Q: What is a Telematics Control Unit (TCU) and how do the designs differ?
Stephen Longden: A TCU is the in-vehicle hardware that provides the platform to enable the delivery of telematics services. The TCU is typically just one element within a distributed system of sensors, antennas and networked Engine Control Units (ECUs) that form the electrical architecture for telematics. The specific telematics architecture varies widely between vehicle manufacturers and by vehicle model. These differences are focused on three factors - the hardware components, the communications approach and the data transfer method. Vehicle manufacturers and their suppliers developing telematics systems have to investigate these three factors before finalising their TCU design.
Q: What are the key design features and options for TCUs?
SL: At the TCU hardware component level, the major design elements are focused on system redundancy features that increase the robustness of the telematics system, but also increase the cost and complexity of the installation. Vehicle manufacturers need to decide what priority to give to these redundancy features that include backup antennae for GSM and GPS, a backup battery and an internal speaker. This priority decision is based on offsetting the cost with the level of security and reliability required from the telematics system.
The main decision to be made in terms of the communications approach is whether the TCU contains all of the hardware necessary for the over-the-air communications, or if the TCU interfaces with the vehicle electronics while the communication is achieved by using a Bluetooth connection to the driver's mobile phone. Vehicle manufacturers offering safety and security telematics services usually specify a fully embedded system with the TCU containing a modem and SIM as this ensures the highest level of reliability. VMs focused on offering non-safety infotainment services are looking to benefit from a lower cost TCU that uses a Bluetooth connection to the driver's phone. This option lowers the cost of the TCU and allows the OEM to avoid the need for a relationship with a mobile network operator. Vehicle manufacturers have to decide if the reduced TCU cost outweighs the performance downsides of using the driver's mobile phone.
For the data transfer method, vehicle manufacturers are faced with multiple delivery methods including SMS, In-band Modem, GPRS, 3G, satellite broadcast and FM/DAB radio. The key selection criteria include whether the communications requirement is one-way or bidirectional, the amount of data and data transfer rate.
Vehicle manufacturers and their suppliers need to select the TCU design most appropriate to the specific telematics services and systems planned for each vehicle model.
Q: Have there been any recent developments in the TCU market?
SL: At the end of July, Continental announced the availability of a new TCU named Novanto. The device is being marketed to OE vehicle manufacturers and aftermarket fleet management, Pay As You Drive (PAYD) insurance providers and Stolen Vehicle Tracking (SVT) companies. Novanto can support a SIM chip if necessary and includes an accelerometer to detect if the vehicle is tilting and trigger SVT. The Novanto TCU also supports over-the-air firmware updates.
Q: What are the future trends for TCUs?
SL: While established automotive Tier 1 suppliers such as Continental, Denso and Harman Becker have strong positions in the TCU marketplace, some vehicle manufacturers are moving their business away from dedicated automotive suppliers and towards less specialist contract electronics manufacturing companies. Ford is a good example of this trend as it has selected Flextronics, not a traditional OE supplier, to provide the TCU for the next version of Sync.
For more information, view a presentation on the assessment of TCU design decisions using real-world examples from telematics systems and services offered by vehicle manufacturers. Or to find out more on SBD’s strategic recommendations and market analysis for telematics systems, contact Juanita Appleby on jappleby@sbd.co.uk
