When we think of writing Telecom applications, multiple skillsets and exposure to technologies is required. To produce a meaningful application or a product, an extensive architecture should drive the development that also defines the underneath technology protocols to be used in various modules.

Fundamentals of Telecom

Telecom is generally used as a short name for Telecommunication. Telecommunication is basically the transmission of information through data signals, messages, words, writings, images and sounds by wire, radio, optical or other electromagnetic systems. Telecommunication occurs when the exchange of information between communication participants includes the use of technology. It is transmitted either electrically over physical media, such as cables, or via electromagnetic radiation. Such transmission paths are often divided into communication channels which afford the advantages of multiplexing.

Since the Latin term communicatio is considered the social process of information exchange, the term, telecommunications, is often used in its plural form because it involves many different technologies and associated protocols for information exchange.

Major applications in telecom involve Audio communication through telephone, Interactive voice response systems (IVRS), Out-Bound Dialers (OBD), Video Conferencing platforms, Multimedia gateways, SMS geteways, text/video chat platforms, ACD / Call-Center applications etc.

The diagram on the side panel depicts the Open Systems Interconnection model (OSI model) which is a conceptual model that characterizes and standardizes the communication functions of a telecommunication system without regard to their underlying internal structure and technology.

Communication Channels

Following communication channels play a vital role in telecommunication: -

• Voice - Audio signals carried over channels like PSTN, GSM, CDMA, VoIP, VoLTE
• Text - Text information carried over through SMS (short message service)
• Video - Visual frames transmission carried over via IP network, SIP, 4G/LTE, via WebRTC etc

Applications in Microsoft ASP.NET platform

When we need to write core Telecom applications, ASP.NET would not be able to help much as only upper level programming can be done in ASP.NET framework. The core protocol level programming can only be done using lower level languages like C/C++. However Microsoft has come up with new frameworks like SignalR for writing real-time Chat and similar applications. Also Windows Sockets can be programmed for creating other real-time applications involving Audio, Text and Video channels.

Writing SMS based Application

SMS / Text communication based applications consist of programming at two major levels. The lower level programming / or module involves interaction with Mobile Service provider equipments like SMSC and SMS-gateways. This programming is generally done using lower level programming language like C/C++ and deep knowledge of communication protocols like SS7 is required.

The high level programming for information control flow can be done using any high level language and framework like Java, PHP etc. Microsoft ASP.NET with C# can be used for programming UI and components. Control modules can also be written that generally use APIs (application programming Interface) provided/exposed by lower level modules that are in turn interacting with SMSC / Gateways etc.

Through high level programming, we can receive text message, send messages to one or multilple users at a time. And now with Microsoft SignalR, we can create real-time Chat applications easily.

Writing Audio (IVR) based Application

Like SMS / Text communication based applications, Audio applications also consist of programming at two major levels. The lower level programming / or module involves interaction with Mobile Service provider equipments like SMSC.

This programming is generally done using lower level programming language like C/C++ and deep knowledge of communication protocols like SIP, SS7 is required. These audio based applications are generally known as IVRS (Interactive Voice Response Systems), and can be programmed using high level programming for information control flow design.

We have an option of using Java, C/C++ for creating Audio programs but now-a-days various audio programming frameworks are being offered by product companies that assist us define program flow as per our requirements. These frameworks are integrated with great IDEs and contain rich set of drag-n-drop components. These components provide facilities like Input Voice, Input Digit, Output Voice prompts etc so as to create a good interactive experience for the user.
So as a high level programmer, you need not worry about writing low-level components.

Writing Video based Application

Developing Video based applications is an exciting field now-a-days, particularly when newer communication protocol technologies are being introduced with a considerable speed. Like Audio based application, being a high level programmer, you need not worry about lower level communication protocols, you may like to create information flow control program using high level programming.

Programming lower level control protocols require a deep knowledge of SS7, SIP and related protocol frameworks along with low level programming language.

WebRTC is comparatively a new framework that allows us to write Video based programs using higher level APIs.
Once you start writing telecom applications, you explore multiple options during the journey, and then you are able to pin-point on what exact technology needs to be implemented /deployed, as per business requirements of the organization.

Telecom Programs at Tesarrow Infocom Systems

At Tesarrow, we have created a wide range of telecom based products using state of the art technology / advanced protocols and codecs. You may like to have a look on the brief description of these telecom products at tesarrow website.