Deploying Real-Time, Wi-Fi- Based RFID for Mobile Asset Tracking, Telehealth

All too often, when a hospital caregiver needs but can't locate an IV pump, he or she must hunt for one. That's time better spent attending to patients or performing other duties. And in an emergency, the inability to quickly locate any required life-saving medical device can have serious consequences.


That's where Wi-Fi-based real-time location systems (RTLS) come in.


A Wi-Fi RTLS combines active radio frequency identification (RFID) technology with a standard enterprise Wi-Fi network to provide real-time asset tracking and mobile asset management, which can include objects (such as mobile medical equipment for telehealth, telemedicine and mobile health care) or people.


Hot Telehealth, Mobile Health Care Trend: Real-Time Asset Tracking

A number of hospitals as well as retailers and other organizations are now using RTLS to reduce equipment and operating costs; increase the usefulness of expensive equipment; improve patient or customer care; and boost employee productivity, among other potential benefits.


The uptick in the trend comes at a time when Apple's iPad is poised to become a hot mobile device for use in mobile health care initiatives, and as stalwarts in the wireless and tech industries roll out new telehealth services. For instance, Verizon is introducing its Telehealth Collaboration Services as Cisco, Dell, Google, Microsoft and IBM unveil a mix of services including electronic medical health records processing and more.


EnterpriseMobileToday talked recently with John C. Shoemaker, executive vice president of Ekahau, Inc., about Wi-Fi RTLS -- what it does, how it's often used and how it can be deployed in enterprises in health care and other industries.


Founded in 2000, Ekahau claims to offer the only Wi-Fi-based location tracking system that can operate on any brand or generation of Wi-Fi network and offer accuracy down to the room and sub-room level. Ekahau provides its Wi-Fi RTLS technology to hospitals and other customers around the world.


EnterpriseMobileToday: What exactly is Wi-Fi RTLS Using RFID and what does it do?

Shoemaker: Many people are familiar with active RFID tags. One example are toll tags in windshields, which automatically deduct the toll amounts from drivers' credit-card accounts, allowing them to pass through tollgates without having to stop and pay.


Active RFID tag solutions are fine for tollgates and other applications that control access, such as garages where an active RFID tag allows you to enter.


But there's a lot of infrastructure involved. You need the battery-powered active RFID tags to transmit a long-range signal. You need the tag antennae to send the signal to the readers, and you need the readers and other appliances connected to IT systems. All this infrastructure gets costly.


Also, once you pass out of range of the active RFID reader, no further transactions are possible until you're back within range.


So we've developed an RTLS that uses standard 2.4 GHz Wi-Fi networks to communicate with active Wi-Fi tags and requires no special readers, cabling, electrical wiring, exciters, or other equipment.


This means you can put an active Wi-Fi tag on an object or a person, and that tag will send a signal by itself across the Wi-Fi network you're already using. No additional infrastructure is required.


The small, battery-operated tags are attached to objects or people (as in the form of a wristband or a badge). Standard Wi-Fi access points measure signal strengths to the tags and then transmit the measurements in real-time to the Ekahau Engine, software that runs on a dedicated Windows server.


The server presents location data to users via a software dashboard, which shows the floor-by-floor layout of a facility, such as a hospital or airport. When you click on a floor, you can see where an asset you're tracking is on that floor, which room it's in, and what its status is. You can also get an audit trail of where the asset has been. You can get this information over the Internet through a Web browser if you want. It can be accessed remotely over a virtual private network (VPN) and across multiple facilities.


We use existing Wi-Fi standards because that's what most enterprises already have in place and it's easily scalable. Some other wireless location tracking systems use proprietary wireless protocols, such as ZigBee and ultra-wideband (UWB).


EMT: What are some potential benefits of Wi-Fi RTLS Using RFID?

Shoemaker: Real-time understanding of an item's location, presented on a computer screen against the backdrop of a floor plan or a facility layout, is huge.


