Self-Healing, Industrial Strength WLANs
Posted: 12.04 - By Arielle Emmett

Everyone has an industrial-strength wireless LAN for sale, but who is buying, and why? In October 2004, the wireless LAN industry lost three of its contenders—AirFlow Networks, Bermai and Legra Systems—as part of an ongoing industry shakeout. In the warehousing and shipping sectors especially, only a few WLAN suppliers remain, among them Cisco, Symbol, Proxim, Intermec and a strong new contender, AireSpace. Even with fewer players, the market is crowded with 802.11-based technology, new security and network management protocols, indoor/outdoor mobility networking architectures and handoff schemes—and, ironically, reluctant industrial buyers.

Analyst group Gartner says that end users in both consumer and enterprise markets spent $2.6 billion on WLAN equipment purchases in 2003. The company forecasts this market to increase at a compounded annual rate of 8.3 percent, from 2002 to 2008, but wireless LANs for the warehousing and shipping sectors are lagging behind.

Reasons? No one really knows. Analysts and suppliers acknowledge that warehousing enterprises, among the earliest adopters of wireless networks, are purchasing the newest WLANs more cautiously than other enterprises. “The warehouses and manufacturers are slower to upgrade than industries such as healthcare, which are buying WLANs for the first time,” says Abner Germanow, a program manager of enterprise networking research at IDC in Framingham, Mass. “The argument for upgrading is not nearly as strong as that for installing WLANs in places that don’t have them at all.”

Yet warehousing operations can reap as much as 500 percent ROI by installing a wireless LAN with handheld computers to automate the manual tasks of picking, receiving and shipping inventory, according to analysts. Kenneth Dulaney, a VP of mobile computing at Gartner, concurs: “If you have a warehouse and you don’t have wireless LANs and handheld computing, you don’t have a competitive warehouse.”

Many warehouses today still operate in a semi-automated batch mode. While they may have some wireless capability for narrowband communications on the floor, most operations still require workers to scan an item with a bar code reader and then physically walk over to a shipping dock to deposit the handheld into a cradle device, where the captured picked item data are then uploaded to a central shipping database. “Only about 10 percent of the warehouses today have true WLAN capability,” Dulaney says. But even a batch system can deliver a 300 percent ROI over strictly manual methods.

The challenge lies in cost-justifying upgrades while ensuring stiff security measures are in place. “Warehousing has been installing systems for 20 years or more, and in the old days, it was very proprietary stuff with no interoperability,” explains Hank Stephens, a product manager for wireless networking products at LXE. Most systems were licensed, using narrowband frequencies for simple transactions such as bar code reading. Security issues were not much of a concern.

Since 1999 and 2000, however, the move toward open protocols based on spread-spectrum technology and the 802.11 wireless LAN standard has changed the industrial landscape. The new Wi-Fi networks were thought to “bleed” RF and hence represented a potential security risk. “The 802.11 networks were implemented before security hit the radar, and standardization brought some problems—namely, that once you publish an open protocol, it’s available to anybody and can lead to vulnerabilities,” says Stephens.

Roughly two years ago, researchers at UC Berkeley broke into one of the first security schemes for 802.11 networks, called Wired Equivalency Privacy (WEP). Though WEP was followed by more robust protection schemes, among them 802.11i, an IEEE standard for wireless security, and Wireless Protected Access (WPA), a Wi-Fi Alliance certification of interoperability between different vendor products (WPA2 is a certification based on the IEEE 802.11i standard), many WLAN infrastructure vendors have had some difficulty selling the warehousing space on upgraded WPA equipment (e.g., firmware for radio cards and APs).

“WAP is something that hasn’t been part of a lot of specialized devices in some vertical industries,” says IDC’s Germanow. As the industry moved toward higher-speed “flavors” of 802.11 (i.e., 802.11g, a higher speed radio standard running at 2.4 GHz, and 802.11a, a 54Mbps standard running at 5 GHz), warehousers found that they had to replace not only radio cards but APs. Adoption slowed with continuing concerns about security and network management despite vendors’ sophisticated offerings in wireless authentication and physical/virtual security, data encryption, message integrity checks and seamless roaming.

“Some customers expressed concern about unauthorized users worming their way into accounting databases or payroll by eavesdropping on data with strategic or legal value,” Stephens notes. A practice known as “war driving” has become commonplace: Wi-Fi hackers in a vehicle use a roaming laptop with an RF card to search for active wireless networks along the road, whether in-building or on a campus. However, the actual number of security breaches in warehousing networks has been minimal, Stephens asserts. “I haven’t heard of any,” he says. “Or people aren’t admitting to it.”

Expanding Security, Functional Use

What people do acknowledge is that wireless LANs are changing very rapidly. Until 802.11, most wireless networks in-facility were rudimentary, narrowband and single frequency. The most common application was inventory control—picking items and recording quantities, returning to a receiving dock and uploading orders through a batch system to complete a fiduciary transaction.

