Lightwave networks can be constructed by exploiting the capabilities of emerging optical technology. One of these technologies is the WDM cross-connect star coupler. This device hased on integrating a two-dimensional array of Bragg diffraction cells, can be used in various wavelength routing network application to overcome the major problems related to the conventional star coupler. In this paper we propose a new logical topology, the hilayered ShuffleNet, which is shown to achieve higher efGciency compared to the conventional ShuffleNet'. We also present a method of using the WDM cross-connect star coupler in the implementation of the bilayered ShuffleNet
.O IntroductionOptical fiber has become the preferred transmission medium tor telecommunication. The single mode fiber which has superior transmission quality because of absence of modal noise [ 11 and low loss, offers an enormous bandwidth; thousands of Ghz are availahle. Various access techniques such as wavelength, tinie, space, and code division multiplexing have been proposed to tap this enormous bandwidth [ 21. Using the available technology, multichannel-multihop lightwave networks are specially designed to achieve efficient use of the channel bandwidth. As an example of multihop lightwave networks we can find the ShuffleNet and the Manhattan Street Network. In this paper we present a new logical configuration that will improve the performance of the multihop lightwave networks.When multihop networks are implemented using basic topologies, such as the bus, the star, and the tree or compound configuration such us the tree-star-tree configuration using optical amplifiers [9], they introduce two major problems. First, the number of different wavelengths needed in the network is very large. Second, the network size is limited by inherent power 1. The support of the Canadian Institute for Telecommunications Research (CITR) is gratefully acknowledged. splitting of the required passive couplers used to interconnect the various nodes.To overcome this problem wavelength division multiplexing cross-connect plays an important role in wavelength routing in multihop networks. One way to implement such wavelength routing devices is to use the WDM cross-connect star that is hased on Rragg diffraction grating.
Bilayered ShuffleNetThe hilayered ShuffleNet connectivity graphs use the same connectivity graph as the conventional ShuffleNet. For a (P, k ) bilayered ShuffleNet, the number of stations is equal to N = k f k arranged in k columns of Pk stations each. Instead of only connecting each station in the network to P different stations in the next column, now we let each station to be connected to a "mirror" image of stations from the previous column; thereby, doubling the connectivity between stations. In this case the connectivity graph of the ShuffleNet will look as though all stations are wrapped around the same cylinder twice, tine from left to right and one from right to left (see Figure 1). The same set of connections is used in both directions. This will increas...
