The IEEE recently gathered more than a dozen stakeholders at an event – mainly researchers and system and chip vendors – to discuss the work invoved in defining the next generation of cellular networking. They share a common timeline for the work under the 3GPP standards body and a set of elements to put in place that includes support for:
- Data services at 20 Gbits/second peak and 1 Gbit/s average;
- Latency as low as 1 millisecond;
- Reception while travelling at up to 500 km/hour;
- Frequencies between 6 and 100 GHz;
- Safety-critical applications such as self-driving cars.
“The faster speeds will come, but the latency and reliability targets will take a lot of work,” said Arogyaswami Paulraj, a wireless expert and engineering research professor emeritus at Stanford in a talk here.
“The biggest challenge with 5G is getting to the reliability so it always works, people talk about the ‘five nines’ concept or may want something even higher,” he said. “Today wireless reliability is a joke in mobile systems, but you can’t afford to let trains or car anti-collision systems go off on their own, so this will be something of a holy grail,” he said.
Today’s cellular systems have latency of about 20-30 milliseconds. Shaving that down to 1ms for a host of applications from virtual reality games to telemedicine will be another one of the toughest challenges of 5G, Paulraj said.
Supporting new millimeter-wave frequency bands and massive MIMO antenna arrays will also be among the top technical challenges, said Paulraj who helped pioneer the MIMO technology used in today’s LTE and Wi-Fi networks
High frequency bands and arrays of hundreds of antennas will “stress everything we have today… there are lots of open issues, and it will take lots of hard work to clean things up and come up with a reasonable design,” he said.