3GRead People Like A Book

3G technology also comes in various forms and platforms. Understanding the

major ones will help you decide which one is the right tool. You should

also tell the technical details, to know if you are getting the right kind

of efficiency and accessibility. Getting information from the internet

other various sources will never be as convenient as fast, since 3G is the

newest available. There are new developments and changes as well to get you

ahead.

Knowing WCDMA or UMTS

W-CDMA wideband code-division multiple-access is among the major

technologies that implement the 3G or third generation cellular systems.

This is founded on the radio access technique suggested by the ETSI Alpha

Group. The details and specifications were finalized in 1999. The

implementation of W-CDMA is going to be a technical challenge due to the

complexity and versatility. The sophistication of the of the systems of

W-CDMA can be seen from various aspects.

These are namely the complexity of the overall system, computation

complexity of the receiver and the complexity of ever single algorithm.

W-CDMA link-level simulations or more than 10 times the compute intensive

compared to 2G simulations. In the interface of W-CDMA, the different

interface users can immediately transmit at varying information rates, with

the data rates even varying in time. Networks of the UMTS are required to

support every 2G service, plus new services and applications.

The Technical Details

As for the FDD technical summary, the frequency band will range from 1920

MHz up to 1980 MHz and 2110 MHz and 2170 MHz or frequency division duplex.

The minimum frequency band needed is 2 x 5 MHz. The frequency re-use is 1.

Carrier spacing is between 4.4 MHz and 5.2 MHz. The most number of voice

channels on 2 x 5 MHz is 96 with a spreading factor of 256 UL and AMR or

7.95 Kbps and 98 with a spreading factor of 128 UL and AMR of 12.2 Kbps.

Other Specs

The voice coding includes AMR codecs ranging from 4.75 kHz up to 12.2 kHz,

GSM EFR is at 12.2 kHz. SID is also included at 1.8 kHz. The channel coding

includes convolutional coding with turbo code for high rate data. The

duplexer required is 190 MHz separation with asymmetric connection

supported. Tx and Rx isolation is MS:55db and BS:80dB. The Receiver is

Rake, while receiver sensitivity is Node B.

More Information

Data type for the device is packet and circuit switch. Modulation is QPSK

and pulse shaping is root raised cosine, rolling off at 0.22. The chip rate

is 3.84 Mcps while the channel raster is 200 kHz. Maximum user data rate on

the physical channel is 2.3 Mbps with a spreading factor of 4, and parallel

codes of 3 DL / 6 UL, with limited interference. HSPDA will provide data

speeds going as fast as 8 to 10 Mps and 20 Mbps for MIMO systems. The

channel it rate is 5.67 Mbps with a frame length of 10 ms or 38400 chips.

There are 15 slots or frames, and 2560 chips. Handovers are soft and

softer, plus a hard interfrequency. The power control period has a time

slot with a rate of 1500 Hz. Power control step size is 0.5, 1, 1.5 and 2

dB while power control range is UL 80 dB and DL at 30 dB.