Interview with Jorge Tello, Core Network Specialist at Entel Peru
In advance of joining our leading speaker line-up at 5G Latin America 2020, Jorge Tello – Core Network Specialist at Entel Peru – took some time to answer our burning questions around how operators can advance their 5G journey in Latin America, the potential challenges they might face, and the key technologies that he sees as being critical to the success of these network transformation plans.
5G Latin America: What is your advice for other operators looking to simplify their network transformation today?
Jorge Tello (JT): They should start to consider the cloudification of the network, because the future network will become more flexible, agile, converged and open. “Three Clouds” as China Telecom has called, is an abbreviation for logic architecture of 5G network and includes three logic domains: Access Cloud, Control Cloud and Forwarding Cloud. This “Three Cloud” concept stated by China Telecom, is now known as a “End to End Network Slicing”
5G network based on “Three Cloud” will be flexible and converged. Control Cloud will have functions such as policy control, session management, mobility management, policy management, information management, service-based capability exposure, and realize customized network and services. Access Cloud will support smart radio access for users and efficiently converge multiple access technologies. Edge computing y converge multiple access technologies. Edge computing is also provided. Forwarding Cloud will effectively forward and transmit different traffic and ensure end-to-end quality of services based on path management and resource scheduling of Control Cloud. “Three Clouds” 5G network architecture is inseparable and collaborative and can be implemented on the basis of SDN/NFV.
5G Latin America: What challenges might they face? What is your advice for overcoming these challenges?
JT: There are many challenges that an operator might face, that includes:
- Challenges of radio chipset: 5G achieves higher throughput and lower user plane delay by adopting shorter scheduling interval and faster HARQ feedback, which requires higher baseband processing capability of 5G system and terminal, and consequently leads to more challenges on the baseband chip technique.
- Challenges of multi-access convergence: Mobile communication system has experienced rapid development from the first generation to the fourth generation. The commercial network gradually forms a complex situation of multiple radio technologies, diverse spectrum utilization and different coverage, while long term coexistence of multiple access technologies become a prominent characteristic. In 5G era, several types of networks in an operator will coexist for a long time, including 4G, 5G and WLAN. How to efficiently run and maintain different networks, reduce operation and maintenance cost, realize energy conservation, and improve competitiveness become the problem that every operator needs to solve.
- Challenges of flexible network architecture: The service driven 5G network architecture aims to flexibly and efficiently meet diversified mobile service requirements, which pose challenges including network diversified mobile service requirements, which pose challenges including network functions, architecture, resources and routing. Based on NFV/SDN and cloud native technology, 5G achieve virtualized and cloudified deployment. However, the container standards are not yet clear and still in the middle stage. The 5G network cloudified deployment must figure out how to meet the requirements of user plane forwarding and provide enough isolation. Combining network modularization and control and forwarding separation, service oriented 5G network can be rapidly deployed according to different service requirements, dynamically scale-in and scale-out , and lifecycle management of network slices, such as end to end flexible network slicing, adaptive scheduling of service routes and flexible allocation of network resources, and cross domain, cross platform, cross vendor, and even cross operator services , all of which pose great challenges to 5G network operation and management.
- Challenges of efficient bearer technology: Compared to 4G network, 5G network bandwidth demand is increasing exponentially. 5G scenarios impose high requirements on bearer network bandwidth, latency, flexibility and cost. Reducing the cost of 25G/50G optical modules and WDM transmission at the edge is a big challenge for bearer network.
- Challenges of terminals: Compared with 4G terminals, 5G terminals become more complex, having diversified types and differentiated techniques. The initial form of 5G terminals is dominated by mobile phones in eMBB, and the planning for the remaining scenarios (such as URLLC and mMTC) will gradually become clear with the maturity of the standard and industry.
As we saw there are many challenges that could appear depending of the operator’s strategy. From Core Network perspective, the biggest challenge is the End-to-End orchestration of the network in order to get the flexibility and the efficiency required by 5G. How to overcome this challenge will depend of the early deployment of an E2E orchestrator that manages the VNF lifecycle and cooperate with the SDN technology. Network slicing can only be achieved after NFV/SDN is implemented. Different slices rely on NFV and SDN to be created through a shared physical/virtual resource pool. Now operators in Germany, China and Japan has already started to deploy an End-to-End orchestrator for their networks paving the way for a true 5G system.
