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Simulation of In-flight Entertainment System Network Using NetSim

 

Objective

The in-flight experience team of an aerospace major wanted to simulate the in flight entertainment system network and analyze for bottlenecks

Network Model - In flight entertainment Network

The customer was testing their new system for an aircraft having a total of 48 display tablets.

  • There are 3 video servers connected to an Ethernet LAN switch
  • This LAN switch connects to 6 access switches
  • Each access switch connected to 8 passenger display tablets and thus a total of 48 display tablets
  • All links have 1 Gbps links throughput
  • Video load would be split equally between all three servers

Based on the performance of this system, they expected to scale it upto 1000 display tables in their subsequent versions of the system

Traffic load

  • Worst case scenario based on a MPEG model (used for movies)
    • Modeled for simultaneous video usage by all passengers
  • Simultaneous audio via an audio codec model

Performance Analysis

A set of simulation runs covering a wide range of input parameters were run to study the system performance. Some of the observations discovered after an in-depth analysis of the simulation results were -

  • With the low bit rates available and with RF propagation losses too many Air Picture packets
  • Time slots were not immediately available for the GS given the round robin slot allocation

Some of the recommendations to the customer were

  • Reduce the Recognized Air Picture (RAP) packet size
  • Move from a round robin to demand based slot allocation
  • Layer 3 routing could be added in the future for communication between nets

Traffic flow in the network

 

Server 1 to display units 11-26 through Access Switches E and F
Server 2 to display units 27-42 through Access Switches G and H
Server 3 to display units 43-58 through Access Switches I and J
48 voice and 48 video applications
Each server handles 16 + 16 = 32 applications