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PDA 04 5/27/03 8:27 AM Page 35
Chapter 4 / Infrared Communications Overview
IrDA specifications are now supported by all divisions of Microsoft
(IDG, WinCE, Win98, Win2000, and Windows XP), and this universal
data port is recommended on PC99 products (mandated on certain
WinCE products—PalmPC, etc.)
PDA Robot will use the IrDA Data protocol, not the IrDA Control pro-
tocol, to ensure a reliable high-speed bidirectional flow of data
between the body and the brain (PDA). All decisions will be made on-
board the PDA, using the software outlined in this book.

Windows CE (Pocket PC) and IrDA

One of the key features of Windows CE-based devices is the ability to
communicate with other devices. Windows CE supports two basic
types of communication: serial communication and communication
over a network. Most devices feature built-in communications hard-
ware, such as a serial port or an IR transceiver. The network driver
interface specification (NDIS) implementation on Windows CE sup-
ports the following communications media: Ethernet (802.3), Token
Ring (802.5), IrDA, and wide area network (WAN). The diagram shown
in Figure 4.4 outlines the communications architecture of the
Windows CE operating system, specifically the components of the
IrDA protocol layer and how IrDA miniport drivers communicate
through the NDIS library, with their network interface cards (NICs)
and applications.

In the Windows CE communications architecture, the NDIS interface
is located below the IrDA, transmission control protocol/Internet pro-
tocol (TCP/IP), and point-to-point protocol (PPP) drivers. The NDIS
wrapper presents an interface to the upper and lower edges of a mini-
port driver. To an upper-level driver, such as the TCP/IP protocol driv-
er, the NDIS interface looks like a miniport driver. To the miniport, the
NDIS interface looks like an upper-level protocol driver. On the bot-
tom of the communications architecture, the NDIS interface functions
as a network adapter driver that interfaces directly with the network
adapter at the lower edge. At the upper edge, the network adapter
driver presents an interface to allow upper layers to send packets on
the network, handle interrupts, reset or halt the network adapter, and
query or set the operational characteristics of the driver.

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