Packet drop increase in changing SuperframeOrder on wpan

[Kwangbaek Lee]

Hi omnet++ users,

 

Let me introduce myself first. My name is Kevin, Lee.

I am a PhD student in University of Melbourne and am preparing for a simulation using omnet++ 4.6 and inetmanet 2.0.

While doing the simulation, I met a problem and asked you for some help.

 

Thanks to your prior implementation, I saved a lot of time.

However I met a problem in changing SO(SuperframeOrder) dynamically.

When I changed SO during the simulation running, the number of packet drop is dramatically increased.

Roughly 50% of the packets were dropped.

To check if it is correct, I did some additional experiment as follows.

 

0.       Simulation environment

a.       Omnet++4.6, inetmanet 2.0

b.      Topology : StarNet (Star network) in inetmanet 2.0,

                      3 nodes (host 1 : PAN coordinator & receiver, host 0/2 : source device)

c.       Simulation parameter (please find attached “omnetpp.ini” file for more parameters)

                               **.host[*].**.mac.ack4Gts                                          = true

                               **.host[*].**.mac.gtsPayload                                    = 10       # should be consistent with that in trafconfig.xml

                               **.host[*].**.mac.dataTransMode                         = 1                         # 1: direct; 2: indirect; 3: GTS

                               **.host[*].**.mac.isRecvGTS                                     = false  # ignored

 

1.       Fix the SO(**.mac.SO=4) from the start(omnetpp.ini) and executed it.

2.       Change the SO(**.mac.SO=7) from the start(omnetpp.ini) and executed it.

a.       The delay was decreased but the number of packet drop rate was similar to the 1^st case.

3.       Change the SO value in the function “void Ieee802154Mac::handleBcnTxTimer()” dynamically.

-    Old code

       txSfSpec.SO = mpib.macSuperframeOrder;

       txSfSpec.SD = aBaseSuperframeDuration * (1 << mpib.macSuperframeOrder);

-    New code

       uint8_t so= (uint8_t)par("SO") + intrand(4);

       mpib.macSuperframeOrder= so;

       txSfSlotDuration = aBaseSlotDuration * (1 << mpib.macSuperframeOrder);

       txSfSpec.SO = so;

       txSfSpec.SD = aBaseSuperframeDuration * (1 << txSfSpec.SO);

      

-    The average delay was decreased, but actually I used acknowledged mode and the number of dropped packets were increased to 50%.

 

scalar Ieee802154StarNet.host[0].nic.mac        "Total simulation time"         179.99452604265

scalar Ieee802154StarNet.host[0].nic.mac        "total num of upper pkts received"      300

scalar Ieee802154StarNet.host[0].nic.mac        "num of upper pkts dropped"     0

scalar Ieee802154StarNet.host[0].nic.mac        "num of BEACON pkts sent"       0

scalar Ieee802154StarNet.host[0].nic.mac        "num of DATA pkts sent successfully"    192

scalar Ieee802154StarNet.host[0].nic.mac        "num of DATA pkts failed"       107

scalar Ieee802154StarNet.host[0].nic.mac        "num of DATA pkts sent successfully in GTS"     0

scalar Ieee802154StarNet.host[0].nic.mac        "num of DATA pkts failed in GTS"        0

scalar Ieee802154StarNet.host[0].nic.mac        "num of ACK pkts sent"  0

scalar Ieee802154StarNet.host[0].nic.mac        "num of BEACON pkts received"   46

scalar Ieee802154StarNet.host[0].nic.mac        "num of BEACON pkts lost"       0

scalar Ieee802154StarNet.host[0].nic.mac        "num of DATA pkts received"     0

scalar Ieee802154StarNet.host[0].nic.mac        "num of DATA pkts received in GTS"      0

scalar Ieee802154StarNet.host[0].nic.mac        "num of ACK pkts received"      192

scalar Ieee802154StarNet.host[0].nic.mac        "num of collisions"     182

 

scalar Ieee802154StarNet.host[2].nic.mac        "Total simulation time"         179.99452604265

scalar Ieee802154StarNet.host[2].nic.mac        "total num of upper pkts received"      312

scalar Ieee802154StarNet.host[2].nic.mac        "num of upper pkts dropped"     0

scalar Ieee802154StarNet.host[2].nic.mac        "num of BEACON pkts sent"       0

scalar Ieee802154StarNet.host[2].nic.mac        "num of DATA pkts sent successfully"    204

scalar Ieee802154StarNet.host[2].nic.mac        "num of DATA pkts failed"       107

scalar Ieee802154StarNet.host[2].nic.mac        "num of DATA pkts sent successfully in GTS"     0

scalar Ieee802154StarNet.host[2].nic.mac        "num of DATA pkts failed in GTS"        0

scalar Ieee802154StarNet.host[2].nic.mac        "num of ACK pkts sent"  0

scalar Ieee802154StarNet.host[2].nic.mac        "num of BEACON pkts received"   46

scalar Ieee802154StarNet.host[2].nic.mac        "num of BEACON pkts lost"       0

scalar Ieee802154StarNet.host[2].nic.mac        "num of DATA pkts received"     0

scalar Ieee802154StarNet.host[2].nic.mac        "num of DATA pkts received in GTS"      0

scalar Ieee802154StarNet.host[2].nic.mac        "num of ACK pkts received"      204

scalar Ieee802154StarNet.host[2].nic.mac        "num of collisions"     176

 

 

Could you please give me a hint to solve out this problem ?

I appreciate your help and support in advance.

Thanks and regards,

 

Kevin