Communications” (DSRC). (DSRC has been used for electronic toll collection for over 10 years; this was essentially the first widespread vehicle-to-infrastructure application.)

In the U.S., signals for V2I and V2V communications are carried over 75MHz of spectrum in the 5.9GHz band, which was allocated for DSRC purposes in 1999. China, Europe, and Japan have also reserved DSRC bandwidth near this range; Japan also uses spectrum in the 760MHz band, and Korea is reportedly considering a move to this range.

However, regional standards for DSRC and other aspects of V2V communication are not always compatible with each other, so it is unclear whether cars designed for one regional market would ever work in another. There are efforts to harmonize them somewhat: For example, Japan might implement security according to IEEE Standard 1609.2, currently being used by the U.S. and the EU.

Public V2V tests began in 2006, when DaimlerChrysler got a Mercedes-Benz and Dodge talking to each other, and General Motors demonstrated crash avoidance between two Cadillacs. The first consumer car with true V2V communication capabilities, according to public announcements, will be a 2017 Cadillac equipped with the company’s “Super Cruise” technology.

Automakers have generally em-
braced V2X technology as a logical
piece of a larger assisted-driving
picture. Hideki Hada, general man-
ager of Integrated Vehicle Systems at
Toyota Motor Engineering & Manu-
facturing North America, described
how diverse sensor, V2I, and V2V
Despite V2V’s readiness and prom-
ised benefits, the public may resist
such mandates—especially in the U.S.
The NHTSA’s notice opened a 60-day
period for public comment, which
elicited nearly 1,000 responses, of
which 482 met the NHTSA’s submis-
sion policy. The consensus was over-
whelmingly negative, citing fears that
V2V technologies would lead to loss of
privacy, inattentive drivers, malicious
hackers, and health risks to those
claiming the widely discredited condi-
tion of “electromagnetic hypersensi-
tivity.” Further, some blanched at the
likely cost of about $300–$350 to build
V2V features into new cars, or retrofit
them into older ones.

Barua believes such opposition pales in comparison to the human costs that would come from blocking V2V technologies. “Studies have shown that vehicle-to-vehicle communications could reduce traffic jams, and a lot of lives could be saved,” he says. “Even pedestrians would benefit—they could know when a vehicle is coming, through vibrations on their mobile phones. I think governments should intervene, and take a lead for V2V communications to be functional as soon as possible.”

On the Road

The U.S. DOT report provides a thorough list of standards for that country, including V2V message contents and transmission performance requirements. The main set of architectural and procedural standards is spelled out in IEEE 1609, “Family of Standards for Wireless Access in Vehicular Environments (WAVE).” Of special interest to those who fear malicious hackers is IEEE 1609.2, “Security Services for Applications and Management Messages,” which was finalized and published in April 2013.

A second set of standards, currently still in development, may be found in SAE J2735 and SAE J2945. These spell out what information each message packet would carry; the latter also includes a section on privacy and security. A third standard, IEEE 802.11p, addresses physical standard specifications for automo-tive-related “Dedicated Short Range

“For drivers,
I think it will be
very seamless;
they won’t know
whether it’s V2V,
V2I, or sensors that
provide guidance.
ACM
Member
News

LIFELONG LOVE OF MATH SPURS TANNEN IN CS

Val Tannen,
professor of
Computer and
Information
Science in the
Engineering
School of the
University of Pennsylvania
(UPenn), has had a lifelong love
of mathematics. “There’s no
ambiguity about math. The
conclusions are inevitable if you
accept the assumptions,” he says.

Language and mathematical logic are the dominant influences on Tannen’s research. He earned his Computer Engineering degree from the University Politehnica of Bucharest; “There’s no Romanian-equivalent master’s degree; one degree covers both bachelor’s and master’s,” he explains. After graduation, he worked as a programmer for a local computer firm and moonlighted as a researcher.

Fate intervened in 1982; Tannen came to the U. S. to visit his ailing father and wound up seeking political asylum here.

He went to the Massachusetts Institute of Technology, where he received his Ph.D. in Applied Mathematics in 1987; a month later, Tannen joined UPenn.

Tannen’s expertise spans programming languages, databases, parallel processing, and logic in computer science and its applications in life sciences. “The word ‘language’ comes up all the time in my research,” Tannen says. During his 27 years at UPenn, he has interwoven mathematical logic and language into his career as a computer scientist. Tannen also specializes in data provenance, a record of the origin and transformation of data.

When he introduced a course at UPenn called “Friendly Logics,” Tannen recalls, the title was approved only after he authored the mathematical definition: “A logic is said to be friendly if and only if, it strikes a good balance between expressiveness and algorithmic tractability.” That neatly sums up Tannen’s career as well.

— Laura DiDio