Legacy RAN vs Cloud RAN-Difference btw Legacy RAN,Cloud RAN
This page compares Legacy RAN vs Cloud RAN (Cloud Radio Access Network) and mentions difference between Legacy RAN and Cloud RAN (Cloud Radio Access Network). The architectures of legacy and cloud Radio Access Networks are also mentioned in addition to benefits of Cloud RAN.
The figure-1 depicts Legacy RAN architecture. As shown it consists of distributed RRH/BBU units across the region to provide connectivity. There is separate BBU (Base Band Unit) along with RRH(Remote Radio Head). RRH and BBU are interfaced using CPRI link. BBUs are connected with optical links with IPAG (IP Aggregation Layer) and EPC (Evolved Packet Core).
Cloud RAN-Cloud Radio Access Network
The figure-2 depicts Cloud RAN architecture. As shown in place of all the individual BBUs, one centralised BBU (i.e. C-BBU) is installed which interfaces with RRHs using CPRI interface. C-BBU is interfaced with IPAG using optical link. It is centralised and cloud computing based architecture. It supports multiple wireless standard based technologies such as 3G, 3G and 4G. Due to its characteristics such as clean, centralised processing, collaborative radio and real time, it is also known by C-RAN. It is also referred by centralised RAN.
It has been developed to have centralised architecture to solve operators problem to address huge growth in traffic capacity and to cover larger areas without installing more infrastructure.
Logical evolution of Cloud RAN or C-RAN is known as Virtualized RAN (or V-RAN). It has programmble architecture which is software definable and tunable.
Cloud RAN is implemented using servers and switches as C-BBU or V-BBU. XILINX FPGAs and DSP cores are used in the design of Cloud Radio Access Network. With the use of FPGAs L1/L2 baseband can easily be configured as per wireless standard requirements such as 2G/3G/4G/5G etc.
With the use of FPGAs following functionalities can also be easily configured in
cloud radio access network architecture.
• Ethernet switching
• SyncE IEEE 1588 protocol
• CPRI/10GbE interface/switching/bridging
• digital radio processing
• CPRI switch for daisy chaining
• L1 (physical layer) processing
Benefits of Cloud RAN (Cloud Radio Access Network)
Following are the benefits of Cloud Radio Access Network over traditional legacy RAN.
• It supports enhanced capacity and coverage.
• It can be easily self optimized, self configured and self adaptable using SDN/NFV based on need.
• It can control operational costs.
• It improves network security.