Rapidly Deployable Radio Network
Project Award Date: 06-20-1997
The primary objective of the RDRN project is to create architectures, protocols, and prototype hardware and software for a high speed network that can be deployed rapidly in areas of military conflicts or civilian disasters where communication infrastructures are lacking and or destroyed (e.g., Desert Storm, Bosnia, Hurricane Andrew, LA earth quake). The rapid deployment requirement, coupled with higher speed requirements and seamless integration with other commercial networks, has lead to an approach that uses wireless technology for the communication links and ATM for networking. The Rapidly Deployable Radio Network (RDRN) being developed by the University of Kansas is a wireless ATM network; it consists of portable (mobile) communication nodes which can be deployed on the ground or on mobile platforms such as trucks, helicopters, or fixed wing aircraft. When deployed, the nodes use GPS derived location information to automatically configure themselves into a high capacity, fault tolerant network infrastructure.
RDRN is made up of two types of nodes: end user nodes providing wireless ATM access for users at a rate of up to 1.5Mbit/sec, and edge nodes which serve as Radio Access Points (RAPs) or base stations and provide switching and connectivity between users. Both types of nodes contain GPS receivers for location determination; software controlled radios with phased-array antennas for beam forming and pointing in the right direction, using GPS derived location information; and Network Control (NC) software. The edge nodes also have built-in ATM (software) switches, and they are interconnected by high capacity (45 to 155Mbit/sec) directional radio links. Edge nodes can also interface to wired ATM networks.
The RDRN architecture consists of three overlaid radio networks:
(1) a low bandwidth, low power, omni-directional order wire packet radio network for broadcasting location information, network configuration, and management;
(2) a cellular-like ATM radio n etwork for end user access to edge nodes with hand-offs; and
(3) a high capacity wireless ATM backbone network providing connection between switches using high capacity radios with multiple directional beams.
When RDRN is initially deployed in a new area, each of the edge nodes initiates the following activities:
(1) determine its location from GPS and broadcast it over the secure orderwire network;
(2) listen for broadcasts from other nodes;
(3) establish the backbone network by forming high capacity, directional radio links to nearby nodes using the steerable phased array antenna; and
(4) begin executing the distributed network configuration and control algorithm and establish connectivity with end user nodes.
Each edge node is capable of forming multiple radio beams in the direction of other edge nodes or towards end users in the vicinity. A phased array antenna with digital beam forming is used to form these multiple beams, and pointing directions are derived from location information. Assignment of beams to users, node to node connections, and hand-offs of users from one edge node to another are controlled by the distributed network configuration and management algorithm. The network control information is broadcast over the orderwire network. Changes in network topology due to mobility or failure of nodes and or links are detected by the NC algorithms, and reconfiguration is carried out automatically in a distributed manner.
RDRN is also adaptable to changes in the quality of the radio communication environment. While ATM is designed to operate on high quality (almost error free) wired links, typical radio links suffer higher error rates and the link quality changes as a function of time due to mobility and changes in the environment. By estimating the channel parameters such as multipath spread and signal to noise ratio, communication parameters at the link and network levels are adapted to provide appropriate throughput and quality of service.
Prototype algorithms, hardware and software have been developed to demonstrate the following key concepts of RDRN:
(1) software controlled radio,
(2) phased array antenna with digital beam forming,
(3) orderwire network for network configuration and control, and
(4) protocol stack(s) for wir eless ATM and IP over ATM.
We have finished Phase I, and a follow-on contract has been awarded. We are now in the initial stages of RDRN Phase 2.
For More Information: http://www.ittc.ku.edu/RDRN/
Faculty Investigator(s): Sam Shanmugan (PI), Joseph Evans, Victor Frost, Gary Minden, David Petr, Glenn Prescott, James Roberts
Staff Investigator(s): Daniel DePardo, Artur Leung, Craig Sparks
Student Investigator(s): John Paden, Ricardo Sanchez
Primary Sponsor(s): DARPA