Swedish Medical Center, whose wireless network project is profiled in this larger story, offers this advice to others looking to implement wireless networks.
Take the disposable access point route. Perhaps the only constant Swedish Medical Center saw during its wireless implementation was that technology changes. Although the firm began implementing Cisco access points in late 2004, the install came to a crashing halt when Cisco announced its purchase of Airespace in January 2005. Rather than implementing Cisco's individually managed access points, the firm switched to Airespace's centrally managed access points. This meant that the organization needed to rip and replace the approximately 300 access points it had already deployed.
Similarly, wireless network standards continued to evolve over the life of the project. Whereas Swedish originally focused on 802.11b for its network, it has since segmented its voice and clinical data to 802.11a (5GHz), while relegating administrative and other tasks to 802.11b/g (2GHz). And as the network grows, it is considering a move to 802.11n to receive even greater increases in bandwidth and performance.
Swedish could have gone with upgradable access points as a hedge against such changes, but in the end, it decided to go with less expensive, "disposable" access points. "Technology changes rapidly and even though the more expensive access points are upgradable, the costs to upgrade are typically more than replacing," says Steve Horsley, IT director at the company. "This strategy saved us over [US]$500,000."
Wireless requires constant monitoring. Horsley's group also found that the wireless network is far more dynamic than a typical wired version. For example, clinicians constantly move equipment around, at times saturating certain access points. "Equipment starts drifting to one area and can all of a sudden overwhelm an access point," Horsley says. "That's the risk we need to watch periodically, making sure we don't have too many devices aggregated onto one access point at a time."
Another area to watch is interference with unrelated wireless networks. In one instance, a new Starbucks, which had its own wireless network, opened up inside one of the hospitals in the Swedish system. Devices used by Starbucks customers were trying to connect to the hospital network and vice versa. "There was overlap in signals," Horsley says.
Good communication is vital. "If a hospital facility does a quick remodel, moves a wall, and you're the last to hear about it, that could change the signal pattern and mess up the network," he says. "You need to make sure you know about these things upfront."