Demonstration of an in-building optical bus network for wireless access

This paper presents the demonstration of a distributed antenna system (DAS) based on a radio-over-fiber (RoF) bus for wireless local area networks (WLANs). The RoF bus has been designed based on the use of cascaded building blocks to support a large number of access nodes using electronic coupling and in-line amplification inside the access nodes. A dedicated emulation protocol has been defined to test the RoF bus, and experimental results have shown that a coverage distance of about 4.5 m is obtained for bidirectional communications up to 18 access nodes. For large buildings, a star-bus network, based on multiple interconnected RoF buses, is proposed, and significant reduction of in-building deployed fiber length is achieved (89%) compared to a RoF star network infrastructure.