The successful commercial use of 4T4R highlights the possibility of evolving digital 2T2R networks into 4T4R networks to deliver a Gbps MBB experience to users in an indoor setting. The success of this feature may also encourage operators to upgrade their legacy indoor digital networks to 4.5G, where virtual 4T4R is an essential component. As a result, this technology helps to continue to increase the investment value of indoor network digitalization.
The commercial network is based on LampSite, Huawei's leading end-to-end indoor digital solution. The virtual 4T4R technology specifies that any two adjacent pRRUs 2T2R models can be combined to implement the virtual 4T4R function without changing the network planning and hardware configuration. As a result the user-perceived peak rate can grow up to 100% and the network average throughput can increase by more than 40% after virtual 4T4R deployment, significantly improving user experience and total network capacity.
Due to the rapid expansion of MBB networks, operators increasingly struggle to achieve high-order MIMO at a low cost. Huawei's virtual 4T4R solution to this problem innovatively applies the distributed MIMO (D-MIMO) technology for future 5G networks to currently widely-deployed small cells. This technical function aims to significantly raise the spectral efficiency and allows operators to convert the interference among cells to network capacity. Both of these benefits can be realized without introducing additional hardware equipment to legacy digital networks.
Traditionally, antennas used for the MIMO function must be present on a single one base station. In contrast, the LampSite-based virtual 4T4R solution allows antennas to come from different pRRUs and radio frontends on a LampSite network. At the same time, this solution can use centralized multi-user scheduling and precoding based on Cloud-BB architecture to perform multi-user spatial multiplexing. With those features combined, capacity can be multiplied and the user experience can be improved. Additionally, virtual 4T4R can be implemented on legacy LampSite 2T2R pRRU models, posing no incompatibility issues with existing base station equipment or user equipment. As a result, network resources can be maximized to offer users a superb service experience.
Peter Zhou, President of Huawei Small Cell Product Line said, "Digital networks have overwhelming advantages on capacity, scalability, and evolution. In the coming 3 to 5 years, digital networks will represent one of the most pioneering trends in the entire MBB industry. Huawei will, as always, be committed to continuous innovation to help operators speed up their indoor digital network upgrades to meet challenges."