CCAMP Working Group J. Zhang, Ed. Internet-Draft Z. Liu, Ed. Intended status: Informational Y. Ji, Ed. Expires: December 18, 2019 bupt June 16, 2019 An Unified Control Plane Architecture for the convergency of radio and optical networks draft-zhang-ccamp-radio-optical-control-00 Abstract This memo specifies an unified radio and optical control architecture based on Software Defined Networking (SDN). The architecture is designed for the purposes of end-to-end 5G Radio Access Networks (RAN) service, which enables joint radio and optical network resoures orchestration. Based on this architecture, some new applications could be achieved, such as enhanced Coordinated MultiPoint (eCoMP) service, Baseband Unit (BBU) aggregation, fronthaul traffic prediction and so on. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on December 18, 2019. Copyright Notice Copyright (c) 2019 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents Zhang, et al. Expires December 18, 2019 [Page 1] Internet-Draft An radio and optical Control Plane June 2019 carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 2 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Motivation and Goals . . . . . . . . . . . . . . . . . . . . 4 4.1. BBU aggregation . . . . . . . . . . . . . . . . . . . . . 4 4.2. eCoMP . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4.3. fronthaul traffic prediction . . . . . . . . . . . . . . 5 5. Overview of Radio and Optical Network Control Architecture . 5 6. Architectural Considerations of Radio and Optical Control . 7 6.1. Interface of Control Architecture . . . . . . . . . . . . 7 7. Security Considerations . . . . . . . . . . . . . . . . . . . 7 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 7 9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7 1. Introduction This memo introduces an unified radio and optical network control architecture based on the Software-Defined Networking (SDN). The architecture consists of three planes: application plane, control plane, and data plane. For data plane, each physical node of radio and optical networks (i.e., BBU, RRU, and optical transport node) is attached with an OpenFlow agent (OF-Agent) that communicates with the OpenFlow controller through the extended OpenFlow protocols (OFP). For the control plane, it realizes the control of the physical devises,such as configuration of optical/radio network nodes and the information collection of network statuses. In addition, the control plane realizes radio and optical resources virtualization, and performs joint resourses allocation (orchestration).The application plane consists of various services, and each service injects a policy rule to the control plane for orchestrating radio and optical resources. 2. Requirements Language The key words are "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL". Zhang, et al. Expires December 18, 2019 [Page 2] Internet-Draft An radio and optical Control Plane June 2019 3. Terminology This memo uses the following terms: SDN, BBU, RRU, Service, Interface, Control. This document uses the following terms: OpenFlow Agent (OF-A): is associated with a physical node to communicates with the controller through extended OpenFlow protocol (OFP). Radio-Controller (Radio-C): is used to control wireless network devices. Transport-Controller (Transport-C): is used to control optical network devices. Resource Maintenance (RM): is to collect and maintain physical resource information. Protocol Control (PC): is to code/decode extended OF messages. Integrated Traffic Engineering Database (Integrated-TED): is a database to store virtualized radio and optical resources which are abstracted from raw physical resources. Virtual Optical Resource (VOR): abstracts the raw data of optical physical network which are reported from the RM module. Virtual Radio Resource (VRR): abstracts the raw data of radio physical network which are reported from the RM module. Orchestrator Engine: is an execution module which has two functions,lightpath management and radio resource mapping. Lightpath Calculation(LPC): is used to establish lightpaths for the connections . Radio Resource Mapping(RRM): is responsible for mapping RRU-BBU pairs . Policy Injection: the scheduling scheme for eCoMP , BBU aggregation scheme and fronthaul traffic prediction could be running in it. South Bound Interface (SBI): the interface between control plane and data plane. Zhang, et al. Expires December 18, 2019 [Page 3] Internet-Draft An radio and optical Control Plane June 2019 Noth Bound Interface (NBI): the interface between application plane and control plane. 4. Motivation and Goals The radio access network (RAN) architecture towards mobile 5G and beyond is undergoing a fundamental evolution, which brings optics into the radio world. Fronthaul is a new segment that leverages on the advantages of optical communication for RAN. However, the current fronthaul architecture shows a fixed connection between an RRU and a BBU, which leads to inefficient resource utilization.In addition, the existing network control architectures of radio and optical networks are built independently, where the convergence of radio and optical networks is inefficient in terms of end-to-end delay and joint resources allocation. Therefore,to provide a good RAN performance, an unified control plane architecture for radio and optical networks SHOULD be proposed. SDN is an emerging paradigm that promises to change this state of affairs, by breaking vertical integration, separating the network's control logic from the underlying devices, promoting (logical) centralization of network control, and introducing the ability to program the network. SDN makes it easier to create and introduce new abstractions in networking, simplifying network management, especially for the convergence of different network pardigms. Based on the advantages of SDN, we have established an radio and optical control architecture to achieve new applications, such as eCoMP service, BBU aggregation, and fronthaul traffic prediction, which are shown as follows. 