Time-deterministic WDM star network for massively parallel computing in radar systems

Abstract

In massively parallel computer systems for embedded real-time applications there are normally very high bandwidth demands on the interconnection network. Other important properties are time-deterministic latency and services to guarantee that deadlines are met. In this paper we analyze how these properties vary with the design parameters for a passive optical star network, specifically when used in a massively parallel radar signal processing system. The aggregated bandwidth and computational power of the radar system are approximately 45 Gbh and 100 GOPS, respectively. The analysis is focused on the medium access control protocol, called TD-TWDMA, for the time and wavelength multiplexed network. It is concluded that the proposed network is very well suited to this kind of signal-processing applications. We also present a new distributed slot-allocation algorithm with real-time properties.

Fiber-optic interconnection networks for signal processing applications

“…Each node transmits on a wavelength unique to the node, while the receiver can listen to an arbitrary wavelength. The configuration is used in the TD-TWDMA network (TimeDeterministic Time and Wavelength Division Multiple Access) [1], which has support for guaranteeing real-time services, both in single-star networks [12] and in star-ofstars networks [13]. One can say that this kind of networks implements a distributed crossbar.…”

“…In Fig. 6, a signal processing chain similar to those described in [17] and [1] is shown together with its bandwidth demands. Each computational module in the figure contains multiple processors itself.…”

“…1, where each box represents a computation node [1]. Each node runs one or several pipeline stages and the arcs only represent the dataflow between modules.…”

Two fiber-ribbon ring networks for parallel and distributed computing systems

“…In 1996, we presented a wavelength division multiplexing ͑WDM͒ star network for highperformance distributed real-time systems and analyzed how it functions in a massively parallel radar signal processing system. 1 Although the WDM star architecture is very attractive and scales well to hundreds of nodes when configured as a star-of-stars network, systems that require only a few tens of nodes can alternatively, and less expensively, be realized using optical fiber-ribbon links. Fiberribbon links offering an aggregate bandwidth of several gigabits per second have already reached the market.…”

Optical interconnection technology in switches, routers and optical cross connects

“…Figure 7 shows an example of a WDM star network configuration. Each node transmits on a wavelength unique to the node, while the receiver can listen to an arbitrary wavelength [37]. One can say that this kind of network architecture implements a distributed crossbar.…”