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