1.UMTS BASICS
1.UMTS BASICS
WIRELESS COMMUNICATION
NETWORKS
3G UMTS (Universal Mobile Telecommunications Service) is
a third-generation (3G): broadband, packet-based
transmission of text, digitized voice, video, multimedia at
data rates up to 2 Mbps .
UMTS is based on the Global System for Mobile (GSM)
communication standard. It is also endorsed by major
standards bodies and manufacturers as the planned
standard for mobile users around the world.
Once UMTS is fully available, computer and phone users
can be constantly attached to the Internet wherever they
travel and, as they roam will have the same set of
capabilities. Users will have access through a combination
of terrestrial and satellite transmissions.
1
Major difference
–
GSM
: TDMA and FDMA
– UMTS:
Wide-band code
(WCDMA)
division multiple access
2
CDMA
Traffic channels: different
users
unique
are assigned
code
over
and
the
band,
transmitted
same frequency
for example, WCDMA
and CDMA2000
TDMA
Traffic
slots
channels: different time
are allocated to different
users, for example,GSM
FDMA
Traffic channels: different frequency
bands are allocated to different users ,
3
Power
Power
Power
DEFECT
frame
control for mobile
4
Advantage
FDMA
1. Simple Implementation 1. Frequency Reuse
2. privacy
TDMA
1.Privacy 1. Need synchronized of
CDMA
W-CDMA
1. Reduction the interference
2. Diversity Hand-over
3. Privacy
1. Sophisticated power
