wireless ad-hoc networks

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???t?a ?ad??pa??t??
? a?µ? (i,j) ?p???e?, ?ta? ? j µp??e? ?a a???e?
t?? i
s????? ???e???? s??????se?? (collision free set
- CFS) ??a s????? s??d?sµ?? p?? µp??e? ?a
µetaf??e? pa??ta s????????, ????? ?a s?µßa??e?
s??????s? st??? d??te?
?a??de??µa d?a??sµat?? ???e???? s??????se??
(collision free vector - CFV)
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????p?e??a µe d?a??es? ?????? (TDM) ??a d??t?a
µet?d?s?? ?ad??pa??t??
CFVs, L ? a???µ?? t?? s??d?sµ??
?????µe µ?a s??sµ? se ???e s????? e?e??e?? ap?
s??????se??
d????sµa p?? d??e? t? ???sµa t?? ?????? ???s??
???e s??d?sµ??
d????sµa ???s?µ?p???s?? (utilization vector)
Ge????te?a ?st? aj t? p?s?st? t?? ?????? p?? t?
j-st? CFV ???s?µ?p??e?ta?
d????sµa p?? d??e? ??a p??? µ???? µ???? (???sµa)
t?? ?????? ???s?? ???e s??d?sµ??

• ?ed?µ???? , ß?e? aj t?t??a ?ste

• A??µa ?e???te?a ta e?e??e?a ap? s??????se??
  s????a a??????? (st?? p?a?µat???t?ta a??µa ?a?
  ??a ??a stat??? d??t??, e??a? NP-complete)

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?e?????? ep???s?? s??????se?? ??a Packet
Radio ?.?. Aloha µe s??sµ?? ?? p??ß??µa e??a?
t? a?a???p?st? feedback. ?a??de??µa 1 1?2 ?a?
4?5 ? s??????s? st? 2, a??? ? 1 de? t?
???e? ?a??de??µa 2 6?1 ?a? 4?5 ? ?a? ?? d??
µetad?se?? e??a? ep?t??e??, a??? ?p???e?
s??????s? st?? 2, p?? de? ???e? a? ? µet?d?s?
p???????ta? ??a a?t??. ??s? ???s? ACK
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e???? e?p?µp?? t?? ?
e???? e?p?µp?? t?? ?

1. t? p??ß??µa t?? ???µµ???? te?µat???? (hidden
   terminal) ? C de? µp??e? ?a a???se? t??
   µetad?se?? t?? A
2. t? p??ß??µa t?? e?te?e?µ???? te?µat???? (exposed
   terminal) ? C a?aß???e? t? µet?d?s? p??? t?? D,
   ??at? a???e? t? µet?d?s? t?? B

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?e ?e?t???? ?p?d?µ? (BS)
????? ???s? BSS
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Wi-Fi s?st?µata (802.11)
st???e?a t?? 802.11 ??a LANs
s????? e?tetaµ???? ?p??es?a? ?a? ?p?st?????
????t???t?ta?
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???e??t? ?e?a???a ?a? ete???e?? as??µata d??t?a
ded?µ????
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eµß??e?a pa?eµß????
eµß??e?a a????e?s?? f????t??
????????
eµß??e?a µet?d?s??
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• 802.11a, p?????ta eµfa??s???a? t? 2001. ?????
  54Mbps, sta 5GHz. OFDM
• 802.11b p?????ta eµfa??s???a? t? 1999. ?????
  11Mbps, sta 2.4GHz. DSSS
• 802.11g d??d???? t?? 802.11b, µ???? 54Mbps, sta
  2.4GHz. OFDM
• 802.11h, ?a e??a? t? e???pa??? 802.11a, sta 5GHz.
• ???a 802.11i p?? ???s?µ?p??e? t? Temporal Key
  Integrity Protocol (TKIP) ??a a??et? ?a??
  asf??e?a. 802.11x t?? Microsoft ??a
  authentication.
• ?a pa?ap??? (Wi-Fi) s?st?µata d???e???? ?a??
  ?????? ??a ap?st?se?? t?? t???? t?? 100µ.
• G?a µe?a??te?e? ap?st?se?? t? WiMax (802.15)
  d??e? µe?a??te?e? ta??t?te? (75Mbps) ?a?
  ap?st?se?? (kms)

