On the road towards 5G, virtualization is viewed as one of the critical technologies to maximize the network flexibility, scalability and efficiency in order to accommodate diverse applications and scenarios. Despite the simplicity of the idea of adopting virtualization to telecom industry, the implementation is more difficult in practice. Wireless communication is distinct from IT data centres in that wireless communication has extremely strict requirements on real-time processing. In this chapter, the virtualization on radio access networks, in particular C-RAN, is carefully studied with the analysis on the challenges and potential solutions. Given that RAN functions, such as baseband processing, require intensive computation and real-time processing, the RAN virtualization then requires joint optimization on various system modules, including the operating systems, the hypervisor, etc. It also requires enhancement and optimization on existing traditional IT technologies including the network acceleration, live migration, VM communication, support of OpenStack and so on. A prototype of optimized virtualization platform with enhanced real-time performance was developed. The tests have shown that the optimized round-trip L2 processing latency of the platform could be reduced to around 30us on average, while it is usually around 300-500us in traditional Linux system. In the meantime,the VM communication latency could be optimized to around 10us, compared to several hundred microseconds for traditional Linux system. Enhancement on the platform real-time performance is just the first step. In future, much more work should be involved such as real-time management, virtualization granularity, hardware acceleration, design of high-speed low-latency switch networks, etc. to realize completely virtualized C-RAN systems.

Chapter Contents:

• 10.1 Introduction
• 10.2 Virtualization basics
• 10.3 Cloud RAN virtualization and its challenges
• 10.3.1 C-RAN basic
• 10.3.2 Challenges on C-RAN virtualization
• 10.4 Key technologies and solutions to RAN virtualization
• 10.4.1 Enhancement on host Linux
• 10.4.2 VM communication improvement
• 10.4.3 Real-time enhancement
• 10.4.4 Live migration
• 10.4.5 Network acceleration
• 10.4.6 Container
• 10.4.7 CAT/CMT
• 10.4.8 Support of OpenStack
• 10.5 Proof-of-Concept development of virtualized RAN
• 10.5.1 Virtualized RAN demo system
• 10.5.2 Test results
• 10.6 Conclusion
• Acknowledgements
• References

Inspec keywords: virtualisation; Linux; telecommunication computing; telecommunication network reliability; 5G mobile communication; cloud computing; radio access networks

Other keywords: network acceleration; IT technologies; enhanced real-time performance; Linux system; telecom industry; virtualized C-RAN systems; IT data centres; wireless communication; radio access networks; live migration; VM communication; joint optimization; baseband processing; operating systems; optimized round-trip L2 processing latency; optimized virtualization platform; hypervisor; OpenStack; wireless networks virtualization; 5G network; VM communication latency

Subjects: Information networks; Reliability; Internet software; Mobile radio systems; Radio access systems; Communications computing