This project aims to develop inter-vehicular networking,
computing, and sensing technologies for next generation smart
vehicles. Such vehicles have embedded computers, GPS receivers,
short-range wireless network interfaces, and potentially access to
in-car sensors and the Internet. Furthermore, they can
interact with road-side wireless sensor networks on roads where
these networks are deployed. These capabilities can be leveraged
into distributed computing and sensing applications over
vehicular networks for safer driving, congestion avoidance,
mobile sensing, or in-vehicle entertainment. To support a large
spectrum of such applications, this research designs and
implements vehicular-specific network protocols, middleware
platforms, and security mechanisms.
::: Vehicular Traffic Re-routing
for Congestion Avoidance
Traffic congestion causes driver frustration and costs billions
of dollars annually in lost time and fuel consumption. We
propose a cost-effective and easily deployable
vehicular re-routing system that reduces the effects of traffic
congestion. The system collects
real-time traffic data from vehicles and road-side sensors, and
computes proactive, individually
tailored re-routing guidance, which is pushed to vehicles when
signs of congestion are
observed on their routes. We designed and evaluated several
re-routing strategies which reduce the average travel time
between 2 and 4 times when applied on congested road networks.
The strategies are robust and lead to significant benefits even
when many drivers ignore the guidance or the system adoption
rate is low. Finally, our strategies are capable
of reducing the travel time comparable to a state-of-the-art
Dynamic Traffic Assignment (DTA)
algorithm, while avoiding the issues that make DTA
impractical, such as lack of
scalability and robustness, and high computation time.
::: Routing in Vehicular Ad Hoc
Analyses of traditional routing protocols for mobile ad hoc
networks demonstrate that their performance is poor in VANETs,
especially in city environments. We propose RBVT, a class of
city-based VANET routing protocols which leverage real-time
vehicular traffic information to create road-based paths
consisting of successions of road intersections that have, with
high probability, network connectivity among them. Geographical
forwarding is used to transfer packets between intersections on
the path, reducing the path's sensitivity to node mobility.
For dense networks with high contention specific to cities, RBVT
forwarding using a distributed receiver-based election
of next hops based on a multi-criteria prioritization function
taking into account the non-uniform radio propagation. We
designed and implemented two RBVT protocols, one reactive and
one proactive. The former performs best for end-to-end delivery
rates, while the latter performs best for end-to-end latency.
On-going work focuses on adaptive queuing mechanisms for
::: Vehicular Traffic Generator
Testing vehicular protocols at scale requires suitable mobility
models and tools to generate mobility traces to be used in
developed a microscopic vehicular traffic generator based
on the car-following and lane-changing models proposed
by Gipps, which belong to the class of collision
avoidance vehicular mobility models. The main goal of
these models is to enable a vehicle to move at the maximum
safest speed that ensures that there will be no collision
with the preceding vehicle. The Gipps car-following model
provides the ability for smooth transitions between
acceleration and deceleration.
Since we target city scenarios, our
generator supports traffic lights at road intersections
as well as bidirectional and multi-lane traffic. We used this
generator in conjunction with the ns-2 network simulator and
digital road maps from the TIGER/Line database. The code for
the generator along with basic documentation can be downloaded
::: Programming Models and
VANETs can be leveraged to provide ubiquitous services capable
of acquiring, processing, and sharing real-time information
from the physical world. Programming such mobile
sensing services is challenging due to frequent context
which often lead to situations where a service cannot produce
semantically acceptable results on its current node. We
proposed a novel service programming model based on the concept
of context-aware migratory services. Unlike a regular service
that executes always on the same node, a migratory service can
migrate to different nodes in the network to accomplish its
task. The migration is triggered by changes of the operating
context and occurs transparently to the clients. We designed
and implemented a middleware for developing migratory
services. We also built TJam, a proof-of-concept migratory
service that predicts traffic jams on the highways.
The software distribution can be downloaded from
here. This code uses the portable smart messages software,
wich can be downloaded from
::: Trusted VANETs
To ensure fair and secure communication in VANETs,
the applications running in these networks must be
regulated by proper communication policies. However, enforcing
policies in ad hoc networks is challenging because they lack the
infrastructure and trusted entities encountered in traditional
distributed systems. To solve this issue, we designed and
implemented policy enforcing mechanisms based
on a kernel-level trusted execution monitor built on top
of the Trusted Platform Module. Under these mechanisms, two
instances of an application running on different nodes may
engage in communication only if these nodes enforce the same
application policies. In this way, nodes can form trusted
application-centric networks. Before allowing a node to join a
trusted application-centric network, the trusted execution
monitor verifies its trustworthiness of enforcing the
application policy. The monitor also protects the policies and
the software enforcing these policies from being tampered
with. If any of them is compromised, it disconnects the
node from the network and potential attacks are
stopped at the originator.
