InterDigital Communications Corporation
"Our initial RTOS comparison included about 8 different RTOS choices. We quickly narrowed the selection down to two alternatives, with Nucleus ultimately becoming the preferred choice on technical merit alone," commented InterDigital Software Development Engineer, Brian Kilgore. "An additional consideration was the scalability available with Nucleus, and we determined through our evaluation that we could produce a far smaller executable using Nucleus than other alternative solutions. Given our tight memory requirements at the time plus life-cycle costs and performance considerations, we decided to go with Nucleus." --Brian Kilgore, Development Engineer, Tantivy Communications, Inc.
Mentor Graphics' Nucleus RTOS, a Key Part of Anywhere, Always-on Portable Wireless Internet-CDMA™ Technology from InterDigital Communications
I-CDMA technology is ideal for anyone who needs the freedom to take the Internet with them and for those needing a fast and reliable connection to the Internet when wired technologies aren't an option. With I-CDMA's anywhere, always-on Internet access, an executive can now immediately access his or her corporate intranet while sitting in an airport, and a realtor on a property site can e-mail property information and photos to a prospective buyer in another state real-time.
Mentor Graphics' Nucleus RTOS expands I-CDMA technology via integration with InterDigital's pioneering TANlink™ system. The Nucleus PLUS kernel, Nucleus NET TCP/IP protocol stack, Nucleus WebServ embedded web server, and support for Telnet server, FTP client/server and TFTP server were implemented into the design of the TANlink system, which is composed of the TANlink Access Unit (TAU) and the TANlink Signal Processor (TSP). These components, built on the flexible and robust Nucleus foundation, have made I-CDMA technology a reality.
Nucleus and TANlink - a Successful Integration
The TANlink Access Unit (TAU) is the subscriber modem connected to a user's laptop or desktop computer through a standard Ethernet connection to provide Wide Area Connectivity through an I-CDMA wireless radio connection. On the other end of that radio connection is the base station containing the TANlink Signal Processor (TSP) to handle the wireless connections to the TAUs. I-CDMA is the physical layer and link layer technology used on the wireless radio link.
The TAU contains a microprocessor that runs I-CDMA software under the Nucleus PLUS kernel. InterDigital also uses Nucleus NET, Telnet, TFTP Server and Nucleus WebServ products on the TAU. The TSP single board computer runs the I-CDMA software using Nucleus PLUS, Nucleus NET, Telnet and TFTP Client.
The I-CDMA software creates a wireless connection that looks like another Ethernet connection to Nucleus NET. A software engineer at InterDigital wrote a Nucleus device driver to encapsulate the I-CDMA logic so they could use the Nucleus NET TCP/IP protocol stack. In this way, he created a virtual device driver under Nucleus to support their custom interface. On the TAU, there is only one virtual device for the single wireless connection to the base station. However, on the TSP, there are many virtual devices, possibly hundreds, as there is one virtual device for each wireless connection to a TAU.
InterDigital developed a custom "packet filter" for Nucleus that allowed packets to be redirected around the normal stack processing. This allowed broadcast packets to be redirected to the custom DHCP server developed for Nucleus. The packet filter allowed the application program to "register" itself to be the desired receiver of a specific packet using MAC address, IP address, and Protocol or UDP/TCP port number.