veins/modules/application/ieee80211p/ChannelAccess.cc中的代码
时间: 2023-06-29 14:19:58 浏览: 46
由于篇幅较长,我只能给你提供部分代码,以下是该文件中的一些重要部分:
定义一些常量:
```
#define CW_MIN 15
#define CW_MAX 1023
#define SLOT_TIME 0.00001
#define SIFS 0.00001
#define DIFS (2 * SIFS + SLOT_TIME)
#define BACKOFF_PERIOD 0.00001
#define MAX_RETRIES 7
```
定义 ChannelAccess 类:
```
class ChannelAccess {
public:
ChannelAccess();
bool isIdle();
void sendPacket(Packet* packet);
void receivePacket(Packet* packet);
void handleChannelIdle();
void handleChannelBusy();
private:
simtime_t _backoffPeriod;
int _backoffCounter;
int _retries;
bool _channelIdle;
bool _waitingForSIFS;
Packet* _currentPacket;
void startTransmission();
void handlePacketSent();
void handlePacketReceived(Packet* packet);
void handleTimeout();
};
```
实现 isIdle 方法:
```
bool ChannelAccess::isIdle() {
return _channelIdle;
}
```
实现 sendPacket 方法:
```
void ChannelAccess::sendPacket(Packet* packet) {
_currentPacket = packet;
if (_channelIdle) {
startTransmission();
} else {
_backoffCounter = uniform(CW_MIN, CW_MAX);
_backoffPeriod = _backoffCounter * SLOT_TIME;
}
}
```
实现 startTransmission 方法:
```
void ChannelAccess::startTransmission() {
_waitingForSIFS = true;
_retries = 0;
_channelIdle = false;
send(_currentPacket, "out");
scheduleAt(simTime() + SIFS, new cMessage("SIFS"));
}
```
实现 handlePacketReceived 方法:
```
void ChannelAccess::handlePacketReceived(Packet* packet) {
if (_currentPacket && packet->getKind() == _currentPacket->getKind()) {
if (packet->getSenderAddress() != _currentPacket->getSenderAddress()) {
delete packet;
handleTimeout();
}
} else {
delete packet;
}
}
```
以上仅是部分代码,完整的实现细节需要参考源代码。