無線網路軟體 NUCLEUS 802.11 STA

Nucleus 802.11 STA is an embedded implementation of the IEEE 802.11 standards. What this means for you is that it was developed with the requirements of the embedded space in mind, rather than being a port of a product that was originally optimized for PC's and workstations. It is also extremely portable, and a new port of the Wireless LAN driver can be developed with little effort.

The "STA" stands for station. There are two types of 802.11 devices, Stations and Access Points. An Access Point can be standalone, but is generally built into a gateway, i.e., a device that moves data from the wireless network to the wired network. A Station is an endpoint. A station that we are all familiar with is a PC. In the embedded world a station could be a digital camera, set-top-box, television, cell phone, or a number of other consumer electronics devices.

The Security component of Nucleus 802.11 STA supports Open System and Shared Key Authentication schemes by default as stated in the 802.11 specifications. This component was designed to be highly modular, enabling the addition of new, future, authentication models to be easily made. For example, the security protocol for 802.11 is currently being re-written by IEEE, known as 802.11i. The design of this component will allow for easier integration with this new protocol.

Nucleus 802.11 STA supports the following IEEE specifications:

• 802.11 - 1999 - Wireless LAN Medium Access Control and Physical Specifications
• 802.11a - 1999 - High-Speed Physical Layer in the 5 GHz Band
• 802.11b - 1999 - Higher-Speed Physical Layer Extension in the 2.4 GHz Band
• 802.11d - 2001 - Specification for operation in additional regulatory domains
• 802.11g - 2003 - Further Higher Data Rate Extension in the 2.4 GHz Band

It is important to note that Nucleus 802.11 STA has been written and tested against wireless Ethernet chipsets supporting one or more of the above listed standards, but for any given version of the driver the underlying chipset defines which of these standards are possible.

Integrating Nucleus STA Into An Existing System
Nucleus 802.11 STA was developed to work as a network driver for Nucleus NET. Applications interfacing with Nucleus NET are isolated from the underlying device driver and Nucleus 802.11 STA is no exception to this rule. The only requirement from the application level is to initialize the 802.11 driver. From that point the application is unaware of the underlying network hardware. In addition to Nucleus NET, Nucleus PLUS is a requirement for those wishing to utilize Nucleus 802.11.

However, if further control of the 802.11 device is required API services are supplied that allow more flexibility. These services allow the application to enable/disable WEP, set the WEP key, retrieve 802.11 statistics, scan for access points, and so on.

Conclusion

802.11 has become the standard for wireless communications. While it originated within the desktop arena the costs have fallen such that it is being widely deployed in a variety of consumer electronics as well as other types of embedded systems. The addition of Nucleus 802.11 STA to the Nucleus family of products allows our customers to cost effectively upgrade their future devices to support these standards. We continue to monitor the 802.11 standards and already have some of the newer addition on our roadmap for future inclusion into the product. We will also be introducing a 802.11 Access Point solution in the future.