Enhancing Cargo Container Security during
Transportation: A Mesh Networking Based
Approach
Su Jin Kim, Guofeng Deng, Sandeep K.S. Gupta
Impact Lab, Department of Computer Science and Engineering
Arizona State University
Tempe, Arizona 85281, USA
http://impact.asu.edu/
Email: {su.kim,guofeng.deng,sandeep.gupta}@asu.edu
Mary Murphy-Hoye
Intel Corp.
Chandler, AZ 85226, USA
Email: [email protected]
Abstract—Cargo containers which transport 90 percent of theworld’s trade transit the countries of the world daily. Despitethe vulnerability of cargo containers, only about 5 percent ofthe over 10 million cargo containers entering the U.S. each yearcan be inspected now. Our primary goal is to develop the smartcontainer security system using RFID and Wireless SensorNetworks in order to enhance the cargo container security. Inaddition, the end-to-end visibility via this networked trackingand sensing capability can bring additional commercial benefitsto supply chain and chain of custody. In this paper, we firstpropose a dynamic mesh container network among neighboringcontainers. Since a group of containers moves together, wecan take advantages of interaction between them via this meshcontainer network instead of focusing an individual container.Second, we introduce the concept of Mobile Edge ComputingDevices (MECD) which is the interface between distributedsensors and the end server in order to reduce processing andbandwidth requirements to the end servers. MECDs can givescalability, flexibility, reliability, and cost-efficiency to our cargocontainer security system.
I. MOTIVATION
With the advent of standardized cargo containers, the
global economy has deployed more than 20 million con-
tainers, and today they are the most commonly used form
of transportation for the world’s trade. With the increased
focus and importance of international security since the
events of 9/11, many government initiatives, regulations
and mandates have introduced new requirements for cargo
security. With cargo containers transporting 90 percent of
the world’s trade, these efforts are focused on addressing the
containers’ inherent vulnerabilities as well as the impracti-
cality and prohibitive cost of 100% manual inspection. To be
viable economically, these necessary security investments for
containers need to also produce new advantages in the global
supply chain and among the participating industry partners.
However, the existing systems which have been developed
for ecosystem players are not yet been sufficient to address
all identified security issues in a robust and cost-effective
manner.
Today, Department of Homeland Security (DHS) research
programs for container security devices focus on detecting
container intrusion (e.g. DHS Advanced Container Security
Device - ACSD [1]) or the tracking of each cargo container
(e.g. DHS Marine Asset Tag Tracking - MATTs [2]). In
order to address the security issues outlined above, and
respond to the myriad government regulations such as ACSD
and MATTs, we propose to take advantage of the fact that
containers are in close physical proximity while in transit or
stacked in container yards or in the port. Instead of focusing
on the security of each individual container in isolation, we
suggest creating a self-configuring container-based dynamic
mesh network which changes with each physical realignment
of the containers. In addition, this approach could also
enhance container network communication to ocean- or land-
based infrastructure which could also be provided in a more
reliable and efficient manner.
The belief is that the security of containers will be en-
hanced by this interaction between neighboring networked
containers. The investment to create mesh container networks
could address the security requirements and provide addi-
tional business benefits.
Security could be enhanced by enabling end-to-end mon-
itoring of containers (anytime, anywhere) and secure hand-
off in the chain of custody addressing many of the DHS
container security concerns. A key approach to attaining rapid
and wide-scale security investment across the supply chain is
to ensure the investment will also create high value business
benefits.
Current global supply chain designs entail multiple hand-
offs (including multiple border crossings) among multiple
parties and cover longer distances, resulting in lengthy ship-
ment cycles. Existing shipments are vulnerable to several
types of product losses, including pilferage, piracy, damage,
and obsolescence.
Shipment location and status are not known during the
conveyance. To offset this uncertainty, firms extend shipment
cycle times, and build in additional inventory which raises
costs and often results in lower service levels. Cycle times
vary making service promises unpredictable.
