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wifi-mac.cc
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2008 INRIA
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: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
19  */
20 #include "wifi-mac.h"
21 #include "dcf.h"
22 #include "ns3/uinteger.h"
23 #include "ns3/trace-source-accessor.h"
24 
25 namespace ns3 {
26 
27 NS_OBJECT_ENSURE_REGISTERED (WifiMac);
28 
29 Time
30 WifiMac::GetDefaultMaxPropagationDelay (void)
31 {
32  // 1000m
33  return Seconds (1000.0 / 300000000.0);
34 }
35 Time
36 WifiMac::GetDefaultSlot (void)
37 {
38  // 802.11-a specific
39  return MicroSeconds (9);
40 }
41 Time
42 WifiMac::GetDefaultSifs (void)
43 {
44  // 802.11-a specific
45  return MicroSeconds (16);
46 }
47 Time
48 WifiMac::GetDefaultRifs (void)
49 {
50  //802.11n specific
51  return MicroSeconds (2);
52 }
53 Time
54 WifiMac::GetDefaultEifsNoDifs (void)
55 {
56  return GetDefaultSifs () + GetDefaultCtsAckDelay ();
57 }
58 Time
59 WifiMac::GetDefaultCtsAckDelay (void)
60 {
61  // 802.11-a specific: 6mb/s
62  return MicroSeconds (44);
63 }
64 Time
65 WifiMac::GetDefaultCtsAckTimeout (void)
66 {
67  /* Cts_Timeout and Ack_Timeout are specified in the Annex C
68  (Formal description of MAC operation, see details on the
69  Trsp timer setting at page 346)
70  */
71  Time ctsTimeout = GetDefaultSifs ();
72  ctsTimeout += GetDefaultCtsAckDelay ();
73  ctsTimeout += MicroSeconds (GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2);
74  ctsTimeout += GetDefaultSlot ();
75  return ctsTimeout;
76 }
77 
78 Time
79 WifiMac::GetDefaultBasicBlockAckDelay (void)
80 {
81  // This value must be rivisited
82  return MicroSeconds (250);
83 }
84 Time
85 WifiMac::GetDefaultCompressedBlockAckDelay (void)
86 {
87  // This value must be rivisited was 68.
88  //CompressedBlockAckSize 32* 8*time it takes to transfer at the lowest rate (6Mb/s)+ aPhy-StartDelay(33)
89  return MicroSeconds (76);
90 }
91 Time
92 WifiMac::GetDefaultBasicBlockAckTimeout (void)
93 {
94  Time blockAckTimeout = GetDefaultSifs ();
95  blockAckTimeout += GetDefaultBasicBlockAckDelay ();
96  blockAckTimeout += MicroSeconds (GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2);
97  blockAckTimeout += GetDefaultSlot ();
98  return blockAckTimeout;
99 }
100 Time
101 WifiMac::GetDefaultCompressedBlockAckTimeout (void)
102 {
103  Time blockAckTimeout = GetDefaultSifs ();
104  blockAckTimeout += GetDefaultCompressedBlockAckDelay ();
105  blockAckTimeout += MicroSeconds (GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2);
106  blockAckTimeout += GetDefaultSlot ();
107  return blockAckTimeout;
108 }
109 
110 void
111 WifiMac::SetBasicBlockAckTimeout (Time blockAckTimeout)
112 {
113  //this method must be implemented by QoS WifiMacs
114 }
115 
116 Time
117 WifiMac::GetBasicBlockAckTimeout (void) const
118 {
119  //this method must be implemented by QoS WifiMacs
120  return MicroSeconds (0);
121 }
122 
123 void
124 WifiMac::SetCompressedBlockAckTimeout (Time blockAckTimeout)
125 {
126  //this methos must be implemented by QoS WifiMacs
127 }
128 
129 Time
130 WifiMac::GetCompressedBlockAckTimeout (void) const
131 {
132  //this method must be implemented by QoS WifiMacs
133  return MicroSeconds (0);
134 }
135 
136 TypeId
137 WifiMac::GetTypeId (void)
138 {
139  static TypeId tid = TypeId ("ns3::WifiMac")
140  .SetParent<Object> ()
141  .AddAttribute ("CtsTimeout", "When this timeout expires, the RTS/CTS handshake has failed.",
142  TimeValue (GetDefaultCtsAckTimeout ()),
