ABSTRACT
Over the last 3–5 years, with more than 70% of the traffic in wireless networks coming from indoors, the network operators have been increasingly looking at small cells to complement macro cells. However, in the last 18–24 months, operators, particularly China Mobile and KT Telecom, have been working on having a centralized radio access network (C-RAN) network; wherein the cell head is limited to being a remote radio head (RRH) while the baseband unit (BBU) of all cells are hosted together in a centralized location. C-RAN primarily separates the radio frequency (RF) and baseband functionalities. While the RF would be handled by a compact RRH, the centralized BBU would be responsible for all operations, configurations, and resource allocation across the coverage area. This could either be a data center or located in a cloud (the reason why C-RAN is alternatively called cloud-RAN). Recently, China Mobile, in collaboration with Intel, carried out 136a detailed investigation. C-RAN not only enables dynamic resource management across different cells, depending on real-time factors like the number of users in a cell, the traffic load, channel conditions, and so on, but also provides a host of other advantages like capital expenditure (CAPEX) and operating expenditure (OPEX) savings, increased asset utilization, energy savings, and so on.
