I am trying to study the performance of B-MAC/X-MAC while varying the duty cycle ratio using INET framework. I know for wireless sensor networks, duty cycle is the ratio of active period and the summation of sleelping period and active period.Can anyone please explain for XMAC, which parameter(s) actually defines the duty cycle ratio?
For example, if I want to set the duty cycle to 5%, which parameters need to be considered in omnetpp.ini file, and what should be those parameters' values?
Thank you.
I think in XMac and BMac you can only set the slotDuration (which is the sleep period of the nodes). The active period can be variable in length, depending on what happens in the network, and what messages the node receives or transmits, etc. So the duty cycle is variable in length as well.
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I'm trying to measure throughput when the distance between two mobile UE is changing. I'm using Omnet++. and measuring throughput in the mac layer.
It's supposed to be that when the distance increases throughput should decrease (well-known inverse relationship)
But in my simulation it doesn't happen. Does anyone have any idea about it in omnet++?
I also attached the chart of throughput during the time
enter image description hereenter image description here
Thanks
#thardes2 Ok, I'm using Omnet++. In my scenario, there is 1 base station and 2 UE without any mobility during the simulation. I run the simulation 20 times (10,20,30 ,... 200m) and try to measure the throughput which is calculated in the MAC layer in the LteHarqBufferRx.cc (in a way total received bytes / simulation time)
double tputSample = (double)totalRcvdBytes_ / (NOW - getSimulation()->getWarmupPeriod());
macOwner_->emit(macThroughput_, tputSample);
I used SinglePair-UDP-Infra scenario in D2D sample in Simulte and verything is working well, but my issue is: Why throughput doesn't reduce when distance increases? Even in some long distance throughput increases!!! Am I calculating throughput in a wrong place?
Thank you for your help
This is a two part question:
I have a fluid flow sensor connected to an NI-9361 on my DAQ. For those that don't know, that's a pulse counter card. None the less, from the data read from the card, I'm able to calculate fluid flowing through the device in Gallons per hour, min, sec, etc. But what I need to do is the following:
Calculate total number of gallons of fluid that has flowed through the sensor since the loop began running
if possible, store that total so that it can be incremented next time the program runs
I know how to calculate it by hand, just not sure how to achieve the running summation required to calculate total amount of fluid that has passed through the sensor, or how to store the variable being incremented at the next program execution. I'm presuming the latter would involve writing a TDMS file, then opening and reading back the data, unless there's a better way?
Edit:
Below is the code used to determine GPM flow through my sensor. This setup is in accordance with the 9361 manual; it executes and yields proper results.
See this link for details:
http://zone.ni.com/reference/en-XX/help/373197L-01/criodevicehelp/crio-9361/
I can extrapolate how many gallons flow per second, or sample period, the 1526.99 scalar is the fluid flow manufacturer's constant - number of pulses per gallon passing through the sensor. The 9361 is set to frequency/period mode, so I'm calculating cycles per second, dividing by the constant for cycles per gallon to get gallons per second/min.
I suppose I could get a time reference by looking at the sample period, so I guess the better question is, how do I keep an incrementing sum?
I use the PIC16F88 for my project, with XC8 compiler.
What I'm trying to achieve is to control 4 LEDs with 4 buttons, when you press a buttons it increases the duty cycle of the corresponding LED by 10%.
When you press the button on RB0 it increases the duty cycle of the LED on RB4, and so on.
Every LED is independent, therefore it can have a different duty cycle.
The problem is that the PIC i'm using only have one PWM module on either RB0 or RB3 (using CCPMX bit).
After some research I decided to implement software PWM to have four different channels, each channels would control one duty cycle, but most of the sources I found didn't provide any explanation on how to do it.
Or is there a way to mirror PWM to multiple pins ?
Thanks by advance for helping me out.
Mirroring is not an option.
PWM is relatively simple. You have to set PWM frequency (which you will not change) and PWM duty cycle (which you need to change in order to have 0-100% voltage range). You have to decide about resolution of PWM, voltage step that you need (built in PWM for example is 8-bit and has 0-255 steps).
Finally, you have to set timer to interrupt based on PWM frequency * PWM resolution. In Timer ISR routine you need to check resolution counts and PWM value of all your channels. Resolution count will have to reset when resolution value is reached (and start to count from 0 again, all outputs go HIGH here, also). When PWM value of output is reached you have to toggle (pull it LOW) corresponding pin (and reset it back to HIGH with every resolution count reset).
This is only one way of doing it, involves only one timer and should be most simple since your PIC is low with resources.
Hope it helps...
I am measuring energy level when the packet comes to one of the specific LCN from anothers.I want to get the current simulation time when packet arrives to this LCN.To do this, I used
SimTime();
function but it always gives me the 0. So, how can I get current simulation time. I need to draw the energy level of the LCN with respect to time until simulation ends.I mean what is energy level of of LCN when the time is 10? (for example)
When you call SimTime() you actually call the constructor for the class SimTime.
What you are looking for is the global function simTime().
I have been using FRDM_KL46Z development board to do some IR communication experiment. Right now, I got two PWM outputs with same setting (50% duty cycle, 38 kHz) had different voltage levels. When both were idle, one was 1.56V, but another was 3.30V. When the outputs were used to power the same IR emitter, the voltages were changed to 1.13V and 2.29V.
And why couldn't I use one PWM output to power two IR emitters at the same time? When I tried to do this, it seemed that the frequency was changed, so two IR receivers could not work.
I am not an expert in freescale, but how are you controlling your pwm? I'm guessing each pwm comes from a separate timer, maybe they are set up differently. Like one is in 16 bit mode (the 3.3V) and the other in 32 (1.56v) in that case even if they have the same limit in the counter ((2^17 - 1) / 2) would be 50% duty cycle of a 16 bit timer. But in a 32 bit, that same value would only be 25% duty so, one output would be ~1/2 the voltage of the other. SO I suggest checking the timer setup.
The reason the voltage changed is because the IR emmiters were loading the circuit. In an ideal situation this wouldn't happen, but if a source is giving too much current the voltage usually drops a bit.