Don’t believe what you see in the side-view mirror. The next generation of in-vehicle applications is closer than it appears. The biggest reason: The rapidly accelerating deployment of LTE (long term evolution) networks. (More basic information here.)
Auto manufacturers recognize that LTE is the future of mobile connectivity, and many are already planning LTE-equipped vehicles for as soon as 2014. With improved range and connection speeds up to 100 times faster than today’s 2G and 3G data services, these LTE-connected systems will enable unprecedented applications in the vehicle.
From an engineering perspective, however, LTE presents some significant challenges. To design an effective LTE-connected car system, you need to understand where LTE networks are today, where they’re going, and what attributes in-car systems should have to bridge that gap.
The promise of LTE
With the ability to connect cars over LTE networks—effectively, the ability to bring wireline broadband speeds to the automobile—a wide range of new applications become available in the vehicle. Services like Internet-streamed video, music, and even video conferencing (used from the passenger or rear seat, of course) will likely be the first examples that spring to mind.
These applications will benefit not just from the supercharged capacity and range of LTE, but from the much lower latency of LTE systems (latency often being the most critical factor in delivering a high quality-of-experience to the user). But the potential for LTE-connected car applications goes beyond entertainment and communications.
For example, superfast vehicle-to-vehicle communications could enable new safety services, such as the ability to stream video of road conditions recorded from other vehicles in real time, or receive alerts when cars up ahead of you slam on their brakes. In theory, the LTE-connected car could become a portal for all sorts of new applications and services—much like the iPhone transformed the mobile phone, and spawned previously unthinkable mobile services and business models.
These and other possibilities are generating tremendous excitement across the industry. But how close are we to actually realizing the potential of LTE-connected applications? Some important barriers remain.
Operating in real-world vehicles
The biggest obstacle is the fact that it will be a while before LTE coverage catches up with LTE devices and applications. Operators around the world are busy deploying LTE networks; according to the Global Mobile Suppliers Association (GSA, complimentary registration required), 237 operators in 85 countries are now investing in LTE technology, making it the fastest-growing mobile system rollout in the history of the industry. But for the most part, these networks are still in early stages of development.
Even by 2014 (the earliest we expect to see LTE-connected cars on the market), there likely will be plenty of regions where LTE is restricted to high-density pockets of coverage, separated by large areas of 3G or even 2G service. To operate in this environment, the LTE-connected car will need advanced multi-mode capabilities—radios for multiple 3G, 2G, and HSPA
(high-speed packet access) technologies, possibly in multiple band combinations.
This presents an immediate and not-insignificant engineering challenge: More operating states means more components, more power consumption, and more heat—and also means a much more extensive testing and certification process.
These multi-mode systems will also need to be intelligent. It’s not enough just to have different cellular radios; the LTE device needs to be smart enough to know which one represents the best possible option at any given moment. Staying connected: Antennas and noise
Another complexity designers need to address is maintaining a good connection, even with less-than-optimal coverage. Under the best circumstances, LTE will require a more sophisticated antenna system than conventional 3G and 2G systems. LTE uses multiple- input multiple-output (MIMO) antennas, for which antenna placement, coherent distance (i.e., separation) polarity, and other factors are extremely important.
In many regions, LTE will also operate at lower frequencies, below 1 GHz. The ability to deploy LTE at lower frequencies is a major benefit for operators, as it provides improved range over most 3G services, and allows operators to “re-farm” their existing 2G spectrum and cell sites for LTE.
The flip-side, however, is that lower frequencies tend to be much noisier. So, not only do LTE system designers have to address more complicated antenna requirements, they have to address them in a more difficult environment. In addition, because many operators are rolling out LTE services using their 2G cell sites, the placement of those cell sites may not be as ideal from a coverage standpoint as a cellular network built from the ground up for LTE.
Put it all together, and you have a big warning sign for LTE-connected car designers: Fail to devote the proper time and resources to antennas, and your users will absolutely notice.