Project Objectives

The ORBIT project was started in September 2003 under the NSF Network Research Testbeds (NRT) program (CNS-0335244), with the objective of developing a large-scale open-access wireless networking testbed for use by the research community working on next-generation protocols, middleware and applications. The project is currently continuing under CNS grant # 0725053, which supports operations and several key technical upgrades including the introduction of software-defined radio capabilities. The ORBIT project is closely aligned with the GENI (global environment for network innovation) experimental network deployment and serves as a proof-of-concept experimental platform for wireless aspects of the program

Technology Rationale

Multiuser experimental facilities for wireless networking are motivated by the fact that this is a field with many new architecture and protocol ideas, and yet individual researchers have so far been restricted to small scale tests which cannot readily be reproduced by other groups due to variations in equipment and radio environment. The availability of a shared wireless testbed enables experimenters to work with significantly larger scale networks and report reproducible results which encourage subsequent validation and follow-on research by their peers. In the longer term, campus-wide network testbeds like ORBIT can also be used to for trial deployment of new mobile/wireless services and software.

Technical Approach:

The ORBIT testbed is centered around the “radio grid emulator” which provides facilities for reproducible networking experiments with large numbers (~100’s) of wireless nodes. The testbed also includes an outdoor “field trial system” intended to support real-world evaluation for protocols validated on the emulator, and for application development involving mobile end-users. Construction of the 5000 sq-ft, 400-node ORBIT radio grid facility at the WINLAB Tech Center II building in North Brunswick, NJ was completed in mid-2005, leading to the first community release of testbed services in October 2005. Some examples of specific research projects carried out on ORBIT are mobile ad hoc networks (MANET) for tactical applications, mesh network protocols used for municipal WiFi access, DTN (delay tolerant networks), media streaming over wireless networks, mobile content delivery and wireless network security. The testbed has also been used for future Internet architecture experiments involving new protocols for both wired and wireless network subsystems.

The 400-node ORBIT radio grid testbed at WINLAB, Rutgers University is shown in the figure below.   The testbed provides 400 programmable radio nodes for at-scale and reproducible emulation of next-generation wireless network protocols and applications.  The ORBIT radio grid can be accessed by experimenters via an Internet portal, which provides a variety of services to assist users with setting up a network topology, programming the radio nodes, executing the experimental code, and collecting measurements.  The testbed also supports end-to-end wired and wireless experiments using a combination of ORBIT and OpenFlow switch/router nodes under the same experimental execution framework.  Upgrade of the testbed with URSP2 radios to support programmability at the radio PHY and MAC layers has recently been completed (with 28 USRP and USRP2 radios installed in the first phase), with the objective of support emerging cognitive radio networking experiments.  The radio grid is also supplemented by a number of outdoor and vehicular nodes (both WiFi and WiMAX) deployed on or around the Rutgers campus, to be used for real-world validation of results or for application trials. The ORBIT testbed has also been federated into the GENI (Global Environment for Network Innovation) future Internet research network and can be used for integrated global-scale Internet experiments involving wireless access networks.  The main ORBIT radio grid and outdoor testbeds have been further supplemented with a number of experimental "sandboxes" which allow researchers to debug and test their code without tying up the resources of the larger radio grid; available sandboxes include WiFi, WiMAX, OpenFlow and USRP2.

Results to Date and Future Work Plan:
  • Addition of software-defined radio (SDR) nodes in support of cognitive networking experiments
  • Hardware upgrade of ORBIT grid nodes to faster processors capable of supporting higher speed SDR experiments
  • Testbed upgrades to include emerging radio technologies such as 802.11n, Zigbee and WiMAX
  • Virtualization of radio grid resources to support multiple simultaneous experiments
  • Software maintenance and operations support including upgrades to the ORBIT user portal
  • Integration of ORBIT with experimental wired networks including OpenFlow and GENI

A total of over 100 papers, PhD/MS dissertations, and technical reports have been published with data obtained from the ORBIT testbed.  The ORBIT project team was awarded the NSF IUCRC Shwarzkopf Proze for Technological Innovation in 2008.

For further information or to obtain a user account, please visit the ORBIT website.