Rapidly Deployable Radio Networks (RDRN)

PRINCIPAL INVESTIGATORS

K. Sam Shanmugan, Professor, shanmugan@eecs.ku.edu, 913-864-4831
Victor S. Frost, Professor, frost@eecs.ku.edu, 913-864-4833
Joseph B. Evans, Associate Professor, evans@eecs.ku.edu, 913-864-4830

Electrical Engineering & Computer Science
The University of Kansas
Lawrence, Kansas 66045-2228
FAX: (913) 864-7789

OBJECTIVE

Create a high speed ATM-based wireless communication system that will be adaptive at both the link and network levels to allow for rapid deployment and response to a changing environment. The objective of the architecture is to use adaptive point-to-point topology to gain the advantages of ATM for wireless networks.

APPROACH

The University of Kansas (KU) will conduct a detailed system design of a high capacity communication network suitable for rapid deployment. Key elements of this system will be implemented to prove the viability of the concept. The system will be adaptable to its environment and automatically configure itself into a high capacity, fault tolerant, and reliable configuration. The system will be distributed in nature, requiring no central controller or management center.

The architecture is composed of three overlaid networks:

  • a low bandwidth, low power omni-directional network for location determination, switch coordination and management;
  • a "cellular like" system for multiple end-user access to the switch; and
  • a high capacity, highly directional, multiple beam network for switch-to-switch communication.
  • Each switch consists of an adaptable and programmable high capacity radio, a phased array steerable antenna, and a communication network controller with switching capabilities. As part of the KU approach the switch initiates three activities:

  • determines its location via the Global Positioning System (GPS) and begins encrypted broadcasting of its location on a low capacity channel,
  • listens for other systems broadcasting their locations, and
  • monitors the radio frequency environment to detect other communication nodes or interfering signals.
  • As other nearby switches are detected, the local switch establishes a high capacity point-to-point RF link to these nearby nodes. Link coordination takes place over the low capacity, omni-directional link, while the local antenna is configured to steer its beams toward nearby switches, establishing the high capacity links. The use of point-to-point links means that link throughput can be maximized and frequencies can be reused on a regular, spatial basis. The development of digital beamforming and adaptive radios for this system will require innovations that will have wide spread applicability. Spatial reuse also will be exploited for end-user/switch communications. Continuous knowledge of the location of all the network elements using GPS will aid this architecture in providing smooth call hand-off. The system will have the capability to predict when a hand-off event should occur, plan for that event and smoothly execute the hand-off. When hand-offs occur, all virtual circuits connected to the end-user will be seamlessly switched. An innovative aspect of the KU effort is the use of GPS derived location information for antenna beamforming, network management, and control; and the extensive use of digital signal processing technology for implementing the radio signal processing functions.

    Should a link between two nodes be broken due to equipment failure, link degradation, or one of the nodes simply moving out of range, the network controllers detect this topology change and initiate a reconfiguration of the network topology. The reconfiguration is carried out automatically in a distributed manner. Another innovative aspect of the KU effort is the integration of reconfiguration algorithms into a high speed wireless ATM network.

    The switches used in this effort will support virtual circuits based on Broadband Integrated Services Digital Network (B-ISDN) concepts, in particular, the ATM protocols. This means that communication nodes are compatible with the evolving telecommunications infrastructure. The final innovative components of the KU effort are the end-to-end use of standards-based ATM technology for seamless integration of the wireless network into existing systems and the subsequent potential for scaling into a large system.

    FY-95 PLANS

  • Develop the detailed overall system architecture.
  • Initiate the design and development of the steerable antenna and RF components.
  • Initiate the design and development of the modulation and DSP components.
  • Complete a validation of the overall system architecture using modeling, analysis, and simulation.
  • Last updated: September 2, 1994