13. Internal Communications
The following requirements were identified for the internal communications systems aboard DL4.
1. Fast and effective communications between buildings aboard the station.
2. Full compatibility with the external communications systems.
3. Communications between automated machines and computers.
4. Perhaps the most important of all the communication systemís functions, is the ability to inform residents of caution and warning messages quickly and easily.
Intra-personnel communications can be divided into two broad categories:
∑ Voice/Audio communications
∑ Video/Text communications
13.1††††† Audio (Voice) Communications (Internal Audio Communications - IAC)
Audio communications on board DaedalusaL4 are managed in much the same way as a terrestrial telephone network. The main components of the system are the audio bus couplers, the audio control centre and the personal communications interface units themselves.
All communications on board the station are managed by the audio control centre, which is in effect a switchboard. This system manages the communications system by automatically routing calls to their destination and also instigates caution and warning messages when required. The audio bus couplers provide the coupling to the different lines of digital fibre optic cabling that runs throughout the station. The bus network is the medium for the transport of internal audio signals aboard the station.
The Personal Communications Interface (PCI) Units are in plain English the telephone units that will be used by the residents. PCI units can be used for one to one conversations, conference calls etc. and they will also automatically announce any caution and warning messages. The units themselves can be activated by touch or verbal command. The units also act as video phones and a 6 inch video display is built into the unit. Each residential dwelling will be equipped with at least one PCI unit and they will also be available in public areas. The PCI units will be linked to the external communications system, to allow for personal extra-station communications. Mobile communications devices will also be available for the use of the residents at their discretion.
The final elements of the audio communications network are the external audio interface units, which provide a hard-line connection with any vehicles docked at the station. This allows direct voice communication and if necessary the transmission of caution and warning messages between the station and the docked vehicle without having to resort to the external communications infrastructure.
13.2††††† Video Communications (IVC)
The video communications system on board the station can be used to send and receive video footage but its most common usage will certainly be connected with the use of video phones and video conferencing applications. In the case of these applications, the systems aboard DaedalusaL4 route audio and visual signals separately.† Therefore, while the video images will be carried by this system, all audio signals must go through the IAC system outlined earlier. The video communications system has several main components.
Video interface units are simply the interfaces between the fibre-optic video line and a component. The video interface units also supply power to the component so that only one connection is required. The PCI units are connected to the video system via these units.
Video control units generate a station sync signal for the video communications system, and generate test patterns, while the video switch units route video signals and distribute sync signals throughout the station.
Video conferencing can be done through the use of PCI units, computers or dedicated video display devices. It is worth noting that all residents on DL4 will have access to the latest computer facilities. These systems could, of course, be used for internal communications applications.