Dealing with Infrared

Bluetooth also needs to perform against an infrared port that is evolving over time. The
ETSI/ARIB IrDAAIR (Area InfraRed) specification defines a point-to-multipoint capability
in which multiple devices can be supported from a host device provided they are
within a 120° beamwidth. The data rate is 4 Mbps over 4 meters and 260 kbps over 8
meters.
The disadvantage with infrared is that it doesn’t work so well in strong sunlight. As
with RF, free space optical transport is an inconsistent delivery medium subject to
blocking, refraction, and reflection. IrDA also suffered, still suffers some would say,
from incomprehensibly difficult driver software, which has to be installed on a target
device—for example, to get a laptop with IrDA to talk to a cellular handset with IrDA
so the laptop can access the Internet. This problem has been carried forward into
Bluetooth—devices that are deaf to each other because of software incompatibility or
user incomprehension.