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 7 input/output ports are connected to nodes 1 thru 7, respectively while the 8th and 9th input/output ports are connect to either nodes 1-8 and 19 or the two Wimax base stations (BS1 and BS2). The selection of devices attached to ports 8 and 9 is controlled by Instrumentation AM service.

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 or wimax BS1
9	node1-9 or wimax BS2

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

Node to Node RF Path

s12 parameters taken with Agilent ENA RF Network Analyzer E5070; instrument dynamic range of 110 dB limits the accuracy of large attenuation results.

Node to WiMAX basestation RF Path