Shared Infrastructure with Network Asset and Spectrum Sharing (ORAN)
Shirish Nagaraj
Published: August 10, 2023
Welcome to part 4 of my ORAN blog series. In the previous ORAN blog, Top 3 considerations of building owners for 5G indoors, I discussed the most important factors of network design and deployment for future-proof in-building mobility networks.
Significant investment has been allocated by U.S. carriers into 5G for a few years now. We expect the momentum in 5G to continue in the coming years, with one caveat. While the focus has been on delivering nationwide coverage since 2019, the future investment will largely focus on ensuring network densification to support high-bandwidth applications in targeted areas, both outdoors and indoors.
High-capacity indoor networks will likely take years to design and build given the unique circumstances and challenges in each key vertical including stadiums, arenas, office buildings, hospitality, healthcare, transit systems and industry 4.0. While carriers have invested heavily in building and operating mobility networks, they’ve collectively spent hundreds of billions of additional USD in acquiring spectrum over the years. Maximizing returns on these investments and providing monetization opportunities for the carriers needs to be the focus for all parties involved going forward.
While macros have long served buildings with signal propagation from the outside, today’s refurbished and new green buildings do not allow the cellular signal to penetrate windows and walls easily. Further, the promise of 5G with ultra-fast and high-capacity connectivity will require the networks to be custom built within the premises. Signals need to be distributed effectively via dedicated in-building distributed antenna systems (DAS) infrastructure and the expectation is for real estate owners to opt for neutral-host architecture delivering multi-carrier connectivity and supported by a fiber-deep architecture to support a plethora of building services.
The concept of “shared infrastructure” is gaining momentum with different levels of spectrum and network asset sharing being evaluated and incorporated in next-generation network architecture. Carriers have historically built and operated their own dedicated networks in the U.S. The shift in approach going forward is largely because of the ability to share costs and potentially increase revenue quicker via the “shared infrastructure” approach.
Carriers typically own 3 significant asset categories – spectrum, access network, and core network. Each will require some level of sharing to effectively build and operate the in-building network of the future. While my goal is to provide some introductory thoughts in today’s blog, I will delve into different levels of sharing - including rights to use – and the responsibilities of the key parties involved in upcoming issues.
Spectrum Sharing
A Citizens Broadband Radio Service (CBRS) is a set of operational rules given to a slice of the shared wireless spectrum and technologies used in that spectrum. CRBS operating in the 3.55-3.7 GHz range is the first instance of mainstream network sharing in the U.S. as the 150 MHz contiguous spectrum. CBRS has been used by the U.S. Navy radar systems and aircraft communications and has now been auctioned by the Federal Communications Commission (FCC) to carriers and enterprises for their use on a tiered priority basis. Many major carriers have invested in CBRS and are now building outdoor and in-building networks leveraging the same. Several large enterprises and utility companies also participated in the CBRS spectrum auctions and are either building their private networks or have plans to build private networks on the spectrum. Eventually, CBRS is expected to become mainstay in the in-building space as it offers a high level of coverage and capacity that only mid-band spectrum can offer. Plus, the 150 MHz contiguous spectrum provides the opportunity to deliver effective 5G connectivity.
Network slicing will play a critical role in enhancing monetization for MNOs. With standalone 5G architecture being increasingly deployed with their dedicated 5G core networks, the carriers will be able to slice their spectrum to offer differentiated, and tiered, services for varied uses. I will be delving further into network slicing in the upcoming shared infrastructure blogs. However, I would like to leave you with an example of a large enterprise with offices spread across the U.S. securing a virtual slice of the spectrum from a carrier and provisioning its own private network or having it operated by the carrier itself. Additionally, a hospital could be running mission-critical applications and delivering healthcare services using a slice of the spectrum themselves from the same carrier. In each case, the service level agreements (SLAs) would drive accretive monetization in the near and long term for the carrier.
Access Network Sharing
For radio access network (RAN) sharing, there are couple scenarios that are building steam. The first is multiple operator core network, or MOCN, topology where carriers keep their core networks but share the RAN. The other is multiple operator radio access network, or MORAN, topology where every element in the access network is shared. These topologies have become increasingly relevant today with the advent of private wireless networks and the network ownership now being shared by carriers and enterprises.
Again, network slicing will play an important role in the sharing of the essential access network. Remember, however, that the access network has a fronthaul and backhaul element that is typically increasingly fiber based. The expectation is that dark fiber will be the essence of future networks with the ability to allocate bandwidth and access levels on demand. A high-capacity fiber architecture will go a long way in ensuring a future-proof network that will last for years, and potentially decades, to come.
Core Network Sharing
The core network has forever remained the domain of individual carriers and our belief is that carriers will prefer to keep their core networks separate. The all-important intelligence, computing, analytics, and content distribution layers - which remain customer touch points - remain an integral part of the core network. With the core network getting more distributed and residing at the network edge to improve network functionality, the monetization opportunities for the carriers have increased. This will lead to their likely preference to limit sharing of the core network as customer retention will come from the services rendered via the network core.
Our view is that spectrum sharing will be essential as we see adoption of CBRS, private networks, and network slicing. This will be followed by the access network, both in the fronthaul and backhaul. The core network will continue to remain in the domain of respective carriers for some time as carriers will look to maintain the “customer touch.”
In the near future, I shall be sharing further thoughts on asset sharing and monetization opportunities. Our endeavor is to ensure you have all the pertinent information on all relevant topics available via our multimedia offerings of blogs, articles, and videos. Whether the topic is C-Band, mmWave or shared infrastructure, we have the topic well covered here to ensure you stay abreast of the ever-changing technology landscape impacting us today, and in future years.
We encourage you to follow our Blog, The Signal, as we will continue to share pertinent 5G ORAN thought leadership.
