You can connect cables from the PC to PC for connecting one computer to another. Similarly you can connect a mobile computer to the printer by means of a cable. But connecting by means of cables has always been a problem. Hence, the Infra Red Data association has developed the IRDA Port for serial communication over an optical (infra red) link.

The Infra red port applications include the following :

 1) Connecting from mobile PCs such as the Laptops or notebooks to the printers without the use of cables.
 2) Connecting the mobile PCs such as the Laptops or notebooks to the Desktop PCs without use of cables.
 3) Achieving synchronisation between the files between the mobile PCs and the Desktop PCs.
 4) Connecting mobile Pcs to the IrDa enabled telephones without use of cables and sending emails and faxes.
 5) connecting the mobile Pcs to the Irda enabled ATMs without use of cables and carrying out banking functions.
 6) Connecting to the network by assessing the Irda enabled Desktop PC (functioning as a node) without use of    cables.

 IRDA has following limitations :

 1) The working range of IR serial ports is limited to 3 meters only.
 2) There must be a direct line of sight between two IRDA ports and no obstruction is allowed in between.
 3) The two IRDA ports must be directly facing one another and there cannot be an angle of more than 30 degrees
 4) It is not possible to connect to multiple infra red devices over the same infra red link.

 Verifying infra red support on your computer.
 
 Check your PC to find out whether there is an infrared transreceiver in your Computer  or not. The infra red transreceiver appears  as a small dark red window on your computer. If you do not have the transreceiver and you want to install one into your PC    find out whether your PC supports Infra red links by referring to the Computer manufacturer's manual. If there is a    transreceiver in your PC find out whether you have the device drivers and the software installed for it to function. This   can  be checked by opening the Device manager and cheking whether the infra red device appears in the list of devices  installed  on your computer.

 Installing IRDA adapters.
 
 The IRDA port is required to be incorporated into the Mobile PC as well as the Peripheral. If you want to connect the mobile PC to the Desktop PC  IRDA port must be incorporated into the Desktop PC as well as the mobile PC.  The IRDA port is now present in many new mobile PCs such as the LAptops and the Notebook computers. The latest peripherals    such as the printers are also enabled with the IRDA port. The Desktop PCs too have IRDA ports installed.  If there is no IRDA port in your Desktop PC or the mobile computer you can install IRDA adapters. The IRDA adapters  (transrecievers) can be attached to the serial port or the USB port. In Windows xp the Add hardware wizard can help you to    install the IRDA adapters. The IRDA adapters come with proprietary software from the manufacturer, hence, installing the    IRDA ports involves installing the IRDA drivers and softwares into your PCS and  mobiles. 
 
 How to connect using IRDA .

 Once IRDA is enabled on the devices the primary Computer (Host) sends data over the automatically established Infra red link  and the secondary Computer or device (Guest) recieves the data.In order to establish the Infra red link you will have to  configure  your PC or mobile. In Window Xp this can be done using the Network connections service. Click on Network  connections icon  from the control panel and configure your computer either as a 'Host' which wants to send data or a  'Guest' which wants to recieve the data.  
 
 IRDA Standards and Protocols.
  
 IRDA has announced two standards for data communincations over an infra reda link. The earlier one is the SIR (serial infra   red link specification) which allows links to work at 1.152  Mb/sec. The IRDA announced one more standard as an extention of  the earlier standard. This standard allows links to work at the increased speed of 4 Mb/sec. 

 IrNET support (protocol)
 
 If you want to connect infrared cellular phone to your Computer you can do so using the IRNet protocol.You can also  establish connection between your computer and a network access point.

 IrLPT printer support (protocol)
 
 If you have infra red transreceiver installed in your computer, an infra red port appears in the Add printer dialog box of  Windows xp. You can associate a printer with this port and then you can print to this printer. The IrLPT printer protocol is  used to connect your computer with the printer using Infra red link and data is transferred from computer to the printer.

 IrTran-P image transfer support (protocol)
 
 If you want to receive digital images from such devices such as the cameras or other digital capture devices, over the Infra  red link than you can use the  IrTran-P protocol do so. You can use this feature to receive digital images from a camera or  other device that supports IrTran-P to your computer  through an IrDA  connection.