M/237 -

The present document applies to the Telemetry, Command and Ranging (TCR) system of Communication Satellites
(geosynchronous or not), operating in the following frequency bands:
• 5 725 MHz to 7 025 MHz uplink, 3 400 MHz to 4 200 MHz and 4 500 MHz to 4 800 MHz downlink
("C-band");
• 12 750 MHz to 13 250 MHz, 13 750 MHz to 14 800 MHz and 17 300 MHz to 18 400 MHz uplink,
10 700 MHz to 12 750 MHz and 13 400 MHz to 13 650 MHz downlink ("Ku-band");
• 27 500 MHz to 30 000 MHz uplink, 17 700 MHz to 20 200 MHz downlink ("Commercial Ka-band").
Although not explicitly addressed in the present document, possible usage in other bands allocated to
FSS/MSS/BSS/SOS between 1 GHz to 51,4 GHz may be envisaged.
The TCR receiver and transmitter can have a frequency flexibility capability over a given RF band, Typical frequency
step is 100 kHz.
The present document sets out the minimum performance requirements and technical characteristics of the
ground/satellite Radio Frequency (RF) interface based on Frequency Modulation (FM), Phase Modulation (PM) and
Code Division Multiple Access (CDMA).
With the growing number of satellites, the co-location constraints and the maximization of bandwidth for
Communications Missions, real and potential interference cases have motivated the elaboration of the present document
for geostationary satellites based on CDMA techniques.
The present document addresses the following applications:
• Telemetry.
• Command (Telecommand).
• Ranging.
• Hosted Payload Management.
The aim of the present document is to replace and enhance the prior document ETSI EN 301 926 [i.2] (V1.2.1). The
present document's provisions also apply for use cases of autonomous control of hosted payloads. It is recognized that
hosted payloads may require only a subset of the functionality.
The present document applies to the typical TCR scenario shown on figure 1. The scenario includes multiple satellites,
which may be located in the same orbital location (GSO), or that can be in common view of a given TCR station during
NGSO phases (such as transfer phase to GEO, or during NGSO operations). These satellites may be controlled by m
different TCR ground stations. The TCR links defined in the present document have also to coexist with the
communication ground terminals also shown on figure 1. Some of the satellites to be controlled may use FM/PM
waveforms, and some may use a CDMA waveform, as defined later in the present document.
The scenario may also include, for some of the satellites, hosted payloads, which can be controlled independently of the
satellite platform and of the main payload.
The present document defines the modulation and coding on the TCR and HPM links. Modulation formats are specified
in clause 4 and coding in clause 7.

REN/SES-00401

The present document applies to Geostationary Communications Satellite architectures based on ISO OSI Reference Model or SOIF Reference Model, but could also be applied to other types of satellites. The present document sets out the minimum definition, services and interfaces requirements of the satellite communication application layer. The present document is complementary to Spacecraft Onboard Interfaces (SOIF).

This EN will cover ECSS E-50 level 3 document, in cooperation with ECSS. ETSI TC SES WG on ECSS, with the help of STF 165, will produce the part of the ECSS standards concerning the communications satellites, which are part of the commercial market. ECSS will produce the part of the ECSS standards concerning mainly Space Agencies programmes. Nevertheless, for synergy reasons a common standard can be envisaged when preparing the standard.

DEN/SES-000-ECSS-2

DEN/SES-000-ECSS-1