Transcript NGFI (xHaul)

World’s Largest 4G Network
Feb, 2106
BS
~1.1M 4G BSs
~720K@2014
Terminal
Sales volume 210M+
Types 1000+, Price <50$
~100M@2014
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Subscriber
~360M 4G Subscribers
~90M@2014
Coverage
~1.2B pop (~86%), Reach Villages
~330 Cities@2014
5G Era: Rethink Fundamentals
Green Communication Research
Center established in Oct. 2011,
initiated 5G Key Tech R&D.
Rethink Shannon
Green
To start a green journey of wireless systems
Rethink Ring & Young
For no more “cells”
Rethink Signaling & Control
To make network application/load aware
Soft
Rethink Antenna
To make BS invisible
Rethink Spectrum & Air Interface
To enable wireless signal to “dress for the occasion ”
Rethink Fronthaul
Super Fast
To enable Soft RAN via NGFI
Rethink Protocol Stack
To enable flexible configuration of diversified access points
and optimal baseband function split between BBU pool & RRS
“Towards Green & Soft: A 5G Perspective” IEEE Comm. Mag, Vol.52, Feb.2014
5G New Requirements
Immersive
Seamless
Ultra Dense
Tactile
Massive
Ultra Reliable
Seamless Coverage, Hot Spot High Capacity, Low-power Massive-connection, Low-latency Ultra-reliable
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New design principles, new key technologies, …
E2E 5G System Key Technologies
Green and Soft
SDN/NFV
Core Network
Transportation
network
PTN
PON
UCN (enabled by C-RAN/NGFI)
SDAI (enabled by MCD)
RAN
Low Freq.
High Freq.
New RIT
RIT
LTE evolution Low freq. eMBB
Seamless wide-area
coverage
Hotspot &
high data rate
Massive-MTC
RIT
NB-IOT
Mission-Critical
RIT
Latency redu.
Low-power &
massive-connections
V2X
Low-latency &
high-reliability
User Centric RAN (UCN): C-RAN a key enabler
mMTC
Mobile
Internet
uMTC
Smart Operation
Autonomous
Network
Service Awareness
HSS/AAA/PCC
CN Entity
Internet/App
CN-RAN Repartition
Centralized
Radio Network Controller
Turbo Charged Edge
Network Slice
as a Service
Radio Data Center
RAN Entity
Localized data,
service & forwarding
Including C-RAN (Centralized and Cloud)
Data
Signaling
Unified Access & Seamless RAN restructure
Mobility
广覆盖通用信令层
Macro signalling (data)
layer
Next Generation Fronthaul Interface
(NGFI)
5G
4G
本地数据接入点
Local Data Access
Multi-Connectivity & Flexible
Topology
WiFi
D2D
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Framework of radio access network
Fronthaul challenges surfaced with C-RAN (2011)
C-RAN
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Centralized Control and/or Processing
Collaborative Radio
Real-Time Cloud
Clean System Target
CMCC has conducted extensive trials to seek costeffecitive FH solutions in LTE era
Distributed BTS
Distributed BTS
Traditional
Traditional BTS
BTS
Fronthaul used to be an issue for LTE C-RAN:
CPRI Compression and WDM
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Traditional FH solutions must be revisited in 5G era
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NGFI (xHaul)
Traffic dependent
Support of statistical multiplexing
Support of cell coordination
Antenna independent
Radio interface technological neutrality
• The key to achieve FH interface redesign lies in the function re-split
b/w BBU and RRU
• The new NGFI will further lead to re-design of underlined transport
networks with packet switching capability
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Decoupling Ant./Non-ant. Related Processing
12000
The evaluation of the existing FH Interface
(CPRI, OBSAI):
The FH bandwidth is proportional to the
number of antennas.
The FH bandwidth is at least 2 orders
of magnitude higher than BH bandwidth.
Considering the C-RAN centralized deployment and the
technologies of 5G, FH is facing a bandwidth explosion.
