A very simple MAC module template which provides de- and encapsulation of messages using the standard addresses and NetwToMacControlInfo of MiXiM. It also provides basic handling of lower layer messages. More...

#include <BaseMacLayer.h>

Inherits BaseLayer.

Inherited by BMacLayer, csma, CSMAMacLayer, LMacLayer, Mac80211, and UWBIRMac.

Collaboration diagram for BaseMacLayer:

[legend]

List of all members.

Public Types
enum	BaseMacMessageKinds { LAST_BASE_MAC_MESSAGE_KIND = 23000 }
	Message kinds used by this layer. More...
enum	BaseMacControlKinds { TX_OVER = 23500, PACKET_DROPPED, LAST_BASE_MAC_CONTROL_KIND }
	Control message kinds used by this layer. More...
Public Member Functions
virtual void	initialize (int)
	Initialization of the module and some variables.
Protected Member Functions
virtual void	handleUpperMsg (cMessage *msg)
	Handle messages comming from the network layer.
virtual void	handleLowerMsg (cMessage *msg)
virtual void	handleSelfMsg (cMessage *msg)
	Handle self messages such as timer...
virtual void	handleLowerControl (cMessage *msg)
	Handle control messages from lower layer.
virtual void	handleUpperControl (cMessage *msg)
	Handle control messages from upper layer.
virtual cPacket *	decapsMsg (MacPkt *)
	decapsulate the network message from the MacPkt
virtual MacPkt *	encapsMsg (cPacket *)
	Encapsulate the NetwPkt into an MacPkt.
virtual Signal *	createSignal (simtime_t start, simtime_t length, double power, double bitrate)
	Creates a simple Signal defined over time with the passed parameters.
Mapping *	createConstantMapping (simtime_t start, simtime_t end, double value)
	Creates a simple Mapping with a constant curve progression at the passed value.
Mapping *	createRectangleMapping (simtime_t start, simtime_t end, double value)
	Creates a simple Mapping with a constant curve progression at the passed value and discontinuities at the boundaries.
ConstMapping *	createSingleFrequencyMapping (simtime_t start, simtime_t end, double centerFreq, double bandWith, double value)
	Creates a Mapping defined over time and frequency with constant power in a certain frequency band.
BaseConnectionManager *	getConnectionManager ()
	Returns a pointer to this MACs NICs ConnectionManager module.
Protected Attributes
MacToPhyInterface *	phy
	Handler to the physical layer.
int	headerLength
	Pointer to the arp module.
int	myMacAddr
	MAC address (simply module id).
bool	coreDebug
	debug this core module?
int	phyHeaderLength
	The length of the phy header (in bits).

Detailed Description

A very simple MAC module template which provides de- and encapsulation of messages using the standard addresses and NetwToMacControlInfo of MiXiM. It also provides basic handling of lower layer messages.

Author:: Daniel Willkomm, Karl Wessel

Definition at line 43 of file BaseMacLayer.h.

Member Enumeration Documentation

enum BaseMacLayer::BaseMacControlKinds

Control message kinds used by this layer.

Enumerator:

TX_OVER	Indicates the end of a transmission
PACKET_DROPPED	Tells the netw layer that a packet to be sent has been dropped.
LAST_BASE_MAC_CONTROL_KIND	Stores the id on which classes extending BaseMac should continue their own control kinds.

Definition at line 53 of file BaseMacLayer.h.

                           {
    TX_OVER = 23500,
    PACKET_DROPPED,
    LAST_BASE_MAC_CONTROL_KIND,
  };

enum BaseMacLayer::BaseMacMessageKinds

Message kinds used by this layer.

Enumerator:

LAST_BASE_MAC_MESSAGE_KIND

Stores the id on which classes extending BaseMac should continue their own message kinds.

Definition at line 47 of file BaseMacLayer.h.

                           {
    LAST_BASE_MAC_MESSAGE_KIND = 23000,
  };

Member Function Documentation

Mapping * BaseMacLayer::createConstantMapping	(	simtime_t	start,
		simtime_t	end,
		double	value
	)			`[protected]`

Creates a simple Mapping with a constant curve progression at the passed value.

Used by "createSignal" to create the bitrate mapping.

Definition at line 183 of file BaseMacLayer.cc.

References MappingUtils::createMapping(), Mapping::LINEAR, Mapping::setValue(), and DimensionSet::timeDomain.

Referenced by createSignal().

{
  //create mapping over time
  Mapping* m = MappingUtils::createMapping(0.0, DimensionSet::timeDomain, Mapping::LINEAR);

  //set position Argument
  Argument startPos(start);

  //set mapping at position
  m->setValue(startPos, value);

  //set position Argument
  Argument endPos(end);

  //set mapping at position
  m->setValue(endPos, value);

  return m;
}

Mapping * BaseMacLayer::createRectangleMapping	(	simtime_t	start,
		simtime_t	end,
		double	value
	)			`[protected]`

Creates a simple Mapping with a constant curve progression at the passed value and discontinuities at the boundaries.

