The Tech that Tracks ULDs

March 18, 2021
More than ever, cargo airlines and ground handlers are playing a key role in keeping the world running. As a result, advancements in how cargo shipments are tracked have taken on more importance.

Even before modern cargo trends grew along with online retail giants and e-commerce spending habits – now amplified by the COVID-19 pandemic – the need to track unit load devices (ULDs) carrying vital cargo has always been important.

But as shipping requirements become more specific, especially for time- and temperature-sensitive cargo, the way the industry traces the location of ULDs has had to evolve. As a result, the industry has trialed and adopted key technologies to help ULD managers, ground service providers and airlines meet present day cargo demands.

Every airline needs to have the right number and the correct type of ULDs for every flight, at all times and every departure point, explains Frank Mühlenkamp, director of operations at Jettainer.

“The biggest challenge is securing ULD availability in the most efficient way,” he says. 

But as Bob Rogers, vice president at ULD Care, points out, there has always been a challenge to record the whereabouts of ULDs. According to Rogers, at any given time approximately 5% of ULDs may be missing.

“Now, 5% doesn’t sound like a lot. But if you were trying to run a restaurant and one day 5% of your knives were missing and the next day 5% of your forks were missing and then the next day 5% of your plates were missing, you’d go out of business very quickly,” he says.

“This is the problem. It’s not the 5% that’s such an issue. It’s that you don’t know which 5% is going to be missing.”

There are different stages along a ULD’s journey that are easier to track than others. Because a ULD is often moved by several involved departments, Alexander Wendorff, solutions manager at INFORM GmbH, notes this can make it difficult to reliably locate a ULD at the airport.

“It is very easy to determine whether a ULD is on an airplane. There are loading and unloading processes,” Wendorff says. “It is getting more difficult in the warehouse. Here, ULDs can be pushed from one parking position to another.

“The apron is then the greatest challenge,” he continues. “You depend on transport, but you do not know whether ULDs on dollies will be parked somewhere else than originally planned. Then there are the safety regulations in aircraft regarding communication and the lack of energy for the transmission of data.”

Efficiently managing a container and pallet fleet requires a high level of accuracy and transparency, according to Martijn van Geest, managing director digital solutions at Unilode.

“Both airlines and ULD management providers are faced with the challenges of data quality and delivery as they depend on data provided by third parties outside of their organization,” van Geest says. “This process usually has a low level of automation that negatively affects the data quality, and this is one of the key areas where ULD trackers can help as they decrease manual and error-prone data entry, which results in more accurate and immediately accessible data.”

ULD tracking, and the resulting efficiency gains, also enables ULD managers to use fewer units and thereby saves significant costs for airline customers.

Tracking Advancements

The cargo industry had high hopes that radio frequency identification (RFID) technology could assist with ULD location services in the same way it has assisted with passenger baggage tracking.

But, according to Rogers, RFID ultimately never became a viable option – in part because of the cost and infrastructure needed to deploy it.

“You need an awful lot of physical infrastructure in the form of scanners,” he says, noting range and frequency of the scanners caused issues. “The frequencies that give the biggest range are the ones that are not acceptable for use in an airport ramp because of interference with other radio transmissions, and the frequencies that are acceptable on a ramp have a range of about three feet. You’d be practically standing on top of the pallet before you could identify it with RFID.”

Arnd Trapp, director of IT at Jettainer, adds that global positioning systems (GPS) and global system for mobile communications (GSM) networks are other examples of technology that did not transfer to ULDs well.

“The main reason why these technologies have not been convincing is that the power supply cannot be guaranteed for a sufficiently long period of time,” he says.

“Generally speaking, power consumption, in particular, is a major challenge for tracking technology,” Trapp continues. “ULDs are normally in constant circulation and are only sent for repair if they are damaged, so the batteries have to be very durable. Taking the ULDs out of circulation at short intervals to change the batteries is not a viable option with our fleet size of 100,000 units.”

According to Rogers, Bluetooth Low Energy (BLE) – which previously had been applied to tagging air mail, has begun being used to tag ULDs. Meanwhile, companies like Sigfox have started utilizing unused bandwidth from mobile phone networks to assist in tracking cargo containers.

“They both have their pros and they both have their cons. BLE is simple in that you have to put readers in. The readers can read up to something in the range of 50 meters, but it’s growing all the time. There’s even this thing called BLE Mesh, where the tags talk to each other and finally reach a reader,” Rogers says. “The interesting thing on both of these, particularly BLE, is Bluetooth is consumer electronics. So, it’s growing at a huge pace and its cost is constantly being driven down.”

Wendorff adds that BLE is currently the only medium that can transmit information over a short distance in such a way that no extremely expensive antennas are necessary for detection.

The development of the Internet of Things (IoT) and the possibilities of active tracking provides a huge field of new opportunities.

“The key however is the transparent and smart use of available data,” Trapp points out. “Based on our high-quality data and the use of artificial intelligence, we have developed a decision support system for our steering and control solutions. This enables us to understand ULD movements better and predict ULD imbalances to act rather than react.”

With the spread of IoT, and with it the combination of different data, tracking ULDs at reasonable costs has become possible, Wendorff adds.

“The possibility of localizing dollies plays a particularly important role for us,” he points out. “We are now increasingly relying on the combination of process data and telemetry data. Manual entries are almost only used for confirmation. We use the fact that a ULD – once it is integrated in the process flow, does not just stand somewhere on the floor.”

