Tag Archives: apn

Spread Spectrum Concept

Dsss – Direct sequence spread spectrum DSSS – Direct Sequence Spread Spectrum is a spread spectrum technology in which original data is expand using PN code randomly to reduce noise

Signal Fading

Slow fading: In case shadow effect is caused by obstacles, and the receiving signal strength decreases but the field strength mid-value changes slowly with the change of the topography, the

CDMA Channel Frequencies & Calculation

The 850MHz CDMA band is most popularly used all over the world.This band as mentioned in the previous slide works between       824-849MHz Used for the Reverse link communication      

QoS Parameters of LTE

The QoS Class Identifier (QCI) is a scalar that is used as a reference to access node-specific parameters that control bearer level packet forwarding treatment (e.g. scheduling weights, admission thresholds,

LTE TCP Throughput vs Round Trip Time (RTT)

•The Transmission Control Protocol (TCP) is designed to provide reliable transport for packet  data. •Today TCP is used for 80-90% of all packet traffic in the internet. •TCP is typically


The uppermost evolution track shown in Figure is that developed in the 3rd Generation Partnership Project (3GPP), which is currently the dominant standards development group for mobile radio systems and

Propagation Path

Radio wave can be propagated from the transmitting antenna to the receiving antenna in many ways: perpendicular incidence wave or ground refraction wave, diffraction wave, troposphere reflection wave, ionosphere reflection

Radio Wave Spectrum

The radio waves are distributed in 3Hz ~ 3000GHz. This spectrum is divided into 12 bands, as shown in the above table. The frequencies in each specific band present unique

How Walsh Code Generate in CDMA

• Definition: Orthogonal functions have zero correlation.  Two binary sequences are orthogonal if the process of “XORing” them results in an equal number of 1’s and 0’s. Example:   0000

Burst in GSM

The Logical  Channel is used in time multiplex in a physical channel, which is categorized according to the types of messages transmitted in the physical channel. Different logical channels are

DTX: Discontinuous Transmission

Actually, during the communication process, the mobile subscriber talks only 40% of the time and there is not much useful information transmitted during rest of the time. If all the

What is Interleaving

If the voice signal is modulated and transmitted directly after channel coding, due to the condition changes in mobile communication channel, a deep of the fading will influence a successive