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Building Low-TCO 5G Network in a Simple and Efficient Manner

Release Date:2020-11-20  Author:By Bai Xiaomei  Click:

Low TCO is a long-term strategy for operators. In the 5G era, great changes in spectrum coverage features and equipment patterns lead to high networking density, high equipment costs, and high power consumption. This increases network investment costs and makes operators face greater pressure on return on investment. Therefore, low TCO is a top priority in 5G network planning. How can low TCO be achieved in 5G medium and long-term planning? First, a TCO calculation model is built to analyze the TCO composition of a 5G network. It is found that controlling network size and reducing single-site costs are the most direct and fundamental means to reduce TCO. Top-level and focus planning are then proposed to achieve low-TCO 5G planning. Top-level planning refers to top-level design of overall network, while focus planning contains simplified sites, energy saving, and AI-based intelligent O&M. Finally, special attention should be paid to low-cost planning of private networks.

Reasonable Top-Level Design Is the Basis of Low TCO
The purpose of top-level design is to reduce network size, simplify network architecture, and thus reduce TCO from the perspective of macro networking. Specifically, it can be divided into the following aspects.
Spectrum Planning
The basic idea is to provide hierarchical coverage by effective combination of high, middle and low frequency bands. Due to the high cost and small coverage of 3.5 GHz and mmWave equipment, it is necessary to focus on high-value areas to control the scale of investment instead of blindly covering the whole network. The 
3.5 GHz band provides continuous coverage for urban and suburban areas to ensure service experience of major mid- and high-end users, while the FDD bands such as 700 MHz featuring wide coverage can achieve low-cost 5G coverage and provide the experience of basic 5G services including URLLC and mMTC. The mmWave bands only provide super-hot and FWA coverage. In the future, existing 4G bands such as 2.1 GHz can be refarmed to 5G NR to supplement the 5G underlying coverage in a low-cost manner.
Service KPI Planning
The 5G network is still limited by uplink coverage, so the uplink edge rate setting is the key to determine the site density. Based on the development trend of front camera resolution of mobile terminals, it is reasonable to set the edge uplink rate at about 1M–2M at 5G initial and development stages. With the improvement of service requirements, terminal capability and in-depth coverage of 5G network, the uplink edge rate can reach about 10M in urban areas. The solutions to improve uplink rates including the FDD assisted super TDD (FAST) solution based on time-frequency carrier-aggregation can be introduced to reduce the number of sites. This is also in line with the idea of spectrum planning through the combination of high and low frequencies.
Network Architecture
The network architecture can start with SA deployment. In the medium and long term, the networking cost is lower than that of starting with NSA and upgrading to SA. Even if it is necessary to start with NSA to control the upfront investment cost, it is also recommended to deploy NSA/SA dual-mode base stations and the core network of converged architecture, so that a smooth evolution can be achieved in the later stage without wasting investment. The C-RAN architecture with centralized CU/DU is also especially planned for urban coverage areas, where fiber to site costs are low and sites are densely distributed. C-RAN can simplify the deployment of wireless sites, improve the utilization of BBU resources, and reduce the cost of operation and maintenance.

Simplified Site Planning Reduces Single-Site Deployment and Evolution Costs
With the evolution of wireless network access technologies, 3G and 4G radio sites coexist, resulting in limited site space and high rental pressure. The industry continues to optimize wireless site solutions. The early 2G sites dominated by indoor equipment rooms and shelters have been gradually developed into highly integrated outdoor cabinets, which simplifies the sites. The continuous innovation of extended RF units, multi-band integrated units, and multi-band multi-port antennas further simplifies the deployment on tower. Therefore, a simplified site solution has been introduced in the 5G era, especially in the scenario where the antenna space is limited and the rental cost is high. Two- or three-band UBRs are used to replace existing multi-band FDD RRUs, and multi-band multi-port antennas are used to replace existing antennas in all bands, which creates antenna space for the introduction of 5G AAUs. Although the cost of early site replacement increases, the new equipment reduces site rents and energy consumption, and has the ability to evolve smoothly through software, so TCO is lower in the medium and long term.

Intelligent O&M Reduces 5G Operation Costs
5G high energy consumption is a concern of the whole society. It not only increases the pressure on operation costs for operators, but also makes it more difficult to expand and transform power supply of the site. 5G energy saving involves core chips, key components, site auxiliary, network architecture, and software functions. The chips, components, and software functions are implemented on the equipment layer and are not directly related to network planning, while some energy saving can be achieved through reasonable network planning. For example, multi-band UBRs and integrated outdoor cabinets can be planned as macro cells in urban areas to reduce energy consumption; integrated pole-mounted small cells that has low power but accurate coverage can be used in local hotspots and blind spots to reduce power consumption; and integrated new-energy macro cells can be planned in rural areas to achieve green 5G. In terms of site auxiliary, new-generation efficient power modules and intelligent lithium batteries can be planned to gradually replace existing batteries, thus achieving lower TCO in the medium and long term. In the 5G era, there may also be a large number of extended RF units that use pad to extend and boost power supply (57 V) to further reduce power loss and save energy.
Intelligent O&M based on AI and big data can run through the whole process of network planning, construction, maintenance and operation. AI and big data tools can implement precise network planning and reduce labor costs. Intelligent fault prediction can be used to reduce O&M costs. AI-based intelligent shutdown can also greatly improve energy saving efficiency. To improve satisfaction, VAP users are identified in advance through user experience assurance in an active mode. User complaints are handled by automatic demarcation and location to improve efficiency. The pipeline visualization capability and user profile technology can also help to identify high-value users and services and promote development.

Precise Cloud Network Expands Industry Applications at Low Cost
Enterprise users generally require fragmented scenarios, heterogeneous synergy and high security. However, public cloud has such disadvantages as weak full-stack cloud customization, high redundancy cost, low data security, and weak E2E SLA guarantee. In fact, to empower industry users, 5G needs to focus more precisely on their scenarios, and find their real pain points and key problems, so as to solve problems with differentiated solutions and create value through precision services. Therefore, it is recommended to expand the industry market at low cost through precise cloud network. 
At the cloud side, one core feature of the distributed precision cloud solution is to build a JAVA-like compatible cloud base that shields hardware differences and provides optional all-scenario hardware. Another core feature is that edge cloud deployment supports ultra-lightweight start. The most basic embedded board only needs to be added on OLT or BBU. This supports the provisioning of basic services, and thus flexibly supports low-cost innovation and reduces trial-and-error costs. At the network side, it is a basic consensus to reduce TCO by sharing public networks with end-to-end slices. Different private network models are also planned to flexibly serve different industry users, including 5G private lines for micro and small enterprises, 5G virtual private networks for small- and medium-sized enterprises, 5G hybrid private networks for medium- and large-sized enterprises, and 5G physical private networks for special large-sized enterprises. At the specific network element side, 5G private networks reduce TCO through compact and lightweight 5GC, integrated UPF and low-cost indoor coverage.

The network and business development in the 5G era is facing more cost pressures, so operators need to take into comprehensive consideration its medium and long-term development goals to reduce costs and increase efficiency. The low TCO effect achieved in the field of operators' networks can also be extended to industries and private networks, making the digitization process of various industries fast, efficient and cost controllable.