Figure 1. Block diagram of IVR System
Interactive Voice Response (IVR) system allows callers to interact with the communications system over the telephone. IVRS is used to enable the caller to retrieve information from a database, enter information into a database, or both. IVR systems allow the user to efficiently exchange information, reducing clerical processing and travelling. In telecommunication IVRS allows customers to interact with a company host system via telephone keypad or by speech recognition, after which they can service their own inquiries by following IVR dialogue. IVR systems can respond with prerecorded or dynamically generated audio to further direct users on how to proceed.Using Inter voice hardware and software, we have developed voice automation applications, which can perform automated transaction processing without human intervention. IVR applications can be used to control almost any function where the interface can be broken down into a series of interactions. IVR systems deployed in the network are signed to handle large call volumes. In our paper, we propose our own model to modify the existing application of gas booking system with library-member Interactive system. In this proposed model, a library user can know the availability of a book, antique article or a magazine in a library staying at their home itself. The model that we propose in this paper is a product of the case study that we have conducted, over a period of time.
Interactive Voice Response (IVR) system is a technology that allows a computer to interact with human beings through the use of voice and DTMF (Dual Tone Multi Frequency) tones input via keypad. [2] DTMF signals (entered from the telephone keypad) and natural language speech recognition interpret the caller's response to voice prompts. Other technologies include the ability to speak complex and dynamic information such as on e-mail, news report or weather.
Text-To-Speech is a computer generated synthesized speech that is no longer the robotic voice generally [1] associated with computers. Real voices create the speech in tiny fragments that are spliced together (concatenated) before being played to the caller. ITD (iletisimTeknolojiDanlsmanlikTicatetA.S) company made the implementation of the first biggest digital IVR system in Turkey. ITD Company launched Turkey's First Speech- Enabled Call Automation System in July 2001 in Global level. Callers dial the main number, respond to various voice prompts using the Turkish language, and tell the system the company name. It has become more common in industries that have recently entered the telecom industry to refer to an Automated Attendant as an IVR. This means that when discussing an IVR application, it is important to ensure that the person you are talking to understand the terms to mean the same thing as you do.
In our IVR based library data gathering system using mobile phone, a library user can gather whatever information he wants about the book availability at that time, location of a book, author of a book, Membership details, or availability of particular article.
There is much advancement in the field of Engineering, and communication in particular. Many IVRS systems have been developed for various purposes. For example, our recent gas booking system is the best one. For indane gas booking system, the procedures are
The basis of our model is simply to break up the complicated task of getting details from library into simpler tasks and dealing with them individually and yet in a parallel cohesive manner so that the expected reaction is obtained from the system. Our proposed system for library will be
Response: Welcome to IVRS based Library Automatic response system (if the phone Number is not registered)
User type as “salman”
Response: press1 for salmanrushdie, 2 for salman aurora, 3 for salman khan
User presses 1
Response: available books - press 1 for midnight's children, 2 for satanic verses
User presses 1
Response: the number of available Copies of midnight's children is 5, rack number 7, rung number 2.
if you want to continue press 1 or 2
user presses 2
Response: Thank you for using library automation system.
If pressed 1 instead of 2 in the beginning
Response: your membership number is 14751. Your membership will end in May 2015. You have borrowed 3 books
Response: the books borrowed: Book1- has time up to June 2
Book2 – has time up to June 21
Book3 – period has expired and you have fine of 5 rupees.
If pressed 2
-Regarding authors details Press 1
-Regarding books details Press 2
User Press 1 for Author names
- Please type the name of the author
- You have typed SALMAN ,
Response: there are 3 salmans
For Salman Rushdie press 1
For Salman khan press 2
For Salman aurora press 3
(Response: you have selected Salman Rushdie, the books available are as follows)
Midnight's children press 1
Indian freedom struggle press 2
(If the copies are not available, sorry we don't have availabilities)
- You have registered for a book midnight's children by Salman Rushdie
User presses 2 for exit
If the user pressed 1
Response: Press 1for Book names
- Please type the name of the book
- Select the books by pressing their respective codes
(If the copies are not available, sorry we don't have availabilities)
- Please type the name of the article
- Select the articles by pressing their respective codes
(If the copies are not available, sorry we don't have availabilities)
Block Diagram
The main blocks of our system are as follows: (shown in Figure 1)
Figure 1. Block diagram of IVR System
The 8751 is the heart of the IVRS system. It controls the operation of various parts of the IVRS system. When a telephone call is detected by the ring detector, the micro controller switches the relay to the DTMF and sends a signal to the PC via RS 232 to run the wave file welcoming the user to the IVRS. The number given by the user is decoded by the DTMF IC and is stored in the memory of the microcontroller [4]. The code stored in the microcontroller is sent to the serial port. The IVRS system makes use of a stand by computer so as to working 24hrs a day for customer satisfaction. In these cases, the microcontroller switches from the first computer to the second [5].
The ring detector is connected directly to the telephone line through the relay which is controlled by microcontroller (8751) as shown in Figure 2. The function of the ring detector is to detect if the telephone is ringing or not [3]. The ring detector consists of op-amp LM 311 which acts as a comparator to convert 98 V (rms, 130 Vpp) ring signal to –5V (low level) step signal for the microcontroller's INT0 pin. The output of the comparator goes high when the operator picks up the telephone provided along with the IVRS. The presence of the ring detector output for 5 sec enables the micro controller to switch the relay to the dual tone multi frequency (DTMF 8870). The capacitor C1 blocks incoming DC and resistors RA and RB are the voltage dividers to reduce the incoming voltage of 13VPP to 15V. Diode D passes only the positive half of the sine wave during which C2 gets charged to maximum value and acts as the DC value for the input signal which triggers the comparator. This charge does not get discharged easily due to high resistance and R3, R4 and R5 are used as voltage dividers to provide reference voltage of 2.5V to pin 2 of LM 311.
