On the same day as Qualcomm’s first public demonstration of millimeter wave (mmWave) - a technology central to 5G - Ericsson announced its prediction of 150 million 5G subscriptions by the end of 2021. This intriguing contrast of 5G reality versus hype suggests it’s time for a 5G reality check.
While there have been many 5G demonstrations to date, Qualcomm’s was interesting because it showed how mmWave will support high-speed mobile connections in high-frequency spectrum. The demo, a TDD prototype system running in the 28-GHz band, included a base station with 128 antennas and a device with 16 antennas. It used intelligent beamforming and beam tracking to maintain a connection as a researcher slowly moved the device. With data speeds near 500 Mbps downstream and 80 Mbps upstream in a 226-MHz channel, it showed how 5G technology will make mobile broadband services viable in high-frequency spectrum.
While the demo was a prototype system, Qualcomm made it clear at the event that it would bring 5G chipsets to market in time to support commercial deployment of 5G services in 2020. It seems the entire industry is working to this timeline.
Three market segments
Amid an increasing number of 5G demos by Qualcomm and other vendors, consensus has emerged about key aspects of the 5G standard. 5G is now designed to serve three different market segments. These are enhanced mobile broadband, massive Internet of Things (IoT) connectivity, and ultra-reliable communications. Key features of the different segments include:
- Extreme mobile broadband: High speeds measured in Gbps, latency down to 1 millisecond (ms) end-to-end, and the use of high-frequency spectrum bands above 6 GHz.
- Massive IoT: Low power consumption, low cost, and the use of low-frequency spectrum bands to provide broad and in-building coverage.
- Ultra-reliable communications: High reliability, high availability, and low latency down to 1ms end-to-end.
Key design features
In order to serve these different segments, 5G is designed to be flexible and scalable at every level - from the physical layer of equipment through to the network architecture. Some key design features:
- Unified air interface: A new 5G air interface is being developed to work across a huge range of spectrum bands and channel sizes and support a variety of different use cases with different requirements across key performance metrics like data speeds, power consumption, latency, and system reliability. This air interface relies heavily on OFDM (the basis of LTE and Wi-Fi) but is a new design with flexibility and scalability to meet new requirements. New wireless technologies - including mmWave and massive MIMO - are key to the new 5G air interface.
- Flexible network architecture: 5G relies on NFV and SDN to create a more distributed and flexible network architecture. The aim is to use virtualization to provide different devices and services using “network slices” containing the requisite network features and functionality. The aim of 5G is to deliver different levels of performance - such as throughput and latency - across a common infrastructure.
- Multi-connectivity framework: 5G will build on existing features such as carrier aggregation and LTE Direct to allow deeper integration of different networks and devices. Devices will connect simultaneously to multiple networks and will aggregate spectrum and services opportunistically. Devices will also become key parts of the network and connect directly to other devices to expand coverage and improve reliability.
The flexibility of the new system will support a variety of new business models. For example: once network features or “slices” are customized to specific devices and/or services, different network slices will carry different costs. By extension, services like Netflix that demand higher levels of speed and quality from the network must pay a premium - as long as this complies with net neutrality regulations. This could help operators fulfill their longstanding ambition of getting OTT players to help pay for networks as all devices and services will effectively be going through the middle (TTM) of 5G networks via their own customized network slices.