Free preview · Slant range, delay, Doppler and moving cells: what "high and fast" actually costs — opens in the course player
NTN & Direct-to-Device: 5G from Orbit
The satellite link taught as arithmetic, not architecture — slant range and delay you can compute, a link budget that closes in both directions, the pre-compensation a handset owes before it may transmit, and the mobility a moving cell forces on a network built for stationary ones.
What you'll learn
- Turn the two properties of an orbiting cell — high and fast — into quantities: the three frames NTN stretches, the two lanes a claim can sit in, and slant range computed from an elevation angle.
- Decide what an orbit buys and charges, where the gNB sits in a transparent or regenerative payload, and read a link budget in both directions until it tells you what service class you may promise.
- Work out what a UE must hold before it may transmit, what it pre-compensates for itself, what breaks when every feedback loop is a round trip long, and how coverage is bought without feedback.
- Hold the cell taxonomy exactly, name every switch a moving constellation forces, and account for what moving cells do to mobility, identity and signalling load — including the trip back to the ground.
- Separate the spectrum routes to orbit, decide who does the compensation work, size what one beam can honestly carry, and read the release train that says which capability is actually specified.
Module 1 — From 'high and fast' to a number you can compute
4 lessons · ≈29 minTurn the two properties of an orbiting cell — high and fast — into quantities: the three frames NTN stretches, the two lanes a claim can sit in, and slant range computed from an elevation angle.
Module 1 — From 'high and fast' to a number you can compute
4 lessons · ≈29 minTurn the two properties of an orbiting cell — high and fast — into quantities: the three frames NTN stretches, the two lanes a claim can sit in, and slant range computed from an elevation angle.
- 17:06Slant range, delay, Doppler and moving cells: what "high and fast" actually costsWatch free
- 27:30The standards lane and the product lane: one ladder, two railsFree with an account
- 37:00Timing advance, HARQ and Doppler: the three frames this course stretchesFree with an account
- 47:03Slant range from elevation angle: the first number you can computeFree with an account
Module 2 — Geometry, payloads and the budget that decides the service
5 lessons · ≈40 minDecide what an orbit buys and charges, where the gNB sits in a transparent or regenerative payload, and read a link budget in both directions until it tells you what service class you may promise.
Module 2 — Geometry, payloads and the budget that decides the service
5 lessons · ≈40 minDecide what an orbit buys and charges, where the gNB sits in a transparent or regenerative payload, and read a link budget in both directions until it tells you what service class you may promise.
Module 3 — Making the radio work at 600 km
6 lessons · ≈51 minWork out what a UE must hold before it may transmit, what it pre-compensates for itself, what breaks when every feedback loop is a round trip long, and how coverage is bought without feedback.
Module 3 — Making the radio work at 600 km
6 lessons · ≈51 minWork out what a UE must hold before it may transmit, what it pre-compensates for itself, what breaks when every feedback loop is a round trip long, and how coverage is bought without feedback.
- 18:14It can hear. It still may not speak.Requires subscription
- 28:54A phone that never moves, on the wrong frequencyRequires subscription
- 38:34The loop that used to do all the workRequires subscription
- 48:30You did everything right, and nothing came backRequires subscription
- 58:42"Turn it off" is a fifth of the truthRequires subscription
- 68:14Say the same thing again, and then againRequires subscription
Module 4 — Cells that move, and the network that follows them
6 lessons · ≈48 minHold the cell taxonomy exactly, name every switch a moving constellation forces, and account for what moving cells do to mobility, identity and signalling load — including the trip back to the ground.
Module 4 — Cells that move, and the network that follows them
6 lessons · ≈48 minHold the cell taxonomy exactly, name every switch a moving constellation forces, and account for what moving cells do to mobility, identity and signalling load — including the trip back to the ground.
- 17:50Cells That Move: Earth-fixed, quasi-earth-fixed and earth-movingRequires subscription
- 28:17Three Things Called A Switch: Service link, feeder link, satelliteRequires subscription
- 38:21Distance And A Clock: The NTN trigger eventsRequires subscription
- 48:31Coming Home: Not the outbound journey, reversedRequires subscription
- 57:40Which Country Are You In: Mapped Cell ID, core selection and verificationRequires subscription
- 67:11The Base Station Goes Up: The regenerative payloadRequires subscription
Module 5 — What is flying, what is specified, and what to track
6 lessons · ≈52 minSeparate the spectrum routes to orbit, decide who does the compensation work, size what one beam can honestly carry, and read the release train that says which capability is actually specified.
Module 5 — What is flying, what is specified, and what to track
6 lessons · ≈52 minSeparate the spectrum routes to orbit, decide who does the compensation work, size what one beam can honestly carry, and read the release train that says which capability is actually specified.
- 18:10Two Routes To Orbit: MSS allocations and leased terrestrial spectrumRequires subscription
- 28:44Who Does The Work: UE pre-compensation and payload compensationRequires subscription
- 38:57What One Footprint Carries: Per-beam capacity, honestlyRequires subscription
- 48:39The Business Already Shipping: Machine-type radios over satelliteRequires subscription
- 59:06What An Operator Signs: Network selection, roaming and emergency routingRequires subscription
- 68:46Reading The Release Train: Which release owns which capabilityRequires subscription
New to the terminology? Look up any acronym in the telecom glossary.
Take the certification exam
Earns a certificate35 questions · 60 min · 65% to pass. Score 65%+ to earn your TELCOMA Certified NTN Specialist — a QR-verifiable certificate.
Not ready yet? Take a free 20-question mock exam first.
Unlock every lesson in NTN & Direct-to-Device: 5G from Orbit
Stream all 27 lessons, follow the 5-module path, and earn the TELCOMA NTN Specialist certificate.
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