A Discrete-Event Network Simulator
API
ofdm-ppdu.cc
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2020 Orange Labs
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation;
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17  *
18  * Author: Rediet <getachew.redieteab@orange.com>
19  * Muhammad Iqbal Rochman <muhiqbalcr@uchicago.edu>
20  * S├ębastien Deronne <sebastien.deronne@gmail.com> (LSigHeader)
21  */
22 
23 #include "ns3/wifi-phy.h"
24 #include "ns3/wifi-psdu.h"
25 #include "ofdm-phy.h"
26 #include "ofdm-ppdu.h"
27 #include "ns3/log.h"
28 
29 namespace ns3 {
30 
31 NS_LOG_COMPONENT_DEFINE ("OfdmPpdu");
32 
34  WifiPhyBand band, uint64_t uid,
35  bool instantiateLSig /* = true */)
36  : WifiPpdu (psdu, txVector, uid),
37  m_band (band),
38  m_channelWidth (txVector.GetChannelWidth ())
39 {
40  NS_LOG_FUNCTION (this << psdu << txVector << band << uid);
41  if (instantiateLSig)
42  {
43  m_lSig.SetRate (txVector.GetMode ().GetDataRate (txVector), m_channelWidth);
44  m_lSig.SetLength (psdu->GetSize ());
45  }
46 }
47 
49 {
50 }
51 
54 {
55  WifiTxVector txVector;
56  txVector.SetPreambleType (m_preamble);
57  //OFDM uses 20 MHz, unless PHY channel width is 5 MHz or 10 MHz
58  uint16_t channelWidth = m_channelWidth < 20 ? m_channelWidth : 20;
59  txVector.SetMode (OfdmPhy::GetOfdmRate (m_lSig.GetRate (m_channelWidth), channelWidth));
60  txVector.SetChannelWidth (channelWidth);
61  return txVector;
62 }
63 
64 Time
66 {
67  Time ppduDuration = Seconds (0);
68  const WifiTxVector& txVector = GetTxVector ();
69  ppduDuration = WifiPhy::CalculateTxDuration (m_lSig.GetLength (), txVector, m_band);
70  return ppduDuration;
71 }
72 
74 OfdmPpdu::Copy (void) const
75 {
76  return Create<OfdmPpdu> (GetPsdu (), GetTxVector (), m_band, m_uid);
77 }
78 
80  : m_rate (0b1101),
81  m_length (0)
82 {
83 }
84 
86 {
87 }
88 
89 TypeId
91 {
92  static TypeId tid = TypeId ("ns3::LSigHeader")
93  .SetParent<Header> ()
94  .SetGroupName ("Wifi")
95  .AddConstructor<LSigHeader> ()
96  ;
97  return tid;
98 }
99 
100 TypeId
102 {
103  return GetTypeId ();
104 }
105 
106 void
107 OfdmPpdu::LSigHeader::Print (std::ostream &os) const
108 {
109  os << "SIGNAL=" << GetRate ()
110  << " LENGTH=" << m_length;
111 }
112 
113 uint32_t
115 {
116  return 3;
117 }
118 
119 void
120 OfdmPpdu::LSigHeader::SetRate (uint64_t rate, uint16_t channelWidth)
121 {
122  if (channelWidth == 5)
123  {
124  rate *= 4; //corresponding 20 MHz rate if 5 MHz is used
125  }
126  else if (channelWidth == 10)
127  {
128  rate *= 2; //corresponding 20 MHz rate if 10 MHz is used
129  }
130  /* Here is the binary representation for a given rate:
131  * 6 Mbit/s: 1101
132  * 9 Mbit/s: 1111
133  * 12 Mbit/s: 0101
134  * 18 Mbit/s: 0111
135  * 24 Mbit/s: 1001
136  * 36 Mbit/s: 1011
137  * 48 Mbit/s: 0001
138  * 54 Mbit/s: 0011
139  */
140  switch (rate)
141  {
142  case 6000000:
143  m_rate = 0b1101;
144  break;
145  case 9000000:
146  m_rate = 0b1111;
147  break;
148  case 12000000:
149  m_rate = 0b0101;
150  break;
151  case 18000000:
152  m_rate = 0b0111;
153  break;
154  case 24000000:
155  m_rate = 0b1001;
