161. What is the primary advantage of LEO (Low Earth Orbit) satellite constellations like Starlink?
- a) Lower latency (20-50ms) compared to GEO satellites
- b) Higher bandwidth than fiber optics
- c) No need for ground stations
- d) Immunity to weather interference
Answer: A - LEO satellites orbit 500-2000km altitude, reducing signal propagation delay versus GEO (35,786km).
162. Which protocol enables network programmability via REST APIs?
- a) RESTCONF
- b) SNMP
- c) BGP
- d) OSPF
Answer: A - RESTCONF (RFC 8040) provides HTTP-based CRUD operations for network devices using YANG models.
163. What is the purpose of inter-satellite links in LEO constellations?
- a) To create space-based mesh networks
- b) To reduce ground station costs
- c) To amplify signals
- d) Both A and B
Answer: D - Laser links between satellites enable routing in space, minimizing terrestrial infrastructure.
164. Which bio-inspired algorithm optimizes network routing?
- a) Ant Colony Optimization
- b) Genetic Algorithms
- c) Artificial Immune Systems
- d) All of the above
Answer: D - Nature-inspired algorithms mimic ant foraging (ACO), evolution (GA), and pathogen defense (AIS) for routing.
165. What frequency bands do modern LEO satellites typically use for user links?
- a) Ku-band (12-18 GHz) and Ka-band (26.5-40 GHz)
- b) HF band (3-30 MHz)
- c) L-band (1-2 GHz)
- d) Visible light spectrum
Answer: A - High-frequency bands allow greater throughput (Starlink uses Ka/Ku, planning V-band for future).
166. Which API standard is used for SDN northbound interfaces?
- a) OpenAPI (Swagger)
- b) SOAP
- c) CORBA
- d) XML-RPC
Answer: A - OpenAPI provides RESTful SDN controller-to-applications communication with JSON/YAML definitions.
167. How do LEO satellites mitigate Doppler shift effects?
- a) Dynamic frequency adjustment
- b) Error correction codes
- c) Quantum encryption
- d) Blockchain timestamping
Answer: A - Rapid orbital motion causes frequency shifts that are compensated by real-time tuning.
168. What is the purpose of TAPI (Transport API) in optical networks?
- a) Standardized control of multi-vendor DWDM systems
- b) Encrypting fiber links
- c) Prioritizing satellite traffic
- d) Replacing TCP/IP
Answer: A - TAPI (MEF 63) provides abstracted control of optical paths via YANG models and REST APIs.
169. Which satellite constellation uses polar orbits for global coverage?
- a) Iridium
- b) Starlink
- c) OneWeb
- d) GEO stationary satellites
Answer: A - Iridium's 66 satellites orbit pole-to-pole, covering polar regions other constellations miss.
170. What does P4Runtime enable in SDN?
- a) Protocol-independent switch programmability
- b) Optical signal processing
- c) Quantum key distribution
- d) Blockchain-based routing
Answer: A - P4Runtime provides an API for controlling P4-programmable data planes (gRPC interface).
171. What is the primary challenge in handovers between LEO satellites?
- a) Rapid cell switching (every ~4 minutes)
- b) Frequency interference
- c) Encryption key rotation
- d) IP address changes
Answer: A - Satellites move at ~7.8 km/s, requiring sophisticated beam and satellite handoff mechanisms.
172. Which bio-inspired approach detects network intrusions?
- a) Artificial Immune Systems
- b) Ant Colony Optimization
- c) Neural Networks
- d) Genetic Programming
Answer: A - AIS mimics immune system behavior to identify "non-self" (malicious) network patterns.
173. What is the purpose of OpenConfig in network APIs?
- a) Vendor-neutral YANG data models
- b) Encrypted API communications
- c) Satellite-ground station handoffs
- d) Blockchain-based authentication
Answer: A - OpenConfig develops standardized YANG models for multi-vendor network automation.
174. How do LEO constellations avoid signal interference with GEO satellites?
- a) Frequency coordination and inclined orbits
- b) Quantum encryption
- c) Blockchain-based spectrum sharing
- d) AI-powered beamforming
Answer: A - ITU regulates spectrum use, and LEO orbits are designed to minimize GEO interference zones.
175. Which API type would you use to query real-time network telemetry?
- a) gNMI (gRPC Network Management Interface)
- b) SOAP
- c) XML-RPC
- d) CORBA
Answer: A - gNMI supports high-frequency telemetry streaming via gRPC and protocol buffers.
176. What is the primary advantage of genetic algorithms in network optimization?
- a) Finding near-optimal solutions in complex search spaces
- b) Lowest computational overhead
- c) Real-time processing
- d) Immunity to local minima
Answer: A - GAs evolve solutions through selection, crossover, and mutation operations.
177. Which technology enables beamforming in LEO user terminals?
- a) Phased array antennas
- b) Quantum repeaters
- c) Optical amplifiers
- d) Blockchain routing tables
Answer: A - Electronically steered phased arrays track fast-moving satellites without mechanical parts.
178. What does NETCONF use for configuration data encoding?
- a) XML
- b) JSON
- c) Protocol Buffers
- d) YAML
Answer: A - NETCONF (RFC 6241) uses XML over SSH for network device configuration.
179. Which satellite system provides backup for GPS navigation?
- a) Iridium Certus
- b) Starlink
- c) OneWeb
- d) GEO TV satellites
Answer: A - Iridium's LEO constellation offers alternative PNT (Positioning, Navigation, Timing) services.
180. What is the purpose of YANG in network automation?
- a) Data modeling for configuration and telemetry
- b) Encrypting API communications
- c) Compressing network traffic
- d) Prioritizing satellite handovers
Answer: A - YANG (RFC 7950) defines hierarchical models used by NETCONF/RESTCONF/gNMI.