3G

1
????

• 3G
• Voip
• Ethernet
• Skype
• GPRS
• 802.11/WiFi
• 41820 ???

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3G

• 3G??
• 3G??third generation,???????????????????????
  ??(1G)????????(2G)?2.5G(?????????????,????????????
  ?),???????????????????????????????????????????????
  ???,3G????????????????
• 3G???
• 3G????????????,???????????????????????????WC
  DMA(????????)?CDMA2000(??????,2000??2GHz)?
• WCDMA?????????????(UMTS)??????3G????????????
  ???????,????2GHz??,??????????????????3G?????,?????
  ?WCDMA??????,??????????????????????

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CDMA2000??????2G?2.5G?????????????????,???3G?CDMA?
????????????????,????????????????,????????????????
??,???????????CDMA2000??????CDMA
1X,???????????????????
3G??? ??3G????????????,???????????????????????????
????????????????????????????????????????,?????????
????????????? ??????????????????????,?????????????
???????????,???????????,?????????????????(2005),??
??????????????
4
VOIP

• VoIP???????
• VoIP(Voice over IP)????????,?????????(Intern
  et)??????????????(package)????????????????????,???
  ???????(PSTN),??????????,??????????????
• VoIP??????????????VoIP???,????1995????Vocalte
  c???????????????,????????????????,??Internet??????
  ???(PC-to-PC)???VoIP?????,???????????TA(Terminal
  Adapter)?VoIP Gateway,???????????????????????,???M
  odem??,??????????????????,????????????????????????
  ?????????,????,???????????????,????????????????
• VoIP?????
• ?????????????????????????,?????????????????,
  ???????????????????,??????????,?????????????????,?
  ???????????????????????????

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VoIP??? VoIP?????????????,?????? PC-to-PC??????
??????,??????,??????????????????(Server)?,????Serv
er?????????????????????????,????????????PC-to-PC??
???????,????????Skype? PC-to-Phone???????????,??
????????????????(Server)?,????????????????????????
???????PC-to-PC?,???????????????,????????????,????
,?????????????????????????Phone-to-Phone???????
????????,???????TA?VoIP Gateway,???Modem??(?????Vo
ice?????Modem???-Combo Modem??)?????????????,?????
??????????,????????????,?????????????????,????????
??,??????????????
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• VoIP?????
• ????,?????VoIP????????,???????????/??????
• ??????????????????????????????????????,??????IP?
  ????????????????????IP PBX?VoIP
  Gateway,??????????????????,???????????????????????
  ????(PSTN)?????????????????????????,??????????????
  ??
• ????/??????????/?????VoIP???????????,???????????
  ?????????????????TA?VoIP Gateway???,??????????????
  ?,?????Modem??,??????????????????,????????????????
  ????????????(PSTN)???????????????/????????????????
  ,?????,??????????

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Ethernet

• Ethernet??
• ???(Ethernet)?????????????IEEE???IEEE
  802.3?????????????????????????????????????????????
  ???????????????????????????????,??????FDDI?ARCNET?
  ?????????????????,?????????(100BASE-T?1000BASE-T?
  ?)???????????,????????????????,?????(Switch)??????
  ????,??,?????????????,?????,??????????????
  CSMA/CD(Carrier Sense Multiple Access/Collision
  Derect ???????????????) ?????????

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ETHERNET?? ????? ????? -- ???3-Mbit/s???,????????
????????????????????? 10BROAD36 --
???????????????????????????????,??????????????????
????? 1BASE5 -- ????????,???1Mbit/s??????????????
?????????? 10Mbps??? 10BASES (?????????)
--????10 Mbit/s???? ??IEEE??,????50????RG-8????,??
??500??????????????????????????????????????N?????A
n AUI cable then connected the transceiver to the
Ethernet device. ???????????,????????????,????????
???????????????? 10BASE2 (?????????) --
50??RG-58????,200?, ???????,??????T????????BNC????
????????????????????10M???? Starl AN --
???????????????10 Mbit/s. 10BASE-T
--??3??????5?????4?? (2???) 100???????????????
????????
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Skype

