wirelessoom
ISDN user part
Part of SS7 protocol for telephone call setup.
In UMTS, part of this is being used for CS call.
IAM: Initial Address Message
ACM: Address Complete Message
ANM: Answer Message
REL: Release message
RLC: Release complete Message
Why do we have a cellular network?
To make a call or do data connection. (something useful)
Here, I post brief step for Mobile Originated call setup.
Detailed call flow can be found at here
What is AN (Access Network, UTRAN)’s role ?
Provide simple connectivity to the core network (CN) – whether it is a CS or PS.
Remember that UE wishes to make a call or data connection to do some useful and helpful thing.
AN just helps it in the middle between UE and CN.
In connected mode, the GTP-U can be established between GGSN and AN (without SGSN), which is more efficient.
The figure depicts the Shannon’s model of communication.
Shannon recognized that interference (noise) plays significant role in communication system.
The analysis of channel capacity is incomplete without including noise in the calculation.
dBm (sometimes dBmW) is an abbreviation for the power ratio in decibels (dB) of the measured power referenced to one milliwatt (mW). It is used in radio, microwave and fiber optic networks as a convenient measure of absolute power because of its capability to express both very large and very small values in [...]
It’s a jargon engineers or physicists are using.
It’s a promise.
It’s about describing a ratio between two quantities.
How big is the one compared to the other?
For example, Chan’s height is 40 inch and Han’s height is 80 inch.
Han is two times higher than Chan.
Using dB, we say
10 log (p2/p1) = 10 log 2 = 3 dB [...]
I drew some figure to clarify the definition of RB, SRB and RAB.
Venturebeat
Apr. 26 2010
The Korea Herald, an English-language newspaper based in South Korea, quotes an unnamed Samsung executive: “We are considering Google TVs. We are examining the business feasibility.”
The television sets would run on Google’s Android operating system, already used on the company’s Nexus One and Motorola Droid phones, among other devices.
Rumors surfaced last month that [...]
04/14/2010
New York Times
Apple is tightening its already firm grip on what software can run on the iPhone and its other mobile devices, as shown by its recent changes to the rules that outside programmers must follow.
The company is locked in a battle with other cellphone makers, particularly those using Google’s Android operating system, for [...]
