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Until now we saw that the integration of electrical components, so called ECUs, into the vehicle play a fundamental task in providing added value functionality to our vehicle.
But still many people will ask, why we need a networked solution for that.
Cannot be we put just the invidiual components inside?
Why we cannot simply wire it one to one between one component and another, like the dedicated power supply?
All these questions are good questions, which have been posed already during the development time of the vehicle.
Basically it is all a matter of cost and therefore time to market, because a delay in the vehicle production by one day can reach several millions of investment loss.
While the first vehicles used a simple one to one wiring,
depending on the vehicle model, at least one dedicated bus system is included. More common are nowadays 7 and up more different busses inside the car.
With an amounth of cabeling the cabeling complexity and interconnection becomes a major issue.
Not only need the component be connected to a common power supply source, but modern functionalities rely on a distributed approach, where components communicate between each other and exchange information.
To interconnect these components by a simple one to one connection the complexity and therefore also the possible failure rate of interconnection, vehicle weight and cost rises exponentially as can be seen in figure 4.
 Figure 4: Amounth of direct one to one connections increase interconnection complexity in exponential range.
Figure 4 shows it. Just by interconnecting 12 components between each other a wiring connection of 66 straight cables would be needed. The requirement that 12 components need to exchange information with each other is considered to be a possible and common scenario. Requirements of interconnection will increase over time and with higher needs for creating saver vehicles by exchanging information between components,sensors and actuator.
At the same time the cost of connectors, the cable length and the weight of the overall vehicle needs to be reduced. For example a lower weight of the overall design enables more economical usage of the engine and a thoroughly considered positioning of the components has also impact on the overall vehicle safety. The less space is occupied, and the more position possibilities exist, the better the overall integration challenge of the overall system can be mastered on time.
Figure 5 demonstrates a simple calculation example comparing a multimedia system with direct cabling with a system which offers bus connectivity.
 Figure 5: Wiring versus bus connection.
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