Satellite Communications/telephone cost

Advertisement


Question
QUESTION: Hello sir,

I have a question regarding telephone communications.

Q) Why doesn't it cost for giving a missed call .i.e. when i ring to my friend it doesn't cost me at all, unless my friend picks up the call. I have a feeling that there is a lot happening in the background like the signal reaching the tower... etc. even if my friend doesn't pick the call. Then , why am I not charged for it.
       If I am not charged b'coz the background processess cost a very little, could u enlighten me with the actual cost and statistics involving just the call/ring.

Thanking you in advance.

ANSWER: Hello Mr Surya,
Glad that the question many people ask has been put!! I am not sure whether you are an Engineer or otherwise. If only I know that, I will be able to find suitable terminology to explain the reasons: Anyway nothing is free in this world. But the methodology is a bonus time available in the technology that enables missed calls not be charged. If you can send the clarification on technical answer or generic answer, I will be able to respond, please!
Cheers/GTRao

---------- FOLLOW-UP ----------

QUESTION: Thank you very much sir, for your time and quick response.

I am an undergraduate, pursuing engineering. I will be happy to receive a technical answer and ofcourse if possible supported by a generic answer.

Thanking you in advance.

Answer
Hello Mr Surya,
The call connect procedure are having a certain protocol formats: that is when s
ome one makes a call, there are some signals that get exchanged between the hand d
evice and the exchange and then only after due verification the call will be
connected to the destination device. For handling this procedures, there is
some specific channel allotted by name: Control Channel in Mobile communications
and Signalling channel in Landline communications. And irrespective of the
call request or not, this channel is perennially active and the costs for
using this channel are borne by the Service provider (of course, he indirectly
collects from you).
When everything is fine i.e. both the persons are available at both ends then
only the call will be connected for Voice purpose and till that connection,
voice channel is not used, only control channel is used. In case of "NOT a
available" report comes then after waiting for a pre fixed period of time,
the service provider disconnects the link. All this time runs into very small
may be milliseconds. So if the duration of missed call happens before the decision
is taken to connect or not that means the called party does not lift phone for
the longer time then disconnection is auto and if the caller hangs before the
called party lifts, still the background process (as you say) proceeds and the
ring is sent to the other side. And charges are applied to the customer only
for usage of VOICE Channels and NOT Control channels. (they are the charges
Service provider collects in the name of service charges!!).
Cheers/GTRao

Satellite Communications

All Answers


Answers by Expert:


Ask Experts

Volunteer


TIRUMALA RAO G

Expertise

Satellite Communications Applications, Link Calculations, Teleports, Earth Stations,VSAT, Tracking, Mobile Communications, Next Generation Networks.

Experience

40 Years. Indian Space Research Organisation, PANAMSAT, Satellite Based VSAT Networks, IP Networks.

Organizations
ISRO, PANAMSAT, Engineering Institution for Higher Education (GVP College of Engineering), Consultancy.

Education/Credentials
Graduate in Electronics and Communication Engineering with Distinction. Guiding scholars for their Doctoral thesis in related areas in Academics.

©2016 About.com. All rights reserved.