Table of Contents:

• ONE Settings files
  • Configuring Process Engines and Processes
  • Other notes

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ONE Settings files

ONE simulations can use 2 configuration files:

1. Default settings, called “default_settings.txt”, this is shared across different simulation scenarios

2. A settings file passed to the ONE simulator program as an argument when running a specific simulation. This settings file can override some settings set in the default_settings.txt or introduce new ones.

   1. e.g. for tutorial 1, we have a settings.txt in the tutorial1_basic_messaging folder.

   The original guidelines for configuring ONE can be found here. In this guide, we take a look at the default_settings.txt used for STEP-ONE tutorials that is shared between all of them. The file specifies various aspects of the simulation:

• The name, duration of the simulation

  ## Scenario settings
  Scenario.name = Tutorial
  Scenario.simulateConnections = true
  Scenario.updateInterval = 1.0
  Scenario.endTime = 3600
    
  Scenario.nrofHostGroups = 2
  

  • Here the simulation should run for 3600 seconds with a timestep of 1s

  • There are 2 groups of hosts. Host groups allow to specify different behaviour and attributes for hosts, e.g. their movement behaviour, the applications & processes they support, their networking capabilities.

• Creating of communication/networking interfaces

  # "Bluetooth" interface for all nodes
  btInterface.type = SimpleBroadcastInterface
  btInterface.transmitSpeed = 250k
  btInterface.transmitRange = 12
    
  # assign network interface to all groups
  Group.nrofInterfaces = 1
  Group.interface1 = btInterface
  

  • In this example, an interface of type “SimpleBroadcastInterface” is created and named btInterface. It is configured to have a range of 12 meters and a fixed transmitspeed of 250kBps.

  • Each host group has exaxctly 1 network interface, btInterface

• Configuration of message routing

  ## Message Router
  Group.router = DirectDeliveryRouter
  Group.bufferSize = 5M
  deleteDelivered = true;
  Group.msgTtl = 99999
  

  • Set up how messages are routed over network interfaces. DirectDeliveryRouter will send a message if a host has a direct connection to the message’s destination. Messages are configured to have a long time-to-live (TTL) time and all host groups are set to have a message buffer of 5Mbytes.

    • Note: ONE includes different routing schemes for opportunistic networks where a direct connection is not needed.

• Host groups are declared. Host groups are an important ONE simulator concept that allow assigning hosts to groups and defining separate behaviour for each group. For example, you could:

  • create a group for servers and another group for clients and specify that servers should not move, while clients should move
  • specify that all host groups should have a process engine, but each host group should have a different set of processes running on their engine

  Group.nrofHosts = 1
  Group1.groupID = A
  Group2.groupID = B
    
  # Assign same movement model to all node groups, but
  # specify different coordinates for Group1, Group2
  Group.movementModel = StationaryMovement
    
  Group1.nodeLocation = 200,200
  Group2.nodeLocation = 200,210
    
  

  • Here, each host group is set to have 1 host, the groups are named A and B. All groups will have StationaryMovement mobility model, which means the hosts are not moving. The groups are assigned different locations on the map via coordinates.

Configuring Process Engines and Processes

ONE hosts can run applications - applications can receive and produce messages. STEP-ONE provides a special kind of application: a process engine.

To use STEP-ONE process management, a host (group) needs to embed the application bpm.BpmEngineApplication

In the below example, there are 2 different configurations for the BpmEngineApplication:

# Declare 2 applications, called processEngineApp1 and processEngineApp2,
# both of type bpm.BpmEngineApplication. They will be configured to run different processes on A and B
processEngineAppA.type = bpm.BpmEngineApplication
processEngineAppB.type = bpm.BpmEngineApplication

# For all host groups, say that they embed exactly 1 application
Group.nrofApplications = 1

# Now specify separately for host group which process engine variant they should embed
Group1.application1 = processEngineAppA
Group2.application1 = processEngineAppB

# Configure the engine variants:

# Set some process definitions to be auto-deployed to the engines once the simulation starts
processEngineAppA.autoDeployedProcesses = samples/tutorial1_basic_messaging/Tutorial_1_Basic_Messaging_B.bpmn20

# Set a process to be auto-started
processEngineApp1.autoStartedProcessKeys = tutorial1_a

Other notes

A very useful feature of ONE settings is the run indexing feature .

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Tutorial 1: Basics of Messaging »

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