Windows CE supports a wide range of communications options for transmitting and receiving data. You can use communications for a variety of tasks, including:
To support the many different types of communication, Windows CE-based devices can include a variety of hardware. Some hardware may be an integral part of the device. For example, many Windows CE-based devices include a connector for a serial cable or an infrared (IR) transceiver. If a PC Card slot is available, users can also extend the built-in capabilities of the device with third-party communications hardware, such as a modem or a bar code reader. Available communications hardware includes:
Windows CE supports two basic types of communications technology: serial and network. While some hardware can support only one type, the same hardware is often used for both. Which type of communication is appropriate is governed in large part by how the communicating devices are connected.
You can use serial communications when two devices have a one-to-one connection. Each sender has only one possible receiver, and vice versa. A common example is two devices connected by a serial cable. Because there is no ambiguity about where the data is from and where it is going, it can be streamed from one device to the other with little or no processing. Examples of serial communications include:
With networks, every transmission is usually seen by many receivers, whether or not they are the intended recipient. For one-to-one communication to take place over a network, simply streaming the information will not work. Each transmission must also include addresses that identify the sender and the intended recipient. A receiver can thus monitor the network and pick out only those transmissions that are addressed to it. It can then use the senders address to respond. The Windows CE network stack handles addressing and related tasks. You use a network for such tasks as: