ETSI - ETS 300 721
Satellite Earth Stations and Systems (SES); MES Providing Low Bit Rate Data Communications (LBRDC) Using LEO Satellites Operating Below 1 GHz
|Publication Date:||1 June 1997|
This European Telecommunication Standard (ETS) provides specifications for the standardization of the characteristics of Mobile Earth Stations (MESs) with both transmit and receive capabilities in order to limit interference to radiocommunications services.
The Low Earth Orbiting (LEO) satellite networks referred to in this ETS operate under the Mobile Satellite Service (MSS). The MESs operate as part of a LEO satellite network providing Low Bit Rate Data Communications (LBRDC).
The frequency bands under which the MESs operate should be within the following bands:
Some LEO satellite networks provide Low Bit Rate Data Communications (LBRDC) using short burst, low duty cycle MES transmissions in order to reduce interference with existing users. The interference levels can also be decreased by modulation techniques: Direct Sequence - Spread Spectrum Multiple Access (DS-SSMA) or Frequency Division Multiple Access (FDMA) using Dynamic Channel Activity Assignment (DCAA) as described in ITU-R Recommendations M 1039 and M 1087.
These MESs generally have the following characteristics:
- the MESs could be either a Based MES (BMES), a Vehicle mounted MES (VMES) or a Portable MES (PMES);
- the MES could consist of a number of modules including suitable interfaces to the user.
The main specifications are contained in two categories related to:
- unwanted emissions limitation: to protect terrestrial and space radiocommunications services, and the radio astronomy services from harmful interference;
- MES control and monitoring functions: to specify a minimum set of Control and Monitoring Functions (CMFs) to be implemented on each MES in order to minimize the probability that they originate unwanted transmissions that may give rise to harmful interference to other systems.