143  MakeTimeAccessor (&WifiMac::SetCtsTimeout,
144  &WifiMac::GetCtsTimeout),
145  MakeTimeChecker ())
146  .AddAttribute ("AckTimeout", "When this timeout expires, the DATA/ACK handshake has failed.",
147  TimeValue (GetDefaultCtsAckTimeout ()),
148  MakeTimeAccessor (&WifiMac::GetAckTimeout,
149  &WifiMac::SetAckTimeout),
150  MakeTimeChecker ())
151  .AddAttribute ("BasicBlockAckTimeout", "When this timeout expires, the BASIC_BLOCK_ACK_REQ/BASIC_BLOCK_ACK handshake has failed.",
152  TimeValue (GetDefaultBasicBlockAckTimeout ()),
153  MakeTimeAccessor (&WifiMac::GetBasicBlockAckTimeout,
154  &WifiMac::SetBasicBlockAckTimeout),
155  MakeTimeChecker ())
156  .AddAttribute ("CompressedBlockAckTimeout", "When this timeout expires, the COMPRESSED_BLOCK_ACK_REQ/COMPRESSED_BLOCK_ACK handshake has failed.",
157  TimeValue (GetDefaultCompressedBlockAckTimeout ()),
158  MakeTimeAccessor (&WifiMac::GetCompressedBlockAckTimeout,
159  &WifiMac::SetCompressedBlockAckTimeout),
160  MakeTimeChecker ())
161  .AddAttribute ("Sifs", "The value of the SIFS constant.",
162  TimeValue (GetDefaultSifs ()),
163  MakeTimeAccessor (&WifiMac::SetSifs,
164  &WifiMac::GetSifs),
165  MakeTimeChecker ())
166  .AddAttribute ("EifsNoDifs", "The value of EIFS-DIFS",
167  TimeValue (GetDefaultEifsNoDifs ()),
168  MakeTimeAccessor (&WifiMac::SetEifsNoDifs,
169  &WifiMac::GetEifsNoDifs),
170  MakeTimeChecker ())
171  .AddAttribute ("Slot", "The duration of a Slot.",
172  TimeValue (GetDefaultSlot ()),
173  MakeTimeAccessor (&WifiMac::SetSlot,
174  &WifiMac::GetSlot),
175  MakeTimeChecker ())
176  .AddAttribute ("Pifs", "The value of the PIFS constant.",
177  TimeValue (GetDefaultSifs () + GetDefaultSlot ()),
178  MakeTimeAccessor (&WifiMac::SetPifs,
179  &WifiMac::GetPifs),
180  MakeTimeChecker ())
181 .AddAttribute ("Rifs", "The value of the RIFS constant.",
182  TimeValue (GetDefaultRifs ()),
183  MakeTimeAccessor (&WifiMac::SetRifs,
184  &WifiMac::GetRifs),
185  MakeTimeChecker ())
186 
187  .AddAttribute ("MaxPropagationDelay", "The maximum propagation delay. Unused for now.",
188  TimeValue (GetDefaultMaxPropagationDelay ()),
189  MakeTimeAccessor (&WifiMac::m_maxPropagationDelay),
190  MakeTimeChecker ())
191  .AddAttribute ("Ssid", "The ssid we want to belong to.",
192  SsidValue (Ssid ("default")),
193  MakeSsidAccessor (&WifiMac::GetSsid,
194  &WifiMac::SetSsid),
195  MakeSsidChecker ())
196  .AddTraceSource ("MacTx",
197  "A packet has been received from higher layers and is being processed in preparation for "
198  "queueing for transmission.",
199  MakeTraceSourceAccessor (&WifiMac::m_macTxTrace))
200  .AddTraceSource ("MacTxDrop",
201  "A packet has been dropped in the MAC layer before being queued for transmission.",
202  MakeTraceSourceAccessor (&WifiMac::m_macTxDropTrace))
203  .AddTraceSource ("MacPromiscRx",
204  "A packet has been received by this device, has been passed up from the physical layer "
205  "and is being forwarded up the local protocol stack. This is a promiscuous trace,",
206  MakeTraceSourceAccessor (&WifiMac::m_macPromiscRxTrace))
207  .AddTraceSource ("MacRx",
208  "A packet has been received by this device, has been passed up from the physical layer "
209  "and is being forwarded up the local protocol stack. This is a non-promiscuous trace,",
210  MakeTraceSourceAccessor (&WifiMac::m_macRxTrace))
211  .AddTraceSource ("MacRxDrop",
212  "A packet has been dropped in the MAC layer after it has been passed up from the physical "
213  "layer.",
