Structure of infrared communication

The following are necessary for infrared communication.

Software/hardware structures

  • Communication protocols
    Indicate mutual promises between equipment to communicate. Also called "communication procedures" and "protocols."
  • ENDEC/controller
    Encodes information (modulation: encode) and decodes it to retrieve the original data (demodulation: decode).
  • Transceiver
    Converts electrical signals into optical signals, and vice versa.

Example of software and hardware structures in IrDA

DMA(Direct Memory Access):A feature of data transmission system in computers that allows certain hardware subsystems within the computer to access system memory for data transmission in RAM independently of the CPU.


Basic protocol

TinyTP (IrDA Infrared Transport Protocol)
Controls data flow to prevent omission in data transfer.
IrLMP (IrDA Infrared Link Management Protocol)
Manages the higher layer by providing it with a logical communication path in place of a physical communication path.
IrLAP (IrDA Infrared Link Access Protocol)
Responsible for selection of the party to communicate, connection/disconnection, and basic data transfer.
IrPHY (IrDA Serial Infrared Physical Specification)
Defines physical media to communicate. Distance, angle, and speed of IrDA communication are defined here.

Application protocol

IrOBEX (IrDA Infrared Object Exchange Protocol)
Infrared object exchange protocol
IrCOMM (IrDA Infrared Communication Protocol)
Infrared serial transfer protocol
IrTranP (IrDA Infrared Transfer Picture Protocol)
Infrared image transfer protocol
IrMC (Infrared Mobile Communication)
Infrared protocol for mobile phones
IrLAN (Infrared Local Area Network)
Protocol for infrared LAN
IrBurst (IrDA Hi-Speed Contents Exchange Protocol)
100 Mbps high-speed content delivery system
IrFM (IrDA Infrared Financial Messaging)
Infrared electronic payment system. By adding a credit card function to a PTD (Personal Trusted Device) such as mobile phones etc. and using IrFM, the card data is sent securely, preventing illegal use of the credit card by magnetic readers etc.

Extra: Our software architecture concept

Our ability to develop software unique to Link Evolution, which achieves memory optimization, ultrahigh speed, and versatility (OS and CPU independent), all of which are required for software porting, is highly evaluated by many customers.

Universal OBEX
  • Supports multiple applications.
  • Supports IrDA, Bluetooth, and TCP/IP.
  • Compliant with OBEX Ver1.3 protocol
  • Event-driven architecture (event-drive, energy saving)
  • Controls multiple OBEX servers and client applications simultaneously (context and state management)
  • CPU and OS independent codes (internal state management)

Support of universal applications: Universal OBEX

Various types of applications and software as follows can be supported:

  • IrFM (IrDA Infrared Financial Messaging)
  • IrMC (Infrared Mobile Communication)
  • IrTran-P (Infrared Transfer Picture, infrared communication protocol for digital cameras)

Support of multi-transport layer: Universal OBEX

Communication standards such as Bluetooth, Internet, and RS232 can be supported.

Support of higher speeds

  • IrSIR: 115 Kbps
  • IrMIR: 1 Mbps
  • IrFIR: 4 Mbps
  • IrVFIR: 16 Mbps
  • IrUIR: 100 Mbps * IrBurst (100 Mbps or more) is in development.

Optimization algorithm which supports all the above.

Upgrade support

Transport layer and OBEX upgrade support does not require changes in existing applications and adopts an architecture that can be upgraded easily.
The adoption of an abstraction layer allows flexible response to HW, CPU, and OS.