Which wireless infrastructure? Applications, architecture, security and growth affect ROI possibilities - Special focus: wireless

Communications News, March, 2003 by Gary Singh

The ideal wireless networking infrastructure is shaped by the growing demands of your business. When considering the co-adoption strategies of Wi-Fi wireless-IEEE 802.11 b, 802.11g and 802.1 la-four considerations should be made to generate the highest return on investment:

1. What application are you trying to support?

Wireless local area networks (WLANs) support a variety of devices-portable laptops, tablet PCs, specialized mobile computing devices, PDAs, wireless VoIP phones. There is also a full spectrum of mobility applications-wireless Internet, e-mail, wireless intranet access, supply-chain management, bar code scanning-running on these devices, each of which has varying bandwidth requirements. In some cases, 11 Mbps provided by 802.11 b Wi-Fi technology is more than adequate, while, in others, 54 Mbps provided by 802.11a Wi-Fi is ideal.

In wireless, bandwidth and range are inversely proportional. Since most WLAN deployments do not require high bandwidth, lowering equipment costs without sacrificing optimal range should first be considered. As systems are developed based on existing and emerging technologies, focus should also be placed on fitting necessary bandwidth requirements to the appropriate applications, helping to lower the total cost of ownership.

2. Centralized or de-centralized architecture:

The traditional approach distributes firmware-based, enterprise-class access points. This requires additional network and security services for WLAN solutions, and is limited to security, management, provisioning, quality of service (QoS), class of service and mobility.

The emerging approach centralizes wireless networking into a single managed wireless switch, with the "network edge" now residing in a wireless switch that essentially collapses a complete set of required services that can be customized to your mobile application circumstances. This then lowers the costs and betters the management of provisioning those collapsed services.

If you are deploying a WLAN for the first time, switched wireless networking makes the most sense. Advanced wireless features and services-security, roaming, management and QoS-can be applied through virtual LANs (VLANs), much like those found on wired networks, at the lowest possible cost.

If you already have deployed a WLAN-unless that network can become part of a switched wireless networking architecture-you should move forward with existing applications and add 802.11 a only when higher bandwidth is required. Enforcing new security standards and technology, however, may require added costs because access points need to be individually updated.

The approach selected will also affect the ability to deploy the new 802.11g standard on the 2.4-Ghz band. If you have already deployed 802.11b Wi-Fi, adding 802.11a Wi-Fi to gain higher bandwidth will be more practical than 802.1 lg. The latter has to share the 2.4-Ghz frequency with the existing 802.1 lb, which results in marginal performance, while the former will result in significant performance improvements.

3. What is the appropriate approach to security?

As you dive into the multitude of encryption and authentication options-WEP, WPA, FIPS-140-2, PEAP, EAP-TLS, EAP-TTLS, Kerberosthe ability to apply multiple security types across different subnets becomes appealing. Why? Applications and type of data vary depending on the environment supported by the wireless network. Again, focus on the clients being deployed, as their support for security approaches varies.

In an office setting, if you want to provide basic Internet access to guests, while also providing corporate network access to employees, you can use wireless VLANs to apply WPA for the former, while deploying WPA plus EAP-TLS or EAPTTLS, for the latter. If you plan to extend mobility to your IP telephony system with wireless VoIP, Kerberos makes sense for voice and data devices.

4. Where do you want your business to be in three to five years?

If you expect to have more employees, greater product velocity, or wider applications, you need to assess how you want your wireless network infrastructure to scale to support growth. A wireless networking architecture that can easily adjust to changing circumstances and be customized to suit a variety of applications is ideal. This means making little or no physical changes to the endpoints that deliver wireless connectivity. Changes should not cost additional money, disrupt existing applications or network service, or require the physical replacement of the existing wireless end-point.

For more information from Symbol Technologies: www.rsleads.com/303cn-257

Singh is the senior director of marketing for Symbol Technologies' wireless systems division, San Jose. CA.