Used by "createSignal" to create the power mapping.

Definition at line 203 of file BaseMacLayer.cc.

References MappingUtils::addDiscontinuity(), MappingUtils::createMapping(), Mapping::LINEAR, MappingUtils::post(), MappingUtils::pre(), and DimensionSet::timeDomain.

Referenced by createSignal().

{
  //create mapping over time
  Mapping* m = MappingUtils::createMapping(DimensionSet::timeDomain, Mapping::LINEAR);

  //set position Argument
  Argument startPos(start);
  //set discontinuity at position
  MappingUtils::addDiscontinuity(m, startPos, 0.0, MappingUtils::post(start), value);

  //set position Argument
  Argument endPos(end);
  //set discontinuity at position
  MappingUtils::addDiscontinuity(m, endPos, 0.0, MappingUtils::pre(end), value);

  return m;
}

Signal * BaseMacLayer::createSignal	(	simtime_t	start,
		simtime_t	length,
		double	power,
		double	bitrate
	)			`[protected, virtual]`

Creates a simple Signal defined over time with the passed parameters.

Convenience method to be able to create the appropriate Signal for the MacToPhyControlInfo without needing to care about creating Mappings.

NOTE: The created signal's transmission-power is a rectangular function. This method uses MappingUtils::addDiscontinuity to represent the discontinuities at the beginning and end of this rectangular function. Because of this the created mapping which represents the signal's transmission-power is still zero at the exact start and end. Please see the method MappingUtils::addDiscontinuity for the reason.

Reimplemented in Mac80211.

Definition at line 166 of file BaseMacLayer.cc.

References createConstantMapping(), createRectangleMapping(), Signal::setBitrate(), and Signal::setTransmissionPower().

Referenced by LMacLayer::attachSignal(), BMacLayer::attachSignal(), and CSMAMacLayer::encapsMsg().

{
  simtime_t end = start + length;
  //create signal with start at current simtime and passed length
  Signal* s = new Signal(start, length);

  //create and set tx power mapping
  Mapping* txPowerMapping = createRectangleMapping(start, end, power);
  s->setTransmissionPower(txPowerMapping);

  //create and set bitrate mapping
  Mapping* bitrateMapping = createConstantMapping(start, end, bitrate);
  s->setBitrate(bitrateMapping);

  return s;
}

cPacket * BaseMacLayer::decapsMsg ( MacPkt * msg ) [protected, virtual]

decapsulate the network message from the MacPkt

Decapsulates the network packet from the received MacPkt

Reimplemented in csma, and CSMA802154.

Definition at line 69 of file BaseMacLayer.cc.

Referenced by CSMAMacLayer::handleLowerMsg(), AlohaMacLayer::handleLowerMsg(), handleLowerMsg(), LMacLayer::handleSelfMsg(), and BMacLayer::handleSelfMsg().

{
    cPacket *m = msg->decapsulate();
    m->setControlInfo(new MacToNetwControlInfo(msg->getSrcAddr(), 0));
    // delete the macPkt
    delete msg;
    coreEV << " message decapsulated " << endl;
    return m;
}

MacPkt * BaseMacLayer::encapsMsg ( cPacket * netwPkt ) [protected, virtual]

Encapsulate the NetwPkt into an MacPkt.

Encapsulates the received NetwPkt into a MacPkt and set all needed header fields.

Reimplemented in AlohaMacLayer, CSMAMacLayer, and Mac80211.

Definition at line 84 of file BaseMacLayer.cc.

References NetwToMacControlInfo::getNextHopMac(), headerLength, and myMacAddr.

Referenced by handleUpperMsg().

{
    MacPkt *pkt = new MacPkt(netwPkt->getName(), netwPkt->getKind());
    pkt->setBitLength(headerLength);

    // copy dest address from the Control Info attached to the network
    // message by the network layer
    NetwToMacControlInfo* cInfo = static_cast<NetwToMacControlInfo*>(netwPkt->removeControlInfo());

    coreEV <<"CInfo removed, mac addr="<< cInfo->getNextHopMac()<<endl;
    pkt->setDestAddr(cInfo->getNextHopMac());

    //delete the control info
    delete cInfo;

    //set the src address to own mac address (nic module getId())
    pkt->setSrcAddr(myMacAddr);

    //encapsulate the network packet
    pkt->encapsulate(netwPkt);
    coreEV <<"pkt encapsulated\n";

    return pkt;
}

BaseConnectionManager * BaseMacLayer::getConnectionManager ( ) [protected]

Returns a pointer to this MACs NICs ConnectionManager module.

Returns:: pointer to the connection manager module

Definition at line 247 of file BaseMacLayer.cc.

Referenced by Mac80211::initialize(), and csma::initialize().

