-Community networking is an emerging model of a shared communication infrastructure in which communities of citizens build and own open networks. Community networks offer successfully IP-based networking to the user. In addition, some hosts are connected to the network nodes in order to provide network management and end user services. Recently, clouds have been proposed for community networks. Some research projects such as Clommunity have started deploying computational infrastructure to enable cloud computing within community networks. In this paper we propose different options for such community clouds to contribute to energy efficient systems, in particular regarding cloud-based services and in relation to Smart Grid. Further discussion and interaction with the research initiatives on energy efficient systems should identify the most promising approach and outline possible ways for implementation. Index Terms-community networks; cloud computing
Community networks are user-driven communication
networks which often originated from the lack of Internet
connectivity in rural areas. There are several community-owned
networks in the range of 500 to 20,000 nodes in Europe such
as FunkFeuer, AWMN, Guifi.net, Freifunk and many more
worldwide. Most of them are based on Wi-Fi technology
(adhoc networks or IEEE 802.11a/b/g/n access points in the first
hop, long-distance point-to-point Wi-Fi links for the trunk
network), but also a growing number of optic fibre links have
started to become deployed [
The community cloud we consider here are cloud
deployment in community networks: A cloud hosted on
communityowned computing and communication resources providing
services of local interest. The concept of community clouds
has been introduced in its generic form before, e.g., [
Such community cloud built in community networks have features which may contribute to energy efficient cloud system design and implementation.
Distributed and heterogeneous hardware: Cloud hardware in community clouds is contributed by the users, hardware can be heterogeneous and it is at the users’ premises.
Decentralized service management: The network and cloud services are managed by the users. Services may be shared among users to build collaborative applications.
Community-driven services: The potential of the community cloud is to deploy services of local interest.
Awareness of energy-efficiency may be brought to the users, which could drive a fast roll-out of services to support energy-efficiency.
We describe in the following section first the characteristics of the cloud deployment that we have started in the Guifi.net community network. Secondly, we sketch some proposals to benefit from community network cloud infrastructure to build energy efficient systems.
I I . C L O U D S I N C O M M U N I T Y N E T W O R K S
In this section we explain some components of the cloud we have deployed in Guifi.net community network, which presents a real case for our proposals for extending towards energyefficiency in section III.
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Cloud in community networks needs to fit into the conditions of how these networks are built, governed and grown.
Regarding their growth, one important aspect is the topology of community networks, which determines the scope of the options how the cloud infrastructure can be integrated. In Figure 2 some node types of a community wireless network are depicted. The picture shows some typical community nodes with a router and some server or clients attached to it. Some clients nodes are shown that are connected to the access point (AP) of a super node. In addition, however, these community nodes have cloud resources attached to them which are part of the community cloud. In addition, depending on the topology of the wireless network and the social structure of the community, several local community clouds may appear which manage locally the cloud resources belonging to a certain zone defined geographically or by its social networks. We call such local clouds microclouds. A set of microclouds are interconnected though the wireless links of the super node backbone network.
In Figure 3 an example of the indoor hardware of a cloud
node is shown. In this case a small Jetway device is used
as cloud resource. A UPS keeps the node running in case of
power failures. It is connected over Ethernet to the outdoor
community network node. This cloud nodes represents the
case of low-end cloud resources such as home gateways, that
users provide to the cloud. These devices have been deployed
through Community-Lab1 [
Since the different local groups providing such microclouds are independently organized, the cloud management platforms (CMP) that are used are also heterogeneous. In the community clouds we have deployed we use mainly Proxmox and OpenStack as CMP. The reason for using Proxmox is that within the community network, there is already some positive usage experience, and the installation and operation of Proxmox is relatively easy compared to other CMPs. OpenStack on the other hand, is popular as a powerful customizable cloud platform, supported by a large user community, though not within community networks.
We provide a community cloud GNU/Linux distribution, codenamed Cloudy, aimed and designed for building clouds in community networks. This distribution contains the platform and application services of the community cloud model. Cloudy is deployed on the cloud resources that form the microcloud and over the different microclouds in the community network, as illustrated in Figure 4.
I I I . S U P P O R T O F C O M M U N I T Y C L O U D S F O R
E N E R G Y E F F I C I E N T S Y S T E M S
In this section we sketch a set of proposals on how to benefit from community clouds for building energy efficient systems.
Community clouds are envisioned as a set of federated microclouds. Microclouds are composed of heterogeneous devices, which can range from resource-constrained home gateways up to server class desktops, even small crowd-funded data centres can be imagined. Depending on the service-level agreements of the requested cloud service, different cloud resources may be able to fulfil the requirements.
2http://wiki.clommunity-project.eu/testbed:start
If an energy model of the different classes of cloud hardware available in the community clouds is available, the most energy efficient cloud infrastructure may be selected to which this job should be allocated. An initial proof of concept of such a system could be studied on a single heterogeneous microcloud. The level of federation support of the used CMP may allow extending such energy-efficient resource allocation over several microclouds.
In this scenario, the heterogeneity of community cloud hardware plays an essential role. Such energy-efficient resource allocation may be less applicable in commercial cloud systems where the hardware is more homogeneous.
Different research initiatives, e.g. the Montblanc project3, consider building energy-efficient cloud computing infrastructures with low-power devices.
Community cloud contributors are expected to target cloud hardware deployed on their premises which has a low energy consumption, for being able to run in a 24/7 mode without noticeable electricity consumption increase. Therefore, such a cloud scenario built upon many distributed low-power devices could be materialized by a user-provisioned cloud infrastructures in community clouds.
In order for such a scenario to be explored, CMPs need
to be evaluated towards their capacity to support hypervisor
solutions which may not require hardware supported
virtualization. Several low-power devices have already been deployed
in Community-Lab [
Smart Grid scenarios build upon advanced metering and
communication infrastructures, which enable to take more
energy-efficient decisions on power consumption. For such
scenarios, computational infrastructure is needed to process
large amounts of data generated by electrical meters and
combine it with additional contextual information. Such processing
could leverage on community cloud hardware and services, and
reduce the need of infrastructure that utility providers need to
deploy in the last mile of the Smart Grid [
The appearance of clouds in community networks can be witnessed nowadays. Such clouds consist of user contributed infrastructures which enable cloud-based services; the cloud hardware is often located at the user premises. Such community clouds offer unique features compared to commercial data centre type clouds, such as distributed and heterogeneous hardware, user-managed services and services of community interest. This paper sketches some opportunities which community clouds could offer to contribute to energy efficient systems. These opportunities are described towards energyefficient resource allocation, clouds made out of low-power devices, and supporting the deployment of the Smart Grid.
This work was supported by the European Community Framework Programme 7 FIRE Initiative projects CLOMMUNITY, FP7-317879, and Community Networks Testbed for the Future Internet (CONFINE), FP7-288535.