156  break;
157  case 36000000:
158  m_rate = 0b1011;
159  break;
160  case 48000000:
161  m_rate = 0b0001;
162  break;
163  case 54000000:
164  m_rate = 0b0011;
165  break;
166  default:
167  NS_ASSERT_MSG (false, "Invalid rate");
168  break;
169  }
170 }
171 
172 uint64_t
173 OfdmPpdu::LSigHeader::GetRate (uint16_t channelWidth) const
174 {
175  uint64_t rate = 0;
176  switch (m_rate)
177  {
178  case 0b1101:
179  rate = 6000000;
180  break;
181  case 0b1111:
182  rate = 9000000;
183  break;
184  case 0b0101:
185  rate = 12000000;
186  break;
187  case 0b0111:
188  rate = 18000000;
189  break;
190  case 0b1001:
191  rate = 24000000;
192  break;
193  case 0b1011:
194  rate = 36000000;
195  break;
196  case 0b0001:
197  rate = 48000000;
198  break;
199  case 0b0011:
200  rate = 54000000;
201  break;
202  default:
203  NS_ASSERT_MSG (false, "Invalid rate");
204  break;
205  }
206  if (channelWidth == 5)
207  {
208  rate /= 4; //compute corresponding 5 MHz rate
209  }
210  else if (channelWidth == 10)
211  {
212  rate /= 2; //compute corresponding 10 MHz rate
213  }
214  return rate;
215 }
216 
217 void
219 {
220  NS_ASSERT_MSG (length < 4096, "Invalid length");
221  m_length = length;
222 }
223 
224 uint16_t
226 {
227  return m_length;
228 }
229 
230 void
232 {
233  uint8_t byte = 0;
234  uint16_t bytes = 0;
235 
236  byte |= m_rate;
237  byte |= (m_length & 0x07) << 5;
238  start.WriteU8 (byte);
239 
240  bytes |= (m_length & 0x0ff8) >> 3;
241  start.WriteU16 (bytes);
242 }
243 
244 uint32_t
246 {
248 
249  uint8_t byte = i.ReadU8 ();
250  m_rate = byte & 0x0f;
251  m_length = (byte >> 5) & 0x07;
252 
253  uint16_t bytes = i.ReadU16 ();
254  m_length |= (bytes << 3) & 0x0ff8;
255 
256  return i.GetDistanceFrom (start);
257 }
258 
259 } //namespace ns3
uint16_t ReadU16(void)
Definition: buffer.h:1029
Protocol header serialization and deserialization.
Definition: header.h:42
Declaration of ns3::OfdmPhy class and ns3::OfdmPhyVariant enum.
Simulation virtual time values and global simulation resolution.
Definition: nstime.h:103
#define NS_LOG_FUNCTION(parameters)
If log level LOG_FUNCTION is enabled, this macro will output all input parameters separated by "...
This class mimics the TXVECTOR which is to be passed to the PHY in order to define the parameters whi...
void SetChannelWidth(uint16_t channelWidth)
Sets the selected channelWidth (in MHz)
Ptr< const WifiPsdu > GetPsdu(void) const
Get the payload of the PPDU.
Definition: wifi-ppdu.cc:79
uint16_t GetLength(void) const
Return the LENGTH field of L-SIG (in bytes).
Definition: ofdm-ppdu.cc:225
def start()
Definition: core.py:1855
LSigHeader m_lSig
the L-SIG PHY header
Definition: ofdm-ppdu.h:130
WifiTxVector GetTxVector(void) const
Get the TXVECTOR used to send the PPDU.
Definition: wifi-ppdu.cc:63
uint64_t m_uid
the unique ID of this PPDU
Definition: wifi-ppdu.h:160
#define NS_LOG_COMPONENT_DEFINE(name)
Define a Log component with a specific name.
Definition: log.h:205
OfdmPpdu(Ptr< const WifiPsdu > psdu, const WifiTxVector &txVector, WifiPhyBand band, uint64_t uid, bool instantiateLSig=true)
Create an OFDM PPDU.