• Skype??
• Skype(???????? /sk??p/,??? type
  ??),??????????????,?KaZaA???????,??P2P??????????,?
  ??????????,?????????
• ?????,Skype?TOM????,????Skype???TOM-Skype?????
  ?????(PChome Online)??,???Skype??PChome-Skype?????
  ?,Skype?????????,???Skype??HGC-Skype?
• Skype?2005?9?12????????eBay???26???(????849???
  ????210??)??????????????13????????13????3240??eBay
  ??,?Skype?2008??2009???????,eBay??????15???,??????
  ???41????

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Skype?? ??????????????,????,??? ?????
?????? ???? ??? ?????
???? ?????? ????,????????????????
?????? ??????????? Skype?? SkypeIn
SkypeIn?????????????????????????,????Skype?????
?????????????????SkypeIn?????
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SkypeOut SkypeOut ?????Skype????????????????,?????
????????,?? SkypeOut ???????????????? ??SkypeOut
??????????,??????????????,???????SkypeOut
?????????? ????????????,????SkypeOut???,????49??20
0??400??1000?? Skype ???? ???????,??????????
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GPRS

• GPRS??
• GPRS ????? ???? (or CSD) ??,???Release
  97??(GSM??????????)??????GSM??????????????????????
  ??????,??????????????????????? GPRS
  ??????,?????????????????????,?????????????????????
  ????????????????????????????,?????????????????????
  ???? WEB??,????????????????????????????
• ??GPRS??????????????????,??????KB????????,????
  ???????,???????????????
• GPRS????(???)??????IP,?????PPP?X.25???????????
  ??????,???????????????X.25??????PPP???IP????,
  ?????????????????????????

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GPRS?? GPRS??GSM??????? ??? (P2P) ??
?? (IP protocols)IP?? and X.25???
??(P2MP)?? ?????????????? ???? (SMS)
??SMS ????MMS ????????????????
??????????? ??????????? ??????POP3??IMAP???
????????? ???? ???????? ????
????????,??????,????,????? ?????
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802.11/WiFi

• ??
• Wi-Fi????????1997?,??????????????(MAC?)???????
  ???????2.4GHz?ISM??????????????????????,??????????
  2Mbit/s????????????????(ad hoc)?????,??????(Base
  Station, BS)?????(Access Point,AP)???????
• 1999?????????? 802.11a??????5GHz
  ISM????????????54Mbit/s????,802.11b??????2.4GHz?IS
  M????????????11Mbit/s????? 2.4GHz?ISM?????????????
  ?,??802.11b?????????????????????802.11?????AirPort
  ?1999???????Wi-Fi??,??????802.11?????????????????
  802.11??????
• 802.11 ,1997?,????(2Mbit/s ???2.4GHz)?
• 802.11a,1999?,?????(54Mbit/s???5GHz) ?
• 802.11b,1999?,?????(11Mbit/s???2.4GHz) ?
• 802.11c,??802.1D????????(MAC) ??(MAC Layer
  Bridging) ?

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• 802.11d,??????????????
• 802.11e ,?????(Quality of Service, QoS) ????
• 802.11f,??????(Interoperability) ?
• 802.11g,?????(54Mbit/s???2.4GHz) ?
• 802.11h,?????????,??(indoor) ???(outdoor) ??
• (5GHz??) ?
• 802.11i,?????(Authentification)??????
• 802.11n,???????? (MIMO) ??,????802.11a???
• ??
• ?????IEEE??,????????IEEE802.11b???,??
• PBCC??(Packet Binary Convolutional Code) ?
• IEEE802.11b(2.4GHz??) ?????22Mbit/s??????????
• ????????IEEE?????,???????????(?????
• ?????,Texas Instruments)????????802.11g???,
• ?IEEE802.11g??????108Mbit/s?????,?802.11b??
• ????????,??????????Atheros??????SuperG?

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THE END