Using tracking technology in the aviation industry requires special criteria and considerations. Additionally, van Geest says, solutions must be reliable in service while meeting aviation certification requirements.

“Devices that are loaded in the hold of an aircraft cannot carry large power packs, tags should have a substantial lifetime beyond five years and there is clear limitation on energy consumption. Furthermore, the radio transmitting technology must meet requirements to avoid interference with aircraft systems,” he says. “At Unilode, we were looking at many technologies and have found Bluetooth Low Energy to be the most suitable to serve our purposes.”

Perceived advantages and disadvantages can depend on the purpose the technology serves. For example, van Geest says Unilode needs data most importantly on geo location, temperature, humidity and light.

“Given the rough environment ULDs are exposed to, Bluetooth serves our purposes the best. However, we are aware technology evolves and we are capable to let our solution also evolve in this process,” he notes. “We have put a lot of efforts on the back-end solution so that we can accommodate any new emerging technologies that would further improve our digitalization goals.”     

According to Trapp, Jettainer works closely with scientific institutes and IT experts to keep up with new innovative and efficient solutions.

“We are keeping a particularly close eye on the development of 5G, Sigfox and LoRaWAN and see great potential here,” he says. “The low-power wireless network protocol Long Range Wide Area Network (LoRaWAN) has particular potential for ULD tracking. LoRaWAN meets both critical challenges for tracking technologies: high network connectivity range and low power consumption. However, further developments are needed here to catch up with BLE technology.”

Trapp adds it is important that any new solutions introduced to the industry are rolled out as widely and quickly as possible, so that they can be used efficiently.

“However, this is where many new developments fail, as tracking regulations vary from country to country. There is a risk that new technology will be obsolete by the time it is globally available on the market,” Trapp says.

According to Rogers, ULD Care is working to integrate a blockchain platform into current systems to assist with tracking transfers of ULDs between airlines.

“Our ambition is wherever a ULD is transferred from any party to any party, it will be possible to record the transfer using a handheld device – a mobile phone – and that data will then be used to update our common neutral platform,” Rogers says.

Technology’s Role Amid the Pandemic

In addition to logistic challenges faced with distributing vaccines, the COVID-19 pandemic has tested the industry in other ways, including limited repositioning capabilities, staff reduction and unbalanced flows.

“The temperature sensor and the location-tracking device in ULDs enable 24/7 monitoring, which is especially important for effective vaccine distribution as they enable to check for unwanted deviations and take appropriate actions to prevent loss or damage of shipments,” van Geest notes. “We prioritized the tagging of special temperature-controlled cool containers in our fleet so that we can offer the benefits of the ULD tracking technology to our ULD management airline customers and contribute to their COVID-19 vaccine distribution efforts.

“We have also noticed an increased interest in digital ULD tracking as pallets have become scarce assets and tracking helps utilize them in a much more efficient way with enhanced availability and much faster turnaround times.”

“When it comes to COVID-19, we are talking more about new ULD types, which in turn are placed differently on dollies and which deliver different telemetry data – such as monitoring the cold chain,” Wendorff says. “Tracking COVID-19 ULDs even makes it very easy, since the vaccines must be transported in a cooled manner and the dollies therefore must have their own energy supply. This is usually also used to record and transmit the position of the dollies.”

The availability of cool containers can present a challenge.

According to Mühlenkamp, the overall number is limited and positioning and return of these units is challenging, as freighter and belly capacity remain limited.

“Consequently, efficient cool container management and monitoring is crucial. Within Jettainer we do not rely on ULD tracking technology as an only source, we offer our customers a comprehensive service. cool&fly is our solution comprising full cool ULD order management, steering, positioning and monitoring of the cool chain as well as after-service management,” he says.

“Due to the already established information and data flow, airlines and ground service providers know which ULDs arrive and depart at their stations, irrespective of tracking technology.”

Future Developments

Digital ULD tracking has fundamentally changed – and will continue to change – how fleets are managed.

“It further increases pooling synergies, thus accelerates our goal of supporting the sharing economy. But the impact will be significant for all actors along the supply chain as it will create a new level of transparency,” says van Geest.

“Moving forward, Unilode will make relevant data available through a blockchain, offering access to non-manipulatable data,” he continues, noting Unilode’s FAST Solution Suite helps airlines and customers avoid making significant IT investments to their existing systems as the FAST mobile app for iOS and Android converts mobile phones and tablets into reading devices that considerably increases the reader infrastructure. 

The major challenge in using tracking technology is still improving energy efficiency and the global network coverage of reading infrastructure, Trapp says.

“Further developments are also welcome in the area of reader technologies,” he adds. “Because of the relatively short range, a number of readers are needed for seamless tracking. Cost also plays an important role. But in just the last few years, we have seen huge progress made in these areas. For example, batteries now last for much longer and are cheaper, and network coverage is also increasing.”

While new technology entering the market can improve operations, Rogers notes that expertise in the field is being stripped away as members of the workforce retire or have left the industry through layoffs and redundancies. Better tracking solutions could help overcome that hurdle.

Good tracking of ULDs means an increase in service quality, which Wendorff says should be considered first and foremost.

“Furthermore, the detailed information enables the utilization of the dolly fleet to be better determined, which in turn leads to a sustainable reduction in the size of the fleet and thus also to a reduction in costs,” Wendorff says. “Aviation is a time-sensitive business – we talk everywhere about time slots. The better the tracking option, the better time slots can be kept and the better it is possible to react to irregularities in the process flow.”