Network Simulation

This readme provides an overview of the code and log files related to a network simulation.

Code Overview

BaseNode Class

The BaseNode class, defined in the provided code (BaseNode.groovy), represents a node in a network simulation using the UNet framework. It includes functionalities for neighbor discovery, TDMA broadcasting.

Functionality Highlights:

• Neighbor Discovery: The BaseNode periodically broadcasts initialization datagrams to nearby nodes for neighbor discovery.

• TDMA Broadcasting: After discovering neighbors, the BaseNode broadcasts TDMA time slots to coordinate communication.

Parameters:

The BaseNode class defines the following parameters:

• tdmaSlotLength: Length of TDMA time slots.
• csmaSlotLength: Length of CSMA time slots.
• delayLength: Delay length between actions.
• neighbours: List of neighboring nodes.

Communication Protocols:

The class defines the following communication protocols:

• INIT: Initialization protocol.
• ACK: Acknowledgment protocol.
• TDMA_INIT: TDMA initialization protocol.
• TDMA: TDMA data transmission protocol.
• CSMA: CSMA data transmission protocol.

Message Processing:

The class includes a method for processing incoming messages, handling acknowledgments, TDMA data, and CSMA data.

DataNode Class

Similarly, the DataNode class, defined in the provided code (DataNode.groovy), represents a data node in the network simulation. It includes functionalities for processing messages, handling initialization requests, and managing TDMA and CSMA transmissions.

Functionality Highlights:

• Initialization Handling: The DataNode processes initialization requests from neighboring nodes, acknowledging requests and exchanging protocol parameters.

• TDMA Transmission: Upon receiving TDMA initialization, the DataNode starts transmitting data in assigned TDMA slots.

• CSMA Transmission: The DataNode initiates CSMA transmission after completing TDMA transmission, managing collisions and backoff periods.

Parameters:

The DataNode class defines parameters such as tdmaSlot, csmaSlotLength, tdmaSlotLength, and delayLength.

Communication Protocols:

Similar to BaseNode, the DataNode class defines communication protocols such as INIT, ACK, TDMA_INIT, TDMA, and CSMA.

Message Processing:

The class includes a method for processing incoming messages, handling initialization requests, TDMA initialization, and CSMA transmission.

Log File Overview

The provided log file (one_cycle.log) captures interactions between different nodes in the network simulation. It includes details such as timestamps, node interactions, network operations, node acknowledgments, and more during one cycle of the protocol. It also contains hand calculation for end to end delay and package delivery ratio for that one cycle.

Click here to view the log file.

The entire log file is also provided as (log.txt).

Pseudo-Algorithm

BaseNode startup()

• Initiates neighbor discovery process.
• Sends out a broadcast with data packets representing:
  • delayLength
  • tdmaSlotLength
  • csmaSlotLength
• Waits for responses from other nodes.
• Processes responses from data nodes:
  • If channel is busy, data nodes initiate a random backoff before responding.
  • Data nodes send back their addresses.
• Once all nodes are acknowledged, the base node orders their addresses in ascending order.
• Broadcasts the ordered list of addresses to assign TDMA time slots.
• Waits for responses from data nodes.
• Initiates transmission of location data in their assigned TDMA time slots.
• Once transmission is over, initiates data transmission using CSMA if there is data to be sent back.
• After TDMA slot broadcast is sent out, the base node waits for incoming messages until it is time again for neighbor broadcast.

DataNode startup()

• Receives initialization broadcast from the base node.
• Decodes initialization data packets to extract parameters such as:
  • delayLength
  • tdmaSlotLength
  • csmaSlotLength
• Responds to the base node with its address.
• If channel is busy, initiates a random backoff before responding.
• Waits for acknowledgment from the base node.
• Upon acknowledgment, awaits further instructions.
• Receives the ordered list of addresses from the base node to assign TDMA time slots.
• Waits for TDMA slot transmission from the base node.
• Initiates transmission of location data in its assigned TDMA time slot.
• Waits for data transmission instructions from the base node.
• If data needs to be sent back, initiates transmission using CSMA.
• Waits for further instructions after completing transmissions.

Function Description

BaseNode startup()

• Subscribe for DATAGRAM service to listen for incoming messages.
• Initialize phy agent for physical layer communication.
• If phy is null, attempt to initialize phy again.
• Subscribe to the topic for phy agent to receive messages from the physical layer.
• Add WakerBehavior to trigger periodic neighborBroadcast() for neighbor discovery.
• tdmaBroadcast() is triggered after the nodes are acknowledged.

DataNode startup()

• Initialize a random number generator (rnd) for randomization.
• Subscribe for DATAGRAM service to listen for incoming messages.
• Initialize phy agent for physical layer communication.
• Initialize node agent to obtain node information.
• Subscribe to the topic for phy agent to receive messages from the physical layer.
• Process incoming messages:
  • If DatagramNtf is received from another node:
    • Set channelBusy flag to indicate that the communication channel is busy.
    • Schedule WakerBehavior to reset the channelBusy flag after 1500 milliseconds.
  • If DatagramNtf with INIT protocol is received:
    • Decode initialization data and extract parameters such as tdmaSlotLength, csmaSlotLength, and delayLength.
    • Respond with an acknowledgment (ACK) if the channel is not busy.
    • If the channel is busy, schedule a WakerBehavior for backoff and CSMA transmission.
  • If DatagramNtf with TDMA_INIT protocol is received:
    • Decode TDMA initialization data and process it.
    • Setup transmission in assigned TDMA slots.
    • Schedule a WakerBehavior for CSMA transmission after completing TDMA transmission.
  • If DatagramNtf with other protocols is received:
    • Ignore.

BaseNode processMessage()

• Process incoming messages:
  • If DatagramNtf with ACK protocol is received:
    • Decode acknowledgment data and update the neighbors list.
    • Increment the counter for received acknowledgments (NBRx).
  • If DatagramNtf with TDMA protocol is received:
    • Decode TDMA data and update counters.
    • Increment the counter for TDMA receptions (TDMARx).
    • Process TDMA data.
  • If DatagramNtf with CSMA protocol is received:
    • Process CSMA data.
    • Increment the counter for CSMA receptions (CSMARx).