When you can see things you couldn't see before, you can act rather than react. You can manage processes and people better. You know where your equipment is at all times so you can use it when you need it. Because we don't require additional infrastructure (other than a dedicated server), you don't have the costs, construction and disruptions of installing equipment as you would with other systems for tracking assets.


EMT: What types of businesses are deploying Wi-Fi RTLS? How are they using the technology?

Shoemaker: We have over 150 hospitals using the system around the world. Hospitals are an ideal environment because of the expense of the equipment they use, and the need to know where that equipment is at the time of need, especially in emergencies and in operating rooms. Given the expense of caregivers, there's also a need to make them more efficient.


Other deployments include manufacturing operations, retailers, coal mining operations, cargo shipping companies, airports, and college campuses. The military is looking at Wi-Fi RTLS for their various healthcare facilities but also to track expensive supply items to support our soldiers.


Security is another important application. With security, you need to know what's going on right now with your people or other tracked assets. You can't rely on a barcode that was read an hour ago to give you real-time information. With security you also need real-time alerts, so that if an airport contractor gets into a restricted zone, you'll know right away.


Cruise ships and resorts are other possibilities. Imagine that you're on a cruise with your family, and you've given your kids a wristband or a backpack badge with a Wi-Fi tag. If your kid wanders off, you could know where she is at all times just by looking at her location on an iPhone. It increases the kids' safety and the parents' peace of mind.


Our Wi-Fi badges have two-line LCD screens, so they can act as two-way pagers, too. You can send a brief text message to the device, and the badges can transmit alerts and trigger alarms based on rules.


EMT: Are there privacy or security concerns with Wi-Fi RTLS? How accurate are the locations given?

Shoemaker: Our system just gathers MAC addresses from the tags. Because they're just numbers, you don't need to encrypt the data. Also, our system doesn't record peoples' names and other personal data on the badges and tags, so there are no privacy issues. In the organization's database, which is managed behind their firewall, the tag ID is then associated to the individual person or asset and assures protection along with privacy.


We provide room-level accuracy, which means we can tell you in which room a tracked asset is. In that room, on average we can be precise within about 2 meters or 6 feet.


If 100 percent accuracy is needed, you can deploy IR beacons in fixed, known locations. For example, a hospital might place an IR beacon above a patient's bed. The tag a patient is wearing would see the IR beam and report it along with its own ID, telling administrators that this particular patient is in this particular bed right now.


EMT: What are the steps for deploying a Wi-Fi RTLS?

Shoemaker: Start by mapping your Wi-Fi network, so you'll know where the weak spots are. We can illustrate an entire enterprise Wi-Fi network with a colorized map that shows the coverage. We also use this model in our RTLS engine that helps drive the algorithms for location determination. This allows us to avoid the use of exciters and other hardware for obtaining high accuracy in locationing.


Next, be clear on what you want to track and why. You can track a lot of different things using different types of tags that are suitable to those assets (such as wristbands for tracking children or the elderly or hang tags for bags/backpacks).


From there, the next step is to install the system and do a pilot test to gauge the results or move to full deployment. Installing is simply a matter of tagging items, installing the server and software, and establishing user-defined rules for defining alerts and alarms and the people who should be notified.


EMT: What's next for Wi-Fi RTLS?

In the future, you'll see GPS combined with Wi-Fi on the same device. For instance, if I'm wearing a Wi-Fi wristband, you could track where I am as long as I don't go about 300 feet beyond a building. Once I do that, I'm no longer within range of the Wi-Fi network and can't be tracked. But if GPS is added, you can now track me when I go offsite using the same RTLS system.


I believe Wi-Fi will continue to be the dominant wireless standard. It's ubiquitous in many enterprises already, and it's starting to be ubiquitous in a few communities, too. It's scalable across multiple applications, whether it's tracking temperatures in refrigerators or kids on cruise ships. Using Wi-Fi, you can get real-time visibility into your assets to effect reactive and proactive decision making. And the wristband takes it all to a new level, so you can deliver safety and services to customers that couldn't be done in the past.


James A. Martin has written about mobile technology since the mid-1990s.





Wi-Fi, RFID, telehealth, mobile health care, asset tracking