• Wireless middleware*
• The Virtual Private Network option*
• Wireless standards

* The following information is intended to be a reference for products and services related to mobile PC computing over GSM networks. Neither Intel nor the Mobile Data Initiative endorse the products or companies listed below. This information has been submitted by the companies listed for informational purposes only. No guarantee is made about its accuracy.

Wireless middleware

There are two scenarios when working with wireless data. In the first scenario you use exactly the same communications software over wireless links as you do over modem or LAN links. Examples might include mail programs, Web browsers, database query programs, groupware, and remote access. In the second scenario, you use additional software called wireless middleware to enhance the operation of your application software. Wireless middleware can address the following kinds of problems:

• Some networks (e.g. RAM and ARDIS) do not use conventional networking protocols and software interfaces. Wireless middleware can act as an interpreter between application software and the specific protocols of the wireless network.
• Operation of the application software may be slow on some networks. Transactions that took seconds over a LAN connection might take tens of seconds or longer over wireless links. Wireless middleware can streamline communications significantly by reducing both the total amount of communications and the amount of back and forth traffic.
• Related to the above problem, operation of the application may generate excessive usage charges. Wireless middleware can help significantly in this area.

Wireless middleware comes with client and server components. The client software is installed on the mobile computer and the server portion on a workstation on a corporate network that acts as a gateway. The client and gateway portions communicate with each other using protocols designed specifically for the wireless environment. These protocols minimize the amount of traffic and use robust methods to recover from transmission errors or dropped connections. Some middleware solutions can queue up messages and automatically dispatch them as soon as a connection becomes available. The gateway component functions as a proxy or agent on behalf of the mobile client, engaging in high bandwidth transactions with destination servers and then returning only the desired information to the mobile computer.

There are two types of middleware solutions. One type enhances the operation of existing applications. For example, AirMobile* from Motorola can speed up remote access to cc:Mail* or Notes servers. The other type comes in the form of SDKs with which software developers and system integrators can retrofit existing applications or develop new ones. Nettech systems provides solutions in the latter category.

Components of a middleware solution.

The following table lists the key middleware providers and their products.

For further information, see
The PCIA Mobile Wireless Communications Guide.

Wireless standards

Standards are crucial in promoting interoperability between products from different vendors. Standards also play an important role in wireless networking since they not only allow plug and play environments, but they permit the same application to readily function over any wireless connection to any mobile device.

The Mobile Data Initiative has played a key role in hastening the development and adoption of computing standards.

Key standards to watch include:

• Portable Computing and Communications Association (PCCA). The PCCA has developed standards for wireless extensions for both AT commands and for the Network Driver Interface Specification (NDIS). See http://www.pcca.org for more details.
• Unimodem. Unimodem is Microsoft's architecture in Windows for supporting modem based communications and applies to cellular connections as well.
• Internet Engineering Task Force (IETF). The IETF defines all the key standards for the Internet, including all the communications protocols. Many of these communications protocols will be used over wireless connections, and some will be optimized specifically for wireless networks. See http://www.ietf.org for more details.
• Wireless Application Protocol. This set of standards defines protocols and interfaces for low bandwidth communications such as short message service with PCS. The standard also addresses microbrowser environments on smart phones and handheld computers. See http://www.wapforum.com for more details.
• Mobile IP. Mobile IP facilitates the use of IP networking for nodes that must maintain constant communications as they move from one IP subnet to another. This standard applies both to wireless and wired communications. Mobile IP is specified by the IETF in the Internet standard RFC 2002.
• Narrowband Sockets. NBS is a standard developed jointly by Intel and Nokia that specifies interfaces and protocols for communicating over low bandwidth wireless connections such as SMS. See http://www.intel.com/ial/nbs/ for more details.