LoRa ECLA Overlay Network

CLI

LoRa ECLA 0.1.0
Daniel Schmidt <info@daniel-schmidt.de>
Configurable LoRa ECLA for dtn7-rs using Protocol Buffer overlay network.
USAGE:
    loclad [OPTIONS]

OPTIONS:
        --airtime_band_width <airtime_band_width>
        --airtime_coding_rate <airtime_scoding_rate>
        --airtime_crc <airtime_crc>
        --airtime_explicit_header <airtime_explicit_header>
        --airtime_low_data <airtime_explicit_header>
        --airtime_preamble_len <airtime_preamble_len>
        --airtime_spreading_factor <airtime_spreading_factor>
    -c, --config <config>                     Specify config file
        --create_config                       Writes default config to --config path
    -d, --debug                               Set log level to debug
        --dtnd <dtnd>
        --dtnd_args <dtnd_args>
        --ecla_addr <ecla_addr>
        --ecla_module <ecla_module>
    -h, --help                                Print help information
        --lora_agent <lora_agent>
        --lora_arg <lora_arg>
        --strategy_config <strategy_config>
        --strategy_name <strategy_name>
    -V, --version                             Print version information
        --webport <webport>

Example Config File

With the --config,-c argument a json encoded config file can be used. All arguments can be overwritten via the CLI args. Priority is Default Value < Config File < CLI Argument.

{
  // LoRa Config
  "lora": {
    "agent_type": "websocket",
    "agent_arg": "127.0.0.1:8291:node1"
  },
  
  // ECLA Config
  "ecla": {
    "addr": "127.0.0.1:3000",
    "module_name": "LoRa"
  },
  
  // DTND config
  "dtnd_executable": "/some_folder/dtnd",
  "dtnd": {
    "args": "-w 3000 -r flooding -e incoming -n node1 --ecla -d -i 7s"
  },
  
  // Strategy config
  "strategy": {
    "name": "quadrant",
    "config": {
      "SEND_INTERVAL": "22s"
    }
  },

  // Airtime parameters for airtime approximation
  "airtime": {
    "preamble_len": 6.0,
    "spreading_factor": 7.0,
    "band_width": 125.0,
    "coding_rate": 5.0,
    "crc": true,
    "explicit_header": true,
    "low_data_rate_optimization": false
  },

  // REST API webport (0 = disabled)
  "web_port": 7262
}

Architecture

The system is split into different sub-systems called actors that all communicate via a central message / event bus. Each actor has different responsibilities. This makes it easy to re-configure and re-start parts of the system without interfering in others and keeping it easy to maintain as the actors are small and decoupled.

LoRa Actor

• Starts, stops and re-starts the connection to a LoRa interface (e.g. via Serial or Websocket)
• Parses raw LoRa packets into Protocol Buffer messages and passes these to the central message bus
• Handles PingPong messages and sends response
• Passes incoming LoRa packets from the central message bus to LoRa
• Passes current GPS location to global watch

DTND Actor

• Handles the spawning, stopping and re-starting of the dtnd process so that the ECLA can connect to it

ECLA Actor

• Starts, stops and re-starts the connection to a ECLA interface
• Passes ECLA messages to the central message bus
• Sends incoming ECLA messages from the central message bus to the ECLA
• Passes dtnd node id to global watch

Strategy Actor

• Starts, stops and re-starts the strategy behaviour (e.g. quadrant, random, ...)

Supervisor Actor

• Handles the start of the full system at process start
• Handles the correct re-start order if a configuration was changed

Routing Strategies

random

Naive baseline routing strategy that sends out bundles with a random priority.

Settings

• SEND_INTERVAL: The interval in which the strategy tries to send. (example values: 5s, 50s, 1m, 30m)
• ADVERTISE_INTERVAL: The interval in which the strategy tries to advertise the node. (example values: 5s, 50s, 1m, 30m)
• SEND_PACKETS: The number of packets to send when the SEND_INTERVAL is reached. (example values: 2, 5, 1)
• MIN_SCORE: The minimum score for randomization. (example values: 0, 10, 100)
• MAX_SCORE: The maximum score for randomization. Should be greater than MIN_SCORE. (example values: 100, 200, 1000)
• MAX_PEER_AGE: The maximum age in seconds to treat a node as present in the neighborhood. (example values: 10, 60, 600)

quadrant

Location-Aware routing strategy adopted from:

L. Baumgärtner, P. Lieser, J. Zobel, B. Bloessl, R. Steinmetz and M. Mezini,
"LoRAgent: A DTN-based Location-aware Communication System using LoRa,"
2020 IEEE Global Humanitarian Technology Conference (GHTC), Seattle, WA, USA, 2020, pp. 1-8, doi: 10.1109/GHTC46280.2020.9342886.

Settings

• SEND_INTERVAL: The interval in which the strategy tries to send. (example values: 5s, 50s, 1m, 30m)
• SPREAD_INTERVAL: The interval in which the strategy checks for packets that should be spread again. (example values: 5s, 50s, 1m, 30m)
• ADVERTISE_INTERVAL: The interval in which the strategy tries to advertise the node. (example values: 5s, 50s, 1m, 30m)
• SEND_PACKETS: The number of packets to send when the SEND_INTERVAL is reached. (example values: 2, 5, 10)
• SPREAD_PRIORITY: The priority value that gets added for the spread. (example values: 5, 10, 0)
• SELF_FORWARD_PRIORITY: The base priority of a packet that is received from the local DTND instance. (example values: 5, 10, 0)
• ADVERTISE_PRIORITY: The base priority of the advertise packet. (example values: 5, 10, 0)

Airtime Calculation

Airtime calculation is build in. If you setup the airtime parameters with identical values to your LoRa modem airtime information will be logged and can be used by routing strategies. To play around with the impact of the parameters see: LoRa Airtime Caluclator.

REST API

There is a simple REST API present. It runs under the cli arg --webport <webport>.

• GET /close/:target: Shuts the :target actor down
• GET /config/:type: Returns the config of ecla, dtnd, strategy, lora