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???????µ?? ???µ?????s?? ??a ?e???a ???t?a
T?µata µe????? d??t??? ? a???s? t?? a???µ?? t??
??µß??, µe sta?e?? p????t?ta ??µß??, ?d??e? st??
a???s? t?? µ?s?? a???µ?? hop ?at? O(N0.5) ??
d?a??s?µ? e???? ????? ??a ???e ???st? µe???eta?
?at? N0.5 ?a ??ass??? p??t?????a e??µ???s??
t?p?????a? d??t??? ap??? de? d???e???? ? ??????
??a ?a d?ad????? st? d??t?? ?? e??µe??se?? ??a t?
d??µ?????s? µe?a???e? µe N0.5. ??t? s?µa??e?, p??
?? p????f???e? a?t?? p??pe? ?a µetad?d??ta? p??
s???? ?a??? µe?a???e? t? d??t??, ?ts?
ep?ßa???eta? t? d??t??. ?? te??????
d??µ?????s?? p?? ?a??d?????ta? ap? ?e????ta
(event-driven routing) de ß?????e p??? ap?
??p??? ????, ??? t? d?a??s?µ? e???? ?????
d?at??eta? ??a t?? p????f???e? d??µ?????s??.
??s? ?pa?t???ta? s??desµ?? ?a??????a????
(backbone), ??a ?a d?asfa??ste? p?? t? µ?s? µ????
t?? d?ad??µ?? µe?a???e? p?? a??? µe t? µ??e???
t?? d??t???.
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• ?e????? ef??t?? p??se???se??
• ?p?????? ?ept?µe?e??? ap? ta µa????? µ??? t??
  d??t???
• ?? ap?f?se?? ??a t? ep?µe?? hop e?a?t??ta? µ???
  ap? t?? t?p??? pe?????.
• F???e? st? µ?a?? ?e?a??????? a??????µ???.
• ?p?st??? p????f????? ??a µa????? µ??? ????te??
  s????
• ?? ep?µe?? hop e??a? ap??a?? ?a a????e?
  d?aµat???, a? se ??p??? µa????? µ???? t?? d??t???
  ?p?????? a??a??? t?p?????a?.
• ???????µ?? a?ta??a??? p????f?????
  s??e?t???t?ta? µe st??µata p??te?a??t?ta?
  (prioritized tier connectivity information
  exchange) ???s?µ?p??e? p?? ?????e? p????f???e?
  ?s? t? pa??t? p??s???e? t?? p?????sµ?.
• ?p?st??? p????f????? µ??? se ??µß??? p?? t??
  ??e?????ta?
• ???????µ?? d??µ?????s?? d?a??sµat?? ap?st?se??
  µe ?at?f?? (threshold distance vector) a? ??
  a??a??? de? ep???e????? t?? p???t?ta t??
  d?ad??µ?? se µe???? ßa?µ?, de? a?af????ta?.

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??st??? ?e?a????? d??µ?????s? ? ??µß??-a??????
t?? ???e ?µ?da?, p?? ?p??????e? ?e?a???????
p??a?e? d??µ?????s??, ?a?????e? t?? ep?µe?? ?µ?da
p?? p??pe? ?a p?e? ??p??? pa??t? ??a ?a ft?se?
st?? ?µ?da t?? p?????sµ?? t??. ?? a??????
d?a??µ??? t?? p????f???a d??µ?????s?? st???
??µß??? µ?sa st?? ?µ?da t??? ????? ft?se? st??
?µ?da p?????sµ??, ???s?µ?p??e?ta? ??p??a te?????
d??µ?????s?? es?te???? st?? ?µ?da, ??a ?a ft?se?
st?? te???? ??µß?-p?????sµ?. ?e???eta? t?
µ??e??? t?? apa?a?t?t?? p????f???a? ??a ?a p??e?
??a? ??µß?? ap?f?se?? d??µ?????s??.
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?? ?e?a?????? a??????µ?? ???????µ??
d??µ?????s?? Bellman-Ford µe ?at?f?? ?e???e?
t?? ap?stas? st?? ?p??a d?ad?deta? ? e??µ???s?
??a t? d??µ?????s? dj cij lt di lt dj a
cij di e??a? ? ap?stas? ap? t?? ??µß? i st??
p?????sµ? j e??a? ? ep?µe??? ??µß?? st?
d?ad??µ? cij e??a? t? ??st?? t?? ???s?? t??
s??d?sµ?? ap? t? i st? j a? a????e? t? a,
µetad?d??ta? ????te?a µ???µata e??µ???s?? ?a? ta
µ??? t?? d?ad??µ?? a??????ta? e?af??
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???µµ???sµa (flooding) ??a pa??d?s? ded?µ????

