关键词: 波分复用（WDM）网络, 有向双环网络, 网络负荷, L-型瓦, 最短路径, 无限族

Abstract: Based on analyzing the structure feature of WDM networks, this paper chooses some representative directed double-loop networks to study. It also provides the solutions of some congruence equations to compute the parameter values of L-shaped tile. According to the structure of L-shaped tile, it provides a formula to compute its network load. The experiment results demonstrate that there may be many load-balanced networks. For anyone of infinite families for [G(N;r,s)], the distribution of loads is axis symmetric figure, and there is a upper bound and a lower bound for loads. The network is called optimal load network when its load equals the lower bound. These results are important to design optimal double networks and improve transmission efficiency about networks.

Key words: Wavelength Division Multiplexing（WDM） networks, directed double-loop networks, network load, L-shaped tile, shortest path, infinite family