                                                          {
  cModule* nic = getParentModule();
  return ChannelAccess::getConnectionManager(nic);
}

void BaseMacLayer::handleLowerMsg ( cMessage * msg ) [protected, virtual]

If message arrives from lower layer, check whether it is for us. Send it up if yes.

This basic implementation just forwards all message that are broadcast (destAddr = L2BROADCAST) or destined for this node (destAddr = nic module getId()) to the network layer

See also:: sendUp

Implements BaseLayer.

Reimplemented in AlohaMacLayer, BMacLayer, csma, CSMAMacLayer, LMacLayer, and Mac80211.

Definition at line 130 of file BaseMacLayer.cc.

References decapsMsg(), myMacAddr, and BaseLayer::sendUp().

{
    MacPkt *mac = static_cast<MacPkt *>(msg);
    int dest = mac->getDestAddr();
    int src = mac->getSrcAddr();

    //only foward to upper layer if message is for me or broadcast
    if((dest == myMacAddr) || (dest == L2BROADCAST)) {
    coreEV << "message with mac addr " << src
         << " for me (dest=" << dest
         << ") -> forward packet to upper layer\n";
    sendUp(decapsMsg(mac));
    }
    else{
    coreEV << "message with mac addr " << src
         << " not for me (dest=" << dest
         << ") -> delete (my MAC="<<myMacAddr<<")\n";
    delete mac;
    }
}

void BaseMacLayer::handleUpperMsg ( cMessage * mac ) [protected, virtual]

Handle messages comming from the network layer.

Here is the place to implement a real medium access functionality.

If message arrives from upper layer, make a MAC packet from it (encapsMsg) and send it down (sendDown).

See also:: encapsMsg, sendDown

Redefine this function if you want to process messages from upper layers before they are send to lower layers.

To forward the message to lower layers after processing it please use sendDown. It will take care of anything needed

Implements BaseLayer.

Reimplemented in BMacLayer, csma, CSMAMacLayer, LMacLayer, and Mac80211.

Definition at line 116 of file BaseMacLayer.cc.

References encapsMsg(), and BaseLayer::sendDown().

{
  assert(dynamic_cast<cPacket*>(mac));
    sendDown(encapsMsg(static_cast<cPacket*>(mac)));
}

void BaseMacLayer::initialize ( int stage ) [virtual]

Initialization of the module and some variables.

First we have to initialize the module from which we derived ours, in this case BaseLayer.

Reimplemented from BaseLayer.

Reimplemented in AlohaMacLayer, BMacLayer, csma, CSMA802154, CSMAMacLayer, LMacLayer, Mac80211, Mac80211MultiChannel, and UWBIRMac.

Definition at line 39 of file BaseMacLayer.cc.

References coreDebug, BaseModule::findHost(), MacToPhyInterface::getPhyHeaderLength(), headerLength, AddressingInterface::myMacAddr(), myMacAddr, phy, and phyHeaderLength.

{
    BaseLayer::initialize(stage);

    if(stage==0)
    {
      // get handle to phy layer
        phy = FindModule<MacToPhyInterface*>::findSubModule(getParentModule());

        headerLength= par("headerLength");
        phyHeaderLength = phy->getPhyHeaderLength();

        hasPar("coreDebug") ? coreDebug = par("coreDebug").boolValue() : coreDebug = false;
    }
    else if (stage==1)
    {
      // see if there is an addressing module available
    // otherwise use NIC modules id as MAC address
    AddressingInterface* addrScheme = FindModule<AddressingInterface*>::findSubModule(findHost());
    if(addrScheme) {
      myMacAddr = addrScheme->myMacAddr(this);
    } else {
      myMacAddr = getParentModule()->getId();
    }
    }
}

Member Data Documentation

int BaseMacLayer::headerLength [protected]

Pointer to the arp module.

Length of the MacPkt header

Reimplemented in BMacLayer.

Definition at line 73 of file BaseMacLayer.h.

Referenced by LMacLayer::encapsMsg(), AlohaMacLayer::encapsMsg(), encapsMsg(), LMacLayer::handleSelfMsg(), csma::handleUpperMsg(), and initialize().

int BaseMacLayer::phyHeaderLength [protected]

The length of the phy header (in bits).

Since the MAC layer has to create the signal for a transmission it has to know the total length of the packet and therefore needs the length of the phy header.

Definition at line 90 of file BaseMacLayer.h.

Referenced by initialize(), and Mac80211::packetDuration().

The documentation for this class was generated from the following files:

base/modules/BaseMacLayer.h
base/modules/BaseMacLayer.cc

BaseMacLayer Class Reference [macLayer - MAC layer modules, baseModules - base module classes of MiXiM]

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Enumeration Documentation

Member Function Documentation

Member Data Documentation

BaseMacLayer Class Reference
[macLayer - MAC layer modules, baseModules - base module classes of MiXiM]