Dear Karima,

After setting the initial energy of your nodes, you need to update it according to an energy model such as the first order radio model or the discrete radio model. You need to select the energy model most appropriate to your nodes and application at hand.

Regards

What do you mean by Nodes? Can you explain it little bit more

In communication networks, a node is either a connection point, a redistribution point (e.g. data communications equipment), or a communication endpoint (e.g. data terminal equipment).

Karima ,  you can use the collect view to determine the power consumed by the nodes and before that you must find out the initial energy of the motes that u r using i.e Z1 mote or whatever , the simplest way is to find the initial  energy  in the mote data sheet then subtract the power consumed from it. 

there are also many ways u can find them in the contiki mailing list

good luck

basically, you must have a Energy consumption model for calculate the remaining energy

Dear Karima,

After setting the initial energy of your nodes, you need to update it according to an energy model such as the first order radio model or the discrete radio model. You need to select the energy model most appropriate to your nodes and application at hand.

Regards

Dear Karima,

If you are good to write a script then try this.

Save the mote output and radio messages and try to evaluate energy, packet loss or many things from that..

Regards.

Dear Karima,

You have to use a specific energy model to calculate the remaining energy of nodes. However, the lifetime is calculated for the network which can be defined as the time till the first node of a network drains out. 

Good luck!

So to calculate lifetime of the network i must let the simulation running until the first node drains out

Yes. Thats how we calculate the network lifetime because even a single node failure can cause the network partition.

Thank you all for your responses,they were very helpful.

the ant colony optimization can be helpful for this purpose,this is done as follows:

* Step 1 First of all initialize WSN with their respective characteristics.

* Step 2 For each node I repeat the following steps

* Step 3 If given node has energy more than 0 that means it is alive node only then                       repeat upcoming steps else move back to step 2.

Step 4    Select node as a CH if it holds the properties of improved node waiting based                   cluster head selection.

* Step 5   Now association of the nodes will be done with their nearest CHs by using                         ACO.

*Step 6     Update the remaining energy of each node I

*Step 7      check if there is any dead node, if NO then move to  the step 2 else count                         the   no. of dead nodes and show the network lifetime.

Step 8        Evaluate energy dissipation and move to step 2.

I have developed an extended version of Powertrace that uses original Powertrace code to provide the remaining energy in the battery. More info and source code: https://github.com/KineticBattery/Powertrace

A simple energy model is Radio energy dissipation model.

where the transmitter dissipates energy to run the radio electronics and the power amplifier, and the receiver dissipates energy to run the radio electronics. The energy required to send data depends on the distance between the nodes and the number of bits which are being transmitted. The energy required for receiving also depends on the number of bits being received. Using this radio model, to transmit k-bit of message at distance‘d’ the radio expends energy as per equation (1) and (2):

ETx (k, d) = ETx-elec (k) + ETx-amp (k, d) (1)

ETx (k, d) = Eelec*k + εamp*k*d2 (2)

Where ETx is the total energy needed to transmit a single k-bit packet to a receiver over a single link of distance d; Eelec is the basic energy to run the transmitter; εamp is the multi-path fading coefficient that depends on the transmitter amplifier model and it is the energy required for transmitter amplifier circuit. To receive this message, the radio expends energy as per equation (3) and (4):

ERx (k) = ERx-elec (k) (3)

ERx (k) = Eelec * k (4)

Where ERx is the total energy needed to receive a single k-bit packet from a transmitter.

Energy Consumption of Sensor network

This section describes formula for energy and distance.

Consider N be the set of all nodes present in the network.

N = {n1, n2, n3, ….}

Energy consumed by a node Ec is given by equation (5).

Ec = Ei – Er (5)

where, Ei = Initial Energy of a node and Er = Residual Energy of a node

Total energy consumed TEC is given by equation (6).

TEC = Σ 𝑁𝑖=1[Ei - Er] (6)

Average Energy Consumption (AEC) is given by equation (7).

AEC = Σ 𝑁𝑖=1 [𝐸𝑖 − 𝐸𝑟] 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑁𝑜𝑑𝑒𝑠 (7)

The distance ‘D’ between any two nodes with x & y coordinates (X1, Y1) and (X2, Y2) is calculated by using the Euclidean distance formula and is given by equation (8).

D = √(𝑋2−𝑋1)2+(𝑌2−𝑌1)2