10000
10000
8000
Radio BW
6000
FH BW
BH BW
4000
2000
400
30
0
0.2
0.013
GSM
1.6
0.384
TD-SCDMA
20
150
8-antenna TD-LTE
Decoupling antenna/non-antenna related processing:
The number of Carriers
in C-RAN
The number of
antennas
FH BW based on the existing
FH Interface
100
8
1Tbps
100
128
16Tbps
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It is proposed that antenna related functions should be
moved from the BBU to the RRH.
FH bandwidth will decrease significantly if the BBU/RRH
function split can decouple the non-antenna related
processing and the antenna related processing.
Decoupling cell/UE Processing
The existing FH interface is a constant bit rate interface, which is load
independent and does not match with the features of mobile traffic.
Decoupling cell/UE processing:
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Cell processing is irrelevant to traffic load and is fixed no matter how many UEs are active.
FH bandwidth will be lower and load dependent.
In C-RAN Mode, cell/UE processing decoupling can further help reduce power consumption.
 When the traffic load is low, part of C-RAN cloud resource can be shut down.
 When there is no active UE, BBU software can be switched to a dormant state
Decoupling UL/DL Processing
Some symmetrical BBU-RRU function
re-split solutions
（Taking LTE as an example）
S1 Termination
PDCP
RLC
High MAC
There are many different aspects between UL
and DL:
Generally, the DL rate is not equal to the UL rate.
The bandwidth of UL and DL are not always in the
1"
same order of magnitude.
 The bit width of UL is usually larger than that of the
DL.
1"
Low MAC
Decoupling UL/DL processing
2
Bit-level
Processing
Bit-level
Processing
 NGFI design should take into account the
asymmetrical function split solutions.
 For example, the function split solution 3 could
4
be used for UL while the solution 4 used for DL.
3
Modulation
IDFT &
De-Modulation
Layer Mapping
& Precoding
Channel Estimation
& Equalization
Resource
Mapping & IFFT
FFT &
Resource De-Mapping
5
To RRU
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From RRU
NGFI Progress
•
Lead of IEEE 1914 (NGFI) WG in IEEE
•
1st NGFI WS held & NGFI WP released in June, 2015
- MoU signing with Broadcom, Intel, Alcatel-Lucent, HuaWei, ZTE,
Nokia, Xilinx & Altera
•
Co-founder of IEEE 1904.3
•
Leading the project of NGFI in CCSA
•
NGFI as the key component in NGMN 5G WP, FuTURE 5G WP
• NGFI/FH promotion and study in ITU-T, IEEE and 3GPP
•
NGFI Paper in IEEE Communication Magazine & GLOBECOM 2015
“Rethink Fronthaul for Soft RAN”, IEEE Comm. Mag. 2015
下一代前传网络接口
白 皮 书
White Paper of
Next Generation Fronthaul Interface
Version 1.0
June 4th, 2015
“NGFI, The xHaul”, GLOBECOM 2015
China Mobile Research Institute
Alcatel-Lucent
Nokia Networks
ZTE Corporation
Broadcom Corporation
Intel China Research Center
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NGFI feasibility study with Xilinx
White Paper on NGFI released in June 2015
Challenges Ahead
 Mapping of FH to Ethernet packet, undergoing in IEEE 1904 WG
 Stage 1: CPRI encapsulation (applicable to 2G, 3G and 4G)
 Stage 2: NGFI encapsulation for 5G
 Latency
 To meet RT requirement of wireless communication
 Limited latency budget for FH (e.g. 250us defined in NGMN for LTE C-RAN)
 Synchronization
 LTE Frequency sync. of 0.05ppm & phase accuracy of +/-1.5us
 Higher in 5G
 Transport of FH packets
 Over IP, MPLS, etc.
 E2E QoS
O&M, protection etc.
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IEEE NGFI (1914) WG
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Target: efficient & scalable FH for
5G
Officially approved: Feb. 2016
Sponsor: IEEE COM/SDB
7 founding companies with more
than 50 subscribers so far from
~30 companies
Scope of 1914.1 project:
- NGFI transport network
architecture
- Requirements
- Function split analysis for LTE
7 Founding members
http://grouper.ieee.org/groups/1914/
The first NGFI WG meeting, April 25-28,
San Jose, CA
Contact: [email protected]
Thank you
For more information, please contact
[email protected]
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