Wi-Fi

Dealership plugs in a WLAN

Hurdles, lessons learned in WLAN deployment

You've probably read or heard about a hospital, university, or manufacturing plant that has successfully implemented a wireless LAN as part of its network infrastructure. However, contrary to many of the current reports, you don’t have to be in the healthcare, education, or manufacturing industry to take advantage of WLAN technology. In fact, I'm going to give you a look at a recent wireless implementation at a large Honda dealership in Birmingham, AL. Not only did wireless meet the dealership's technology requirements, but it also added some great enhancements for its employees and customers.

Objective
The objective for the dealership was clearly defined by Honda’s e-business strategy group: Implement a new IP-based Dealer Management System (DMS) that handles lead management for sales, the parts catalog, customer-facing applications, and more than 120 core business transactions. This new client/server network would incorporate two servers and 18 workstations into a subscription-based system that requires connectivity to the Honda Interactive Network Web servers via the Internet. The new system would replace the existing dumb terminal network running over coax cables.

Challenges
Budgetary limitations are almost always a challenge in any IT project, and this one was no different. An initial assessment revealed that no CAT5 wiring existed within the building. The parts and service departments were in separate buildings, and the only connectivity that either of them had to the main building was coax and phone lines. In addition, talks were on the table to move the location of the dealership within the coming year to a slightly larger facility a few miles away. All these challenges, along with the open design of the showroom and office space, led us to consider the possibility of a wireless LAN solution.

Site survey
A complete site survey was performed on all three buildings to answer some critical questions about the WLAN possibilities. These questions addressed:
  • The number of access points and types of antennas needed for the required coverage and throughput.
  • Possible causes of RF interference.
  • Line-of-sight issues for building-to-building connectivity.
  • Potential AP channel configuration to prevent self-induced interference.

The site survey revealed some interesting findings. Many of the offices located within the main building were separated by thick, tinted glass. Moderate RF loss was noted when passing through this glass. This resulted in several more access points proposed than was estimated in the initial walkthrough. It also prompted some changes to the proposed AP locations. However, the effects of the glass were not totally negative. Similar glass surrounded the main showroom floor that took up a large part of the building, so minimal RF signals were transmitted outside of the interior of the building. This was a security benefit because it reduced the possibility of an attacker being able to snoop on their network traffic from outside the building using a standard WLAN card.

Solution
To provide complete wireless coverage for the dealership, eight Cisco Aironet 1200 Series Access Points were purchased, along with three 350 Series bridges. The 1200 Series APs allowed the dealership to take advantage of 802.11b capabilities today, while enabling the possible use of 802.11a and 802.11g radio cards in the near future without major changes to its wireless infrastructure.

New wiring was kept to a minimum with the only CAT5 runs being those provided to the access points, bridges, and servers. The servers and routers connected via CAT5 to a Cisco 2900 Series switch (a 24-port powered switch), which supplied both connectivity and power to the access points and bridges. The parts and service department used the Cisco Aironet bridges to connect to the main building. Desktops were equipped with Cisco Aironet Wireless PCI cards. Security was implemented using a combination of SSIDs and 128-bit encryption WEP keys. Figure A provides a look at the topology in the main building.

Figure A
Diagram of WLAN implementation


Highlights
This wireless solution also introduced some added value to the dealership. One advantage was the placement of a wireless access point within the parts area. This could reap strong rewards, since the company is exploring solutions that will allow the parts department to utilize a wireless handheld device to inventory and track parts. The dealership also placed a wireless access point in the waiting area so that customers, who typically need to wait for their vehicles to get repaired, can use their own WLAN-enabled PDA or laptop to connect to the Internet.

The entire wireless solution ended up costing approximately $2,800 more than was estimated. To the dealer, this additional cost was well justified by the additional benefits and by the fact that the solution can be transported in the event the company moves in the near future.
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