C-RAN αλγόριθμος υλοποίησης RRH σε BBU
Στεργίου, Ζωή Αστ.
KeywordsΔεδομένα κινητής τηλεφωνίας ; Αλγόριθμοι ; Ασύρματα δίκτυα ; C-RAN ; Base Band Unit (BBU) ; Remote Radio Head (RRH)
In recent years there has been a rapid increase in the load served by mobile telephony due to the widespread use of smartphones and tablets. One of the most effective methods in cellular systems, to serve the ever increasing volume of data, is to reduce the radius of each cell. In this way, spatial reuse of wireless resources is achieved. However, the reduction in the beam of the hive leads to increased costs associated with their construction and management. Reducing the beam requires a larger number of base stations to produce uninterrupted coverage equivalent to that of a macrocell. The load changes during the day. As a result, the spatial and temporal imbalance of the load, increases as the traffic of the network increases. Existing cellular systems use base stations to meet the data volume requirements at peak times. Thus, a large number of base stations or baseband resources are needed every time, resulting in increased costs. To address the above-mentioned problems, an innovative Wireless Access Network (RAN) structure, the C-RAN Wireless Cloud has been proposed. The C-RAN consists of a Base band Unit (BBU) and a Remote Radio Head (RRH) with naturally separated Radio Frequency (RF) functions. RRHs are installed at each of the local points along with the antenna equipment. BBUs, on the contrary, are concentrated in selected locations, such as network centers. Centralized signal processing significantly reduces the number of necessary equipment areas needed to cover the same area. Therefore, the power consumed for cooling the network equipment and other operational requirements is drastically reduced. Additionally, the logical interfaces between BBU and RRH change dynamically while allowing a BBU to serve more than one RRH. By distributing BBUs to RRH according to the data volume, we can achieve reduced costs due to the smaller number of required BBUs and more efficient use of restricted band resources. In this diploma thesis, a flexible RRH assignment and matching model is proposed in BBU on a C-RAN network. Interconnections between BBU and RRH are reviewed at any time depending on the use of the resources of each BBU and the upcoming RRH load. The resources available to each BBU play a key role in implementing the proposed model, and they are best committed to serving the RRH requirements. When using a BBU exceeds a critical threshold, one or more of the RRHs served are assigned to other BBUs available. The purpose of the algorithm is to reduce active BBUs by grouping RRHs so as to save energy and resources in cloud computing.