This paper proposes an innovative application of passive optical networks with optimized bus topology for local backbone data networks. Passive optical networks represent a promising solution for modern access networks to meet the increasing demands on transmission rate for demanding multimedia services. As these networks rely exclusively on passive components implemented in their entire infrastructure, it is necessary to consider their certain specific features and optimize properly necessary parameters, especially an attenuation balance. Considering the possibility of such optimization, the passive optical network with optimized bus topology provides several interesting opportunities for specific applications. Its potential application is, for example, a high‐speed local backbone infrastructure connecting local data switches and routers. For that purpose, the passive optical splitter with adjustable power splitting ratio at its outputs can be used for the optimization process of attenuation balance. This paper presents a mathematical apparatus for calculating the maximum number of splits and the number of bridge taps in the passive optical network with the bus topology and an example of obtained results. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2351–2355, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26291