• ? ap?st???a? S e?p?µpe? t? pa??t? ded?µ???? P se
  ????? t??? ?e?t???? t??
• ???e ??µß?? p?? ?aµß??e? t? P, t? p????e? se
  ????? t?? t??? ?e?t??e?
• Sequence numbers ???s?µ?p?????ta? ??a t?? ap?f???
  t?? p??a??t?ta? p?????s?? t?? ?d??? pa??t??
  pe??ss?te?e? t?? µ?a? f????
• ?? pa??t? P p??ta ft??e? st?? p?????sµ? D, a??e?
  ? D e??a? p??spe??s?µ?? ap? t?? ap?st???a S
• ? ??µß?? D de? p????e? t? pa??t?

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???µµ???sµa (flooding) ??a pa??d?s? ded?µ????
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a?apa??st? ??µß? p?? ??e? ??ße? t? P
a?apa??st? t? ?t? ?? s??dedeµ???? ??µß??
ß??s???ta? ? ??a? µ?sa st? e???? µet?d?s?? t??
?????
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???µµ???sµa (flooding) ??a pa??d?s? ded?µ????
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µet?d?s? e?p?µp??
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a?apa??st? ??µß? p?? ?aµß??e? t? P ??a p??t? f???
a?apa??st? µet?d?s? t?? P
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???µµ???sµa (flooding) ??a pa??d?s? ded?µ????
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• ? ??µß?? H ?aµß??e? t? pa??t? P ap? d??
  ?e?t??e?
• p??a??t?ta ??a s??????s?

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???µµ???sµa (flooding) ??a pa??d?s? ded?µ????
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• ? ??µß?? C ?aµß??e? t? pa??t? P apt??? G ?a? H,
  a??? de? t?
• p????e? ?a??, ??at? ? ??µß?? C ??e? ?d?
  p?????se? t? pa??t?
• P µ?a f???

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???µµ???sµa (flooding) ??a pa??d?s? ded?µ????
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• ?? ??µß?? J ?a? K µetad?d??? ?a? ?? d?? t?
  pa??t? P p??? t?? ??µß? D
• ef?s?? ?? J ?a? K ???ß??ta? ? ??a? apt?? ????,
  ?? µetad?se?? t???
• µp??e? ?a s??????st???
• gt t? pa??t? P µp??e? ?a µ? µetafe??e?
  st?? ??µß? D ?a?????,
• pa?? t? ???s? t?? a??????µ??
  p??µµ???sµat??

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???µµ???sµa (flooding) ??a pa??d?s? ded?µ????
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• ? ??µß?? D de? p????e? t? pa??t? P, ??at? ?
  ??µß?? D
• e??a? ? ep???µ?t?? p?????sµ?? t?? pa??t?? P

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???µµ???sµa (flooding) ??a pa??d?s? ded?µ????
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• t? p??µµ???sµa ???????????e
• ??µß?? µ? p??spe??s?µ?? ap? t?? S de ?aµß?????
  t? pa??t? P (p? ? Z)
• ??µß?? t?? ?p???? ??a ta µ???p?t?a ap? t?? S
  d??????ta? µ?s? t??
• p?????sµ?? D, ep?s?? de ?aµß????? t? pa??t? P
  (p? ? N)

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???µµ???sµa (flooding) ??a pa??d?s? ded?µ????
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• t? p??µµ???sµa µp??e? ?a µetaf??e? pa??ta se
  p??a p??????
• ??µß??? (st? ?e???te?? pe??pt?s?, ???? ??
  p??spe??s?µ?? ap?
• t?? ap?st???a ??µß?? µp??e? ?a ??ß??? t? pa??t?)

