Tholos Indoor Testbed

The NITOS indoor testbed consists of 40 Icarus nodes and is deployed in an isolated environment at the University of Thessaly's campus building. Each Icarus node consists of multiple heterogeneous interfaces giving the user/ experimenter the ability to design and implement a wide range of realistic scenarios. A more detail review of the ICARUS node could be found here.

NITOS Topology

Icarus nodes are placed in a symmetrical way around the isolated environment of NITOS testbed forming a Grid architecture. The distance amongst the nodes is fixed to 1.2 meters and the height level is identical for all them as well. As a result, a uniform environment is created where all nodes are isobaric and of equal capabilities.

Figure 1. NITOS Grid View

Deployment

Two Gigabit Ethernet switches interconnect the nodes with NITOS server of each testbed, namely the Control switch that provide for control of experiment execution and measurement collection and the Experimental switch, which can be used for conducting wired experiments. The latter is an HP 3800 series Openflow switch, thus enabling SDN and NFV experimentation on top of NITOS. A third Gigabit Ethernet, namely the Chassis Manager switch, is dedicated in controlling the operational status of the nodes through the transmission of custom http requests that control solid state relays on the Chassis Manager cards attached on each node.

The NITOS server is used to run experiments on the testbed through OMF, and to host various network services including DHCP, DNS, NTP, TFTP, PXE, Frisbee, MySQL, OML and Apache. It is also responsible for scheduling of the testbed’s resources and for handling users’ requests to access the testbed. It also keeps valuable information for experimentation such as users’ hard disk images, databases containing measurements from experiments and other useful information.

Figure 2. Rack View

Hardware Extensions

NITOS indoor testbed features a software defined radio (SDR) testbed that consists of 2 Universal Software Radio Peripheral (USRP) devices attached to the NITOS ICARUS nodes. USRPs allow the researcher to program a number of physical layer features (e.g. modulation), thereby enabling dedicated PHY layer or cross-layer research.

In advance, five smart handheld devices, i.e. Google Nexus Smartphones hosting Android OS, are mounted on equal number of nodes thus enabling experimentation over mobile technologies, i.e. Bluetooth, A/V Streaming, LTE, WiFi, etc. The availability of multiple and heterogeneous devices, in the concept of technology and interfaces provisioning, sustain NITOS as a cross platform testbed; thus allowing the research community to design and implement highly advanced scenarios on top of state of the art equipment.

Figure 3. Mobile Devices

Figure 4. USRP Devices