Spotlight on Tech

Take A Look Inside the Award-Winning Small Cell Network Powered by Rakuten Symphony

By
Paul Black
VP, Global Product Marketing
Rakuten Symphony
July 20, 2022
5
minute read

More mobile users and higher wireless bandwidth means more small cells are needed to fill in gaps and accommodate locations with a high concentration of users.

Small cells are utilized to provide much-needed capacity in high utilization hotspots—both indoor and outdoor—in urban parts of the network, as well as in high traffic locations in suburban areas. You see them on lampposts, sides, and tops of buildings as well as in office buildings, shopping malls, airports, restaurants, etc. They are also cost effective to improve coverage in low-volume or hard-to-reach areas as well as for private 5G applications.

Just how big will small cells be for the rollout of 5G networks?

According to the Small Cell Forum, 77% of all virtualized RAN (vRAN) implementations will be on small cell architectures by 2026. The numbers of sites deployed are staggering—CTIA reports that 80% of future infrastructure deployments will be small cells (Source: CTIA).

In addition, also according to Small Cell Forum, deployment of Open RAN small cells will grow at a CAGR of 146% from 2021-27, accounting for 51% of total small cells deployed at the end of that period.

Rakuten Mobile, in conjunction with Rakuten Symphony, is a pioneer in deploying small cell networks and just recently won the “Excellence in Commercial Deployment by an MNO” award from the Small Cell Forum with Airspan for its small cell network in Japan. The award-winning deployment was powered by Rakuten Symphony in collaboration with Airspan.

Rakuten Mobile can deploy sites in a fraction of the time that other operators take and has a far smaller operations team, which includes 250 people running a network with over 270,000 cells.

Behind the Scenes of a Nationwide Small Cell Network

Rakuten Mobile is well known for having deployed an industry-first open virtualized radio access network (Open vRAN) network across Japan. Also well-known is the speed that this network was deployed—achieving 96% population coverage four years ahead of schedule—and its high performance. The network was named as one of the world’s top performing mobile networks by independent analyst firm umlaut.

What’s lesser known is the role that small cells—which have been deployed in tens of thousands of dense urban hotspots in Japan—played in the success of this network.

Rakuten Mobile’s strategy has been to build a network with seamless operation between small cells and macro cells. This network design has yielded encouraging performance metrics which have spurred the company to continue to expand the deployment.

According to the Small Cell Forum, 77% of all vRAN implementations will be on small cell architectures by 2026.

Innovative small cell solutions

The small cells in the Rakuten Mobile network use Open RAN “Split 2” where the vCU (virtualized centralized unit) is deployed in a separate server, but the vDU (virtualized distributed unit) and the RU (radio unit) are co-located in the small cell unit. The vDU and RU operate in real-time and need significant processing capacity, which is provided by a powerful System on a Chip (SoC) processor included in the RU.

Vivek Chadha, Rakuten Symphony’s SVP of Global Telecom Sales for Unified Cloud, with Abel Mayal, Airspan’s SVP of Technology & Marketing, celebrating Airspan Networks and Rakuten Mobile’s win at the Small Cell Forum Awards for “Excellence in commercial deployment by an MNO.”

One of the key success factors of the Rakuten Mobile network build out is optimizing the deployment process and automating most of the activities involved in bringing up a new site. This automation, fueled by Rakuten Symphony's Symworld platform, helps Rakuten Mobile not only reduce the cost associated with the deployment and maintenance of new sites, but also rapidly build the network. Rakuten Mobile can deploy sites in a fraction of the time that other operators take and has a far smaller operations team, which includes 250 people running a network with over 270,000 cells (as of April 2022).

Rakuten Mobile utilizes different models of small cells from its RU ecosystem partners, each of which is specifically optimized for Rakuten Mobile’s unique requirements.

Rakuten Symphony is taking the solution deployed in Rakuten Mobile’s network to operators across the world so they can take advantage of fully virtualized cloud-native network architectures utilizing the Symworld solution.

It was announced that Telefónica is working with Rakuten Symphony and its partners in Germany in building a small-cell based Open RAN network that will be part of an initial deployment of 800 sites for commercial use starting in 2022. Telefónica has a goal of reaching 30-50% radio network growth based on Open RAN by 2025.

Open RAN on small cells is a precursor of the way networks will be built in the future and Rakuten Symphony is at the forefront of this development.

Small Cells
Open RAN
Cloud-Native