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??e??e?t?µata

• ap??t?ta
• µp??e? ?a e??a? p?? ap?d?t??? ap? ???a
  p??t?????a, ?ta? t? overhead ??a t??
  a?a??????/d?at???s? d??µ??????? p?? ep?f??eta?
  ap? ta ???a p??t?????a e??a? ?????
• a?t? t? se????? µp??e? ?a eµfa??ste?, ??a
  pa??de??µa, ?ta? ?? ??µß?? e?p?µp??? µ???? pa??ta
  ded?µ???? s?et??? sp???a ?a? p????? t?p????????
  a??a??? s?µßa????? a??µesa se d?ad?????? e?p?µp??
  pa??t??
• p??a??? ?????te?? a???p?st?a st?? pa??d?s? t??
  pa??t?? epe?d? ta pa??ta pa?ad?d??ta? st??
  p?????sµ? µ?s? p???ap??? µ???pat???

?e???e?t?µata

• p??a??? p??? µe???? overhead
• ta pa??ta ded?µ???? µp??e? ?a pa?ad????? se p??a
  p?????? ??µß???, ?? ?p???? de? ta ??e?????ta?
• p??a??? ?aµ???te?? a???p?st?a st?? pa??d?s? t??
  pa??t??
• --- ???s?µ?p??e?ta? e?p?µp? e??a?
  d?s???? ?a ???p????e? a???p?st? pa??d?s? µe
• e?p?µp? ????? s?µa?t??? a???s? t??
  overhead
• st? pa??de??µ? µa?, ?? ??µß?? J ?a? K µp??e? ?a
  µetad?s??? st?? ??µß? D ta?t?????a, µe ap?t??esµa
  t?? ap??e?a t?? pa??t?? - se a?t? t?? pe??pt?s?,
  t? pa??t? de ?a ft?se? ?a????? st?? p?????sµ?

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???µµ???sµa t?? pa??t?? e??????

• p???? p??t?????a ???s?µ?p????? (e?de??µ????
  pe?????sµ???) p??µµ???sµa pa??t?? e?????? ?a?
  ??? t?? pa??t?? ded?µ????
• ta pa??ta e?????? ???s?µ?p?????ta? ??a t??
  a?a?????? d??µ???????
• ta d??µ?????a a?t? a???????? ???s?µ?p?????ta? ??a
  t? µetaf??? pa??t?? ded?µ????
• ?? overhead ??a t? p??µµ???sµa t?? pa??t??
  e?????? ep?µe???eta? ep? t?? pa??t?? ded?µ????,
  p?? µetad?d??ta? a??µesa se p??µµ???sµata
  pa??t?? e??????

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???aµ??? ???µ?????s? ?????(Dynamic Source
Routing - DSR)

• ?ta? ? ??µß?? S ???e? ?a ste??e? ??a pa??t? st??
  ??µß? D, a??? de ??????e? ??p??? d??µ?????? p???
  t?? D, a?????p??e? µ?a a?a?????? µ???pat???
• ? ??µß?? afet???a S p??µµ????e? ??a pa??t?
  ??t?s?? ???µ??????? (Route Request - RREQ)
• ???e ??µß?? p??sa?te? t? d??? t?? de??t? ?a???
  p????e? t? RREQ

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??a?????? d??µ??????? st? DSR
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a?apa??st? ??µß? p?? ??e? ??ße? RREQ ??a t?? D
apt?? S
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??a?????? d??µ??????? st? DSR
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µet?d?s? e?p?µp??
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a?apa??st? µet?d?s? RREQ
X,Y a?apa??st? ??sta ap? de??te?
p??sa?t?µ????? st? RREQ
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??a?????? d??µ??????? st? DSR
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S,E
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• ? ??µß?? H d??eta? pa??t? RREQ ap? d?? ?e?t??e?
• p??a??t?ta ??a s??????s?

