Sept/Oct 2003

Wireless networking, or radio-frequency technology, is relatively commonplace in stock-picking operations these days, but there are still misconceptions about how it works. Marcia MacLeod offers some invaluable illumination

As with so many new and heavily promoted technologies, radio frequency has begun to capture the attention of warehouse managers in every sector - retail, manufacturing, e-fulfilment and third-party logistics. But while people continue to sprinkle their conversations with "radio frequency" or "RF", too often they do so without really understanding what it is or what it can do.

Radio frequency doesn't just mean RFID (radio frequency identification), a common misconception - perhaps perpetuated by the recent hype about that technology. Nor is it the same as warehouse management systems (WMS), which is something that Stuart Scott, director of marketing and business development at Intermec, says potential customers sometimes believe. "We get enquiries from people who want RF, but don't have a WMS," he says. "They think RF systems are WMSs with RF in them; they don't understand that RF only extends WMS."

And that points to the core definition of RF: it is a wireless technology that allows you to run your WMS in a more flexible and efficient manner. Before wireless technology was deployed, warehouse workers had to scan barcode labels and then go to a base station or PC to download the scanned data into the core system. Pick lists were produced by PC, but not on a handheld or truck-mounted terminal; pickers had to retrieve hard copy instructions. All data transfer was in batch mode, and therefore never 100 per cent up-to-date.

Radio frequency allows real-time information to be provided at all time. Scanned data is available to all system users as soon as the scan is made; pick lists can be sent direct to the picker's terminal; details of any problem can be relayed to the right people as soon as they occur. Any device - PDA, laptop, barcode scanner, PC, even printer - can be connected to the wireless network, making data accessible any time, from any place.

Barcode scanning and order picking were the first applications to rely on radio frequency, but other warehouse applications are now going wireless too, thanks primarily to the progressive enhancement of the wireless devices. "The biggest change in our products is that everything is now available on a Windows CE.Net platform," comments Duncan Smillie, UK managing director for Psion Teklogix. "This allows all sorts of applications to be introduced."

Psion Teklogix isn't the only vendor to make wireless devices Windows-compatible, as Damian Penney, LXE sales and marketing director, points out. "Devices are being updated to be more like PCs. This allows users to see what else they can do with one terminal, rather than get different terminals for different applications. And software vendors are waking up to the possibilities, too: a lot of ERP and WMS vendors are wireless-enabling their products so that SAP, for example, can be put into the hands of the mobile workforce.

"You can put GPRS and Bluetooth cards in a device that is based on RF; you can use the same terminal for, say, order picking, integration to ERP, RFID and voice - both in the sense of telephone usage and in speech recognition. Companies want to maximise investments; warehouse staff walk around with mobile phones, but now, using Voice over IP (VoIP), mobile phones can be incorporated into the same terminal that does barcode scanning.

"The same device can also be used in the lorry, so that it could use GPRS on the road, but switch to spread spectrum radio frequency in the warehouse. If you look at one Windows application on its own, it's not very exciting, but take it all together and it becomes much more interesting."

New applications

New applications are emerging, too. While RFID is not the only, or even the main, use of radio frequency, its popularity is growing. For the benefit of anyone who has been on another planet for the past year, RFID involves microchipped tags attached to totes, cartons, pallets or even individual items. The tags, containing a wealth of information on the goods tagged, are scanned either by fixed readers located around the warehouse, or by handheld scanners. A key advantage of RFID is that it can enable users to track the exact location of any tote, carton, pallet and so on - and its contents - at any time, improving warehouse efficiency and reducing loss.

Other newly emerging wireless applications include imaging and voice. Imaging enables users literally to take a picture of a barcode label, a damaged package, an individual SKU, or, when used on the road, a consignee's front door. Any disputes over damage, shipment time, delivery and so on can be resolved with irrefutable proof one way or the other.

Voice is also beginning to take off. As already mentioned, VoIP - provided by companies such as Spectralink - enables any wireless device to be turned into a telephone. Text to speech and vice versa are more complicated, but two major software developers, Vocollect and Voxware, are gaining a foothold in Europe. Vocollect's largest UK distributor is VoiteQ, but it also sells through WMS vendor Microlise. Voxware works with WMS vendors EXE, OMI and Chess and hardware manufacturers Symbol, LXE and Intermec. VoiteQ in turn is also working with a number of WMS suppliers.

The technology enables users to take a text message from the WMS system - say a picking list - and transfer that to speech, so that the picker is literally told where in the warehouse to pick from and what item to pick. The employee can then confirm the pick, at which point another instruction is "spoken". Additional information, such as "replenishment of item Y required at aisle 1" can also be given. Spoken information is translated back to text and forwarded to the relevant part of the WMS.

"The UK is lagging behind France and Italy in the use of voice," says Greg Tanner, managing director of Vocollect Europe. "It is best established in the US, but in Europe more people are using voice for more applications, whereas in the US it is primarily used for picking."

