==== SB4 ====
[[TOC(Hardware, Hardware/bDomains, Hardware/bDomains/cSandboxes*, depth=6)]]

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 [http://www.ramseytest.com/ 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 [http://www.jfwindustries.com/documents/50PMA-012_specsheet.pdf  RF Transceiver Test System] from [http://www.jfwindustries.com JFW Industries]. This configuration enables fairly tight control of RF attenuation matrix between the nodes. The topology is controlled through the [http://omf.mytestbed.net OMF] based [wiki:Software/bAM/mInstr Instrumentation AM].

  || [[Image(SB4.jpg, 600px, align=center)]] || [[Image(IMG_0376.jpg, 200px)]] ||

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 =====

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

[[Image(SB4-Equiv-WiFi.jpg)]]


|| [[Image(S12-A-24.jpg, 250px)]] || [[Image(S12-A-25.jpg, 250px)]] || [[Image(S12-A-52.jpg, 250px)]] ||
 
===== Node to WiMAX basestation RF Path =====

[[Image(SB4-Equiv-WiMAX.jpg)]]

[[Image(S12-B-25.jpg, 400px)]]