The DEUS project aims to develop an easy to deploy and use versatile wireless network infrastructure for dynamic environments. It identifies four network domains: a wireless backbone, wireless sensor networks, access points, and backend servers. The backbone mesh provides a secure, self-organizing transport network between components. Wireless sensor networks share features with the mesh but support multiple routing protocols. Global routing optimizes paths between sensors and connects different network domains in a transparent way. Access points deployed on the mesh provide seamless client mobility. The architectural concept forms the basis for DEUS proof of concept implementations across different use cases.

1. DEUS
Deployment and Ease Use of wireless Services
Network Architecture
Main challenges
Current infrastructures in buildings and public areas are predominantly based on wired
network technologies. Although wired infrastructures have proven to be very reliable,
once they have been properly installed, wired solutions are not desired in dynamic
environments, where the setting may change from day-to-day.
These dynamic environments demand for a specific approach. Where wired networks can
survive with a onetime install and a minimum of management, constantly changing
networks could be an administrative nightmare. DEUS will prove the opposite by
providing an easy configurable, self-healing and easy manageable, flexible wireless
network.
DEUS approach
Delivering services on such flexible networks to users in an efficient way could be the
baseline of the DEUS project. As users have various requirements depending on the
services they rely on, the network used to provide the needed connectivity should be
flexible and versatile. This requires interactions between various kinds of devices and
technologies and could easily lead to complicated and hard to manage networks. Within
DEUS we demonstrate the opposite by developing an easy to deploy and to use versatile
network infrastructure.
In DEUS, four different network domains are identified as illustrated in Figure 1:
• a wireless backbone, providing the core transport network between all involved
components,
• a Wireless Sensor Networks (WSN), consisting of low power sensor and actuator
devices, interacting with the environment,
• deployment of Access Points (AP) at the edges to provide user access to the
network,
• backend servers used for network management and service provisioning.

2. DEUS
Deployment and Ease Use of wireless Services
Autoconfiguration mechanisms ensure that the mesh and WSNs can be set up with a
minimum of user intervention. At the same time, security measures are in place to
prevent malicious nodes to join the network. Using transparent routing solutions, all four
domain are interconnected which makes it possible that:
• sensors can be reached by the backend,
• WiFi users can connect to the backend and the Internet,
• WSN paths can be optimised via the mesh.
Figure 1: DEUS logical network components
DEUS solutions
Backbone Mesh
The backbone mesh network consists of a collection of routers which create a secure,
multi-hop, autoconfiguring, self-organizing and reliable transport network supporting
Quality of Service (QoS). The primary role of this network is to transparently transport
data from other connected networks.
The links in this mesh can be as well wireless as wired. Wireless clusters can be easily
interconnected by wired links to overcome physical barriers as walls or concrete floors. It
can even be used to connect mesh networks across various buildings or sites.
Hop-by-hop link encryption techniques make eavesdropping on the mesh network
useless. The basic OLSR routing protocol has been extended with advanced routing
metrics to optimize paths within the network and to introduce a high level of reliability.
In the event of link deterioration or node failure, new routes will automatically be created
to bypass the failed node or link.

3. DEUS
Deployment and Ease Use of wireless Services
Wireless Sensor Network
The Wireless Sensor Network (WSN) shares a lot of features with the mesh network: it is
autoconfigured, self-organising, multi-hop and supports QoS. At the same time it is quite
different from the backbone mesh. By using a modular architecture, the WSN
simultaneously supports multiple routing protocols.
Depending on the application, a different type of protocol can be used. One protocol will
support convergecast routing, having routes to the sink available at all times, while other
applications, like e.g. voice calls, need a reactive protocol which will set up a path and
possibly reserve resources to guarantee a certain level of QoS. The diversity of traffic this
WSN needs to handle also calls for a specific hybrid MAC which has been developed
within DEUS. This MAC is able to dynamically enable links between sensors and schedule
slots such that QoS can be supported.
Global Routing
The purpose of Global Routing is twofold:
• Optimise sensor paths by combining sensor and mesh links in sensor to sensor
communications,
• Connect WNS and non-WSN devices (like the backend servers or regular mesh
nodes).
In the first case, long paths through a sensor cloud, as illustrated in Figure 3 can be
avoided by routing to the nearest mesh gateway supporting global routing. Global routing
will set up a path to the mesh gateway nearest to the destination device, as shown in
Figure 4. Doing so, power and bandwidth can be saved on intermediate sensor nodes and
latency on the path between the two devices is lowered which is especially interesting in
the case of voice routing.
The transparent nature of global routing, gateway device advertise themselves as one
hop neighbours, avoid specific changes to the WSN routing protocol. As such, global
routing is also used to transparently connect disjoint WSN clouds, constructing one large
WSN cloud which is easily managed and controlled. Finally, Global Routing also preserves
QoS requests. Both WSN and Mesh support QoS and Global Routing will make sure that
WSN levels will be translated and packets adequately marked when entering the
Backbone Mesh.

4. DEUS
Deployment and Ease Use of wireless Services
Figure 3: global routing path
Figure 2: Sensor path
Global routing also interacts with default IPv4 and IPv6 networks (Figure 4), e.g. from
the backend domain. The WSN itself uses 6LowPAN, an IP like networking scheme
tailored to low power networks. It has been designed with IPv6 compatibility in mind, but
in DEUS, we bring it into practice. Global Routing will bridge between the more static
routing paths in the IPv6 domain and the reactive routing within the WSN. Finally, a NAT-
PT solution will interconnect IPv4 and IPv6 networks, and thus IPv4 to the sensors using
global routing as intermediary.
Figure 4: Sensor connectivity

5. DEUS
Deployment and Ease Use of wireless Services
WiFi Access Points
Access points can be deployed on the mesh routers. Although strictly separated logic is
used, some close integration between mesh and access network is introduced to support
mobility. The presence of clients on the access network is propagated within the mesh
network at a minimum of signalling cost, but with the result of transparent mobility
across the access network. Clients moving from one access point to another will remain
connected without the need of a specific mobility protocol at the client side.
DEUS Proof of Concept implementation
This architectural concept is the basis of the set-up of the different use cases
demonstrated in the Deus project.
Project partners
In cooperation with
IBBT research groups
UGent - IBCN http://www.ibcn.intec.ugent.be
UGent - WiCa http://www.wica.intec.ugent.be
UA - PATS http://www.pats.ua.ac.be
KU Leuven – DistriNet http://www.distrinet.cs.kuleuven.be
KU Leuven – CUO http://www.soc.kuleuven.be/com/mediac/cuo
UHasselt – EDM http://www.edm.uhasselt.be/