E-Plus, Germany 's third-largest mobile communications provider, has chosen the Optimux-34 multiservice PDH fiber multiplexer from RAD Data Communications to guarantee no-gaps indoor network coverage in public buildings. Known for its excellent indoor network coverage, the E‑Plus Group is the only mobile communication provider that supports mobile phone use in Hamburg 's subway stations. Because walls and reinforced concrete get in the way, mobile communications only works properly indoors if a special infrastructure is set up within the buildings in which coverage is required. "Microcells" are installed at busy facilities such as trade show halls, airport terminals and sports stadiums. Each discrete section of a building - a floor of a shopping mall, for example - requires one or more dedicated mobile communication antennas. To hook these indoor antennas up to the network, the E‑Plus Group rents existing optical cables from the building operator. The problem is that mobile communications equipment usually has digital E1 interfaces instead of optical interfaces. This is precisely where RAD's multiservice Optimux-34 PDH optical multiplexer comes in. The Optimux-34 converts E1 circuits into optical signals and fans an E3 out onto E1 lines. Installed equipment can now pick up the E3 coax cable from the radio relay system on the roof and carry mobile traffic into the building over fiber optic infrastructure. Inside the building, a chain of Optimux multiplexers forms a cascaded optical access network and lets the E1 coax interfaces "talk" to the mobile antennas.
www.rad.com