Is LTE cellular the right technology for vehice-vehicle comms?

May 15, 2014 // By Christoph Hammerschmidt
During the recent GSA meeting in Munich, the perspectives of Vehicle-to-X technologies were one of the topics for a keynote speech. Dirk Lindemeier, Head of Liquid Applications at Nokia Solutions & Networks (NSN), argued for LTE as the more cost-efficient technology to deploy vehicle-to-infrastructure services. The crunch is the latency time.

Lindemeier sketched a future mobile telecommunications landscape characterised by two main features: Very high bandwidth and very low latency. NSN's vision are mobile networks capable of delivering one Gigabyte of data per user and day. At the same time, the latency times will come down to the millisecond level - low enough to enable real-time applications.

Relevant for the automotive and transportation industry is Lindemeier's suggestion, to implement a roadside infrastructure based on LTE instead of 802.11p (a modified WiFi technology). The latter would offer extremely short latencies but also lacks transmission range. For this reason, roadside units would have to be installed at relatively frequen intervals alongside the major arterial roads - not only in urban areas but also in rural regions. To achieve a good coverage, a very high number of such stations would be required - which would drive the cost level to unacceptable heights, Lindemeier warned. Alternatively, the utilisation of modified LTE mobile radio networks would be much more cost-effective, he said. "Our proposal is to deploy LTE base stations with some additional intelligence", the expert suggested.

The V2X-specific application logic could be implemented as a 'virtual roadside unit', a software that runs on a server in each base station. This proposal would not only offer cost advantages but it also could be implemented in a shorter time than rolling out a network of dedicated V2X roadside units. "In a medium-sized country like Germany, the upgrade of the existing network of base stations would take some two months", Lindemeier said. With such a scenario of edge computing to implement the V2X applications, latencies of around 10 millisecond could be achieved - good enough for even most direct car-to-car communications.

According to Lindemeier, currently several telecommunications equipment manufacturers are working on this topic.