The automotive industry has been working to develop industry standards for in-vehicle networks that will ultimately simplify incorporating electronics. Networks allow easy connection of electronic devices while reducing cost, weight and complexity compared with point-to-point wiring. Networked devices also allow simplified sharing of information between devices on the network.
While most vehicles already house some form of network, typical vehicle functions are separated into individual networks: power train, body electronics and entertainment. The industry approaches these networks differently due to requirements of safety-critical applications in power train and body electronics vs. nonsafety applications that are communicated on the entertainment network.
While safety-critical networks are closed to plug-and-play applications, the entertainment network has become the area of focus as manufacturers scramble to incorporate the latest in consumer electronic devices. From cellular phones to mobile DVD, consumers are bringing electronic devices to their vehicles as never before. Manufacturers are likewise challenged to introduce OEM versions of these devices in a timely fashion, though keeping up with the marketplace has traditionally been difficult since new electronics products are introduced at a faster pace than automotive. Auto makers have typically integrated devices that were developed especially for their proprietary OEM networks, likewise slowing the process and increasing costs.
Two distinct approaches have emerged to address the OEMs' need to incorporate entertainment devices in vehicles, but they differ in both technology and assumption. The first is an "open-architecture" approach, spearheaded by a collaborative group of automotive OEMs and electronics device manufacturers that embrace an approach that allows the incorporation of hot plug-and-work devices into a vehicle at any time in its life.
The open-architecture community has embraced the IDB family of specifications that includes an entry-level network based on CAN 2.0B called IDB-C (C for CAN) running at a relatively low 250 kbits/second. Initial applications of open-architecture networks will enable consumers to gain access, with the automotive OEM's permission, to vehicle data from the body electronic network. For example, this will enable devices such as navigation systems to access the odometer and sensor information of the vehicle to improve accuracy and performance. Likewise, fleet applications like rental cars will be able to use odometer and vehicle fuel level to automate the vehicle rental process with simple plug-in devices that can be easily added to a vehicle when it enters the fleet and moved to subsequent vehicles just as easily.
Since most on-board vehicle networks are already implemented on the control-area network (CAN) or some variant, the implementation of IDB-C is simplified while maintaining a cost per node that is expected to be a low $1 or less in production. Implementation in a vehicle environment is also simplified, as CAN has seen automotive implementation for many years. Although it is slow, IDB-C still provides vehicle sensor information fast enough so that it will do well in the market. Vehicle OEMs consider IDB-C to be the entry point of open-architecture networking that will pave the way for the introduction of new value-added services to telematics products such as OnStar. It is expected that the first commercial introduction of IDB-C-equipped vehicles will be in the 2003 model year.
True high-speed open-architecture networking will arrive as early as model year 2004, when vehicle manufacturers will introduce IDB-1394 to select vehicle platforms.
Designed to take advantage of the large number of consumer 1394 devices already in the marketplace, IDB-1394 is a next-generation automotive network that will initially be introduced as a 400-Mbit/s specification with architectural support to speeds over 3,200 Mbits/s.
IDB-1394 maintains compatibility with legacy 1394 consumer devices, but is designed specifically for vehicle applications, implemented on plastic optical fiber cable with an automotive grade connector and system components. The specification includes all seven layers of the ISO model to assure compatibility among devices already available in the marketplace as well as new devices designed specifically for vehicle use.
To assure vehicle integrity, a power budget of 14.5 dB has been developed, along with in-line connector technology to assure low-cost assembly. A minimum bend radius of 15 mm has been specified to assure ease of implementation in even the smallest vehicle compartments. Building on the strength and applications already introduced in consumer electronics and computer applications, IDB-1394 is ideally suited for Internet Protocol, video and HDTV, and will allow previously designed consumer products to be incorporated.
In both IDB technologies, a number of complementary technologies have emerged that will be integrated in a gateway strategy. Current efforts are focused on Bluetooth and 802.11, each of which is a wireless network that will allow interface to a variety of specific devices such as phones and home networks. There is another alternative to open-architecture IDB technology that has been introduced by the MOST Cooperation and is currently being considered for implementation by several German automakers.
Closely controlled networks
To date, manufacturers that are considering MOST technology have made it clear that vehicle manufacturers need to control the devices that are added to a vehicle system, resulting in a network that is closely controlled.
Likewise, devices designed for implementation on manufacturers' platforms will be unique to those platforms to assure manufacturer oversight of all in-vehicle devices. MOST is currently implemented at 22.4 Mbits/s on plastic optical fiber cable with an automotive grade connector and interface. The first MOST equipped vehicle is expected in model year 2002.
Automakers and consumer electronics manufacturers are headed toward an even greater level of electronics integration in vehicles, both in OEM and aftermarket installations. Clearly, the industry is moving toward greater openness in architecture, to allow simplified plug-and-work technologies to penetrate the marketplace in response to increased consumer demand. The integration of gateway to wireless technologies will increase as implementation of IDB gets under way.