::: VANET - Wireless Sensor Networks
Improving driving safety is a top objective for
VANETs. However, the lack of sensing in the
absence of cars ahead on the road and frequent network
disconnections could lead to driving hazards: these
networks cannot detect dangerous road conditions
with good accuracy and cannot guarantee timely propagation of
alert messages. To address these problems, this on-going
to merge inexpensive wireless sensor networks (WSNs)
with VANETs to create a VANET-WSN symbiotic architecture. In
this architecture, sensor nodes are deployed along road sides
to detect dangerous road conditions and facilitate timely
information sharing among vehicles; in return, VANETs provide
richer computation, communication, storage, and power resources
to help WSNs overcome their resource constraints. On top of
this symbiosis, we plan to build more effective on-road
information systems for traffic safety.
Exploring the Design and Implementation of Vehicular Networked
Systems. NSF, 2005-2008. Collaborative research with
Real-time Information Systems for Driving Safety atop VANET-WSN
symbiosis. NSF, 2008-2010. Collaborative research with
Themis: A Participatory Navigation System for Balanced Traffic
R. Liu, H. Liu, D. Kwak, Y. Xiang, C. Borcea, B. Nath, and L.
The 2014 IEEE Vehicular
Conference (VNC), December2014.
Proactive Vehicular Traffic Re-routing for Lower Travel
Juan (Susan) Pan, Iulian Sandu Popa, Karine Zeitouni, and Cristian
To appear in IEEE
Transactions on Vehicular Technology, 2013.
Proactive Vehicle Re-routing Strategies for Congestion
Juan (Susan) Pan, Mohammad A. Khan, Iulian Sandu Popa, Karine
Zeitouni, and Cristian Borcea
Proceedings of the 8th IEEE International Conference on Distributed
Computing in Sensor Systems (DCOSS '12), May 2012.
Lane Recognition for Moving Vehicles Using Multiple On-car RFID
Receiver Antennas - Algorithm and Its Experimental Results
Hiroaki Togashi, Cristian Borcea, and Shigeki Yamada
Proceedings of the 2012
IEEE Intelligent Vehicles Symposium, June 2012.
On Deriving and Incorporating Multi-hop Path Duration
Estimates in VANET Protocols
Josiane Nzouonta, Marvin Nakayama, and Cristian Borcea
ACM Transactions on Modeling and Computer Simulation. Vol 21, No.
A Policy Enforcing Mechanism for Trusted Ad Hoc
Gang Xu, Cristian Borcea, and Liviu Iftode
IEEE Transactions on Dependable and Secure Computing. Vol 8, No.
Impact of Queuing Discipline on Packet Delivery
Latency in Ad Hoc Networks
Josiane Nzouonta, Teunis Ott, and Cristian Borcea
Elsevier Performance Evaluation Journal, Special Issue on
Performance Evaluation of Wireless Ad Hoc, Sensor, and Ubiquitous
Networks. Vol 66, No. 12, 2009.
VANET Routing on City Roads using Real-Time
Vehicular Traffic Information
Josiane Nzouonta, Neeraj Rajgure, Guiling Wang, and Cristian
IEEE Transactions on Vehicular Technology, Vol 58, No. 7,
Context-Aware Fault Tolerance in Migratory Services
Oriana Riva, Josiane Nzouonta, and Cristian Borcea
Proceedings of the 5th International
Conference on Mobile and Ubiquitous Systems: Computing,
Networking and Services (MobiQuitous 2008), July 2008.
Context-aware Migratory Services in Ad Hoc Networks
Oriana Riva, Tamer Nadeem, Cristian Borcea, and Liviu
IEEE Transactions on
Mobile Computing, December 2007.
Trusted Application-Centric Ad-Hoc Networks
Gang Xu, Cristian Borcea, and Liviu Iftode
Proceedings of the 4th IEEE International
Conference on Mobile Ad-hoc and Sensor Systems (MASS
2007), October 2007.
» The Urbanet
Revolution: Sensor Power to the People!
Oriana Riva and Cristian Borcea
Pervasive Computing, Special Issue on Building a Sensor-Rich
World. Apr-Jun 2007.
Satem: Trusted Service Code Execution across Transactions
Gang Xu, Cristian Borcea, and Liviu Iftode
Proceedings of the
25th IEEE Symposium on Reliable Distributed Systems (SRDS 2006)
, October 2006.
EZCab: A Cab Booking Application using Short-range Wireless
Peng Zhou, Tamer Nadeem, Porlin Kang, Cristian Borcea, and
Proceedings of the
3rd IEEE International Conference on Pervasive
Computing and Communications (PerCom 2005), March 2005.
STEID: A Protocol for Emergency Information
Dissemination in Vehicular Networks
Josiane Nzouonta and Cristian Borcea
NJIT Technical Report, 2006.
Vechicular Networks Security Project
CAR-2-CAR Communication Consortium
» General Motors Collaborative Research Lab/CMU