Vocollect's rugged Talkman units are flexible, enabling them to be used for scanning, in-cab communication and other functions. The company has developed VoiceLink middleware, launched this summer, to sit between Talkman and the WMS, providing applications such as picking, inventory counting and labour management (for instance, job allocation). It is also bringing out a new range of headsets to ensure individuals can work in comfort.

VoiteQ also developed middleware to connect Talkman to WMSs. Emerging out of convenience stores Day and Night in 1997, VoiteQ's voice picking system is said to be the world's first. Middleware offers the easiest voice option, but users can opt for a direct interface to the WMS if they are prepared to invest more money and time. "Modification to WMSs can be a lengthy process," points out VoiteQ's managing director, David Stanhope. "Often customers start with middleware and move on to a direct interface."

Voxware's Voice Logistics offers a standard applications suite which can then be customised. All customisation goes back into the standard suite. New features include picking by best before date and temperature checking before loading onto vehicle.

As mentioned earlier, many wireless devices include GPRS, Bluetooth and traditional radio frequency technology. Bluetooth is best for peripherals, as it only has a very short range. But, says Duncan Smillie of Psion Teklogix, its uses are ingenious. He has even seen a coffee machine run on Bluetooth, accessed by swipe cards.

It is still early days for RF technology; there are issues such as security that need to be addressed. But with the ever-increasing demand for accurate, up-to-date data and the need to remain flexible to maintain efficiency, however many options available, there is only one solution: wireless.

RF networks - two flavours

Radio frequency technology comes in two main flavours - narrow band or spread spectrum. Narrow band, or 2Mb, the older of the two, is still used, but is slow and can't cope with many of the new applications. "People still use narrow band," admits Intermec's Stuart Scott, "but spread spectrum avoids interference, and is the first open standard for wireless networks, so is much more flexible." Intermec doesn't supply narrow band any more, although some vendors find some people don't want to swap legacy systems, or else need the wide range narrow band offers for use in yards.

Spread spectrum is better known as 802.11b, the most widely-used standard, which works on the 2.4GHz band. "802.11b allows you to hang lots of devices off the network," says Duncan Smillie of Psion Teklogix. "You can also have a more attractive graphical user interface. And even if users don't need spread spectrum's capabilities now, a lot of makers are putting it in for the future. Three quarters of our customers are installing their first wireless system - and they want it to last."

Other spread spectrum standards are being developed. The 802.11g standard will achieve faster transmission - 54 megabits per second instead of 11. A further variant, the older 802.11a, is also fast, but uses a wider band - 5 GHz instead of 2.4 Ghz - so can have 12 non-overlapping channels. But its range reduces as frequency grows. Because 802.11a is primarily for use in the US, 802.11h will allow the same technology to be used in Europe. And 802.11i is a wireless security standard.

How much impact any of these will have in the warehouse is debatable. "I think the warehouse will stay with 802.11b for some time," says Andy McBain, UK product marketing manager for Symbol. "802.11a and g need more radios to achieve the same speed as 802.11b."

Stuart Scott agrees. "802.11b will be dominant for a long while," he says, "as people don't need the extra bandwidth." But Intermec is developing a range of devices which can run on 802.11g, just in case.

What people might also want, though, is to look at Symbol's new way of deploying wireless. Instead of access points, it is incorporating switches into ports dotted around the warehouse. It claims that when a company needs more than five or six access points, Symbol's switches and port technology would become more cost-effective. In addition, Symbol's solution provides a central control, making it easy to distribute software to devices. Symbol is also considering putting

VHF readers for RFID into handhelds.

RF - some hardware options

When it comes to hardware for using with RF systems, suppliers are constantly bringing out new devices. Intermec, for example, has just launched a range of devices combining imaging, wireless printing and communication via Bluetooth, GPRS and 802.11b and g. The CT60 pen tablet mobile computer, in a weatherproof rugged housing, can be used in a docking station or remotely. Based on Windows XP Tablet PC Edition, it allows users to run Windows-based applications using pen or speech.

The CV60 vehicle-mounted terminal for forklifts and other equipment features a 12.1 inch high-resolution colour display, while the CK30 hand-held is available with colour or mono screen and 42, 50 or 52-key keypad. Other new products include the EasyCoder PM4i bar code printer and entry-level CK1 terminal for retail and light industrial applications.

LXE, which expects its voice-operated system to come out in the autumn, also introduces the MX6 handheld based on Windows CE in November. This is the newest version of the popular MX2, incorporating integrated laser scanning and high-volume beeper. The recently launched MX5, another Windows CE-based device, boasts integral heater that allows it to be used in low-temperature environments, and a large colour reflective screen to provide clear viewing.

Psion Teklogix's 7535, another Windows CE product, came out this summer as a rugged device offering a wide range of radio, scanning, keypad and display options. It can be used over 802.11, GSM/GPRS or Bluetooth, and has integrated RFID reader.