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??a?????? d??µ??????? st? DSR
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S,E,F
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• ? ??µß?? C d??eta? RREQ apt?? G ?a? t?? H, a???
  de? t? p????e?
• ?a??, ??at? ? ??µß?? C ??e? ?d? p?????se? RREQ
  µ?a f???

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??a?????? d??µ??????? st? DSR
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S,E,F,J
B
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S,C,G,K

• ?? ??µß?? J ?a? K µetad?d??? ?a? ?? d?? RREQ
  st?? ??µß? D
• ef?s?? ?? ??µß?? J ?a? K ???ß??ta? ? ??a? ap?
  t?? ????,
• ?? µetad?se?? t??? µp??e? ?a s??????st???

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??a?????? d??µ??????? st? DSR
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S,E,F,J,M
F
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• ? ??µß?? D de? p????e? RREQ, ??at? ? ??µß?? D
• e??a? ? ep???µ?t?? st???? t?? a?a???????
  d??µ???????

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??a?????? d??µ??????? st? DSR

• ? p?????sµ?? D ?aµß????ta? t? p??t? RREQ, st???e?
  ??a pa??t? ?p??t?s?? ???µ??????? (Route Reply -
  RREP)
• t? RREP st???eta? µ?s? t?? d??µ???????, t? ?p???
  p????pte? a?t?st??f??ta? t? d??µ?????? p?? ??e?
  p??sa?t??e? st? ??f??? RREQ
• t? RREP pe???aµß??e? t? d??µ?????? ap? t?? S st??
  D, µ?s? t?? ?p???? t? RREQ ?ftase st?? ??µß? D

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?p??t?s? d??µ??????? st? DSR
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RREP S,E,F,J,D
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a?apa??st? RREP µ???µa e??????
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?p??t?s? d??µ??????? st? DSR

• ? ap??t?s? d??µ??????? µp??e? ?a sta?e?
  a?t?st??f??ta? t? d??µ?????? t?? RREQ, µ??? a? ??
  s??desµ?? e??a? e????µ??a bidirectional
• ??a ?a ßeßa???e? ??t? t?t???, p??pe? t? RREQ ?a
  p????e?ta?, µ??? a? ?aµß??eta? µ?s? s??d?sµ?? p??
  e????µ??a e??a? bidirectional
• a? µ??? directional (as?µµet???) s??desµ??
  ep?t??p??ta?, t? RREP µp??e? ?a ??e???eta? ?a?
  µ?a a?a?????? d??µ??????? ap? t?? S st?? D
• e?t?? a? ? ??µß?? D ?d? ??????e? ??a d??µ??????
  p??? t?? ??µß? S
• a? µ?a a?a?????? d??µ??????? a?????p??e?ta? ap?
  t?? D ??a ??a d??µ?????? p??? t?? S, t?te ?
  ap??t?s? d??µ??????? µetaf??eta? µa?? µe t??
  a?t?s? d??µ??????? apt?? D.
• a? t? IEEE 802.11 MAC ???s?µ?p??e?ta? ??a t??
  ap?st??? ded?µ????, t?te ?? s??desµ?? apa?te?ta?
  ?a e??a? bidirectional (ef?s?? ???s?µ?p?????ta?
  Acks)

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DSR

• ? ??µß?? S de??µe??? t? RREP, ap????e?e? t?
  d??µ?????? p?? pe????eta? st? RREP
• ?ta? ? ??µß?? S st???e? ??a pa??t? ded?µ???? st??
  D, ???????? t? d??µ?????? pe????eta? st??
  ep??efa??da t?? pa??t??
• ??a?t? ?a? t? ???µa d??µ?????s? p????
• ?? e?d??µes?? ??µß?? ???s?µ?p????? t? p??a??
  d??µ?????? p?? pe????eta? se ??a pa??t?, ??a ?a
  ?a????s??? se p???? p??pe? ?a p??????e? t? pa??t?

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?a??d?s? ded?µ???? st? DSR
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ded?µ??a S,E,F,J,D
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t? µ??e??? t?? ep??efa??da? pa??t?? µe?a???e? µe
t? µ???? t?? d??µ???????
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p?te p?a?µat?p??e?ta? a?a?????? d??µ???????

