Abstract
The Centralized Radio Access Network (C-RAN) provides a valid solution to overcome the problem of traditional RAN in scaling up to the needed processing resource and quality expected in 5G. The Common Public Rate Interface has been defined to transport traffic flows in C-RAN and recently some market solutions are available. Its disadvantage is to increase by at least 10 times the needed bandwidth and for this reason its introduction will be gradual and will coexist with traditional RAN solutions in which Ethernet traffic is carried towards the radio base stations. In this paper, we propose an Xhaul optical network architecture based on Optical Transport Network (OTN) and Dense Wavelength Division Multiplexing (DWDM) technologies. The network allows for a dynamic allocation of the bandwidth resources according to the current traffic demand. The network topology is composed of OTN/DWDM rings and the objective of the paper is to evaluate the best configuration (number of rings and number of wavelengths needed) to both to minimize the cost and to provide an implementable solution. We introduce an analytical model for the evaluation of the number of wavelengths needed in each optical ring and provide some results for 5G case studies. We show how, although the single ring configuration provides the least cost solution due to the high statistical multiplexing advantage, it is not implementable because it needs switching apparatus with a too high number of ports. For this reason, more than one ring is needed and its value depends on several parameters as the offered traffic, the number of Radio Remote Units (RRU), the percentage of business sub-area and so on. Finally, the analytical model allows us to evaluate the advantages of the proposed dynamic resource allocation solution with respect to the static one in which the network is provided with a number of wavelengths determined in the scenario in which the radio station works at full load. The bandwidth saving can be in the order of 90% in a 5G traffic scenario.
Highlights
In recent years, the evolution of mobile networks into 5G has become the industry focus. 5G will penetrate into almost all areas of our future society
We assume that the area is divided into T = 200 squared sub-areas and each sub-area is covered with a given number of Radio Remote Units (RRU) and Radio Base Station (RBS) that generate CPRI and GEthernet flows, respectively
We have proposed an Optical Transport Network (OTN)/WDM network architecture to transport Ethernet and CPRI flows generated in a Cloud Radio Access Network (C-RAN)
Summary
The evolution of mobile networks into 5G has become the industry focus. 5G will penetrate into almost all areas of our future society. Union (ITU) defined three major application scenarios for 5G: Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC) and Ultra Reliable Low Latency Communication (uRLLC) [1]. These applications require that 5G bearer networks provide the capability to flexibly and dynamically allocate and release the network resources required by different services, optimize. Sci. 2018, 8, 612 network connectivity, reduce the costs of the entire network and enhance energy and transport efficiency. Cloud Radio Access Network (C-RAN) or centralized RAN is a technology in which most of the functionalities of a classical e-node of a Long Term Evolution (LTE) network, except the radio ones are centralized and shared in a pool [2]. Traditional C-RANs are organized as a three elements network that contains Base Band Unit (BBU) pool, Radio Remote Unit (RRU) and the network interconnecting
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
