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The Wireless Communication System. Xihan Lu. Wireless Communication. Cellular phone system Cordless telephone system Bluetooth Infrared communication Microwave communication IEEE Wireless LANs (Wi-Fi) Satellite communication. Why “ Cellular ” ?. Three Generations. AMPS NMT TACS

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wireless communication
Wireless Communication
  • Cellular phone system
  • Cordless telephone system
  • Bluetooth
  • Infrared communication
  • Microwave communication
  • IEEE Wireless LANs (Wi-Fi)
  • Satellite communication
three generations
Three Generations

AMPS

NMT

TACS

HCMTS

GSM

GPRS

WCDMA

CDMA2000

TD SCDMA

1G

2G

3G

slide5
1G
  • Start early 80’s
  • Analogue technique
  • AMPT (Advanced Mobile Phone System): North America
  • NMT (Nordic Mobile Telephony):North Europe
  • TACS (Total Access Communication Service):Europe, China
  • HCMTS (High Capacity Mobile Telephone System):Japan
slide6
FDMA
  • Frequency Division Multiple Access
  • Different carrier frequencies are assigned to different traffic channels(speech)
  • One carrier frequency can only carry one single speech channel at one time
shortage
Shortage
  • Voice information only
  • Unsafe (eavesdropping)
  • Waste of frequency resource
slide9
2G
  • Start early 90’s
  • Digital technique
  • GSM : Global System of Mobilephone
  • GPRS : General Packet Radio Service
  • D-AMPS : Digital AMPS
slide10
GSM
  • TD/FDMA: A mix of FDMA and TDMA
  • The whole useable spectrum was divided to many 200k Hz carrier frequencies —FD
  • Each carrier was divided into 8 timeslots (burst) —TD
  • Each burst is assigned to a user(a logical traffic channel)
  • One carrier frequency can carry up to 8 logical traffic channels (voice or data) at the same time
  • The maximum data communication rate is 14.4 kbps
bts bsc and msc
BTS,BSC and MSC
  • BTS & BSC: Base Transceiver System and Base Station Controller. Radio signal transceiver, a connection between handset and MSC
  • MSC: Mobile services Switching Center, switching center of the GSM network, and connect to other networks
databases
Databases
  • HLR : Home Location Register, contains static information of subscribers and location update data
  • VLR : Visitor Location Register, embedded in MSC to avoid delay, contains current location information of handsets
  • AUC : Authentication Center, stores secret keys for authentication and encryption of the radio channel
  • EIR : Equipment Identity Register, contains a list of all valid mobile equipment in the network, by its International Mobile Equipment Identity (IMEI)
slide15
GPRS
  • Upgrade of existed GSM network
  • Improves the data communication ability
network nodes
Network nodes
  • GGSN: Gateway GSM Support Node,
  • Protocol transferring, data encapsulation, a connection to external networks
  • SGSN: Service GSM Support Node,
  • Communicate with HLR and mobile handsets, authorization and admission control, charging, mobility management
data communications
Data communications
  • In GSM, one user occupies one traffic channel to exchange voice/data information
  • In GPRS, up to 8 traffic channels(a whole carrier) can be dynamically combined together for one data communication application
  • The theoretically maximum data transmission rate: 14.4k bps * 8 = 115.2k bps
advantages of gprs
Advantages of GPRS
  • Higher data rate
  • Seamless connection to internet
  • Packet switching rather than circuit switch, bandwidth is only used when the data is actually used, even though it is always connected
  • A primary step to 3G
shortage1
shortage
  • Not fast enough for the multimedia service
  • The data rate falls when the network is busy
  • Upgrade of handset
3g standards
3G-Standards
  • Three CDMA standards approved by ITU:
  • Direct Spread CDMA(WCDMA) : Europe, Japan
  • Multi-Carrier CDMA(CDMA 2000) : North America
  • TD-Synchronous CDMA(CDMA TDD) : Europe, China
3g cdma
3G-CDMA
  • Code Division Multi Address
  • Spread spectrum technology
  • Each single traffic channel occupies the whole spectrum, but distinguished by a unique digital code
  • Walsh code: an orthogonal 64 bit pattern, unique in the network
features
Features
  • Better voice quality
  • Up to 2 Mbps data communication rate
  • Increase battery life
  • Soft hand-off
  • Excellent data safety
  • More effective spectrum usage than 2G
references
References
  • www.gsmworld.com/technology/gprs/index.html
  • www.3gsmamericas.com/pdfs/EOF_Cannes_2003/Nortel_David_Smith.pdf
  • http://www.fcc.gov/Bureaus/Wireless/Reports/fcc98091.pdf
  • www.rogers.com
  • http://www.itu.int/ITU-D/ict/publications/wtdr_99/material/glossary.html
  • www.itu.int/home/imt.html
  • http://www.boeschatt.at/Mobil/mobilfunk_html.php?gsm_netzarchitektur.php
  • http://www.pt.com/products/gsmintro.html
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