While the security requirements of DHS are a primary
motivation, these operational issues must be addressed. There
must be additional commercial benefits to enable the business
investments required for scale to occur. These networked
intelligent containers can provide end-to-end visibility from
a supplier to end customers via the networked tracking and
sensing capabilities. This end-to-end visibility can enhance
the operational performance and efficiency as well as the
security of the global supply chain.
In addition, the transportation ecosystem is a disparate
and loosely coupled collection of players, with distinct roles
and responsibilities. Currently, there is no comprehensive
method for understanding and managing the history of the
conveyance from origin to destination available to the Chain
of Custody (CoC). However, using intelligent containers, this
data could be locally recorded and maintained. With trans-
parent visibility to information created through container-
based wireless technologies, access and interaction in the
chain of custody could be simplified Because of these reasons
we believe that intelligent networked containers could bring
collateral benefits to the supply chain and the chain of
custody.
II. INTELLIGENT CONTAINER NETWORKS
The Intelligent Container research project focused on
”networked” security and commercial benefits for the 20
million world-wide ship-based cargo containers.
In this research we explored a new set of business models,
architectures, and emerging technologies that together we
believe create a new level of security. We identified and in-
stantiated a system architecture using emerging technologies
such as RFID and Wireless Sensor Networks to enhance the
security of each cargo container via the creation of ad-hoc
dynamic container networks. We also completed an ”in-situ”
implementation of ”networked containers” to demonstrate
the technology capability and constraints, generated large
volumes of physical environment data as well as dynamic
network interaction data from container, stack, container
yard/port, and en-route ship-board tests.
From our experiments, we believe that our approach can
achieve security goals driven by the government as well as
create new business commercial value for global supply chain
participants.
III. SYSTEM REQUIREMENTS
The characteristics of a container create unique challenges
for instrumentation including:
• Containers make several roundtrips per year,
• have an extended multi-decade lifespan, and
• do not have an entity with umbrella ownership for
maintenance and support
Therefore solutions must be standalone and relatively
maintenance-free, preferably taking advantage of ambient
vibration to harvest power for any embedded devices.
Fig. 1. Mesh Network Characteristics [3]
Smart containers also require several layers of technology
solutions to make networked container visibility a reality.
The layer closest to the container is instrumentation for
sensing (of both identity and state), monitoring, and tracking.
This is achieved through an integrated architecture of RFID
transponders and container-based RFID readers interacting
with internal and external wireless sensor network nodes.
Another layer enables decision making through data pro-
cessing, filtering, and management as well as real-time an-
alytics and presentation capabilities. A foundational layer
includes the edge computing devices that allow local and
distributed interaction with the containers and their informa-
tion and well as the localized data processing necessary to
create meaning from the instrumentation.
For this paper, we will focus on the Intelligent Con-
tainer Instrumentation Layer, its architectural components,
and three scenarios which demonstrate the applicability of
this mesh network approach to cargo container monitoring
and management.
IV. MESH NETWORK CHARACTERISTICS
In order to achieve these distributed dynamic networks
of containers, the solution needed to take advantage of the
key characteristics of wireless mesh sensor networks, which
enable a dynamic self-configuring network topology between
autonomous nodes.
A mesh network is a generic name for a class of networked
embedded systems that establish an ad hoc network and
maintain mesh connectivity [4]. Mesh networking shares
several characteristics: self-configuring, self-healing, multi-
hop, dynamic routing, distributed application architecture and
low power. These characteristics bring advantages to mesh
networks. A mesh network is reliable because of redundant
paths. If one node can no longer operate, all the rest can still
communicate with each other, directly or through one or more
intermediate nodes. Through multi-hop communications, the
same coverage can be achieved with much lower transmission
power. Mesh networking also delivers flexibility, robustness,
and easy network maintenance.
Fig. 2. Networked Container Lifecycle
V. INSTRUMENTATION - THREE SCENARIOS
The Intelligent Container research focused on commu-
nications first and foremost: container to container, intra-
container, container to outside world.
A. Scenario 1: End-to-end Container Lifecycle
With this as a primary driving force, the first set of
instrumentation tests were designed to determine viability
in a cargo container and its environment, addressing its
physical infrastructure limitations (battery powered, limited
maintenance and accessibility, etc) and adaptability to the
dynamics of the container’s lifecycle, from warehouse to
yard, to port, to ship, and through the distribution chain.
