Draft System Specification

Draft Systems Specification  

Principle of Operation

The main operation of Intelligent Phone Service Selector (IPSS) is to provide the consumers with the ability to dial phone calls through a computer and letting the computer distinguish the type of call it should be.  When the user decides to make a phone call the program must be opened and a Graphic User Interface (GUI) is turned on to run the IPSS program.  The software will choose between a modem or an Ethernet with VoIP.  In the case of a 911 call, the software will automatically route the call to the RJ-11 jack and dial the nearest emergency center. 

The main task for IPSS is for the PC to make the decision for the phone call that is using either a landline or VoIP. If the landline is needed, the PC will send a signal through a serial port to close a switch in the circuitry to allow voice to travel to the RJ-11 jack.  If the GUI receives a Skype username or number that is decidedly cheaper to dial through Skype, the software will open Skype, log the user in, and dial the number.

• A system block diagram of IPSS is shown below in Figure A.1.

• A state machine for IPSS is shown in Figure A.2.

• The following describes the specification for the block diagram and the specification of the state machine.

 A.1

Specification of the Block Diagram

There are six blocks in the block diagram (Figure A.1.)  An overview of the block diagram entails the headset, including microphone and speaker components, connecting to the audio transformer and PC.  If a VOIP call is decided from the intelligent software the call will be made through the Internet.  If a landline call, such as in the case of an emergency is the route, the PC sends a control signal from the serial port to the relay switch completing the circuit.  This allows the call to be dialed through the RJ-11 and the voice through the microphone will be forwarded to the landline.  The functions of the six blocks are described below.  Note the headset will include the microphone and speaker

Headset: A headset with a microphone and speaker is connected to the PC and audio transformer.  When a user talks on VOIP the voice will work like a normal conversation without any external hardware.  When they talk on the landline the audio transformer allows the conversation to carry out normally with users being able to talk and listen simultaneously.  In other words it allows full duplexing.   

PC: The PC is the most important part of IPSS. It contains IPSS.exe which is the intelligent software.  The software is installed onto the PC. The IPSS software is opened and the user has a GUI interface to dial a phone number or Skype username for a call.

Once the software is running the user dials the number on the GUI keypad, or enters the Skype name of a person if they want to use Skype.  The PC has two options. The computer now either routes the phone call to Skype, invoking Skype automatically and dialing the number, or dials the number through the modem. If Skype is the path the software chooses it dials out through RJ-45 cable on the Internet. If the landline is chosen to be the most efficient method, serial line from the PC closes the relay, the modem dials the number, and the call is made through the RJ-11.  When the call is finished the connection is terminated and the serial port opens the relay switch.

Audio Transformer: The purpose of the audio transformer is to allow full duplexing of conversation when the user needs to make a call through the landline.  This means that when the user is talking they do not hear their own voice.  It also means people do not have to pause and wait for someone to finish what they are saying in order to talk. 

Relay:  The relay is a coil that acts as a switch.  It is high conductivity.  When it receives a signal from the serial port on the PC it will switch allowing voice to move to and from the phone line.  When a call is complete the serial port will send another signal causing the relay to switch again and voice will not go through.

RJ-11: The RJ-11 Splitter is a piece of hardware that can be purchased at many electronic stores. Its main function is to allow the connection from the relay unit to the phone line.  The output of the RJ-11 Splitter is the telephone network.  When IPSS chooses the phone line, the modem of the personal computer will be active and dial the call through the RJ-11 Splitter.

Software Description:

The software package is the construct that will take care of the entire decision making process in this project. It will consist of many forms. The first form will include an option to localize the program as well as an option to dial a number. There will be a form for dialing a phone number, and a form that will be present during the call. Another form will ask the user if he or she wants to make another call or quit the program. The forms follow in more detail.

 

Main forms

·         Entry Form:

The entry form has the option to make a call.  It will detect an Internet connection and display a box to enter a number or Skype username.  If the user decides to make a call, the next form will be used.

·         Keypad on the GUI Form:

The keypad allows the user to dial a number in the GUI. Like a cell phone, the user will be able to delete numbers or a Skype username until he or she is satisfied with the input.  Once the number is chosen, the user hits the ‘Dial’ button.

·         In Call Form:

This form appears when the user is dialing a number.  If the call is successful a dialog will show this.  After the call is complete, the user will be able to choose to dial a new number or to exit the program.

 Updated December 6 2005