SB4

As shown in Figure 1, sandbox 4 consists of 9 nodes and a WiMAX subsystem that consists of a basestation and a controller. To prevent interference, each node is housed in ​Ramsey Electronics RF enclosure that provides 80 dB of isolation. There are 8 nodal wireless devices (with Atheros 5000X mini-PCI card and Intel 6250 mini-PCIe 802.11/802.16); these are connected to a power combiner and fed through the enclosure access port to the outside SMA connector which is wired to one of the input/output ports of the ​RF Transceiver Test System from ​JFW Industries. This configuration enables fairly tight control of RF attenuation matrix between the nodes. The topology is controlled through the ​OMF based Instrumentation AM.

As can be seen in figure 1, there are a total of nine (9) input/output ports on the transceiver test system. The first 8 input/output ports are connected to nodes 1 thru 8, respectively and the 9th input/output port is connect to the Wimax base station (BS).

RF Test System Port	Attached device
1	node1-1
2	node1-2
3	node1-3
4	node1-4
5	node1-5
6	node1-6
7	node1-7
8	node1-8
9	wimax BS

This configuration creates two distinct set of RF paths that are used to create various topologies.

Node to Node RF Path

Node to WiMAX basestation RF Path