using System.DateTime.Now.Ticks for seed value

Question

I have started a wireless sensor network simulation code but I don't understand the meaning of the seed and what is the return value of System.DateTime.Now.Ticks in the method below.

public void Reset(bool bNewSeed) {
    // this function resets the network so that a new simulation can be run - can either be reset with a new seed, or with the previous seed (for replay.)
    this.iProcessTime = 0;
    this.iPacketsDelivered = 0;
    foreach (WirelessSensor sensor in aSensors) {
        sensor.iResidualEnergy = sensor.iInitialEnergy;
        sensor.aPackets = new ArrayList();
        sensor.iSensorRadius = iSensorRadius;
        sensor.iSensorDelay = 0;
        foreach (WirelessSensorConnection connection in sensor.aConnections) {
            connection.iTransmitting = 0;
            connection.packet = null;
        }
    }
    aRadar = new ArrayList();
    if (bDirectedRouting == true)
        SetRoutingInformation();
    iLastUpdated = iUpdateDelay;
    if (bNewSeed == true)
        this.iSeed = (int) System.DateTime.Now.Ticks;
    r = new Random(iSeed);
}

Answer 1

DateTime.Now.Ticks returns a long which represents the number of ticks in that instance.

By providing a seed value to an instance of Random you are specifying the number used to calculate a starting value for the pseudo-random number sequence.

So if you have the 2 instances of Random both with the same seed they will generate the same value e.g.:

var randomOne = new Random(1);
var randomTwo = new Random(1);

var valOne = randomOne.Next(1, 1000);
var valTwo = randomTwo.Next(1, 1000);

valOne.Equals(valTwo); // True

So in order to make a random instance more random one can use a value which is less likely to be predictable, in your case the number of ticks on the instance of DateTime e.g.

var random = new Random((int)DateTime.UtcNow.Ticks);

or a much better method is:

var random = new Random(Guid.NewGuid().GetHashCode());