How to Implement 6TiSCH Sensors Communication in NS2

To implement the 6TiSCH (IPv6 over the TSCH mode of IEEE 802.15.4e) in NS2 (Network Simulator 2) which encompasses simulating the Time-Slotted Channel Hopping (TSCH) associated with IPv6 for low-power wireless sensor networks. This architecture make certain that reliable, deterministic, and secure communication for the industrial IoT (Internet of Things) applications, especially in constrained environments such as wireless sensor networks (WSNs).Stay with us you can get beat implementation assistance from us.

However, NS2 does not have built-in support for 6TiSCH, thus we will want to extend NS2 by integrating the vital features of TSCH and IPv6. We guided how to proceed step by step approach to it in NS2:

Key Features to Implement for 6TiSCH in NS2:

  1. TSCH (Time-Slotted Channel Hopping): Execute the time-slotted communication including channel hopping to mitigate interference and enhance the reliability.
  2. IPv6 (Internet Protocol version 6): Execute the IPv6 networking for communication among the sensor nodes.
  3. RPL (Routing Protocol for Low-Power and Lossy Networks): We can use the RPL protocol as the routing layer that is the standard for 6TiSCH networks.

Step-by-Step Guide to Implement 6TiSCH in NS2

  1. Implement the TSCH MAC Layer

TSCH is a Medium Access Control (MAC) layer mechanism that splits time into slots and uses channel hopping to mitigate interference. It make sure that every nodes are communicates in predetermined time slots and on changing the channels.

Modify or Extend the MAC Layer:

  1. Extend or alter the MAC/802_15_4 class to support TSCH. We will want to execute the time slots and a scheduling mechanism for communication.
  2. Execute the channel hopping that the communication channel alters at every time slot.

Example C++ Code for Time-Slotted Communication:

In the C++ implementation of the MAC layer:

class TschMac : public Mac {

public:

TschMac();

void transmit(Packet *p);

void receive(Packet *p);

private:

int currentSlot;

int slotframeSize;

int hoppingSequence[16];  // Example channel hopping sequence

void scheduleTransmission();

void hopChannel();

};

// Constructor to initialize the TSCH MAC

TschMac::TschMac() : Mac(), currentSlot(0), slotframeSize(10) {

// Define a simple channel hopping sequence (example)

int tempSequence[16] = {11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26};

memcpy(hoppingSequence, tempSequence, sizeof(tempSequence));

}

// Transmit packets in a time slot

void TschMac::transmit(Packet *p) {

// Check if it’s the right time slot for transmission

if (isMyTimeSlot(currentSlot)) {

// Send packet on the current channel

hopChannel();  // Hop to the next channel

send(p);

}

}

// Receive packets during the correct time slot

void TschMac::receive(Packet *p) {

// Check if it’s the right time slot for receiving

if (isMyReceiveSlot(currentSlot)) {

hopChannel();  // Hop to the next channel

recv(p);

}

}

// Hop to the next channel based on the hopping sequence

void TschMac::hopChannel() {

int channel = hoppingSequence[currentSlot % 16];

setChannel(channel);  // Set the new channel for communication

currentSlot = (currentSlot + 1) % slotframeSize;

}

  • Time Slots: The MAC layer verifies if it is a correct slot for transmission or reception. If it is, these node communicates on the present channel, else it waits.
  • Channel Hopping: The MAC layer hops to the next channel according to a predefined hopping sequence, after each time slot.
  1. Integrate IPv6 Support

Because 6TiSCH works with IPv6, we want to execute or incorporate the IPv6 addressing and packet processing. The simulation NS2 has limited support for IPv6, thus it will encompass either extending existing IPv4 functionality or integrating new IPv6-specific functionality.

Implement IPv6 Packet Handling:

We will require to change the network layer to manage the IPv6 packet structures and address assignments.

