On the Same Wavelength Integrated solutions for Wireless LAN in office and industry environmentsAccess to servers and networks from any location, and free movement between locations: for many companies, an integrated wireless LAN (WLAN) solution for offices and manufacturing offers many advantages. However, industrial production poses altogether different demands for the sturdiness and reliability of radio networks than do office areas. Siemens now offers an integrated solution for both the industry and office environments based on a joint concept that utilizes HiPath Wireless and Scalance W systems. It thereby creates the basis for optimal mobility of crucial information across departmental boundaries.

The combination of wireless networking for office and production environments enables the creation of mutual networks for mobile speech transmission (Voice over WLAN) and also facilitates the transfer of machine or storage data directly to materials management. In addition, communication with machines and notebooks, or Personal Digital Assistants (PDAs), is very easy via WLAN, for example, when performing tasks such as diagnostics, commissioning, service and maintenance. For many companies, an integrated WLAN solution thus offers many advantages. Not only is it less expensive and more efficient, it also allows for optimization of many operating processes. Voice over WLAN means the user is not longer tied to a specific workplace, but rather is able to communicate wirelessly from anywhere within the company.

Common architecture for production and office environment

Both in the industrial environment as well as the "normal" office world, wireless communication using WLAN is based on the IEEE 802.11 standard. In most cases, however, a company possesses two independent networks, one for the office and the other for the production areas. These networks are managed separately. Roaming between conventional networks requires assigning a new IP address, which can lead to delays in time-critical applications. With speech transmissions, the changeover from one IP address to the other can even lead to a call being lost. In data links, communication faults can occur, for example, with operatorless transport systems.

Siemens has developed a complete WLAN architecture to link these two areas. This architecture is based on proven products and solutions from the HiPath Wireless series for office environments and the Scalance W products for Industrial Wireless LAN (IWLAN) in industrial production environments. HiPath Wireless and Scalance W are designed for mutual operation without problems, and thereby ensure integrated wireless communication throughout the entire company.

The HiPath Wireless portfolio comprises WLAN controllers and access points. In addition to common wireless access for data, it also permits voice and data communication as well as multimedia cooperation within large radio networks. Consequently, wireless networks can be created which allow resources and data to be accessed from any location.

The access points and client modules of the Scalance W product line were specifically developed for industrial use. Scalance W housings with protection class IP65 are designed for extended temperature ranges. Shock-proof and vibration-proof, they are also characterized by a high degree of EMC robustness. As a result, the devices can even be used on buses and railways.

Common "switching point" offers security and speed

In the integrated solution, the HiPath Wireless controller assumes the role of the central "control point". It is linked to the IP infrastructure and controls up to 200 access points installed throughout the company. These are members of either the Scalance W family or the HiPath Wireless product portfolio. The controller itself serves as a layer 3 router linking the wire line to the wireless network. So-called Virtual Network Services are made available for the end devices and are distributed over the access points. This ensures that each end device is assigned an IP address only once, and retains the same IP address even when roaming across the various access points. As a result, delays during the transfer from one IP address to the next can be reduced below the critical threshold of 50 milliseconds without difficulty, so that transfers are imperceptible even during speech transmission.

The design concept of a central WLAN controller also offers major advantages with respect to the issue of security, an important aspect in sensitive office and production environments. Based on the information in the user data management system, the controller can decide whether an end user device should be granted access to the network at all. Thus, unauthorized users are quickly identified.

Office and production perfectly integrated

Thanks to the mutual WLAN controller, the manufacturing and office environments within an enterprise are now able to also grow together in terms of mobile communication. Users stand to benefit in two ways: for one, from the performance capabilities of the perfectly matched HiPath Wireless and Scalance W solutions for the respective application area, as well as from the seamless vertical integration of the mobile network stations, thereby enabling them to interact with greater flexibility, speed and reliability than before.