Radio Access Networks For 5G

- 5G High-Frequency Bands

5G is the next generation of mobile broadband that will eventually replace, or at least augment, your 4G LTE connection. 5G is different from traditional 4G LTE. From spectrum bands to small cells. 5G networks will operate in a high-frequency band of the wireless spectrum, between 28 GHz and 60 GHz. This range is known as the millimeter wave (mmWave) spectrum. The sub-6 GHz range that LTE calls home will also be used. 5G is expected to add unlicensed frequencies such as the 3.5 GHz to its list of new frequencies for mobile use. This means a lot of bandwidth will be available to users. In addition to greater bandwidth, the new 5G networks will have a dense, distributed network of base stations in the small cell infrastructure. This will allow more processing to happen on the edge, leading to lower latencies.  

Technologies for 5G and future generations of connectivity will provide higher bandwidth and lower latency than current-generation 4G technology. “5G and Beyond” will enable bandwidth in excess of 100 Mb/s with latency of less than 1 millisecond (ms), as well as provide connectivity to billions of devices. Most importantly, these technologies are expected to enable fundamentally new applications that will transform the way humanity lives, works, and engages with its environment.

- 5G Radio Access Networks and RAN Evolution

Radio access networks have evolved over the years as cellular technology is now at 5G. To make the performance goals of 5G a reality, New Radio Access Network Architecture based on Fiber-Wireless Integration and Networking (FiWIN) is essential in serving diverse user scenarios, which require high wireless throughput, extremely low-latency, ultra-reliability and seamless multi-device connectivity. 

The Centralized/Cloud Radio Access Network (C-RAN) has attracted tremendous attention from the wireless infrastructure industry in the recent years.  This is due to the substantial benefits introduced by the C-RAN architecture including lower total-cost-of-ownership (TCO), enhanced spectral efficiency and simplified support of multi-standards and future evolution. Perhaps more importantly, this architecture complements the industry’s migration toward Network Functionality Virtualization (NFV) and Self Organized Networks (SON) in terms of network architecture convergence.

Today, RANs can support multiple-input, multiple-output (MIMO) antennas, wide spectrum bandwidths, multi-band carrier aggregation and more. This evolution of RAN for 5G will have a huge impact on wireless technologies, including enabling Mobile Edge Computing (MEC) and network slicing. These RANs of the future will also contribute to the lower latency that makes 5G so powerful.

- The Evolution of Mobile Fronthaul Towards 5G

As wireless networks rapidly advance towards the 5th generation (5G), optical fiber communication is playing a more and more important role to provide the needed high bandwidth connectivity in both mobile backhaul and mobile fronthaul. Mobile backhaul connects baseband units (BBUs) with core networks to transport the baseband data streams to their respective destinations, while mobile fronthaul connects centralized BBUs with remote radio units (RRUs) for purposes such as cloud radio access networking (C-RAN) and massive MIMO (M-MIMO). In addition to high requirement on transport bandwidth, future 5G networks also require low transport latency and highly accurate synchronization among connected central and remote nodes. Much efforts have been made to address these demands. 

[More to come ...]