Major brands such as Audi have already recognised that LTE is the future of mobile connectivity, by planning to bring LTE-connected vehicles to market as early as 2014. With improved range and connection speeds up to 100 times faster than 2G and 3G, LTE is set to enable unprecedented applications in the vehicle.
However, from an engineering perspective, LTE still presents some significant challenges. To design an effective LTE-connected car system, the industry needs to understand where LTE networks are today, where they’re going and what attributes in-car systems should have to bridge that gap.
With the ability to connect cars over LTE networks – effectively bringing wired broadband speeds to the wireless automobile – a wide range of new applications will become available in the vehicle. Services like Internet-streamed video, music and even video conferencing (used from the passenger seat or backseat, of course) are just the first that spring to mind.
These applications will benefit not only 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 consumer communications. For example, superfast 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 ahead stop suddenly. In theory, the LTE-connected car could become a portal for all sorts of new services.
These, and other possibilities, are generating tremendous excitement across the industry. But, whilst we may be close to realising the potential of LTE-connected applications, some important barriers remain. 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 and, according to the Global Mobile Suppliers Association (GSA), 456 operators in 134 countries are now investing in LTE, making it the fastest-growing mobile system rollout in the history of the industry.
Sporadic coverage
For a while to come, there 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. Vehicles frequently cross borders and therefore may need broad roaming capabilities to avoid losing connections. Thus an LTE-connected car needs advanced multi-mode capabilities, – this means radios for 2G, 3G and 4G technologies, usually in multiple band combinations.
These multi-mode systems also need to be intelligent. It is 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 and as the vehicle travels at speed.
Another complexity that designers need to address is how to maintain a good connection, even with less than optimal coverage. Under the best circumstances, LTE requires a more sophisticated antenna system than 3G and 2G. 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 operates at lower frequencies, below 1GHz. 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 or 3G 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, but they also have to address them in a more difficult environment. In addition, since many operators are rolling out LTE services using their existing cell sites, the placement of those 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.
Beyond these considerations, it is important to understand that, while LTE is clearly the technology of choice for next-generation cellular services, it is still very much an evolving technology. For example, attention is already beginning to turn to the expansion of LTE services, including LTE Advanced, to deliver even faster speeds.
What this means is that you cannot build a solution designed specifically for LTE networks as they exist now. You need to build in flexibility to adapt the solution as LTE technology itself continues to evolve, in addition to how the coverage of LTE services changes over time market by market.
Building a better connected car
Clearly, some challenges remain before we will see the full-scale vision of the LTE-connected car realised in every driveway. But the promise and momentum of LTE are too great to ignore.
As system designers evaluate LTE devices and vendors in the coming months, there are several words of advice they would be wise to adhere to: choose cellular vendors with proven expertise building LTE, 3G and 2G devices that operate successfully in real-world multi-mode environments; look for wireless providers with expertise in the often overlooked field of antenna design and testing, and that have proven successes delivering different types of devices – USB modems, hotspots, networking devices – in many parts of the world; seek out programmable wireless solutions with operating system-like capabilities, if not actual lightweight operating systems. You will need this headroom to keep pace with evolving requirements; select wireless solutions that can be maintained and upgraded over-the-air to always keep communication devices up to date; choose partners who have close relationships with operators in markets around the world and experience certifying solutions for multiple networks. This expertise will be extremely important as you shepherd your system through the sometimes difficult certification process.
There can be little doubt: LTE is the future of in-vehicle connected services. By making smart choices now, system designers can be confident that their solutions will fulfil the full promise of the connected car – in 2014 and beyond.
Olivier Pauzet is VP of Marketing and Market Strategy at Sierra Wireless
