Wireless Remote Monitoring

U’ntil recently, ‘remote monitoring’ and ‘control of temperatures’ and other parameters were perceived to be an expensive proposition, warranted by only very expensive reefer cargo. However, the scene today has changed. This is attributed to two reasons. First: the arrival of fully functioning Low Earth-Orbiting satellites (or ‘LEOs’ for short). For the international multimodal transport industry this has been a change of the highest significance. Up till now, communication options have severely limited any sort of end-to-end tracking service for multimodal transit. The second change is the increasing presence and accessibility of the Internet. Its low cost, increasing use by those engaged in international transportation and worldwide access make it a key delivery means for cross-domain information. There have been many communication options available to the shipper. Wireless transmission can be using one or many of the multiple transmission methods (Zigbee, GSM, satellite, Wifi). VHF radio has many offerings but is limited by national licensing arrangements and the need to build terrestrial stations: thus there is no viable multi-country option.

Zigbee

ZigBee was conceived in 1998, standardised in 2003, and revised in 2006. The name refers to the waggle dance of honey bees after their return to the beehive. ZigBee is a specification for a suite of high-level communication protocols used to create personal area networks built from small, low-power digital radios. ZigBee is based on an IEEE 802.15.4 standard. Though low power consumption limits transmission distances to 10–100 meters line-of-sight, depending on power output and environmental characteristics ZigBee devices can transmit data over long distances by passing data through a mesh network of intermediate devices to reach more distant ones. ZigBee is typically used in low data rate applications that require long battery life and secure networking (ZigBee networks are secured by 128 bit symmetric encryption keys.)

ZigBee has a defined rate of 250 kbit/ s, best suited for intermittent data transmissions from a sensor or input device. Applications include wireless light switches, electrical meters with in-home-displays, traffic management systems, and other consumer and industrial equipment that require short-range low-rate wireless data transfer. The technology defined by the ZigBee specification is intended to be simpler and less expensive than other Wireless Personal Area Networks (WPANs), such as Bluetooth or Wi-Fi.

ZigBee is a low-cost, low-power wireless mesh network standard targeted at wide development of long battery life devices in wireless control and monitoring applications. Zigbee devices have low latency, which further reduces average current. ZigBee chips are typically integrated with radios and with microcontrollers that have between 60-256 KB flash memory. ZigBee operates in the Industrial, Scientific And Medical (ISM) radio bands: 2.4 GHz in most jurisdictions worldwide; 784 MHz in China, 868 MHz in Europe and 915 MHz in the USA and Australia. Data rates vary from 20 kbit/s (868 MHz band) to 250 kbit/s (2.4 GHz band).

ZigBee network layer natively supports both star and tree networks, and generic mesh networking. Every network must have one coordinator device, tasked with its creation, the control of its parameters and basic maintenance. Within star networks, the coordinator must be the central node. Both trees and meshes allow the use of ZigBee routers to extend communication at the network level. ZigBee builds on the physical layer and media access control defined in IEEE standard 802.15.4 for low-rate WPANs. The specification includes four additional key components: network layer, application layer, ZigBee Device Objects (ZDOs) and manufacturer-defined application objects which allow for customisation and favour total integration. ZDOs are responsible for a number of tasks, including keeping track of device roles, managing requests to join a network, as well as device discovery and security.

ZigBee is one of the global standards of communication protocol formulated by the relevant task force under the IEEE 802.15 working group. The fourth in the series, WPAN Low Rate/ZigBee is the newest, and provides specifications for devices that have low data rates, consume very low power and are thus characterised by long battery life. Other standards like Bluetooth and IrDA address high data rate applications such as voice, video and LAN communications.

GSM

GSM (Global Standard for Mobile telephony) is an improvement on VHF radio but is still not good enough. It has three (900, 1800 and 1900 megahertz) standards, and it is expensive when used cross-border owing to international gateway charges. In any case, it covers less than 6% of the land-mass of the world and, of course, none of the sea. By comparison, satellites have been in use for over three decades. But the traditional, or geostationary, options have had only very limited use in cargo transportation. This is because their costs have been high and the equipment used has needed large antennae with high power requirements. This is inconvenient to say the least if installed on containers with no power source, which then cannot make intermodal moves because of the large antenna!

Low Earth Orbiting Satellites

Launch of the first commercially available LEOs changed the scenario drastically. These in effect provide GSM-type digital messaging, but over a global footprint and at much more competitive rates. A key advantage of LEO usage is the small antennae used and their low power requirements. These mean that the devices can be battery-supported and are not reliant on ship or vehicle power supply. Just as importantly, the flat antenna used does not interfere with intermodal movement or container stacking.

The most successful of these new LEO operators is Orbcomm, which was started up by Orbital Science Corporation Inc of Dulles, Virginia, in the US, and went live to its customers at the beginning of 1999. Orbcomm is now a worldwide consortium with representatives in every major country. Already most of the world has high-availability coverage and future launches will improve this even further.

ORBCOMM is a company that offers Machine to Machine (M2M) global asset monitoring and messaging services from its constellation of more than 30 LEO communications satellites orbiting at 775 km.

ORBCOMM provides satellite data services with control centres in the United States, Brazil, Japan, and Korea, as well as U.S. ground stations in New York, Georgia, Arizona, and Washington State, and international ground stations in Curaçao, Italy, Australia, Kazakhstan, Brazil, Argentina, Morocco, Japan, Korea, and Malaysia. This is best suited for users who send very small amounts of data. To avoid interference, terminals are not permitted to be active more than 1% of the time, and thus they may only execute a 450ms data burst twice every 15 minutes. The latency inherent in its network design prevents it from supporting certain safety-critical applications.

