Specifications

Remote Control and Receiver-Transceiver Specifications and Requirements
for Windows Media Center in Windows Operating Systems
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Differences between Learning (Wide Band) Receiver and Long Range (Narrow
Band) Receiver
There are two types of light detectors needed for an IR transceiver:
 Long Range Receiver. This is the receiver that is used during normal operation of Windows
Media Center. It is designed to receive input from 3 to 30 feet away. It de-multiplexes the signal
in hardware. It is optimized to receive a 36 kilohertz (kHz) signal, but it can also receive a
(degraded) signal from 30 kHz to 60 kHz (or more).
If your long-range receiver has a narrow band pass filter (BPF), you must set the
V2_DEV_CAPS_NARROW_BPF bit. Note that this results in a less-than-optimal experience for
uses while setting up Windows Media Center for set-top box control because they will have to
complete the long learning process instead of the shorter parse-and-match process.
 Learning Receiver. This is the receiver that is used during IR Learning. It is designed to be used
from 2 inches away. It does not de-multiplex the signal in hardware. It is optimized to receive a
signal from 30 kHz to 60 kHz (or more).
If your IR transceiver is input only (no blasting and therefore no learning), a long-range receiver is
required. If your IR transceiver also does IR output (blasting), both a long-range and learning
receiver are required.
Emitter Detection
When responding to the IOCTL_IR_GET_EMITTERS request, the hardware only needs to detect
if something is plugged into the emitter port. If, for instance, a user plugs a pair of headphones
into an emitter port, it is acceptable to return that an emitter is detected in that port.
Emitter Multiplexing
In reading the reference for IOCTL_IR_TRANSMIT, you may notice that the transmit port is a
bitmask. This means that it's possible to transmit to two different emitter ports with the same
IOCTL. There is some freedom for design here. If your hardware can only output to one port at
the same time, and the IOCTL is asking you to transmit to two ports, your driver can first transmit
to the first transmit port and then transmit to the second port.
Pulse Mode Remotes
Pulse mode is no longer required.
Wake From Remote
To support the "Wake From Remote" feature, your hardware needs to do several things:
 It must resume from standby mode using the Sleep button for the particular IR protocol for which
the hardware is optimized. Resume-from-standby must do hardware decoding of the protocol and
operate when the Windows Media Center computer is in a state of lower power consumption.
 It must wake from S1 or S3. Resuming or waking from S4 or S5 is optional.