•To attain a general understanding of UMTS systems
–GSM Evolution Towards UMTS
–3g Standards
–Code Division Multiple Access Technology
–UMTS Network Elements and Architecture
–UMTS Air Interface
** **
•1st
and 2nd Generation Cellular Systems Overview
•3rd
Generation Drivers and Standards
•CDMA
Mobile Technology Overview
•UMTS
Architecture Overview
•UMTS
Air Interface
•People
talk about mobile technology in terms of generations:
–1st
Generation or 1G
–2nd
Generation or 2G
–2.5G
–3rd
Generation or 3G
*** 1st Generation
•1976+, though really the technology of
the 1980’s
•Analogue modulation
•Frequency Division Multiple Access
•Voice traffic only
•No inter-network roaming possible
•Insecure air interface
•AMPS
(Analogue Advanced Mobile Phone System)
–North
American Standard in cellular band (800MHz)
•TACS
(Total Access Communications System)
–UK
originated Standard based on AMPS in 900MHz band
•NMT
(Nordic Mobile Telephony System)
–Scandinavian
Standard in 450MHz and 900MHz bands
•C-450
–German
Standard in 450MHz band
•JTACS
(Japanese Total Access Communications System)
–Japanese
Standard in 900MHz band
•Macrocellular
–High
sites for coverage driven planning
–Antennas
above roof height
•Frequency
planning required
–For
networks with more cells than frequencies these must be planned
•Large
cell size
–Order
30km
•Handover
–Mobile
only ever connected to a single cell
*** 2nd Generation
•1990’s
•1st system to use Digital modulation
•Voice and low rate circuit switched data
•Same technology allows international
roaming
•Secure air interface
•First
networks in 1992
•European
developed standard, but with worldwide subscriber base
•Different
frequency bands
–GSM450,
GSM900, GSM1800, GSM1900
•Largest
2nd Generation subscriber base
•Frequency/Time
Division Multiple Access
•Macrocells and microcells
–Capacity
driven planning
•Frequency
planning required
•Optional
parameters requiring planning
–Hierarchical
Cell Structures
–Frequency
Hopping
–Discontinuous
Transmission
–Power
Control
•Simple
subscriber/traffic analysis
–Capacity
limited by number of TRX’s
•Handover
- yes
•TDMA
(D-AMPS)
–North
American TDMA/FDMA based standard based upon AMPS
–Predominantly
used in North and South America
–ANSI-41
Core Network
–Planning
Similar to GSM
•First
networks in 1996
•Derived
from Qualcomm IS-95 air interface
•Largely
American subscriber base with some Asian networks
•Code
Division Multiple Access
–The
closest 2nd generation standard to many of the 3rd generation standards
•ANSI-41
core network
•Chip
rate of 1.2288Mcps
•Macrocells and microcells
•Single
Frequency
–multiple
frequencies for hotspots
•Soft
Handover (multiple connections between mobile and network)
•Code
Planning
•Capacity
Interference Limited
**** Who
does IMT-2000 serve?
•Integrating
all the following users
–fixed
–cellular
–cordless
–professional
mobile radio
–paging
–satellite
–specialised
(aeroplane, etc)
2002+
•Digital
modulation
•Voice
and high rate data
•Multi
technology roaming
•Secure
air interface
•Standards
• UMTS FDD (CDMA based)
• UMTS TDD (CDMA based)
• cdma2000 (CDMA based)
• EDGE (TDMA based)
*** UMTS FDD
•UMTS
Frequency Division Duplexing Mode
•
•Built
onto enhanced GSM core network
•
•Utilises:
–QPSK
modulation (Quadrature phase shift keying)
–Multiple
channel coding and bearer rates
–Variable
spreading factors and multi-code transmission
–CDMA
–FDD
–
•Data
up to rates of 2Mbps
•UMTS
Time Division Duplexing Mode
•
•Built
onto enhanced GSM core network
•
•Utilises:
–QPSK
modulation
–Multiple
channel coding and bearer rates
–CDMA
–TDD
–
•Data
up to rates of 2Mbps
•
•Will
happen after UMTS FDD
*** CDMA 2000
•Built onto ANSI - 41 core network
•
•Utilises:
–QPSK modulation
–Multiple channel coding and bearer rates
–CDMA
–FDD
–Multiple carriers on the downlink
•allows compatibility with cdmaOne
–Synchronous operation
–
•Data up to rates of 2Mbps (typically
less)
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