The public address system is a mean of delivering voice information over large areas. Depending on the information and the area to cover the PA specification may require a means to transport the signal large distances. A long-line public address (LLPA) system is any public address system with a distributed architecture, normally across a wide geographic area. Systems of this type are commonly found in the rail, light rail and metro industries and allow announcements to be triggered from one or several locations to the rest of the network. Traditionally LLPA systems use low bandwidth legacy copper, normally PSTN lines using DSL modems, or media such as optical fiber, or IP-based networks. Inter-M has developed solutions to transmit High quality uncompressed multi-channel audio and control over Optical fiber cables. High quality digital voice and BGM signal can be transported over long distances using Inter-M’s FTA/FRA-108S products. FTA/FRA-108S will transport high quality 8-channel audio signals, serial data and contact closure triggers over long distances (up to 15km) using Single-mode fiber-optic cable. These products will transport high quality uncompressed audio signals combined with data and contact triggers with very short and relatively small propagation delay of 1.0 ms. As the requirements of public address systems changes the R&D engineering team of Inter-M is ready to deliver new innovative products to meet market and systems demands.