The Interactive Voice Response (IVR) System serves as a bridge between people and computer databases by connecting the telephone network with the database. The telephone user can access the information from anywhere at anytime simply by dialing a specified number and following an on-line instruction when a connection has been established.
The IVR system uses pre-recorded or computer generated voice responses to provide information in response to an input from a telephone caller. The input may be given by means of touch-tone or Dual Tone Multi-Frequency (DTMF) signal, which is generated when a caller presses a key of his/her telephone set, and the sequence of messages to be played is determined dynamically according to an internal menu structure (maintained within the IVR application program) and the user input.
The IVRS system which will be designed will provide an ideal platform for the operation of start-ups and existing small concerns. It will be a highly economical and efficient way to replace the Dialogic card which is very costly and requires a high maintenance and regular up gradation.
The IVRS system which will be designed will consist of simple components like microcontroller and some basic application chips interfaced to a PC which will have a small software running in the backend while the other jobs are performed on the front end.
ALL ABOUT IVRS:
In telephony, interactive voice response, or IVR, is a phone technology that allows a computer to detect voice and touch tones using a normal phone call. The IVR system can respond with pre-recorded or dynamically generated audio to further direct callers on how to proceed. IVR systems can be used to control almost any function where the interface can be broken down into a series of simple menu choices. Once constructed IVR systems generally scale well to handle large call volumes.
A caller dials a telephone number that is answered by an IVR system. The IVR system executes an application which is tied to the number dialed (DNIS Dialed number information service). As part of the application, prerecorded audio files or dynamically generated Text to Speech (TTS) audio explain the options available to the caller. The caller is given the choice to select options using DTMF tones or spoken word. Speech recognition is normally used to carryout more complex transactions and simplifies the application menu structure.
IVR systems are typically used to service high call volumes, reduce cost and improve the customer experience. Examples of typical IVR applications are,telephone banking, televoting, and credit card transactions.
- Large companies use IVR services to extend the business hours of operation. The use of the VUI (Voice User Interface) is designed to match the customer experience of the web interface. Companies have realized that access to voice services is impulsive and readily available. This is down to the high penetration of mobile phones.
- Call centers use IVR systems to indentify and segment callers. The ability to indentify customers allows the ability to tailor services according to the customer profile. It also allows the option of choosing automated services. Information can be fed to the caller allowing choices such as, wait in the queue, choose an automated service, or request a callback. (At a suitable time and telephone number) The use of CTI(Computer Telephone Integration) will allow the IVR system to look up the CLI (Calling Line ID) on a network database and indentify the caller. This is currently accurate for about 80% of inbound calls, but will increase as mobile phones become more popular. In the cases where CLI is withheld or unavailable, the caller can be asked to indentify themselves by other methods such as a pin number or password. The use of DNIS (Dialed number information services) will ensure that the correct application and language is executed by the IVR system.
- Entertainment and information. The largest installed IVR platforms are used for applications such as voting in TV game shows such as American Idol, X Factor,Big Brother, etc., which can generate enormous call spikes. IVRs have also been widely used to take orders for mobile content, such as ringtones and logos, weather forecasts, crossword answers, and the whole spectrum of adult entertainment.
- Anonymous Access. IVR systems also allow callers to obtain data relatively anonymously. Hospitals and Clinics have used IVR systems to allow callers to receive anonymous access to test results. This is information that could easily be handled by a person but the IVR system is used to preserve privacy and avoid potential embarrassment of sensitive information or test results.
- Clinical Trials. IVR systems are used by large pharmaceutical companies to conduct global clinical trials and manage the large volumes of data generated. The application used by the IVR in clinical trials is generally referred to as a Voice form application. The caller will respond to questions in their preferred language and their responses will be logged into a database and possibly recorded at the same time to confirm authenticity. Applications include patient randomization and drug supply management.
The various working blocks of IVR systems are:
1) Ring Detector
2) Relay Circuit
3) DTMF Decoder
4) Telephone Interface circuit
Ring Detector is starting block of IVR system. The basic function of this section is to detect the incoming ring. When a person calls the institute this section detects the bring and generates pulse accordingly and off-hooks the telephone.
It is form very simple circuit consisting of zener diode and simple diode with MCT2E which is a opto coupler. The Opto-couplers typically come in a small 6-pin or 8-pin IC package, but are essentially a combination of two distinct devices: an optical transmitter, typically a gallium arsenide LED (light-emitting diode) and an optical receiver such as a phototransistor or light-triggered diac. The two are separated by a transparent barrier which blocks any electrical current flow between the two, but does allow the passage of light.
The basic function of Relay is to switch the telephone line between ‘Ring Detection’ and ‘DTMF Decoding & Audio transmission’. Telephone line is generally monitored by microcontroller via Opto coupler to detect the ring. Once the ring is detected the relays is activated by Microcontroller to Off-Hook the phone and decode the DTMF signals pressed by caller.
This circuit detects the dial tone from a telephone line and decodes the keypad pressed on the remote telephone. The dial tone we heard when we pick up the phone set is call Dual Tone Multi-Frequency, DTMF in short. The name was given because the tone that we heard over the phone is actually make up of two distinct frequency tone, hence the name dual tone. The DTMF tone is a form of one way communication between the dialer and the telephone exchange.
MT-8870 operating functions include a bandsplit filter that separates the high and low tones of the received pair, and a digital decoder that verifies both the frequency and duration of the received tones before passing the resulting 4-bit code to the output bus.
Telephone Interface circuit:
This circuit allows you to couple audio from a computer soundcard into telephone line.The RJ-45 jack is set up to feed the circuit through the phone line. The active signal for a single phone is on the red and green wires. The capacitor blocks any DC current from flowing through the transformer. The resistor limits the current of the 90V ringing signal. The transformer isolates the telephone side of the circuit from the soundcard side. The zener diodes clamp the 90 volt ringing signal and other transient spikes to protect your recorder.
It is a heart of the circuit. It accepts a suitable signal from ring detector circuit and triggers the relay activation circuit.
It is also used to generate control signals. It receives the decoded DTMF pulses from the DTMF decoder. On receiving the pulses it generates the control signals which are then given to the computer. The computer in return generates the sound signal. Once the signal is generated and played on telephone line, the microcontroller starts scanning the telephone line for DTMF pulses. Now when the caller dials the respective key, the microcontroller receives the pulse and generates corresponding control signal.