Figure 2. Ring Detector
The DTMF (Dual Tone Multi Frequency) decoder is a specific IC which performs the function of converting the DTMF frequency tones into BCD codes. These BCD codes are fed to the microcontroller to process the data and take necessary action. DTMF decoder 8870 IC has an external crystal oscillator to generate the clock signal, the pins to detect the presence of DTMF tone at its inputs and pins to transmit the BCD codes to the microcontroller.
The input signal from the telephone line is fed to the IN-pin of the DTMF after blocking all the DC in the line. These frequencies are compared with the Vref at the IN+ pin. This comparator pin output is then filtered and fed to the digital detection algorithm within the IC. It then passes to the code converter where it is converted into 4 BCD codes. The resistors R1 and R2 determine the gain of the differential amplifier incorporated in the IC. Figure 3 shows the DTMF Detecoder.
Figure 3. DTMF Detecoder
The audio amplifier, TDA 2006 shown in Figure 4 can amplify the output of the PCs sound card 12W thereby making the PC output audible on the telephone line. In addition the audio amplifier acts as a buffer between the telephone line and the sound card thereby protecting the sound card from the high voltage present on the telephone line. Figure 4 shows the Audio Amplifier.
Figure 4. Audio Amplifier
The relay switch is used in IVRS to switch between the ring detector circuits and the DTMF decoder circuit. The relay connects the telephone to the ring detector when the call is not processed by the microcontroller. On receiving a high signal from the microcontroller, the relay switches to the DTMF. Transistor BC 548 is used to drive the relay by providing the required current.
The simplest and the most common way to do the isolation is by using audio transformer which is a 1:1 isolation transformer.
It is the output device. The caller will get to hear the information through this voice card. The voice card use digital signal processing (DSP) technology and support DTMF. Voice cards can process analog or digital voice information, allowing for hybrid applications or pure VoIP applications.
When the telephone is in the idle condition, the voltage will be -48V.
When the ringing occurs, it will be 125V peak to peak AC signal superimposed on - 48V.
The opto isolator is used to isolate the microcontroller from high voltage AC signals and it consists of GaAs infrared emitting diode optically coupled to a monolithic silicon phototransistor
The microcontroller will detect the ring through the port 1.5 and it will count the number of rings.
After a fixed number of rings, the microcontroller will send a signal to the relay and then the automatic off-hooking of the telephone takes place. At the same time, microcontroller will transmit '#' to the computer which is an indication to play the 'Welcome' message.
The relay used is DPDT type and after automatic offhooking takes place, the relay connects the telephone lines to the decoder IC 8870 and isolation transformer.
The transformer used is a line transformer used to isolate voice card from high voltages.
As the telephone lines are connected to the voice card, the caller gets to hear the stored messages like your membership number is 14751, your membership will end in may 2015, you have borrowed 3 books Book1- has time up to June 2, Book2 – has time up to June 21, Book3 – has expired and you have fine of 5 rupees.
Then the computer will send the desired information to the voice card and the caller will get to hear the result on his telephone through the voice card.
Software to be used
The Office object model was created with optional parameters, a feature of VBA, in mind and makes heavy use of it. As Visual Basic supports this it has an advantage over C#.
In this case we specifically refer to COM interop without a complete type library, something common in VB6 or Visual FoxPro. This is where Option Explicit Off is a great helper and time saver.
Although there is always overlap, the following rules might help when deciding when or when not to use MS Access:
MS Access is best used for long-term data storage and/or data sharing.
MS Excel is best used for minor data collection, manipulation, and especially visualization.
Statistical Package for the Social Sciences (SPSS) is best used for minor data collection and especially data analysis.
It is easy to export data from MS Access to Excel.
Cheap, readily available Easy to use (relative to other systems –Oracle may require one FTE to maintain the server as a database administrator and another FTE to serve as an application developer).
Advantages
The greatest disadvantage of IVR systems is that the instructions must be made easier so everyone can use it easily.
In future, the concept of Interactive Voice Response System can be used in various transport departments like Bus transport, Metro rail, Railways and Airports as the transport companies not only need to be fast and responsive, but also need to provide customers with an easily accessible information system such as.
So, in near future, all the information regarding routes, timings etc. will be known through the Interactive Voice Response System. Also, this concept may be implemented in Cinema halls and Multiplexes where the caller will get to know the timings of his favorite movies as well as he can book his tickets through this system.
Interactive Voice Response System has been the latest technology, which provides the foundation for providing convenient new IVRS services for customers as well as at reduced operational costs, improved customer satisfaction and increased return on investment and a stronger market presence for the IVRS services provider. A speech interface gives caller more flexible navigation outputs that are less complex and more rigidly hierarchical touch to nemenu options.
It can display photo of an article or front page of a book. Hardware circuitry of IVRS is very compact and it can be used as a card in computer. Internet phone calls information from anywhere in the world with the advanced features of Interactive Voice Response System can be made available everywhere.