中移动c-ran白皮书 C-RAN The Road Towards Green RAN White Paper （v3.0）

Today‟s mobile operators are facing a strong competition environment. The cost to build, operate and upgrade the Radio Access Network (RAN) is becoming more and more expensive while the revenue is not growing at the same rate. The mobile internet traffic is surging, while the ARPU is flat or even decreasing slowly, which impacts the ability to build out the networks and offer services in a timely fashion.. To maintain profitability and growth, mobile operators must find solutions to reduce cost as well as to provide better services to the customers. On the other hand, the proliferation of mobile broadband internet also presents a unique opportunity for developing an evolved network architecture that will enable new applications and services, and become more energy efficient. The RAN is the most important asset for mobile operators to provide high data rate, high quality, and 24x7 services to mobile users. Traditional RAN architecture has the following characteristics: first, each Base Station (BS) only connects to a fixed number of sector antennas that cover a small area and only handle transmission/reception signals in its coverage area; second, the system capacity is limited by interference, making it difficult to improve spectrum capacity; and last but not least, BSs are built on proprietary platforms as a vertical solution. These characteristics have resulted in many challenges. For example, the large number of BSs requires corresponding initial investment, site support, site rental and management support. Building more BS sites means increasing CAPEX and OPEX. Usually, BS‟s utilization rate is low because the average network load is usually far lower than that in peak load; while the BS‟ processing power can‟t be shared with other BSs. Isolated BSs prove costly and difficult to improve spectrum capacity. Lastly, a proprietary platform means mobile operators must manage multiple none-compatible platforms if service providers want to purchase systems from multiple vendors. Causing operators to have more complex and costly plan for network expansion and upgrading. To meet the fast increasing data services, mobile operators need to upgrade their network frequently and operate multiple-standard network, including GSM, WCDMA/TD-SCDMA and LTE. However, the proprietary platform means mobile operators lack the flexibility in network upgrade, or the ability to add services beyond simple upgrades. ability to build out the networks and offer services in a timely fashion.. To maintain profitability and growth, mobile operators must find solutions to reduce cost as well as to provide better services to the customers. On the other hand, the proliferation of mobile broadband internet also presents a unique opportunity for developing an evolved network architecture that will enable new applications and services, and become more energy efficient. The RAN is the most important asset for mobile operators to provide high data rate, high quality, and 24x7 services to mobile users. Traditional RAN architecture has the following characteristics: first, each Base Station (BS) only connects to a fixed number of sector antennas that cover a small area and only handle transmission/reception signals in its coverage area; second, the system capacity is limited by interference, making it difficult to improve spectrum capacity; and last but not least, BSs are built on proprietary platforms as a vertical solution. These characteristics have resulted in many challenges. For example, the large number of BSs requires corresponding initial investment, site support, site rental and management support. Building more BS sites means increasing CAPEX and OPEX. Usually, BS‟s utilization rate is low because the average network load is usually far lower than that in peak load; while the BS‟ processing power can‟t be shared with other BSs. Isolated BSs prove costly and difficult to improve spectrum capacity. Lastly, a proprietary platform means mobile operators must manage multiple none-compatible platforms if service providers want to purchase systems from multiple vendors. Causing operators to have more complex and costly plan for network expansion and upgrading. To meet the fast increasing data services, mobile operators need to upgrade their network frequently and operate multiple-standard network, including GSM, WCDMA/TD-SCDMA and LTE. However, the proprietary platform means mobile operators lack the flexibility in network upgrade, or the ability to add services beyond simple upgrades.