
   | the network    | companies, and supporters of a crowdshared       |
   |                | approach                                         |
   | Purpose        | sharing connectivity and resources               |
   | Governance and | users share their capacity, coordinated by a     |
   | sustainability | Virtual Network Operator (VNO); different models |
   | model          | may exist, depending on the nature of the VNO    |
   | Technologies   | Wi-Fi [IEEE.802.11]                              |
   | employed       |                                                  |
   | Typical        | urban and rural                                  |
   | scenarios      |                                                  |

        Table 4: Characteristics Summary for Crowdshared Approaches

   These networks can be defined as a set of nodes whose owners share
   common interests (e.g., sharing connectivity; resources; and
   peripherals) regardless of their physical location.  They conform to
   the following approach: the home router creates two wireless networks
   -- one of them is normally used by the owner, and the other one is
   public.  A small fraction of the bandwidth is allocated to the public
   network to be employed by any user of the service in the immediate
   area.  Some examples are described in [PAWS] and [Sathiaseelan_c].
   Other examples are found in the networks created and managed by city
   councils (e.g., [Heer]).  The "openwireless movement"
   ( also promotes the sharing of private
   wireless networks.

   Some companies [Fon] also promote the use of Wi-Fi routers with dual
   access: a Wi-Fi network for the user and a shared one.  Adequate
   Authentication, Authorization, and Accounting (AAA) policies are
   implemented, so people can join the network in different ways: they
   can buy a router, so they can share their connection and in turn,
   they get access to all the routers associated with the community.
   Some users can even get some revenue every time another user connects
   to their Wi-Fi Access Point.  Users that are not part of the
   community can buy passes in order to use the network.  Some
   mainstream telecommunications operators collaborate with these
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   communities by including the functionality required to create the two
   access networks in their routers.  Some of these efforts are surveyed
   in [Shi].

   The elements involved in a crowdshared network are summarized below:

   o  Interest: A parameter capable of providing a measure (cost) of the
      attractiveness of a node in a specific location, at a specific
      instance in time.

   o  Resources: A physical or virtual element of a global system.  For
      instance, bandwidth; energy; data; and devices.

   o  The owner: End users who sign up for the service and share their
      network capacity.  As a counterpart, they can access another
      owner's home network capacity for free.  The owner can be an end
      user or an entity (e.g., operator; virtual mobile network
      operator; or municipality) that is to be made responsible for any
      actions concerning his/her device.

   o  The user: A legal entity or an individual using or requesting a
      publicly available electronic communications service for private
      or business purposes, without necessarily having subscribed to
      such service.

   o  The VNO: An entity that acts in some aspects as a network
      coordinator.  It may provide services such as initial
      authentication or registration and, eventually, trust relationship
      storage.  A VNO is not an ISP given that it does not provide
      Internet access (e.g., infrastructure or naming).  A VNO is not an
      Application Service Provider (ASP) either since it does not
      provide user services.  VNOs may also be stakeholders with socio-
      environmental objectives.  They can be local governments,
      grassroots user communities, charities, or even content operators,
      smart grid operators, etc.  They are the ones who actually run the

   o  Network operators: They have a financial incentive to lease out
      unused capacity [Sathiaseelan_b] at a lower cost to the VNOs.

   VNOs pay the sharers and the network operators, thus creating an
   incentive structure for all the actors: the end users get money for
   sharing their network, and the network operators are paid by the
   VNOs, who in turn accomplish their socio-environmental role.
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5.5.  Rural Utility Cooperatives

   | Entity behind the   | rural utility cooperative                   |
   | network             |                                             |
   | Purpose             | to serve underserved areas and to reduce    |
   |                     | capital expenditures in Internet access     |
   | Governance and      | the cooperative partners with an ISP who    |
   | sustainability      | manages the network                         |
   | model               |                                             |
   | Technologies        | wired (fiber) and wireless                  |
   | employed            |                                             |
   | Typical scenarios   | rural                                       |

      Table 5: Characteristics Summary for Rural Utility Cooperatives

   A utility cooperative is a type of cooperative that delivers a public
   utility to its members.  For example, in the United States, rural
   electric cooperatives have provided electric service starting in the
   1930s, especially in areas where investor-owned utility would not
   provide service, believing there would be insufficient revenue to
   justify the capital expenditures required.  Similarly, in many
   regions with low population density, traditional Internet Service
   Providers such as telephone companies or cable TV companies are
   either not providing service at all or only offering low-speed DSL
   service.  Some rural electric cooperatives started installing fiber
   optic lines to run their smart grid applications, but they found they
   could provide fiber-based broadband to their members at little
   additional cost [Cash].  In some of these cases, rural electric
   cooperatives have partnered with local ISPs to provide Internet
   connection to their members [Carlson].  More information about these
   utilities and their management can be found in [NewMexico] and
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5.6.  Testbeds for Research Purposes

   | Entity behind    | research/academic entity                       |
   | the network      |                                                |
   | Purpose          | research                                       |
   | Governance and   | the management is initially coordinated by the |
   | sustainability   | research entity, but it may end up in a        |
   | model            | different model                                |
   | Technologies     | wired and wireless                             |
   | employed         |                                                |
   | Typical          | urban and rural                                |
   | scenarios        |                                                |

               Table 6: Characteristics Summary for Testbeds

   In some cases, the initiative to start the network is not from the
   community but from a research entity (e.g., a university), with the
   aim of using it for research purposes [Samanta] [Bernardi].

   The administration of these networks may start being centralized in
   most cases (administered by the academic entity) and may end up in a
   non-centralized model in which other local stakeholders assume part
   of the network administration (for example, see [Rey]).

(page 22 continued on part 2)

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