HELIOS^® Digital FTTA™ Fiber to The Antenna

Statistics show 70% of 4G mobile services takes place indoors. Considering the diversified 5G mobile services and expanded mobile industry boundary, this figure will increase to 85%. Therefore, the quality indoor network will be the core competitive edge of mobile operators in the 5G era.

As the network evolves from 4G to 5G, it will face multiple challenges in indoor mobile network, such as user experience, capacity expansion, network coverage, etc. 5G mobile network uses C-band and mmWave that are on much higher frequency than 2G, 3G, and 4G counterparts. Higher frequency bands lead to greater link losses. The signals on the even higher mmWave band will experience difficulty in penetrating through a wall as the link loss exceeds 60dB.

Generally traditional RF cables and indoor network couplers do not support new frequency bands of 5G NRs (including the C-band and mmWave bands). Deploying new RF cables in indoor areas is costly and in a number of unique cases can prove impossible due to a lack of extra room for new cables. In addition, in traditional indoor distributed network, RF signals are carried over feeders, and each antenna needs dedicated feeders. This limitation requires multiple parallel RF feeders for multi-antenna solutions such as 5G 2T2R or 4T4R MIMO. If MIMO is used for extra expansion, new feeders must be routed, leading to a linear increase in engineering and deployment costs. And high-frequencies signals are subject to huge link loss when transmitted over traditional RF cables, which mean a much narrower coverage area and deteriorated performance. Therefore, it is difficult to use traditional indoor distributed network to increase network capacity. So, operators must use transmission cables that are easy to deploy and deliver high bandwidth. The best option is to use optical fiber to replace RF cables in order to meet the potentially huge bandwidth demand while ensuring superb 5G services.

Utilizing ultra-wide bandwidth RF front-end design with Software Define Radio (SDR) architecture, Helios^® Digital FTTA™ (Fiber to The Antenna) system enables the most flexible, scalable and complete solution for addressing small & medium coverage and capacity needs for 4G LTE and 5G NR together. Helios^®Digital FTTA™ is a three-tier architecture consisting of the Radio Access Unit (RAU), HUB Unit (Option) and Active Antenna Units (AAUs):

• Radio Access Unit (RAU)

The RAU has up to 4T4R RF paths and each RF path supports max 100MHz bandwidth and can be configured to be FDD or TDD mode in factory, which will very easily address a Single Band 5G NR 4T4R or Dual Band 4G LTE 2T2R + 5G NR 2T2R together. It has four 10Gbps SFP+ digital optic ports and supports up to 8 AAUs by star, chain, ring and hybrid network topologies, even up to 32 AAUs by adding HUB in some scenarios. It generally accesses & synchronize outdoor 5G gNB signals on air via an outdoor MIMO antenna, the signal is filtered, amplified and then converted to a digital CPRI data stream as well as synchronization signal. The digital CPRI packet data stream is transported via single mode fiber and received by the remote AAUs

• 5G NR HUB Unit (Option)

Helios^® 5G NR HUB Unit is an option element in Helios^® Digital FTTA™ solution, it has eight 10Gbps SFP+ optical ports to provide expandable connectivity up to eight Distributed Active Antenna Units (AAUs) over hybrid powered fiber cable based on CPRI protocol by star topology, and an additional 32 AAUs by cascading more HUBs for middleprise coverage. It receives the CPRI data from RAU and transmits to the Distributed AAUs after shunting, the uplink CPRI data stream from AAU will be sent to the RAU after routing processing. It’s also able to provide innovative Power Over Fiber (PoF) features for remote Distributed AAUs to enable flexible & simplifies installation both for HUBand AAU through hybrid powered fiber cable.

• Active Antenna Unit (AAUs)

The AAUs then convert the digital CPRI packet data stream back to RF and control the switcher to DPD PA based on synchronization signal from RAU, then amplify the signal to the embedded 2T2R or 4T4R MIMO services antennas. On the reverse path (uplink), the AAUs and RAU perform the inverse functions and delivery the signals back to the corresponding 4G & 5G Base Stations.

Innovative Power-over-Fiber (PoF) feature enables flexible & simplifies installation for the AAUs through fiber by star topology, and all AAUs adopt compact & fashion design with very low power consumption, typical mounting options include wall-mount and ceiling-mount.

The 5G Digital FTTA™ utilizes an embedded WEB management system for system configuration and network monitoring. The embedded WEB management system collects alarm information from both RAU and AAUs.