• ?ta? ? ??µß?? S ???e? ?a ste??e? ded?µ??a st??
  ??µß? D, a??? de ??????e? ??a ?????? d??µ??????
  p??? a?t??

ße?t?st?p???s? t?? DSR ap????e?s? d??µ???????

• ???e ??µß?? ap????e?e? (caches) ??a ???
  d??µ??????, t? ?p??? µa?a??e? µe ?p????d?p?te
  t??p?
• ?ta? ? ??µß?? S a?a?a???e? t? d??µ??????
  S,E,F,J,D p??? t?? ??µß? D, ? ??µß?? S ep?s??
  µa?a??e? t? d??µ?????? S,E,F p??? t?? ??µß? F
• ?ta? ? ??µß?? K de?te? ??t?s? ???µ??????? S,C,G
  ?ate?????µe?? p??? ??p???? ??µß?, µa?a??e? ?a? t?
  d??µ?????? K,G,C,S p??? t?? S
• ?ta? ? ??µß?? F p????e? ?p??t?s? ???µ???????
  S,E,F,J,D, µa?a??e? ?a? t? d??µ?????? F,J,D
  p??? t?? ??µß? D
• ?ta? ? ??µß?? E p????e? ded?µ??a S,E,F,J,D
  µa?a??e? ?a? t? d??µ?????? E,F,J,D p??? t??
  ??µß? D
• ??a? ??µß?? µp??e? ?a µ??e? ??a d??µ?????? a??µa
  ?a? ???fa??????ta? pa??ta ded?µ????

65
???s? t?? ap????e?s?? d??µ???????

• ?ta? ? ??µß?? S µa?a??e? p?? ??a d??µ?????? p???
  t?? ??µß? D ?atast??feta?, ???s?µ?p??e? ??a ????
  d??µ?????? apt?? t?p??? t?? µ??µ?, a??e? ??a
  t?t??? d??µ?????? p??? t?? D ?a ?p???e? e?e? -
  a?????, ? ??µß?? S a?????p??e? ??a a?a??????
  µ???pat???
• ? ??µß?? X de??µe??? µ?a ??t?s? ???µ??????? ??a
  ??p???? ??µß? D µp??e? ?a ste??e? µ?a ?p??t?s?
  ???µ???????, a? ??????e? ??a d??µ?????? p??? t??
  D
• ???s? t?? ap????e?s?? d??µ???????
• µp??e? ?a ep?ta???e? t?? a?a?????? µ???pat???
• µp??e? ?a e?att?se? t?? p?????s? a?t?se??
  µ???pat???

66
???s? t?? ap????e?s?? d??µ???????
S,E,F,J,D
E,F,J,D
S
E
F,J,D,F,E,S
F
B
J,F,E,S
C
M
L
J
A
G
C,S
H
D
K
G,C,S
I
N
Z
P,Q,R a?apa??st? ap????e?µ??? d??µ?????? se
??µß? (t? DSR d?at??e? ta ap????e?µ??a d??µ?????a
se de?d??e?d? d??ta??)
67
???s? t?? ap????e?s?? d??µ???????µp??e? ?a
ep?ta???e? t?? a?a?????? µ???pat???
S,E,F,J,D
E,F,J,D
S
E
F,J,D,F,E,S
F
B
J,F,E,S
C
M
L
J
G,C,S
A
G
C,S
H
D
K
K,G,C,S
I
N
RREP
RREQ
Z
?ta? ? ??µß?? Z st???e? µ?a a?t?s? d??µ???????
??a t?? ??µß? C, ? ??µß?? K ep?st??fe? µ?a
ap??t?s? d??µ??????? Z,K,G,C p??? t?? ??µß? Z,
s?????? ???s?µ?p????ta? ap????e?µ??? d??µ??????
68
???s? t?? ap????e?s?? d??µ???????µp??e? ?a
e?att?se? t?? p?????s? a?t?se?? µ???pat???
Y
S,E,F,J,D
E,F,J,D
S
E
F,J,D,F,E,S
F
B
J,F,E,S
C
M
L
J
G,C,S
A
G
C,S
H
D
K
K,G,C,S
I
N
RREP
RREQ
Z
?st? ?t? de? ?p???e? s??desµ?? a??µesa st?? D
?a? t?? Z. ? ?p??t?s? ???µ??????? (RREP) apt??
K pe??????e? t? p??µµ???sµa t?? RREQ. Ge????,
? µe??s? µp??e? ?a e??a? ????te?? d?aµat???.
69
Sf??µa ???µ???????(Route Error - RERR)
Y
Z
RERR J-D
S
E
F
B
C
M
L
J
A
G
H
D
K
I
N

