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PDA 04 5/27/03 8:27 AM Page 32
PDA Robotics
IrDA Data protocols consist of a mandatory set of protocols and a set
of optional protocols. The mandatory protocols include the following:
• Physical Signaling Layer (PHY)
• Link Access Protocol (IrLAP)
• Link Management Protocol/Information Access Service (IrLMP/
IAS)

Characteristics of Physical IrDA Data Signaling:

• Range: Continuous operation from contact to at least one (typical-
ly two can be reached). A low-power version relaxes the range
objective for operation from contact through at least 20 cm
between low-power devices, and 30 cm between low-power and
standard-power devices. This implementation affords 10 times
less power consumption. These parameters are termed the
required maximum ranges by certain classes of IrDA featured
devices, and set the end-user expectation for discovery, recogni-
tion, and performance.
• Bidirectional communication is the basis of all specifications.

• Data transmission from 9600 b/s with primary speed/cost steps
of 115 kb/s and maximum speed up to 4 Mb/s.

• Data packets are protected using a cyclic redundancy check (CRC)
(CRC-16 for speeds up to 1.152 Mb/s and CRC-32 at 4 Mb/s).
Characteristics of IrDA Link Access Protocol (IrLAP):

• Provides a device-to-device connection for the reliable, ordered
transfer of data.
• Device discovery procedures.

• Handles hidden nodes.

Characteristics of IrDA Link Management Protocol (IrLMP):
• Provides multiplexing of the IrLAP layer.

• Provides multiple channels above an IrLAP connection.
• Provides protocol and service discovery via the Information
Access Service (IAS).

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