The rollout of 5G, particularly at the 3.5 GHz frequency band and eventually at the 26 GHz frequency, introduces several challenges for indoor coverage, which is currently supported by outdoor base stations. As 5G networks become more widespread, customers will increasingly expect reliable 5G coverage indoors, whether in homes, offices, or public places. With higher expectations for 5G data speeds, especially in densely populated areas and hot spots, there’s a growing demand for specialized indoor solutions. However, indoor environments vary greatly, so there’s no single solution that works for every scenario. As a result, multiple strategies need to be considered and tailored solutions proposed. So, now let us see addressing challenges and exploring solution in 5G indoor coverage along with Accurate LTE RF drive test tools in telecom & RF drive test software in telecom and Accurate Best wireless site survey software, site survey tools for wireless networks & Indoor cellular coverage walk testing tool in detail.

Key Factors in Indoor 5G Deployment

When planning for 5G indoor coverage, several factors must be considered, including coverage, capacity, latency, and reliability. One of the first decisions involves determining which services need to be supported and whether existing installations can be upgraded to 5G NR (New Radio). This could mean deciding whether to use the 3.6 GHz frequency band, which is more commonly available, or to expand directly to higher frequency bands in the millimeter-wave range, such as the 26/28 GHz bands. The decision largely depends on the ease of deploying new networks and the ability to expand existing ones. Additionally, it’s essential to consider whether the current setup is single-operator or multi-operator, as this will impact the approach taken.

Providing 5G NR Indoor Coverage

Selecting the right 5G NR solution for indoor coverage depends heavily on the specific use case. For frequencies below 3 GHz, existing indoor solutions can often be reused if they support 5G NR. In such cases, Dynamic Spectrum Sharing (DSS) between LTE and NR can be applied, following similar principles to outdoor deployments, such as the need for an anchor band in a non-standalone (NSA) scenario. If a new frequency band, such as 700 MHz, is to be introduced, it’s crucial to ensure that this band is supported and that any potential interference issues are addressed.

The 3.6 GHz frequency band is a strong candidate for use cases that require higher data rates and multi-gigabit connectivity. However, this band comes with a higher path loss (about 6 dB) compared to the 2 GHz bands, so different options need to be considered based on the specific scenario and use case.

For frequencies at 26 GHz and above, a completely new deployment is typically required. While spectrum availability may still be limited in some countries, it is expected to become more widespread in the near future. These higher frequencies will also experience significant path loss, particularly in areas where high data throughput is necessary. It’s worth considering whether this may become a standard solution in the future, and if so, planning for dedicated fiber deployments to facilitate easy upgrades. However, it is unlikely that a homogenous coverage solution will be achievable with these frequencies.

Distributed Antenna Systems (DAS)

When deploying 5G indoors, operators have the option to choose between Passive DAS and Active DAS, each with its own set of advantages and challenges depending on the deployment scenario.

Passive DAS

With Passive DAS, operators can quickly roll out Frequency Division Duplex (FDD) 5G with DSS on top of existing 2G, 3G, and 4G infrastructure that supports current legacy bands. Updated passive components are available for new bands, and various operators globally are already considering this option. Passive DAS is particularly useful in cases where operators share infrastructure, and it allows for the reuse of existing installations, potentially saving on costs.

However, Passive DAS has limitations, such as the lack of support for higher-order MIMO configurations (e.g., above 4×4). Most existing systems are single-input single-output (SISO), meaning they don’t use multiple antennas on the transmitter or receiver side. While there are some 2×2 MIMO systems, which use multiple antennas on both ends to improve communication performance, the overall throughput is limited due to narrow spectrum availability and basic MIMO capabilities. Upgrading or sectoring Passive DAS systems can be complex and expensive, making it less futureproof. Additionally, these systems consume more copper, adding to costs, and have limitations in the Radio Access Network (RAN), such as the lack of support for 1T1R (1 Transmit, 1 Receive).

Active DAS

Active DAS, on the other hand, offers better 5G performance compared to legacy 4G networks. This solution is more flexible, easier, and less costly to scale and upgrade. Active DAS provides full control over the active elements, supporting both 2×2 and 4×4 MIMO configurations. This makes it a more futureproof solution, as it can handle increased capacity and performance demands over time.

However, Active DAS systems come with higher initial costs, and operator sharing can be more challenging depending on the specific case. Deploying new Active DAS systems also requires additional fiber and cabling installations. Despite these challenges, Active DAS systems generally offer better scalability and performance, making them a viable option for more demanding environments.

5G Upgrade Options

Upgrading existing systems to 5G and choosing between legacy and new frequency bands can be complex for operators. Using Passive DAS on existing bands, such as 800, 900, 1800, 2100, and 2600 MHz, allows for 5G deployment with the added benefit of DSS functionality. This approach can provide immediate 5G coverage, with operator sharing as a possibility. However, it also has its downsides, including the limitations of SISO systems and minimal MIMO upgrade potential. Essentially, while the 5G logo might appear, the performance could be similar to 4G, with no significant improvement in user experience.

The higher power required for these systems also increases the risk of passive intermodulation (PIM), leading to potential performance issues. Overall, using existing legacy bands may offer a quick solution but will likely deliver a 4G-like experience rather than true 5G performance.

Deploying 5G on New Bands with Passive DAS

Another option is to use existing Passive DAS systems to deploy 5G on new bands, such as 700, 1500, and 3600 MHz. This approach benefits from the availability of passive components, and for the 700 and 1500 MHz bands, existing cabling can be reused, with antenna replacements being relatively quick and low-cost. Operator sharing is also possible with this approach.

However, the 3400-3800 MHz band introduces higher feeder attenuation, meaning that all passive elements need to be replaced to support these new bands. This makes the upgrade path more complex and costly, requiring operators to redesign their network architecture and incur additional expenses.

Deploying 5G on Existing Active DAS

These systems can support 4×4 MIMO and are more futureproof, capable of handling increased capacity and performance needs over time. However, as with Active DAS in general, operator sharing can be difficult, and new fiber and cabling installations are required.

Conclusion

There is no one-size-fits-all solution for 5G indoor coverage. The choice of strategy and deployment depends heavily on the specific use case, existing infrastructure, and future requirements. While upgrading existing systems offers a quicker path to 5G, the performance may be limited compared to deploying new systems on higher frequency bands. As 5G continues to evolve, operators will need to carefully consider their options to provide the best possible indoor coverage while managing costs and complexity. Also read similar articles from here.