UE switched ON

We all use handsets and the question we can ask ourselves are:

1. How does the Mobile phone (UE) knows about the Operator's signal presence in it's vicinity?

2. How does the UE get the signal?

3. How does the signal indicator bar on the UE increases?
4. Since there are many service providers in the location then how come the UE logs into a particular provider?
5. How the call is initiated and reaches the called party within few seconds?

The answer to the queries are explained below:

The base station -in LTE it is termed as eNB (Evolved NodeB)- is continuously transmitting signal which contains certain information about the network. When the UE is switched on it searches for this broadcast information and syncs itself with the network. The actual parameters which are exchanged will be explained later but for an initial entry to the field it is important to understand the technology from a layman's point.

It is when the UE syncs with the eNB it starts to establish a connection so that other entities in the network knows the presence of the UE. (click here to know the sequence now)

Now, when the UE is in complete sync with the network it can start it's data exchange. The term 'data exchange' means that it can be either/all voice, video, chat, messaging and Internet browsing. 

The question is: If this is data exchange then what will be the term used before the data exchange. Well, the answer is: It is signaling. 

So, we can say that there are two parts involved when an exchange of information happens.

1. Control Plane (Signaling)

2. User Plane (User data)

An user plane occurs only after the Control plane has played it part.

In the next post, I will provide the architecture of LTE technology.

(click here) to know the UE switch ON procedure in more detail.