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Modulation Techniques
Published in Stephen Horan, Introduction to PCM Telemetering Systems, 2018
One characteristic of telemetry and telecommand links is that the link planner does not require the same bandwidth on the telecommand and telemetry links. For example, the telecommand link at 450 MHz in Table 10.4 has a relatively narrow bandwidth and, consequently, only a low data rate can be supported. Since commands generally do not require the same data volume as the telemetry return link to support operations, this is not a problem. The telemetry link, usually in another band, would be chosen to support the data bandwidth requirements of that link and not the telecommand link. The one condition where this may affect operations is when TCP/IP-based transmissions are used as discussed in Chapter 4. The unequal data rates do not allow acknowledgments to flow as quickly as equal-rate channels allow so the throughput may drop.
General regulations
Published in G.D. Lees, W.G. Williamson, Handbook for Marine Radio Communication, 2015
(3) The third symbol:N No information transmitted.A Telegraphy – for aural reception (e.g. Morse).B Telegraphy for automatic reception (e.g. telex, DSC, etc.).C Facsimile.D Data transmission, telemetry, telecommand.E Telephony (including sound broadcasting).F Television (video).W Combination of the others.X Cases not otherwise covered.
Mission Concept and Trade-Off Study
Published in Shen-En Qian, Hyperspectral Satellites and System Design, 2020
Telemetry/telecommand and data downlink includes two subsystems: telemetry and telecommand (TTC) and payload data downlink. The TTC subsystem enables ground-based operators to monitor and control the functions and behavior of the satellite throughout telecommand and telemetry. The payload data downlink subsystem transmits the data gathered by the payload through a high rate data downlink channel.
Applications of artificial intelligence in powerline communications in terms of noise detection and reduction: a review
Published in Australian Journal of Electrical and Electronics Engineering, 2018
Olamide M. Shekoni, Ali N. Hasan, Thokozani Shongwe
Power line communication (PLC) is a scheme that is used to transfer data (information) through some existing electrical cables. Its main advantage is the avoidance of the installation of new cables as PLC can be designed using the existing electrical cables to transfer data, but on a different frequency to that of electric power. The process of transferring data over electrical lines was first introduced for the exchange of telecommand and telemetry which involved very low data rate (Hashmat 2012), and presently used for broadband services all over the world. PLC has been in use for over a hundred years. In 1838, remote-metered electricity supply to examine the level of batteries voltages at sites was suggested. In 1897, the testing of electricity meter for a power line signalling was implemented. However, from 1900 to 1970, many developments for reading electricity supply remotely have been introduced following the advancement in electronics (Wang, Xu, and Khanna 2011; Tonello and Pittolo 2015). PLC can be classified into two: The broadband (BB) and narrowband (NB) PLC. Table 1 illustrates the main difference between a narrowband PLC and a broadband PLC system (Tonello and Pittolo 2015).