Over time, however, the newest WLANs have become extensible, with wireline Ethernets and integrated LAN to WAN functionality. Many are plugged into sister Ethernet wireline networks and power sources to
conserve power. In addition, industrial-strength wireless networks now support corporate back-office functions, accounting and ERP systems, mobile client device location tracking and voice over IP (VoIP) for roaming workers. New devices even combine VoIP with cellular network handoff.

“There has been a push to develop dual-mode client devices over Wi-Fi that ensure everything is linked over the large enterprise network,” says Ben Gibson, a VP of corporate marketing with Proxim, a leading wireless LAN vendor. For example, Proxim is partnering with Motorola to develop dual-mode cellular handsets supporting both VoIP and cellular services. The solution features a hand-off between an indoor wireless LAN and cell phone carriers, ostensibly to offer customers a more economical one bill option.

Proxim is also supporting extensible WLAN configurations with dual-radio APs on high-end systems. “This, in essence, is a wireless distribution system that’s daisy-chained via a dedicated wireless connection to eight wireless APs. The eighth AP has an Ethernet connection, creating an extended Ethernet-wireless mesh network ideal for factory and mobile warehouse operations. The mesh will ultimately support seamless VoIP. However, problems with voice latency over these mesh networks still exist; the technology must be optimized to sustain a 50ms delay only—a capability Gibson says is not far down the road.

One Network Mantra: Capture, Move, Manage

Ann Sun, a senior manager of Cisco Wireless and Mobility, calls the industrial-strength WLAN a real-time extension of Cisco’s one network mantra. This will support mission-critical functions such as just-in-time inventory.

“From a Cisco point of view, it will all be one network—all IP and Web-browser based,” says Sun. What this means is that Cisco, among other vendors, is concentrating more intelligence, QoS features, roaming and network management capability in fat wireless switches and controllers. This takes the cost out of APs, enabling more economical RF extensions into large warehousing and shipping spaces where networks must be optimized to reduce cost per square foot.

However, very few operations contain pervasive wireless/wireline networking at this time, says Gil Bautista, a senior director of Symbol’s Warehouse Mobility Solutions Group. “We’re moving toward mobility environments with workers carrying around handheld devices and communicating with factory floor applications,” he says. But companies haven’t pervasively implemented wireless throughout every enterprise function.

Symbol is moving toward a new mantra, Bautista explains: CM2—Capture, Move and Manage. The company is also concentrating more network intelligence and very robust security protocols into its centralized Wi-Fi controllers. “No one has developed a seamless systems approach to mobility network management thus far, but that’s the direction we’re headed.”

What will the future bring? Cisco’s Sun believes that RF industrial networks will be self-healing—i.e., if an AP goes down, centralized RF management will respond dynamically, in real time, to re-map the airspace for continued coverage. A heavier emphasis on mobile client tracking and dynamic RF management will win the day, says Jeff Aaron, a director of marketing for AireSpace, a successful entrant into the WLAN space, climbing to third place this year. APs will become cheap and thin. By contrast, “a central controller will handle mobility [location tracking], roaming and QoS,” Aaron notes.

So-called hands-free VoIP will also be critical. An early example is a voice-enabled warehouse picking system that uses AireSpace technology in conjunction with a Voxware Voice Logistics picking system. This application speeds warehouse productivity at Dunkin’ Donuts in Swedesboro, N.J. In operation, workers drive carts or other small vehicles at the warehouse and do picking using the hands-free voice-activated system without having to print or consult paper instructions. The system learns the sound of a worker’s voice through speech algorithms. It then instructs the worker to pick specific items from the warehouse inventory and where to deposit them safely for shipment. Today, the picking system is being deployed with six AireSpace multimode 802.11a/b/g lightweight APs and an AireSpace 4000 WLAN switch, which segregates voice and data traffic for better performance.

Other advanced wireless systems are being tested. Vivato Networks has developed a switch product with a phased array antenna providing wide area coverage in the warehousing space, enabling APs to cover up to half a kilometer, almost the distance of a wireless WAN. Other vendors foresee extensions of 802.11g networks into mobile IP mini LANs within police cars and other public safety vehicles, where embedded security makes seamless handovers from cellular networks and satellite into confined (and mobile) spaces. Still others are talking about integrating radio frequency identification (RFID) networks into wireless LANs. At present, RFID tags for inventory items are handled separately.

The question now is when the manufacturing sector will choose to jump at the new WLAN technologies. “Do customers buy what’s available now or wait a year or two?” asks Hank Stephens of LXE. “There is still a lot of movement in the technologies—we still have to get security problems solved in the field, and network management is a big issue going forward.” The most likely answer is that warehouses will proceed cautiously until a solution becomes so compelling—and so cost-effective—that it cannot be ignored.•

Arielle Emmett is a freelance writer in Pennsylvania.


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