4.1. BBU aggregation BBU aggregation is to turn off the low-utilized BBUs and migrate their RRUs to other active BBUs through lightpath reconfiguration. With the help of BBU aggregation, BBU resource utilization can be significantly improved, and this is enabled through the unified radio and optical networks control architecture. 4.2. eCoMP The eCoMP exploits the fronthaul flexibility by dynamically reconfiguring the lightpath between RRUs and BBUs, which is to reassociate coordinated RRUs (connected to different BBUs) within a single BBU. With the help of eCoMP, several geographically-adjacent RRUs jointly process/transmit as a single antenna system that serves for the cell-edge users.It realizes the backhaul bandwidth saving between the coordinated BBUs. Zhang, et al. Expires December 18, 2019 [Page 4] Internet-Draft An radio and optical Control Plane June 2019 4.3. fronthaul traffic prediction The date rate of new fronthaul interfaces, such as eCPRI and NGFI CPRI, are depending on the wireless traffic load. Therefore, the wireless traffic prediction is an important thing to improve the fronthaul bandwidth utilization. It could be predicted by using machine learning approach to perceive user's behavior (e.g.,traffic load, mobility), which can be enabled by this unified control architecture. 5. Overview of Radio and Optical Network Control Architecture Zhang, et al. Expires December 18, 2019 [Page 5] Internet-Draft An radio and optical Control Plane June 2019 o-----------------------------------------------------------------o | +------+ +-----------------+ +-------------------+ | | |eCoMP | | BBU Aggregation | ... |Traffic Prediction | | | +------+ +-----------------+ +-------------------+ | | Application Plane | o----------------------------|------------------------------------o |North Bound Interface (NBI) | o----------------------------Y------------------------------------o | +----------------------+ | | | Policy Injection | | | +------Y-----------Y---+ | | -------------| |------------ | | | | | | +----------Y----------+ +-----------Y----------+ | | | Inergrated TED | | Orchestrator Engine | | | | ---- ---- | | ---- ---- | | | | |VOR | |VRR | Y-------------Y | LPC| | RRM| | | | | ---- ---- | | ---- ---- | | | +----------Y----------+ +----------Y-----------+ | | | | | | +----------Y----------+ +----------Y-----------+ | | | Transport Controller| | Radio Controller | | | | ---- ---- | | ---- ---- | | | | |VOR | |VRR | | | |VOR | |VRR | | | | | ---- ---- | | ---- ---- | | | +---------------------+ +----------------------+ | | | | Control Plane | o----------------------------|------------------------------------o | South Bound Interface (SBI) | o----------------------------Y------------------------------------o | | | +-------Y------+ +-------Y------+ +--------Y-------+ | | | RRU_Agent | | BBU_Agent | | TN_Agent | | | +--------------+ +--------------+ +----------------+ | | Data Plane | o-----------------------------------------------------------------o Figure 1: Unified Radio and Optical Control Architecture based on SDN The framework of SDN-enabled control architecture is consisting of three planess: application plane, control plane, and data plane, are interconnected via a northbound interface (NBI) and a southbound interface (SBI). For data plane, each physical node (i.e., BBU, RRU, and TN) is attached with an OpenFlow agent that communicates with the controller through extended OpenFlow protocols (OFP). Zhang, et al. Expires December 18, 2019 [Page 6] Internet-Draft An radio and optical Control Plane June 2019 The control plane is consisting of five modules: Policy Injection module, Optical-Controller (Optical-C) module, Radio-Controller (Radio-C) module, and Integrated Traffic Engineering Database (Integrated-TED) module. Policy Injection (eCoMP) runs application policies, such as the eCoMP algorithm, BBU aggregration. Radio- Controller (Radio-C) is used to control radio devices. Optical- Controller (Optical-C) is used to control optical devices. Integrated Traffic Engineering Database (Integrated-TED) is a database to store virtualized radio and optical resources which are abstracted from raw physical resources. The application layer includes some applications implemented in the framework of SDN-enabled control architecture, such as eCoMP, BBU aggregation, traffic prediction and so on. 6. Architectural Considerations of Radio and Optical Control 6.1. Interface of Control Architecture SBI:In radio and optical control architecture, control plane and data plane are interconnected via SBI. Existing SBI includes: NETCONF, OpenFlow, SNMP, OpenCONFIG, PCEP, et al. NBI:In radio and optical control architecture, application plane and control plane are interconnected via NBI. The NBI is mainly REST API. 7. Security Considerations 8. Acknowledgments 9. Contributors Authors' Addresses Jiawei Zhang (editor) Beijing University of Posts and Telecommunications Xitucheng Road Beijing, Haidian District 100876 China Phone: +86-010-61198422 Email: zjw@bupt.edu.cn Zhang, et al. Expires December 18, 2019 [Page 7] Internet-Draft An radio and optical Control Plane June 2019 Zhen Liu (editor) Beijing University of Posts and Telecommunications Xitucheng Road Beijing, Haidian District 100876 China Phone: +86-010-61198422 Email: liuzhen207@bupt.edu.cn Yuefeng Ji (editor) Beijing University of Posts and Telecommunications Xitucheng Road Beijing, Haidian District 100876 China Phone: +86-010-61198422 Email: jyf@bupt.edu.cn Zhang, et al. Expires December 18, 2019 [Page 8]