• ? J st???e? ??a Sf??µa ???µ??????? st?? S ?at?
  µ???? t?? d??µ??????? J-F-E-S, ?ta? ? p??sp??e??
  t?? ?a p?????se? ??a pa??t? ded?µ???? t?? S (µe
  d??µ?????? SEFJD) µ?s? t?? J-D ap?t?????e?
• ?? ??µß?? p?? a???? t? RERR a?a?e????? ta
  ap????e?µ??a d??µ?????? t???, ??a ?a afa???s???
  t? s??desµ? J-D

70
?p????e?s? d??µ??????? ???s???!

• ?? pa???? ap????e?se?? µp??e? ?a ep?d??s???
  a???t??? st?? ap?d?s?
• µe t?? p???d? t?? ?????? ?a? t?? ????s? t??
  ???st??, ta ap????e?µ??a d??µ?????a µp??e? ?a
  ?atast??? ????a
• ??a? ap?st???a? µp??e? ?a p??spa??se? ?a ste??e?
  µ?s? d??f???? pa???? d??µ??????? (p?? p????pt???
  apt?? t?p??? µ??µ? ? ????? ep?st?afe? ap? t??
  ap????e?s? ????? ??µß??), p??? t?? e??es? e???
  ?a??? d??µ???????

71
DSR p?e??e?t?µata

• ta d??µ?????a d?at?????ta? µ??? µeta?? ??µß?? p??
  ??e???eta? ?a ep??????????
• µe???eta? ? ep??efa??da t?? d?at???s?? t??
  d??µ???????
• ? ap????e?s? µ???pat??? µp??e? ep?p???? ?a
  µe??se? t?? ep??efa??da t?? a?a???????
  d??µ???????
• µ?a µ??? a?a?????? µ???pat??? µp??e? ?a ?d???se?
  se p???? µ???p?t?a p??? t?? p?????sµ?, ???? t??
  e?d??µes?? ??µß?? p?? apa?t??? µe t? ???s? t??
  t?p???? t??? ap????e?se??

72
DSR µe???e?t?µata

• t? µ??e??? t?? ep??efa??da? t?? pa??t?? µe?a???e?
  µe t? µ???? t?? d??µ???????, ???? t??
  d??µ?????s?? p????
• t? p??µµ???sµa ap? a?t?se?? d??µ??????? µp??e?
  p??a??? ?a ft?se? se ????? t??? ??µß??? t??
  d??t???
• p??pe? ?a ap?fe?????? ?? s??????se?? a??µesa st??
  a?t?se?? d??µ???????, p?? d?ad?d??ta? ap?
  ?e?t??????te? ??µß???
• e?sa???? t??a??? ?a??ste??se?? p??? t?? p?????s?
  t?? RREQ
• a???µ???? a?ta????sµ??, a? p??a p????? apa?t?se??
  d??µ??????? ep?st??f???, ???? t?? ???s?? t??
  t?p???? ap????e?se?? t?? ??µß?? (p??ß??µa
  ?ata???sµ?? t?? RREP)
• t? p??ß??µa µp??e? ?a d?e???????e?, µe t? ?a
  ap?t??peta? ? ap?st??? RREP ap? ??a? ??µß?, a?
  a?t?? a???e? ??a ???? RREP µe s??t?µ?te??
  d??µ??????
• ??a? e?d??µes?? ??µß?? µp??e? ?a ste??e? ?p??t?s?
  ???µ??????? ???s?µ?p????ta? ??a pa???
  ap????e?µ??? d??µ??????, µ??????ta? ?ts? ?a?
  ???e? ap????e?se??
• t? p??ß??µa µp??e? ?a d?e???????e?, µe t??
  e?s?µ?t?s? ??p???? µ??a??sµ?? p?? ?a ?a?a???e?
  (p??a???) ????a ap????e?µ??a d??µ?????a ??a
  a????s? ap????e?se??,
• stat??? timeout
• p??sa?µ?st??? timeout ßas?sµ??a st?? e?st??e?a
  t?? s??d?sµ??