Definition: ofdm-ppdu.cc:33
uint64_t GetRate(uint16_t channelWidth=20) const
Return the RATE field of L-SIG (in bit/s).
Definition: ofdm-ppdu.cc:173
static WifiMode GetOfdmRate(uint64_t rate, uint16_t bw=20)
Return a WifiMode for OFDM corresponding to the provided rate and the channel bandwidth (20...
Definition: ofdm-phy.cc:359
Declaration of ns3::OfdmPpdu class.
WifiPhyBand m_band
the WifiPhyBand used to transmit that PPDU
Definition: ofdm-ppdu.h:128
iterator in a Buffer instance
Definition: buffer.h:98
void SetRate(uint64_t rate, uint16_t channelWidth=20)
Fill the RATE field of L-SIG (in bit/s).
Definition: ofdm-ppdu.cc:120
uint32_t GetSize(void) const
Return the size of the PSDU in bytes.
Definition: wifi-psdu.cc:260
WifiMode GetMode(uint16_t staId=SU_STA_ID) const
If this TX vector is associated with an SU PPDU, return the selected payload transmission mode...
uint32_t GetDistanceFrom(Iterator const &o) const
Definition: buffer.cc:783
static Time CalculateTxDuration(uint32_t size, const WifiTxVector &txVector, WifiPhyBand band, uint16_t staId=SU_STA_ID)
Definition: wifi-phy.cc:1616
WifiPreamble m_preamble
the PHY preamble
Definition: wifi-ppdu.h:157
WifiPpdu stores a preamble, a modulation class, PHY headers and a PSDU.
Definition: wifi-ppdu.h:51
Every class exported by the ns3 library is enclosed in the ns3 namespace.
void SetPreambleType(WifiPreamble preamble)
Sets the preamble type.
virtual Ptr< WifiPpdu > Copy(void) const override
Copy this instance.
Definition: ofdm-ppdu.cc:74
virtual WifiTxVector DoGetTxVector(void) const override
Get the TXVECTOR used to send the PPDU.
Definition: ofdm-ppdu.cc:53
void SetMode(WifiMode mode)
Sets the selected payload transmission mode.
#define NS_ASSERT_MSG(condition, message)
At runtime, in debugging builds, if this condition is not true, the program prints the message to out...
Definition: assert.h:88
virtual Time GetTxDuration(void) const override
Get the total transmission duration of the PPDU.
Definition: ofdm-ppdu.cc:65
WifiPhyBand
Identifies the PHY band.
Definition: wifi-phy-band.h:32
virtual ~OfdmPpdu()
Destructor for OfdmPpdu.
Definition: ofdm-ppdu.cc:48
void Print(std::ostream &os) const
Definition: ofdm-ppdu.cc:107
Time Seconds(double value)
Construct a Time in the indicated unit.
Definition: nstime.h:1289
TypeId GetInstanceTypeId(void) const
Get the most derived TypeId for this Object.
Definition: ofdm-ppdu.cc:101
OFDM and ERP OFDM L-SIG PHY header.
Definition: ofdm-ppdu.h:55
uint8_t ReadU8(void)
Definition: buffer.h:1021
void Serialize(Buffer::Iterator start) const
Definition: ofdm-ppdu.cc:231
uint32_t GetSerializedSize(void) const
Definition: ofdm-ppdu.cc:114
uint32_t Deserialize(Buffer::Iterator start)
Definition: ofdm-ppdu.cc:245
void SetLength(uint16_t length)
Fill the LENGTH field of L-SIG (in bytes).
Definition: ofdm-ppdu.cc:218
static TypeId GetTypeId(void)
Get the type ID.
Definition: ofdm-ppdu.cc:90
a unique identifier for an interface.
Definition: type-id.h:58
TypeId SetParent(TypeId tid)
Set the parent TypeId.
Definition: type-id.cc:923
uint64_t GetDataRate(uint16_t channelWidth, uint16_t guardInterval, uint8_t nss) const
Definition: wifi-mode.cc:100
uint16_t m_channelWidth
the channel width used to transmit that PPDU in MHz
Definition: ofdm-ppdu.h:129