星期五, 5月 19, 2006

2G, 2.5G, 3G

cellular: 2G/3G
channel bandwidth: 200 kbps (8 time slots) / 5 MHZ
multiple access: TDMA / CDMA

SMS, Short Message Service, up to 160 bytes
SMS, EMS use control channels while MMS use regular channels shared by data and voice.

Data Services
  • GSM, Circuit Switching, 9.6 (*2), 12.4(*2, HSCSD)
  • GPRS, General Packet Radio Services, Packet Switching, 9.05 kbps/13.4 kbps (*1,2,3,4), speed denoted as *u*d
  • EDGE, 3 times of speed of GPRS by using 8-PSK instead of binary GMSK
  • 3G, 384kbps, up to 2 Mbps, uplink is 128 kbps
  • 3.5G HSDPA (High Speed Downlink Packet Access) 8-10 Mbps (R5), and 20 Mbps (R6) by MIMO, uplink is 384 kbps

Worldwide deployment of HSDPA

WAP, content bearer protocol, certificate, cookies
WML, wireless markup language (or HTML-C as in i-Mode, XHTML)
MMS, Multimedia Messaging Service

Tariff
3G, GPRS vs. GSM
flat rate, data volume or air time

Security features
WIM: A Wireless Identity Module (WIM) can contain
both trusted and client certificates, private keys
and algorithms needed for WTLS handshaking,
encryption/decryption and signature generation.
The WIM module can be placed on a SIM card
and is then referred to as a SWIM card.

authentication and billing of wlan with SIM card
  • authentication
  • billing
  • coverage of both 802.11 & GPRS/3G
  • roaming across APs and WISPs
  • user base

2 則留言:

  1. 老師.我在GOOGLE找到一偏文章,我找了很久終於找到,是關於低功率系統PHS的介紹,有營運模式跟技術方面.雖然可能跟老師你教學的主題沒什關係,但是我還是想跟你分享一下^^
    PS:連結有點長喔.
    http://images.google.com.tw/imgres?imgurl=http://www.mcu.edu.tw/icwang/images/phs/history.jpg&imgrefurl=http://www.mcu.edu.tw/icwang/mobile/phs01.asp&h=300&w=450&sz=33&tbnid=hksMNhI4XCzHaM:&tbnh=82&tbnw=124&hl=zh-TW&start=1&prev=/images%3Fq%3Dphs%2B%25E5%259F%25BA%25E5%259C%25B0%25E5%258F%25B0%26svnum%3D10%26hl%3Dzh-TW%26lr%3D%26sa%3DG

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