214  MakeTraceSourceAccessor (&WifiMac::m_macRxDropTrace))
215 #if 0
216  // Not currently implemented in this device
217  .AddTraceSource ("Sniffer",
218  "Trace source simulating a non-promiscuous packet sniffer attached to the device",
219  MakeTraceSourceAccessor (&WifiMac::m_snifferTrace))
220 #endif
221  ;
222 
223  return tid;
224 }
225 
226 void
227 WifiMac::SetMaxPropagationDelay (Time delay)
228 {
229  m_maxPropagationDelay = delay;
230 }
231 
232 Time
233 WifiMac::GetMsduLifetime (void) const
234 {
235  return Seconds (10);
236 }
237 Time
238 WifiMac::GetMaxPropagationDelay (void) const
239 {
240  return m_maxPropagationDelay;
241 }
242 
243 void
244 WifiMac::NotifyTx (Ptr<const Packet> packet)
245 {
246  m_macTxTrace (packet);
247 }
248 
249 void
250 WifiMac::NotifyTxDrop (Ptr<const Packet> packet)
251 {
252  m_macTxDropTrace (packet);
253 }
254 
255 void
256 WifiMac::NotifyRx (Ptr<const Packet> packet)
257 {
258  m_macRxTrace (packet);
259 }
260 
261 void
262 WifiMac::NotifyPromiscRx (Ptr<const Packet> packet)
263 {
264  m_macPromiscRxTrace (packet);
265 }
266 
267 void
268 WifiMac::NotifyRxDrop (Ptr<const Packet> packet)
269 {
270  m_macRxDropTrace (packet);
271 }
272 
273 void
274 WifiMac::ConfigureStandard (enum WifiPhyStandard standard)
275 {
276  switch (standard)
277  {
278  case WIFI_PHY_STANDARD_80211a:
279  Configure80211a ();
280  break;
281  case WIFI_PHY_STANDARD_80211b:
282  Configure80211b ();
283  break;
284  case WIFI_PHY_STANDARD_80211g:
285  Configure80211g ();
286  break;
287  case WIFI_PHY_STANDARD_80211_10MHZ:
288  Configure80211_10Mhz ();
289  break;
290  case WIFI_PHY_STANDARD_80211_5MHZ:
291  Configure80211_5Mhz ();
292  break;
293  case WIFI_PHY_STANDARD_holland:
294  Configure80211a ();
295  break;
296  case WIFI_PHY_STANDARD_80211p_CCH:
297  Configure80211p_CCH ();
298  break;
299  case WIFI_PHY_STANDARD_80211p_SCH:
300  Configure80211p_SCH ();
301  break;
302  case WIFI_PHY_STANDARD_80211n_2_4GHZ:
303  Configure80211n_2_4Ghz ();
304  break;
305  case WIFI_PHY_STANDARD_80211n_5GHZ:
306  Configure80211n_5Ghz ();
307  break;
308  default:
309  NS_ASSERT (false);
310  break;
311  }
312  FinishConfigureStandard (standard);
313 }
314 
315 void
316 WifiMac::Configure80211a (void)
317 {
318  SetSifs (MicroSeconds (16));
319  SetSlot (MicroSeconds (9));
320  SetEifsNoDifs (MicroSeconds (16 + 44));
321  SetPifs (MicroSeconds (16 + 9));
322  SetCtsTimeout (MicroSeconds (16 + 44 + 9 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));
323  SetAckTimeout (MicroSeconds (16 + 44 + 9 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));
324 }
325 
326 void
327 WifiMac::Configure80211b (void)
328 {
329  SetSifs (MicroSeconds (10));
330  SetSlot (MicroSeconds (20));
331  SetEifsNoDifs (MicroSeconds (10 + 304));
332  SetPifs (MicroSeconds (10 + 20));
333  SetCtsTimeout (MicroSeconds (10 + 304 + 20 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));
334  SetAckTimeout (MicroSeconds (10 + 304 + 20 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));
335 }
336 
337 void
338 WifiMac::Configure80211g (void)
339 {
340  SetSifs (MicroSeconds (10));
341  // Note no support for Short Slot Time as yet
342  SetSlot (MicroSeconds (20));
343  SetEifsNoDifs (MicroSeconds (10 + 304));
344  SetPifs (MicroSeconds (10 + 20));
345  SetCtsTimeout (MicroSeconds (10 + 304 + 20 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));
346  SetAckTimeout (MicroSeconds (10 + 304 + 20 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));