In the global supply chain, cargo containers move together
in a ship, truck, or train and are stored in various configu-
rations in a warehouse or container yard. Figure 2 shows
the mesh network characteristics inherent in a global supply
chain. As an instrumented container moves from one location
to the next, its participation in the current mesh network will
occur automatically through the self-configuring nature of
the network. The network is dynamically realigned with new
neighbors throughout the whole process of the supply chain,
and can be between containers within close proximity or
directly between the container and the gateway. This ensures
visibility to the container throughout its lifecycle as well as
providing insight into the paths of its neighboring containers
along the way.
B. Hazardous Material Segregation
Containers which transport hazardous materials are rigor-
ously tracked throughout the supply chain.
Fig. 3. Hazardous Container Communication
“A hazardous material is any solid, liquid, or gas that can
harm people, other living organisms, property, or the environ-
ment. Hazardous materials may be radioactive, flammable,
explosive, toxic, corrosive, biohazardous, an oxidizer, an
asphyxiant, a pathogen, an allergen, or may have other char-
acteristics that render it hazardous in specific circumstances.
Mitigating the risks associated with hazardous materials may
require the application of safety precautions during their
transport...” [5]
In the UN Recommendations on the Transport of Danger-
ous Goods], the following requirements are defined for the
transport segregation of dangerous goods:
“Incompatible goods shall be segregated from one an-
other during transport. For the purposes of segregation, two
substances or articles are considered mutually incompatible
when their stowing together may result in undue hazards
Fig. 4. Network Diffusion
in the case of leakage, spillage, or any other accident. The
extent of the hazard arising from possible reactions between
incompatible dangerous goods may vary and the segregation
arrangements required shall also vary as appropriate. In some
instances such segregation may be obtained by requiring
certain distances between incompatible dangerous goods.”[6]
Through this approach to instrumentation, the container
network can routinely ensure the segregation of incompati-
ble materials through automatic sensing and interchange of
information via the mesh.
Exchanging information about hazardous materials con-
tents with neighboring containers can extend the safety of
the entire network. Expensive chemical or biological sensors
may not be installed in every container. In this case, sensed
data is communicated to not only a container on which the
sensors are mounted, but by taking advantage of the mesh
network characteristics, also to containers in the vicinity.
C. Container Visibility & Location
Each node of a mesh network continuously assesses its
relationship to other nodes and its ability to create reliable
and redundant pathways for its data communication.
Localization-Based Systems (LBS) applying network-
based techniques can use the inter-node signal strength of
the mesh to determine the location of each container in an
environment (e.g. container yard, port, etc).
VI. MOBILE EDGE COMPUTING DEVICES (MECD)
In this section, we will discuss the requirements of the
system for container-based mesh networking. The system first
requires sensing capabilities. Digital or analog sensors (for
humidity, motion, shock, heat, radiation, toxic chemicals, etc)
or RFID reader/antennas can be placed inside a container to
sense the environment or scan a container for tagged items.
Second, the system should have the intelligence to determine
the meaning of the data from a container. Data processing
and decision making based on sensed data are required
here. Third, there must be a distributed dynamic network
Fig. 5. Network-based LBS
which supports self-configuration, low power consumption,
low cost, scalability, reliability, robustness, etc.
In order to support these requirements as well as maximize
performance, the system architecture requires key capabilities
in the devices supporting and managing the mesh. Here, we
introduce the concept of Mobile Edge Computing Devices
(MECD) to handle large scale sensor networks and data, and
demand a highly scalable and efficient approach.
MECD are mobile and low power devices which become
pivotal to the application of wireless sensor networks in
the enterprise. In a hierarchical architecture (see Figure 6)
MECDs interface between various highly distributed wireless
sensors and cooperative high-end servers. On the one side,
MECDs manage various wireless sensor nodes; on the other,
MECDs accept configuration and query commands from
high-end servers. To further improve the scalability and relia-
bility of the system, MECDs may form a distributed network.
