Satellite Glossary: M-R

This glossary provides definitions for common terms used in satellite communications. This article covers terms M through R.

M

MEO (Medium Earth Orbit)

Orbits at altitudes between approximately 8,000-20,000 km. Used for navigation satellites (GPS, Galileo) and some communication systems.

MF-TDMA (Multi-Frequency Time Division Multiple Access)

An access method combining frequency and time division, commonly used in modern VSAT systems.

MIR (Maximum Information Rate)

The maximum bandwidth a user can achieve during low-congestion periods, higher than the CIR.

MODCOD

Modulation and Coding combination. In DVB-S2/S2X, each MODCOD represents a specific pairing of modulation scheme and FEC code rate.

N

NMS (Network Management System)

A system for monitoring, configuring, and managing a satellite network from a central location.

NOC (Network Operations Center)

A centralized facility for monitoring and managing satellite network operations.

O

ODU (Outdoor Unit)

The components of a satellite terminal located outdoors, including the antenna, BUC, and LNB.

P

Pointing Loss

Signal loss due to imperfect alignment of an antenna with the satellite.

Polarization

The orientation of the electric field of an electromagnetic wave. Satellite systems use linear (horizontal/vertical) or circular (LHCP/RHCP) polarization.

Q

QoS (Quality of Service)

The overall performance of a network as experienced by users, including factors like bandwidth, latency, and reliability.

R

Rain Fade

Attenuation of satellite signals caused by rain in the propagation path. More significant at higher frequencies (Ka > Ku > C).

RTT (Round Trip Time)

The total time for a signal to travel from source to destination and back. For GEO satellites, typically 550-650ms.

Glossary A-F - Terms A through F
Glossary G-L - Terms G through L
Glossary S-Z - Terms S through Z