Internet DRAFT - draft-zhang-ccamp-radio-optical-control
draft-zhang-ccamp-radio-optical-control
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
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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".
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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.
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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.
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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
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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).
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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
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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
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