After necessary processing by MECDs, raw data collected
from wireless sensors is forwarded to high-end servers on a
pull or push basis, by first dynamically selecting from a range
of protocols for communication based on efficiency and cost.
The advantages of the hierarchical architecture include
the following. It is highly scalable since MECDs manage
wireless sensors in a distributed manner, reducing processing
and bandwidth requirements to the back-end servers. It
reduces the initial system cost by assuming a small number
of expensive high-end servers and a large number of very
low cost wireless sensors that have very limited processing
power. The hierarchical architecture is very flexible in the
sense that MECDs are designed to manage various types of
wireless sensors and may be remotely configurable in order
to accommodate various applications.
Fig. 6. MECD Hierarchical Architecture
VII. SOLUTION ARCHITECTURE
In our previous work [7], we described a system ar-
chitecture using both wireless sensor network (WSN) and
RFID technologies. We also implemented and tested a sys-
tem prototype to demonstrate technological capabilities and
constraints in [7]. In this paper, we will apply the concept of
MECD to our system architecture and describe the configu-
ration in details.
In this design, a CrossBow Stargate device [8] which acts
as a MECD connects the physical sensing wireless sensor
networks to the external hosts (e.g. neighboring Stargate de-
vices, the central server, and PDA) through various networks
(2.4GHz ZigBee, WiFi, Cellular, etc). The CrossBow Stargate
gateway is a low-power mobile computing and communi-
cation device and a powerful single-board embedded Linux
computer designed for sensor signal processing, control, and
wireless sensor networking application [8].
A single node of the wireless sensor network, e.g. a
”mote”, is a tiny wireless computing platform with a CPU,
memory, storage, I/O, and radio components, optimized for
long life on low power. The MicaZ [9] and TelosB [10]
motes, 2.4GHz, IEEE 802.15.4/ZigBee compliant modules,
and a SkyeTek 915MHz RFID reader connected to a MicaZ
mote were placed inside containers. These motes report
sensed data periodically or by query from the Stargate. Sim-
ilarly, the RFID reader reported sensed data to the Stargate
through the MicaZ mote.
In the system prototype, each container was instrumented
with two networks: an Internal Network, for environmental
sensing and reading RFID tags, and an External Network, for
node-to-node communication between containers. Attached
to the Stargate through a 51-pin connector is a MicaZ mote,
shared by both networks. To avoid contention and collision
between the networks, multiple antennas can be used, and
dynamic channel selection may be employed. To alleviate
collision, an additional circuit, antenna selector, may help.
This particular architecture may not scale in the case of large
networks, since the mote cannot receive packets from the two
networks at the same time, resulting in a degradation of the
Fig. 7. Solution Architecture
overall performance.
A USB-based memory card for data storage, a GPRS
PCMCIA modem, and an 802.11 DF card were also installed
in the Stargate. Due to the limitation of the connectors, an
MTS420 sensor board [11] was used to provide the additional
GPS module and the MicaZ mote with the MTS420 was
placed outside a container.
VIII. CONCLUSION
With cargo containers transporting 90 percent of the
world’s trade, efforts are focused on addressing containers’
inherent vulnerabilities as well as the impracticality and
prohibitive cost of 100% manual inspection to ensure inter-
modal security. Through this research we propose to take
advantage of the fact that containers are in close physical
proximity while in transit or stacked in container yards or
in the port. Instead of focusing on the security of each
individual container in isolation, we suggest creating a self-
configuring container-based dynamic mesh network which
changes with each physical realignment of the containers. In
addition, this approach could also enhance container network
communication to ocean- or land-based infrastructure which
could also be provided in a more reliable and efficient
manner. We’ve reviewed different scenarios in the supply
chain potentially aided by mesh network characteristics, and
discussed insights from the prototype architecture. Research
continues is this area across a variety of supply chain and
transportation applications to ready this technology for wide-
scale deployment.
ACKNOWLEDGMENT
We would like to thank Intel Corp. and Embedded System
Consortium for supporting the research.
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