"IrDA Implementation, Instant Solution and Certification"
Dr. Keming W. Yeh (Yr2001, 2000 Chair: IrDA Test/Inter-Op Committee),
Dr. Lichen Wang (Yr2001, 2000 Chair: IrDA Technical Committee)

INTRODUCTION 

In the past 6 years since the formation of Infrared Data Association (IrDA), the Industry has gone through hype to bottom and now, re emerge as strong, mature technology solving well defined mobile connectivity needs. It is not just wireless, but with complete specifications from Physical, Protocol To application layers. It has also established itself as the leading organization that can effectively and quickly develop useful application protocol specifications, which are licensed by Bluteooth, and 3GPP international standardization organizations. Recent example includes OBEX (Object Exchange: vCard, vCalendar, vNotes, vMessage, vBookmark) and is now developing wireless e-payment application standards, IrFM (Infra-red Financial Messaging system). In this short history, IrDA has also progressed through three generations; SIR-115.2Kbps, FIR-4Mbps, VFIR-16Mbps and an impressive installation base of more than 325M units of mobile devices cumulated by end 2000. It grows at more than 50% annual rate seeing it proliferated from notebook PC, PDA, digital camera, printer, industrial date terminal, portable instrumentation, to smart cellular phones and e-toys.

BACKGROUND 

The IrDA stack has three mandatory protocol layers, Physical Layer (IrPHY), Infrared Link Access Protocol (IrLAP) and Infrared Link Management Protocol (IrLMP). On top of these, there are many optional layers. Tiny Transport (TinyTP) is one of them and is often needed to support other upper layers such as IrCOMM, IrLAN, IrTranP, Obex, and IrMC.

PHYSICAL LAYER

The Physical Layer consists of an IR transceiver, an encoder/decoder, a serializer/deserializer and a framer. The IR transceiver converts electrical signals to and from IR signals. The serializer/deserializer converts the serial bits to and from bytes. The framer assembles and dissembles IrDA frames by adding or removing the frame wrapper to or from the payload and generates or checks the CRC error checking. IrDA compliant IR transceivers are available from many component manufacturers. They fall into two categories, the FIR or IrDA-1.1 transceivers, and the SIR or IrDA-1.0 transceivers. The former can handle data rates of up to 4 Mbps, while the latter can only handle data rates of 115.2 Kbps or below. There is also the MIR at 1.115Mbps. There are various made switching schemes of SIR-MIR-FIR among FIR transceiver modules. This causes many problems and will soon be standardized at 16 Mbps. more...

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