Example IPv6 Packet Header:

struct hdr_ipv6 {

nsaddr_t src_addr;  // IPv6 source address

nsaddr_t dst_addr;  // IPv6 destination address

int payload_length; // Length of the IPv6 packet’s payload

int next_header;    // Type of the next header (e.g., UDP, TCP)

};

  1. Implement RPL (Routing Protocol for Low-Power and Lossy Networks)

The RPL is the routing protocol normally used in 6TiSCH networks. It is enhanced for low-power, lossy networks such as wireless sensor networks.

Basic RPL Functionality:

  • DODAG (Destination-Oriented Directed Acyclic Graph): RPL constructs a tree-such as structure in which nodes are forward data upwards towards a root (the sink).
  • Rank: Every node has a rank, signifying its distance from the root. The lower ranks are closer to the root.

Example Implementation of Basic RPL:

We can execute the RPL protocol to route packets to the root node (sink).

class RPL : public RoutingAgent {

public:

RPL();

void recv(Packet *p);  // Process incoming packets

protected:

void handleDioMessage(Packet *p);  // Handle RPL DIO (DODAG Information Object)

void sendDioMessage();  // Broadcast DIO message

private:

nsaddr_t root_addr;  // Root of the DODAG (sink)

int rank;            // Rank of the node

};

// Constructor

RPL::RPL() : RoutingAgent(), root_addr(0), rank(INFINITY) {

// Initialization of RPL node

}

// Receive incoming packets and process them

void RPL::recv(Packet *p) {

hdr_rpl *rpl_hdr = HDR_RPL(p);

if (rpl_hdr->type == RPL_TYPE_DIO) {

handleDioMessage(p);

}

}

// Handle DIO message and update rank

void RPL::handleDioMessage(Packet *p) {

hdr_rpl *rpl_hdr = HDR_RPL(p);

if (rpl_hdr->rank + 1 < rank) {

rank = rpl_hdr->rank + 1;  // Update rank to reflect a better parent

sendDioMessage();  // Broadcast updated rank to neighbors

}

}

// Send a DIO message to advertise the current rank

void RPL::sendDioMessage() {

Packet *p = allocpkt();

hdr_rpl *rpl_hdr = HDR_RPL(p);

rpl_hdr->type = RPL_TYPE_DIO;

rpl_hdr->rank = rank;

send(p);

}

  1. Simulate 6TiSCH in NS2

We can replicate the 6TiSCH network in NS2, after executing the TSCH MAC layer, IPv6, and RPL. We want to make a Tcl script which sets up the network topology, allocates IPv6 addresses to nodes, configures the RPL routing, and runs the simulation.

Example Tcl Script for 6TiSCH Simulation:

# Create a simulator instance

set ns [new Simulator]

# Create a mobile node (representing a 6TiSCH sensor)

set node1 [$ns node]

set node2 [$ns node]

# Set IPv6 addresses for the nodes

$node1 set addr_ “fe80::1”

$node2 set addr_ “fe80::2”

# Set up TSCH MAC and attach to nodes

set tsch_mac1 [new Mac/TSCH]

set tsch_mac2 [new Mac/TSCH]

$node1 set mac_ $tsch_mac1

$node2 set mac_ $tsch_mac2

# Set up RPL for routing

set rpl1 [new Agent/RPL]

set rpl2 [new Agent/RPL]

$ns attach-agent $node1 $rpl1

$ns attach-agent $node2 $rpl2

# Start the RPL protocol (nodes will form a DODAG)

$rpl1 start

$rpl2 start

# Define traffic sources (UDP, TCP, etc.) and run the simulation

…

$ns run

  1. Evaluate the 6TiSCH Network Performance

We can compute the performance of the 6TiSCH network by examining vital metrics:

  • Packet Delivery Ratio (PDR): The percentage of packets are successfully delivered.
  • Latency: The end-to-end delay of packets from the source to end.
  • Energy Consumption: Calculate the energy usage because of time-slotted communication.
  • Network Reliability: Measure the effect of the channel hopping on network reliability.

Here, we showed the stepwise techniques with some instance that helps to execute and examine the 6TiSCH sensors communication in the tool NS2. Comprehensive informations will be provided as per your needs.