= Hardware = [[TOC(Hardware*, depth=3)]] The ORBIT laboratory is comprised of several different test '''[wiki:Hardware/bDomains domains]''' in which experimenters can use the hardware provided by WINLAB for use in wireless experimentation. The Orbit grid as illustrated in Figure 1 consists of a multiply interconnected, 20-by-20 grid of '''[wiki:Hardware/hNodes ORBIT radio nodes]''', some non-grid nodes to control R/F spectrum measurements and interference sources, and front-end, application and back-end servers. These servers support various ORBIT services. In addition to the main grid, there are also 9 additional smaller //test grids//(a.k.a. sandboxes). All this is supported by the back end '''[wiki:Hardware/dInfrastructure orbit infrastructure]''' which provides services and control to the test facility. [[Image(hardware-50.png)]] [[BR]]Figure 1. ORBIT Hardware. Each radio node is a PC typically with two 1000BaseT Ethernet ports, radio cards and a '''[wiki:Hardware/jCM chassis manager(CM)]''' to control the node. The two Ethernet ports are connected to Data and Control subnets. While Control is used primarily for node access, experiment management and measurement collection, the Data subnet is exclusively available to the experimenter. In addition to the standard radio cards on most of the nodes, there are many other '''[wiki:Hardware/fDevices devices]''' throughout including devices for various communication protocols as well as software radio platforms such as the USRP & USRP2. The full list is found under the devices description page. In addition to the nodes, the grid has a number of USRP X310s that are connected to the control and data networks directly, instead of being individually hosted on nodes. Virtual machines are also available, with access to the control and data networks on their respective domains. Currently they are available in column 23 of the grid, and column 3 of sandbox 1. Detailed information on the various hardware components that are used to realize the ORBIT testbed can be found by following the links above.