RDRN Software

Overview

Linux has been chosen as the operating environment for the RDRN system running on the laptops. The RDRN software is divided into two major components: the Orderwire Modules and the WATM Modules, that work in close coordination. The following describes the high-level architecture in terms of the algorithm embedded in the RDRN software for both the Orderwire network and the WATM network.

The Orderwire Network

The wireless topology is setup by initially having the edge-nodes (ENs) broadcase their position over the orderwire network and listen for location broadcast from other RDRN nodes. Similarly, remote nodes (RNs) broadcast their position over the orderwire system. A location-based distributed network configuration algorithm is executed to establish link-level connectivity among ENs and sets of RNs or among adjacent ENs. The algorithm not only controls the assignment of node to node link connection but also the assignment of beam to users and the handoff of users from one EN to another. At this stage, handoff support is only provided at the physical WATM link level by the orderwire; however, we are currently studying the implications of such support on the RDRN architecture at large. Survivability is ensured by continuously exchanging location and status information over the orderwire network. As RDRN nodes move, position updates from GPS receivers are used to steer the beams in the correct direction.

Once the RDRN network topology is initialized at the WATM link-level using the orderwire network, the RDRN nodes may start their configuration at the ATM level over the WATM network. Local WATM link configuration strictly follows the orders of a local link manager which works on behalf of the orderwire to setup, adapt, and tear-down WATM point-to-point links. Point-to-point WATM links are established at the physical level by close cooperation between the orderwire and the beamforming antenna system that communicates through the WATM adapter.


Last Update: November 02, 1999 04:37pm (GMT-0600)