On July 14, 2014, SpaceX successfully launched 6 OG2 satellites. The launch of the remaining 11 satellites is expected to be completed shortly.

Tracking and monitoring solutions 

ORBCOMM’s dual-mode, ruggedized ReeferTrak device provides visibility, control and decision rules to dispatch and operation centres, maintenance organisations and operational managers of transportation companies worldwide via a web platform. Using a unique direct interface to every reefer’s microprocessor, it provides comprehensive temperature, fuel management, maintenance, and logistical applications services to revolutionise refrigerated transportation operations.

Application of LEOs

Tri-mex, an Anglo-Norwegian company, was one of the first to recognise the potential of using LEO communication in the movement of perishable cargoes. Its cargo-tracker service is designed specifically for the requirements of the transportation of temperature-regulated cargo. It integrated its Windows-based tracking and monitoring technology with Orbcomm LEO communicators, and has generated a service where a cargo can be tracked and monitored anywhere in the world – whether on land or at sea. The information generated is shown on its dedicated website ‘www.cargo-tracker.com’ that can be accessed via any internet-connected terminal, anywhere in the world.

From the beginning, Tri-mex Noticing that its customers wanted more than just tracking and monitoring – they wanted a service that would respond and provide direct action if required, Tri-mex, in 1999, opened a control centre in Oslo, dedicated to monitoring cargo in transit worldwide, 24X7, providing direct, multi-lingual responses in the event of problems. This is equipped with electronic maps and charts covering the world, linked to databases on emergency services and with feeds that update information on transportation conditions, minute by minute, across the world. The Tracar 2 consortium appointed Tri-mex to provide the Cargo-Tracker service for its project. Tracar 2 is a project partly funded by the European Union and managed by Cable & Wireless with major transport companies such as K-Lines, Bluewater Shipping and Scan Shipping. The project is aiming to test the tracking and monitoring of dry containers and reefers moving dry and perishable goods between Aarhus in Denmark and Oporto in Portugal. Tri-mex is installing the technology needed on each container and then providing the tracking and monitoring service through www.cargo-tracker.com. For perishable cargoes, if temperature-tolerance bands are breached, the control centre will respond by making calls to the ship or port and summon manual assistance. This process will take only a few minutes, wherever the cargo is in Europe. Integration of low-frequency tags with the Tri-mex service has allowed precise tracking of containers in port areas. Another innovation being tested live for the first time will be the capability to ‘interrogate’ a container wherever it is loaded on the ship – be it above or below deck. This will allow genuine end-to-end monitoring of an intermodal transit through the sea passage, a movement phase that, to date, has been ‘blind’ or in which containers have had to be pre-positioned on deck to communicate.

Tracar 2 went live in October 1999 and ran through to the end of the year. In addition to this, a capability that leading shippers of perishable goods are looking to test is direct intervention across the network. This involves correcting a temperature variance by an electronic message communicated directly to the instrumentation of the refer.

Other applications

In 2011, Refrigerated Temperature Electronics Inc. based in USA, had launched the first Wireless Reefer Acquisition Device (WRAD). WRAD provides wireless monitoring option for reefer containers on board the ship. It consists of a hardware device which attached magnetically to the container and connects to the data port of the containers. It is powered with a rechargeable battery. It connects to GRASP 3.0 Reefer Monitoring System developed by RTE.

GRASP 3.0 is a Software which is available as both Microsoft and Web based application. It generates accurate connection and disconnection times, reducing the likelihood of a reefer container not getting plugged in. Data is stored in electronic format, which can be retrieved on demand in the event of a claim. RTE has developed Reefer Remote Communications engines (RRCE) of which one consists of a Modem (RRCE-Zigbee) which is fitted inside the Reefer Container’s Control Box. It provides local Wireless Monitoring while the container on board a vessel or a terminal.

It uses short range RF to transmit data. 802.15.4. Another member of RRCE family is (RRCE-T), which can take up to 10 inputs per unit. It is ideal for vessels and terminals with Rack systems. It can work on LAN or Wi-Fi connection. It has a permanently mounted hardware with IP66 enclosure. It has a networked switchover in case of a power loss.

In addition to the above, in 2006, RTE has also developed GRIP, a handheld Data Acquisition device which connects to reefer container’s data port. It facilitates users to manually monitor temperatures, download trip records, and operating data from various reefers. It is compatible to all reefer container makes and models. It is enclosed in a rugged waterproof enclosure (Trimble). Information downloaded is synchronised with GRASP 3.0 using standard cradle or Wi-Fi.

In addition to the above, all major reefer container manufacturers have developed hand held data downloading devices suitable for their models of machinery.

Most of them are wired devices. RTE and Psion had held devices are suitable and can be used for downloading data from all makes and models of Reefer Container machinery.

Conclusion

For the perishables transportation industry a new age is dawning. Low-cost technology is allowing tracking, monitoring and intervention for the first time on all classes of cargo. This increases the information available to the client and improves the delivered quality of the goods. For the first time conditions being experienced by cargoes in reefers can be monitored remotely and responded to in minutes in many cases electronically. This will improve the service record of movements of perishables and will bring down operational costs – to the benefit of shipper and customer alike. There is also a good possibility of insurance rates going down with the advent and availability of this new technology.