Vehicular communication systems
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Vehicular Communication Systems are systems that allow motorists to communicate freely and safely with others while driving. Such systems typically use voice as the main method of communication, and can be built from simple devices such as walkie-talkies, cellular phones, or more sophisticated devices specifically made to address the needs of the system. The desirability of vehicular communication systems arise in scenarios where a motorist needs information (e.g. directions or notification of a flat-tire), or wants to send a message to a nearby motorist.
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[edit] Overview
The underlying motivation for vehicular communication systems is convenience. Take the scenario of a motorist driving in a new, unfamiliar area. He is looking to get to his friends house, but has taken a wrong turn and now he is lost. Does he stop and get out to ask for directions? This may seem like a logical solution, but it poses an inconvenience to the motorist. Moreover, chances are that there will be other nearby drivers who are local to the area and could easily direct him. Although the driver could receive the directions to his destination, he does not have the means to communicate with another nearby motorist whom he does not know. This is the type of situation which a vehicular communication system is designed to address.
Other communication systems have been developed worldwide to support a vast assortment of needs. For instance, the cellular phone industry in recent history has experienced massive growth, from 7.6 million subscribers in 1991 (in the U.S. alone) to more than 120 million in 2001 [1]. Currently it is estimated that 2/3rds of adult Americans own a cell phone [2]. However, despite the popularity of cell phones and other technologies such as e-mail or internet chat, none of these technologies can adequately be used to build an effective intra-vehicular voice communications system. These systems are meant for person-to-person communication rather than vehicle-to-vehicle. Moreover, they require prior knowledge or some means of identifying the other person to contact. Thus, another key motivation for creating such vehicular communication systems is that they have not yet been developed.
[edit] State of the Art
Cellular phones are a popular wireless communication method for drivers today. Two friends who are traveling to the same destination can keep in contact with each other, relaying information regarding their location and estimated time of arrival. However, with regards to vehicular communication systems, cellular phone technology is inadequate. Cell phones have been shown to detract from the visual attention of the driver, possibly leading to more accidents [3]. Additionally, in order for two people to communicate using cell phones, one person must know the other person's phone number. Thus, cell phones lack the ability to address a core competency of vehicular communication systems -the ability for a driver to safely communicate with any other driver, regardless of their identity. The system like ESITrack give the alternative with handsfree communication, so the vehicle can only call to one number, or received from any number.
Other devices such as walkie-talkies can address this problem by allowing messages to be broadcasted using radio waves, but have an inherent flaw. By design, walkie-talkies are half-duplex -in other words, a user cannot both forward and receive messages simultaneously. Moreover, walkie-talkies operate on low radio frequencies which can easily be intercepted, jeopardizing the confidentiality of the message.
Integrated automobile devices like OnStar have begun to make a presence on U.S. markets, with automobile manufacturers like GM offering them as options on their vehicles. Third party companies use these devices to offer services such as directions and emergency assistance to their customers. Although these devices may add an extra level of safety and peace of mind, they do not offer drivers the freedom to communicate with each other.
[edit] Possibilities
In designing vehicular communication systems, a good design should follow certain criteria (aside from core competencies). A few examples ares listed below:
- Intuitive and easy-to-use interfaces
- Meaning: The driver's attention should not be disrupted when using the system.
- A reasonable range of communication
- Meaning: The system must be able to operate reliably within a reasonable range that motorists are expected to be in for a sustained period of time.
- Confidentiality
- Meaning: Any conversations currently taking place should remain private to only those whom the conversation is intended.
One challenge in designing vehicular communication systems is finding an appropriate technology that can satisfy all the criteria. Bluetooth (IEEE 802.15.1) is one such technology. It was developed in 1998 by a consortium of five companies (Sony Ericsson, IBM, Intel, Toshiba and Nokia), with the design goals of making Bluetooth a low-cost, low-power, wireless radio specification. Many devices today, such as PDAs, laptops, and PCs come "Bluetooth-enabled," referring to the bluetooth hardware (chipset) installed in these devices.
Bluetooth can also be used to form wireless ad hoc networks, or networks based on a collection of wireless nodes that dynamically form a temporary network as long as these devices are within a sufficient range [4]. The flexibility in ad hoc networks is what makes it a suitable choice for modeling common on-road vehicle-to-vehicle communication scenarios -where multiple cars would be traveling at different rates but potential connectivity exists.
For example, in the diagram (right), the top and bottom car are traveling at a given rate. The middle car approaches both cars and is within range of the top car, so a connection is established. The middle car has now formed an ad-hoc network with the top car. However, the bottom car is not within range of the middle car, so the bottom car could not connect to the ad-hoc network. In more practical terms, this means that a motorist would be able to communicate with adjacent vehicles, as long as those vehicles are in range of the vehicular communication system. Such a device could be built upon the application layer of Bluetooth's protocol stack, in effect not changing any internal behavior of Bluetooth, but integrating the specification into software.
[edit] Privacy and Other Issues
Vehicular communication systems have several ethical and social issues that must be addressed in the design of such a system. In a system where drivers can anonymously communicate with anyone else on the network, privacy issues in particular are important issues that stand out. With any computer system, there is a possibility for hackers to launch an attack on either the device operating in the system, or the network itself. Hackers could potentially break into other drivers’ devices, propagating unwanted messages or threats throughout the network. This is known as "spamming" the network, or repeatedly posting messages or communication session initiations, which floods the network with traffic. It could drive peoples’ attitudes towards such a system to distrust or annoyance, causing them not to initiate or accept conversations with other drivers, thereby defeating the purpose of the system. Moreover, a motorist who receives unwanted messages might feel harassed, rather than helped by the system. Another issue arises from the affect of a vehicular communication system on the driving dynamics of the road. As with any other system or device integrated within automobiles, the driver would need to divert some attention from the road to operate the vehicular communication system. Diverted attention from the road could be a cause of more frequent traffic accidents.
These systems may have economic impacts as well. With the freedom in expressing information that these systems offer, people could gain knowledge of more frequented places such as restaurants and hotels, increasing patronage to such places. Such an impact might instill in companies a desire for marketing, or for drivers to sell "airtime" to continually send advertisements to adjacent vehicles.
[edit] See also
- Bluetooth
- Bluejacking
- Cell phones
- Mobile ad hoc network
- Radio
- WiFi
- Walkie-talkies
- Wireless LAN
[edit] References
[1] Lance, K. Cell phone statistics Retrieved Nov. 30, 2005.
[2] News: Cell phone usage continues to rise (April 22, 2002). IMedia Connection
[3] Strayer, D. L., Drews, F. A., Johnston, W. A. (2003). Cell phone-induced failures of visual attention during simulated driving. Journal of Experimental Psychology, 9, 23-32
[4] Broch, J., Maltz, D. A., Johnson, D. B., Hu, Y., Jetcheva, J. (1998). A performance comparison of multi-hop wireless ad hoc network routing protocols. Carnegie Mellon University, PA
