Laying the Foundation for 5G
By Ray Butler, VP Wireless Network Engineering, CommScope
The road to 5G begins with the evolution of wireless networks to the two meanings of C-RAN: initially, Centralized RAN, which brings with it operating expenditure and capital expenditure savings, and then true Cloud RAN. The C-RAN architecture enables virtualization and brings computing capabilities closer to “the edge.” Virtualization engenders optimization and provides capacity elasticity, meaning a better user experience with more efficiency, throughput capacity and lower latency.
Making all of this possible will be the addition of more cell sites in a denser wireless network. Network densification will include more small cells supporting areas with high user demand. Bringing power and backhaul to these sites, after the initial obstacle of acquiring them, will remain the primary challenge of densification. Stadiums and large enterprise buildings will emerge as the first test beds and microcosms of the 5G network.
When we talk about 5G being a network of networks, one of those networks is LTE. Today’s evolved LTE network is going to be a cornerstone in 5G’s network of networks. LTE will be the workhorse of the wireless industry for many years to come. We’re going to see incremental improvements in LTE capabilities on the way to 5G, and 4G, 5G and Wi-Fi will all coexist—along with some earlier wireless air-interfaces depending on the region. MNOs will use slices of different networks to address different applications and provide connectivity resources to them.
The general shift in the wireless industry for new site builds is from cell towers to street poles, from large-sized structures to miniaturized equipment. Densification means adding more sites where users congregate—on city streets and inside large buildings. Metro cell deployments continue to attract a lot of attention, and deployments have begun to accelerate in North America. The question is when there will be a major uptick in other parts of the world. I expect to see a significant increase for these kinds of deployments in the coming two to four years.
The in-building wireless market continues to move from a carrier-funded to enterprise-funded model.
We’re going to see incremental improvements in LTE capabilities on the way to 5G, and 4G, 5G and Wi-Fi will all coexist
We’ve been talking about this transition for a while, and it continues to make headway. The big challenge here is getting the MNOs and enterprises on the same page in terms of roles and responsibilities, deployment quality and other logistics. CommScope continues to strengthen our extensive partner network to better serve and empower enterprises in their wireless needs.
Densification also includes adding more spectrum to existing sites. For macro network base station antennas, we continue to integrate more capability and add more ports on antennas (up to 8, 10 or 12 ports) to help push more capacity to existing sites. The evolution to the 4.3-10 connector size is important here. The industry is also exploring millimeter wave spectrum, which we see playing a role in fixed wireless access networks.
Everything is being virtualized in wireless networks. The first step in network evolution toward capacity virtualization is deploying centralized radio access networks (C-RAN), which pull baseband processing into a centralized location serving multiple cell sites. A US MNO is already utilizing C-RAN to link three macro sites and 30 metro sites across the downtown area of a major city. Fiber cabling connects all of these sites. In the future, such deployments will enable true C-RAN, meaning Cloud-RAN, where network capacity can be moved around to hot spots, as needed, throughout the day.
At the cell tower site, the C-RAN architecture makes it possible for operators to use smaller cabinets and platforms at the bottom of the tower because there is less equipment required at the edge. CommScope now offers pre-assembled steel platforms with cabinets and generators already installed and tested to address this market need. MNOs will hopefully enjoy some cost savings due to lower power requirements and leasing costs in the C-RAN model.
Operators are still highly focused on providing a secure, reliable user experience, and rightly so. Keeping customers happy is the core of their businesses. How to make the best use unlicensed spectrum is a question being sorted out now. The rudimentary first steps involve offloading traffic onto Wi-Fi, but that does not enable the level of service quality MNOs want. LTE-Unlicensed and License-Assisted Access make carrier-controlled use of unlicensed spectrum possible. MNOs still get the benefits of offload but can better control the experience. Ultimately there will be a co-existence of Wi-Fi, other unlicensed technologies and licensed spectrum especially inside buildings. Managing spectrum to minimize network performance issues remains a mission-critical concern.
Looking down the road a bit further, an emerging trend–and buzz word for last 10 years–is network convergence. It’s been talked about a lot, but I see it truly happening in 5G. Network convergence means wireline and wireless networks coming together to best serve users. Fiber networks will become more pervasive in carrying wireless network traffic, migrating from the core to the network edge. The last mile can be fiber or wireless, with millimeter wave competing with fiber for short drops in the RAN. Wireless has clearly won in user preferences, but it will be a combination of wireless and fiber that links them back to the core.
None of these trends—densification, virtualization, optimization and convergence—is brand new. But CommScope is seeing more work being done, and more resources being deployed, for each of them. The deployment of more cell sites, capacity, virtualization, spectrum and fiber will all continue. The one constant in the wireless industry is “more.” Users want more bandwidth, MNOs need more capacity, and vendors like CommScope are moving quickly ahead to develop more solutions and make them more efficient in the process. While that might sound like “more of the same,” current efforts are laying the foundation for 5G.