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Driving the Connected Car Revolution | 赛普拉斯半导体

Driving the Connected Car Revolution

Wi-Fi functionality in cars enables a variety of use cases, broadly classified into in-car applications (infotainment) and external Wi-Fi applications (telematics). As the use cases for Wi-Fi expand, it becomes challenging to enable all these use cases concurrently, while maintaining a good user-experience.

The car is undergoing an unprecedented evolution, particularly from the connectivity perspective. Currently about 20% of cars worldwide include Wi-Fi® capabilities, and we expect that number to increase to 50% by 2023. This growth is accelerated by the transformation of the car from strictly being a mode of transportation, to include a place for work and entertainment.

Wi-Fi functionality in cars enables a variety of use cases, broadly classified into in-car applications (infotainment) and external Wi-Fi applications (telematics). As the use cases for Wi-Fi expand, it becomes challenging to enable all these use cases concurrently, while maintaining a good user-experience.

 

Infotainment

Bluetooth® has been the primary in-car wireless connectivity technology for infotainment systems over the past 15 years. The primary use case for this is to enable hands-free calling using a mobile phone. In the past five years, in-car applications have expanded to include music streaming from a phone to the car’s music system, and the ability to pair multiple phones simultaneously for hands-free calling. With the addition of Wi-Fi capabilities in head units and cellular connectivity in telematics units, cars have started providing Wi-Fi hotspot functionality for devices like laptops, tablets, and phones. This has enabled greater consumption of rich media content in the car, either by downloading the content to the car via the home Wi-Fi before leaving on a road trip, or by streaming it while on the road using cellular data connectivity.

While all of these new use cases have brought consumer entertainment features to the world of automobiles, the user interfaces that take advantage of these features have been a challenge. The experience of setting up an address for navigation or to stream music from a phone app in a rental car that one is unfamiliar with is a case in point. This has created a need to enable user interfaces that most people are very comfortable with, that is, their iOS- or Android-powered mobile phones. Everyone has favorite apps for maps, music, and messaging. Apple CarPlay and Android Auto deliver these apps to car head units via display-mirroring technologies. These mirroring technologies have been enabled with wired connectivity (USB) over the past three- to four years, but are shifting to wireless using Wi-Fi.

With this technology, a user could setup a destination on his or her phone and be listening to a podcast while walking up to a car, and as the car was powered on, the head-unit display would show the driving directions while the podcast would automatically play through the car speakers, with no setup required or buttons pressed.

 

Telematics

While infotainment generally encompasses in-car applications for Wi-Fi, telematics broadly deals with external Wi-Fi connectivity, that is, the car connecting to an external Wi-Fi network. These could be home Wi-Fi networks when parked in the garage, public hotspots, car dealership Wi-Fi networks, or factory floor Wi-Fi networks.

There are several use cases for external Wi-Fi connectivity, but the primary application is FOTA (Firmware Over-the-Air) updates. There are several ECUs in cars that need to be programmed in the factory after they are assembled, periodic updates to ECU software for enhancements or to deal with defects that typically cause recalls to update the software, obtain diagnostic information from a car when it is brought in for servicing at a dealership, etc. While cellular data connectivity can be used for these applications, it is rather expensive, especially with software content in cars growing significantly. Wi-Fi provides a low-cost alternative to offload LTE when a Wi-Fi network is available.

Body Domain

There are several emerging use cases related to the body domain enabled by connectivity.

The ability to use a phone as an alternate to key fobs is a highly desired feature. With car sharing becoming increasingly popular, this capability allows one to send digital keys through an app to allow others access to the car. The digital keys can be provisioned to be usable during a limited time window or enable usage in a geo-fenced area, etc.

This can also enable personalizing the driving experience by pairing with a phone. Cars could track a driver who is approaching a car, to turn on welcome lighting, soft-start systems, or lock and arm security when the driver leaves the car.

Car rental companies can leverage this technology to enable a wide array of experiences from selecting a car model through an app, completing rental agreements with pre-entered credentials and payment info, and opening and driving a car from the lot, all with just a phone!

Multi-role, Dual-band Concurrent Operation

While each of the use cases described earlier are not complex by themselves, enabling concurrent operation of all of them is a significant technical challenge.

Wi-Fi devices built for the IoT world (such as phones, TVs, smart speakers, and home appliances) typically operate as station/client devices that connect to Wi-Fi access points. Automotive use cases require the Wi-Fi device to operate in multiple concurrent roles: as an Access Point (AP) to provide hotspot services, as a Peer-to-Peer (P2P) device, or as a Station (STA) device to connect to external Wi-Fi networks. All these roles must be accessible while the device is handling coexistence issues associated with Bluetooth, such as hands-free calling.

Cypress’ Real Simultaneous Dual-Band (RSDB) technology addresses these challenges by integrating two complete Wi-Fi systems into a single chip and by providing a common host interface and software driver layer.

A typical wireless LAN device is dual-band capable, but can operate in only one band at a time. Using such a device to operate as an AP in 5GHz and STA in 2.4GHz requires switching between the two bands in a time-shared fashion. This is sometimes referred to as Virtual Simultaneous Dual Band (VSDB). Wi-Fi standards and architecture are defined with an assumption that an AP is always available. While implementing AP+STA using a VSDB architecture is technically possible, there are several technical limitations that cause this band switching to eat away up to 40% of the total available throughput. Moreover, it can cause a poor user experience, with dropped connections and reconnections. Applications that require AP+AP concurrent operation on both bands are not possible to implement with VSDB architecture. The only way to achieve this is with an RSDB device.

 

Cypress’ pioneering RSDB architecture implements two complete MACs in a single chip to provide simultaneous operation in both 2.4GHz and 5GHz bands. This allows implementing multiple concurrent role combinations of AP, P2P and STA that enable passengers and drivers to enjoy the same connectivity, rich multimedia content and user experience in a vehicle that they have when they’re at home.

 

Learn more about our broad portfolio of automotive connectivity solutions:

https://www.cypress.com/products/automotive-wireless

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