347 }
348 
349 void
350 WifiMac::Configure80211_10Mhz (void)
351 {
352  SetSifs (MicroSeconds (32));
353  SetSlot (MicroSeconds (13));
354  SetEifsNoDifs (MicroSeconds (32 + 88));
355  SetPifs (MicroSeconds (32 + 13));
356  SetCtsTimeout (MicroSeconds (32 + 88 + 13 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));
357  SetAckTimeout (MicroSeconds (32 + 88 + 13 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));
358 }
359 
360 void
361 WifiMac::Configure80211_5Mhz (void)
362 {
363  SetSifs (MicroSeconds (64));
364  SetSlot (MicroSeconds (21));
365  SetEifsNoDifs (MicroSeconds (64 + 176));
366  SetPifs (MicroSeconds (64 + 21));
367  SetCtsTimeout (MicroSeconds (64 + 176 + 21 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));
368  SetAckTimeout (MicroSeconds (64 + 176 + 21 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));
369 }
370 
371 void
372 WifiMac::Configure80211p_CCH (void)
373 {
374  Configure80211_10Mhz ();
375 }
376 
377 void
378 WifiMac::Configure80211p_SCH (void)
379 {
380  Configure80211_10Mhz ();
381 }
382 void
383 WifiMac::Configure80211n_2_4Ghz (void)
384 {
385  Configure80211g ();
386  SetRifs(MicroSeconds (2));
387  SetCtsTimeout (MicroSeconds (10 + 52 + 20 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));
388  SetAckTimeout (MicroSeconds (10 + 52 + 20 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));
389 }
390 void
391 WifiMac::Configure80211n_5Ghz (void)
392 {
393  Configure80211a ();
394  SetRifs(MicroSeconds (2));
395  SetCtsTimeout (MicroSeconds (10 + 52 + 20 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));
396  SetAckTimeout (MicroSeconds (10 + 52 + 20 + GetDefaultMaxPropagationDelay ().GetMicroSeconds () * 2));
397 }
398 
399 void
400 WifiMac::ConfigureDcf (Ptr<Dcf> dcf, uint32_t cwmin, uint32_t cwmax, enum AcIndex ac)
401 {
402  /* see IEE802.11 section 7.3.2.29 */
403  switch (ac)
404  {
405  case AC_VO:
406  dcf->SetMinCw ((cwmin + 1) / 4 - 1);
407  dcf->SetMaxCw ((cwmin + 1) / 2 - 1);
408  dcf->SetAifsn (2);
409  break;
410  case AC_VI:
411  dcf->SetMinCw ((cwmin + 1) / 2 - 1);
412  dcf->SetMaxCw (cwmin);
413  dcf->SetAifsn (2);
414  break;
415  case AC_BE:
416  dcf->SetMinCw (cwmin);
417  dcf->SetMaxCw (cwmax);
418  dcf->SetAifsn (3);
419  break;
420  case AC_BK:
421  dcf->SetMinCw (cwmin);
422  dcf->SetMaxCw (cwmax);
423  dcf->SetAifsn (7);
424  break;
425  case AC_BE_NQOS:
426  dcf->SetMinCw (cwmin);
427  dcf->SetMaxCw (cwmax);
428  dcf->SetAifsn (2);
429  break;
430  case AC_UNDEF:
431  NS_FATAL_ERROR ("I don't know what to do with this");
432  break;
433  }
434 }
435 
436 void
437 WifiMac::ConfigureCCHDcf (Ptr<Dcf> dcf, uint32_t cwmin, uint32_t cwmax, enum AcIndex ac)
438 {
439  /* see IEEE 1609.4-2006 section 6.3.1, Table 1 */
440  switch (ac)
441  {
442  case AC_VO:
443  dcf->SetMinCw ((cwmin + 1) / 4 - 1);
444  dcf->SetMaxCw ((cwmin + 1) / 2 - 1);
445  dcf->SetAifsn (2);
446  break;
447  case AC_VI:
448  dcf->SetMinCw ((cwmin + 1) / 4 - 1);
449  dcf->SetMaxCw ((cwmin + 1) / 2 - 1);
450  dcf->SetAifsn (3);
451  break;
452  case AC_BE:
453  dcf->SetMinCw ((cwmin + 1) / 2 - 1);
454  dcf->SetMaxCw (cwmin);
455  dcf->SetAifsn (6);
456  break;
457  case AC_BK:
458  dcf->SetMinCw (cwmin);
459  dcf->SetMaxCw (cwmax);
460  dcf->SetAifsn (9);
461  break;
462  case AC_BE_NQOS:
463  dcf->SetMinCw (cwmin);
464  dcf->SetMaxCw (cwmax);
465  dcf->SetAifsn (2);
466  break;
467  case AC_UNDEF:
468  NS_FATAL_ERROR ("I don't know what to do with this");
469  break;
470  }
471 }
472 } // namespace ns3