73
??e???? ?s????

• ? ?s??? µet?d?s?? ?a?????e?
• t? e???? t?? µet?d?s??
• t?? pa?eµß??? p?? p???a?e?ta? st??? ??????
  ??µß???

B
C
D
A
74
???s?µ?t?ta t?? e?????? ?s????

• ?et?d?s? e??? pa??t?? µe t?? e????st? a?a??a?a
  ?s?? µet?d?s??, ?ste ?a pa?a??f?e? apt??
  p?????sµ?
• ????????µ?s? e????e?a? s?µa?t??? ???d?? se
  ???ste? p?? ?e?t??????? µe µpata??a
• ?e??s? pa?eµß????
• ?p??e? ?a ep?t???e? pe??ss?te??
  epa?a???s?µ?p???s? ?????

75
??e???? ?s????

• ? ??e???? ?s???? e?s??e? as?µµet??a
• ? D µetad?de? st?? C se ?aµ??? ?s??, a??? ? B
  ???s?µ?p??e? ????? ?s?? µet?d?s?? ??a ?a
  µetad?se? st?? A
• ? B µp??e? ?a µ? ??????e? ??a t?? D-p???-C
  µet?d?s?, a??? µp??e? ?a ep?d??se? se a?t??

B
C
D
A
76

Ad-Hoc ??t?µata

• d??µ?????s? e????st?? ?s????
• d??µ?????s? se multihop d??t?? ßas?sµ??? st??
  e????st? ?s??.
• ???µap?d?s? vs. ?a??st???s?? vs. ?s????
• ??a? ???st?? µp??e? ?a a???se? t?? p??a??t?ta
  ep?t????? µet?d?s?? a??????ta? t?? ?s?? t??
• s??ep??eta? ?s????p?a µeta?? ?a??st???s?? ?a?
  ?s????
• µp??e? ?a a?????e? ? apa?t??µe?? ?s???, ?a??? t?
  µ??e??? t?? buffer a????eta? ??a ?a ap?t???e?
  ?pe??e???s?

77

?ß??d??? pe??ß?????ta

• ???s?µ?p??e?ta? ?e?t???? ?p?d?µ? ?ta? e??a?
  ß?????
• ???s?µ?p??e?ta? ad hoc s??e?t???t?ta a? e??a?
  a?a??a?? ? ap?te?e? t?? ?a??te?? ??s?

?e?t???? ?p?d?µ?
BS1
BS2
E
A
Z
ad hoc s??e?t???t?ta
X
78

???t?a a?s??t????

• ???t?a a?s??t????
• ?a ded?µ??a ????? s?s?et?sµ??a st? ????? ?a? st?
  ????.
• ?aµ???? ???µ?? ?µ??????e?a?.
• ?? s??desµ?? t?p??? as?µµet???.
• ?a ded?µ??a ????? p??? µ?a ?e?t????p???µ???
  pe?????.
• ? e????e?a ap?te?e? t? ßas??? pe?????sµ?.
• 1000-100000 ??µß??.
• ????? µ?a ????? ap?st???.
• ???? d?af??et??? apta t?p??? ad-hoc d??t?a.

79
?ate????t???? ?e?a?e?

80
???s?µ?p????ta? µ? ?ate????t???? ?e?a?e?

??a? pa??µ???? ??µß??
B
D
S
A
81
?ate????t???? ?e?a?e?

ad??at? µe µ? ?ate????t???? ?e?a?e?
B
D
S
C
A
82

? ep?d?as? t?? t?p?????a?

• ?? ??µß?? t?p??et?µ???? se ??aµµ?????
  s??µat?sµ??? µe?????? t?? epa?a???s?µ?p???s?
  ????? ??a t?? d?e????t???? ?e?a?e?

83
?p????pa slides

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