Thursday, June 01, 2006

TDM Telecom, IP Telecom LAYMAN's View

TDM (Time Division Multiplexing) Telecommunication is the present Circuit based Telecom network which we are using in Public Communication for many years. Now this is the time to move to IP based Telephone exchange for better usage, Economic advantage, New Services. This is due to the Technology advancement and Deregulation in policies.

All Telecom Operators and Vendors are in the way to migrate from TDM switching to the IP Switching. Now Telecom and IP is merging and the border between these two domains is narrowing. This article will give an intro for Telecom expert, IP expert and even a common man to visualize the difference between TDM and IP.

Let us compare the TDM and IP telecom to the present Public Transport System. Suppose you are in Place (A) want to meet your friend in place (B). If you are hiring a TAXI to go to place (B) from place (A) then it is a TDM telecom model. If you are going in a TRAIN then it is a IP telecom model. Now any common man can able to tell the difference between the two types transport system and there by he can visualize difference between the TDM and IP telecom.

Yes first important thing for a common man going by TRAIN than hiring a TAXI saves lot of money for him. This is true if you are using IP telephone, call charges are very less compared to TDM phones and because of the use of IP technology in the backbone Telecom rates are slashing down.

Now let us see the technology comparison between TDM telephone and IP telephone with our Public Transport Model. When you are making a TDM phone call a presently free Circuit or Channel will be allocated for you mean a 64 Kbps of bandwidth (Time Slot) is totally dedicated for you both. This channel is only for you and your friend from end to end like how a presently free TAXI is dedicated for you till your destination. Nobody can share the Circuit or Channel dedicated for you till you finish your speech. Like that nobody can enter into your TAXI till you reach your destination.

After your conversation when you disconnect the line, the Channel or Circuit dedicated for you will be marked free and ready for next call. The charge for the call duration will be deducted from your account if you are a prepaid customer or will be added to your monthly bill if you are a postpaid customer. Like that after you reach your destination in the TAXI you will get down, Pay the Hire for the usage distance and free the TAXI. Now the Taxi is available for the next user.

The TAXI transport is totally different from the TRAIN transport system; likewise there are lot of differences between the TDM telecom and IP Telecom. In IP telecom you are like a TRAIN passenger. You will be using a BIG Transport system TRAIN which is going to all places where there is track. IP telecom user is using the large bandwidth or IP Cloud which is available where and all the network is there to every one.

When you are using a IP telephone to speak from place (A) to your friend in place (B) is like going in a TRAIN from place (A) to Place (B). TRAIN will come to place (A) you have to get in and when the TRAIN reach the place (B) you will get down there. You will be paid for the service you used which will be very less compared to the TAXI transport model between place (A) and (B).

In IP telecom your speech at the source will be digitized and packetised and labeled to the mentioned destination and put in a common IP Cloud. As each packet is having the destination mentioned, it will reach the correct destination through the network and at the destination, the IP Packets will be reverse engineered (depacketised, dedigitized=made analog) to get the VOICE which is carried from the source.

Interesting fact in VOIP is after you make a call and when you are keeping silent you will not use the network bandwidth and it will be used for some others' voice. In other words when you are not speaking during a call, the back ground noise will not be send to the destination and it is not required also. During the Silence period the VOIP system at the other end will create a comfort noise to make both the person to have a sense that the call is not disconnected and it is still in process.

Monday, May 22, 2006

Existing Telecom Network Vs Next Generation Networks

Existing Telecom Network

01. Circuit based
02. Hierarchy based
03. Vendor specific - Proprietary Software
04. TDM switching and transport
05. SS7 is the main signaling between exchanges
06. Mainly SDH is used for transport
07. Difficult to launch operator specific new services
08. End user will have voice service, data service with less bandwidth
09. All telephones are identified by numbers (International Numbering Format)
10. Fully standardized

Next Generation Network

01. Packet based
02. IP Cloud based
03. Open Standard Architecture
04. IP & TCP switching and transport
05. Different new signaling Viz MGCP. MEGACO, H.248, H.323, SIP, RIP
06. SDH are replaced by Gigabyte routers
07. Very easy to launch new operator based services
08. End user can enjoy Voice, Data, Video Triple Play with unlimited bandwidth
09. All telephones are identified by IP address
10. Standardization is going on as it is new technology with many new vendors

Advance Telecom -- ALWAYS ADVANCED

Telecommunications is one of the Technical domains which is facing a fundamental shift in the core technology. This page is for those who are in Telecom and Information Technology fields to see the Migration and to be specific the marriage between various technologies to give an easy and fast life to the man kind.