How Can Network Signal Boosters Accelerate 5G mmWave Deployments?

Millimeter Wave (mmWave) promises multi-Gigabit speed and extreme capacity to unlock the full potential of 5G, but it is accompanied by coverage and building penetration issues, leading to a lower performance and higher cost to deploy. A network signal booster takes signals from nearby sites, amplifies, and then retransmits the signals to previously underserved areas. Deploying network signal boosters may be a fast and inexpensive option to expand network coverage compared to building more gNodeB stations, but they do not necessarily add additional capacity to the network.

Poor coverage and penetration are the main obstacles for mmWave. To achieve the coverage and speeds promised by mmWave, it is necessary to add more cell sites. However, the level of network densification required poses challenges such as cost, space, regulation, and the complexity of building thousands of sites. The introduction of network signal boosters helps to address some of the issues in some cases, creating a greater degree of certainty and encouraging more investments in mmWave.

By installing network signal boosters between the sites and the served areas, network coverage can be increased significantly which in turn leads to higher user experience, but not too much in terms of physical infrastructure, which is convenient and particularly helpful in busy city areas. By using network signal boosters where possible, operators can minimize the number of gNodeB installation, which reduces network deployment cost. Moreover, signal boosters do not require fiber backhaul, consume less power, and provide even more benefits if there is the option to be powered by solar, contributing to an overall lower network deployment expenditure and operational cost.

To estimate the savings delivered by mmWave boosters, a case study was carried out to compare the cost between deploying a SureCall signal booster and an additional gNodeB site when providing mmWave-based service. Results showed that deploying a network signal booster requires around 10-15% of the cost of a new gNodeB installation, depending on whether the cost of building fiber to the pole is included. While a network signal booster is capable of offering similar coverage of a gNodeB, it does not contribute to any capacity improvement. The study concludes that a hybrid mmWave network architecture combining network signal boosters and gNodeBs could become the preferred way for operators to mitigate network deployment costs while still reaching a large proportion of users.

Sustainability is becoming a fundamental purpose for operators, as they are actively investing in options that enable low energy, low carbon, and low cost. Using network signal booster is a good solution as they consume little power (i.e., 30 Watts) and have the option to be powered by renewable energy sources such as solar, which saves energy costs and mitigates carbon footprint.

Although network signal boosters offer greater flexibility and lower costs, they can equally create issues. For example, operators may still need to obtain permits when installing them onto street furniture and buildings in some regions, which can be a lengthy and complex process. There could be a limitation on the number of signal boosters that can be installed within a network. Network signal boosters do help with coverage, but they use the existing capacity of the existing gNodeB and do not add to the overall capacity. Although this is not an issue for mmWave for now, as there is massive bandwidth available, it may become a concern in the future.

Network signal boosters could play a role in speeding up mmWave deployment, but it is not clear how big the potential is. Access to mmWave spectrum is still limited and sub-6 GHz networks may not become congested in the next two years for many regions. Many operators will not turn to mmWave until they are forced to do so.