5G Latin America: In your opinion, what are the next steps in RAN evolution and strategy?
JT: RAN is not my speciality, I am a Core Network guy, but following the current trend of the technology as it was mentioned in the first question, we need to cloudify the RAN which is also known as C-RAN. The Cloud Radio Access Network (C-RAN) software converts the wireless access network functions into virtualization functions and deploys them in a standard cloud environment. The C-RAN concept was developed from a centralized RAN with the goal of increasing design flexibility and computational scalability, improving energy efficiency and reducing integration costs. In the C-RAN framework, the BBU function is virtualized, centralized, and pooled. The RRU and the antenna are deployed in a distributed manner. The RRU connects to the BBU pool through the pre-transmission network. The BBU pool can share resources and flexibly allocate processing from each RRU.
5G Latin America: How do you view network automation in today’s 5G ecosystem? How might it increase agility and visibility on operators
Right now, network automation for the purpose of E2E network slicing is in its early phase. Only a few vendors offer an E2E orchestrator (Mavenir and NEC), and the major telco vendors (Huawei, Ericsson and Nokia) have in their roadmap this technology. But this is only the first part, since 5G introduces the network slicing, which is about transforming the network/system from a static "one size fits all" paradigm, to a new paradigm where logical networks partitions are created, with appropriate isolation, resources and optimized topology to serve a particular purpose or service category or even individual customers. Once this automation is fulfilled, the flexibility and agility will be the result, which is the aim of 5G systems.
5G Latin America: What do you see as other key technologies for 5G? What are the role of the likes of NFV, Cloud Native and Edge?
5G network technologies are mainly divided into three categories: core networks, backhaul and fronthaul networks, and wireless access networks. Key technologies of the core network include: Network Function Virtualization (NFV), Software Defined Network (SDN), Network Slicing, and Multiple Access Edge Computing (MEC).
In my opinion, the key technologies for 5G will be:
- Network Slicing: scenarios for network mobility, security, latency, reliability, and even billing methods. The requirements are different. Therefore, a physical network needs to be divided into multiple virtual networks, each of which faces different application scenarios. Virtual networks are logically independent and do not affect each other.
- Multi-access edge computing (MEC) is a cloud-based IT computing and storage environment at the edge of the network. It enables data storage and computing power to be deployed closer to the user's edge, reducing network latency and better providing low latency, high bandwidth applications.
- Device-to-device communication (D2D) means that data transmission does not pass through the base station but allows one mobile terminal device to communicate directly with another mobile terminal device. D2D originated from the 4G era and is called LTE Proximity Services (ProSe) technology. It is a short-range communication technology based on 3GPP communication system, which mainly includes two major functions:
- Direct discovery, direct connection discovery function, the terminal finds that there are terminals directly connected to it;
- Direct communication, and data interaction with surrounding terminals.
- In the 4G era, D2D communication is mainly used in the public security field. In the 5G era, IoT applications such as car networking, autonomous driving, and wearable devices will be greatly developed. The application range of D2D communication will be greatly expanded, but it will face security and resource allocation fairness challenges.
Now, what is the role of NFV, SDN and cloud native in all this? Well, Network slicing can only be achieved after NFV/SDN is implemented. According to 3GPP TS 23.501 a Network Slice is a logical network that provides specific network capabilities and network characteristics. And a Network Slice instance is a set of Network Function instances and the required resources (e.g. compute, storage and networking resources) which form a deployed Network Slice.
Network slices are network instances for individual customers and are enabled by Software Defined Networking (SDN), Network Function Virtualization (NFV), cloud technologies, automation, end-to-end service provisioning and orchestration. Virtualization enables separation of the software from the hardware to implement many functions on common infrastructure. SDN enables dynamic capacity planning, routing and service chaining, based on real-time needs. Finally, orchestration allows end-to-end slice management during its lifecycle.