Module 03: Starlink Ground Network, Gateways, POPs, and Internet Peering

Phase: 1 - Foundation Builds on: Modules 01 and 02

Math You’ll Learn

Trigonometry: Law of Cosines, Elevation Angles, Slant Range, and Latency Geometry

This is where trig becomes operational: which gateways can see which satellites, what delay a path adds, and when a gateway/POP choice is better or worse.

• Law of sines and cosines - compute slant range from Earth radius, satellite altitude, and elevation angle.
  • Starlink application: determine whether a satellite can use a candidate gateway at a given time.
• Inverse trig - compute elevation and azimuth from geometry.
  • Starlink application: gateway visibility and antenna pointing.
• Radians, angular velocity, and arc length - understand how fast geometry changes.
  • Starlink application: estimate pass duration and gateway handover timing.
• Latency decomposition - add terminal-to-satellite, satellite-to-gateway, gateway-to-POP, and POP-to-destination components.

After this: You can model gateway visibility, POP egress latency, and the terrestrial networking side of Starlink service.

Resources:

• Khan Academy - Trigonometry
• Public Starlink gateway/POP research and FCC gateway filings
• Internet routing references for BGP, peering, and transit

What You’ll Learn

The ground segment is where Starlink becomes the internet. This module focuses on gateways, POPs, optical transport, subscriber services, and routing protocols rather than generic ground-station-as-a-service models.

Gateway and POP Architecture

• Gateway earth stations vs user terminals vs POPs.
• Satellite feeder links, gateway antennas, RF/baseband, and terrestrial handoff.
• Colocation facilities, long-haul fiber, WDM/DWDM, circuit turn-up, and capacity planning.
• POP egress, IXPs, private peering, transit, and regional latency.
• Gateway diversity for weather, capacity, and failure resilience.

Service-Provider Networking

• BGP peering and transit policy.
• Internal routing: IS-IS/OSPF, MPLS, Segment Routing, ECMP.
• IPv4/IPv6 addressing, CGNAT, IPv6 prefix delegation.
• DNS, DHCP, NTP, RADIUS/AAA, QoS, and subscriber management.
• Route selection when satellite, gateway, POP, and terrestrial paths all matter.

Operations

• Inventory and configuration management.
• Telemetry, alerting, link utilization, latency, packet loss, and route churn.
• Maintenance windows, safe rollout, rollback, and incident response.
• Where software engineering and gRPC/API design fit into network operations.

C++ and Python Skills

C++ focus: OOP, STL containers (vector, map, unordered_map), algorithms, lambdas, clean data modeling.

Python focus: Skyfield for satellite propagation, NetworkX for path models, matplotlib/Plotly for maps.

Projects

Project 1: Gateway Visibility and POP Path Calculator (C++)

Build a gateway/POP path model for Starlink-like service.

What you’ll build:

• Define Gateway, Pop, Satellite, and UserTerminal classes.
• Compute whether a gateway can see a satellite above an elevation mask.
• Estimate terminal-satellite-gateway delay and gateway-POP terrestrial delay.
• Rank candidate gateway/POP egress choices by latency and availability.
• Output route candidates as JSON for later visualization.

C++ skills used: classes, STL containers, algorithms, JSON serialization.

Toolkit: Add GatewayPopModel.

Project 2: Gateway/POP Route Planner (Python)

Visualize ground-network choices.

What you’ll build:

• Place a set of gateways, POPs, and user locations on a map.
• Load TLEs or simplified shell positions.
• Compute gateway visibility windows over 24 hours.
• Select the lowest-latency egress for several user/destination pairs.
• Plot route choices and show how weather or gateway failure changes egress.

Python skills used: Skyfield, NetworkX, matplotlib/Plotly, tabular output.

Technology Reference

Where This Tech Is Used

Books and Resources