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1 | © 2016 Infinera
Mobile Backhaul / FronthaulTechnology Overview
Andres MaderoDirector, Service Provider Architecture
2 | © 2016 Infinera
Mobile Network Evolution
3 | © 2016 Infinera
Evolution of Mobile Networks (3GPP)
Key Additions in LTE-A• EICIC
• Coordinated Multi-point
• 20MHz to 100Mhz
• Increased user throughput up to 1Gbps
• Self Organizing Networks Improved (SON)
• Heterogeneous Networks (HetNet)
• Relay Nodes
• Beamforming and higher order MIMO
• Carrier Aggregation
2G/GSM
UMTSGERAN U-TRAN
eU-TRAN
GERAN = GSM/Edge RAN, UTRAN = UMTS Terrestrial RAN, eUTRAN = Evolved
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Evolution of Backhaul Networks
Started as ATM, IP became an alternative in
R5
ATM Backhaul Only All IP Backhaul
2G/GSM
Right now there is no anticipated migration of backhaul to anything else
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Trends/evolution of mobile transport networks
More capacity is needed in mobile transport networks
Fiber is becoming the media for mobile transport networks
• Macro cells become more dense
• Small cells are introduced
• Multiple technologies, frequencies, cell sizes and network architectures are mixed
− LTE-Advanced address multi-antenna techniques
• Het-Nets are being deployed
• Mobile Fronthaul networks to bridge distance between antenna and base station
6 | © 2016 Infinera
WDM is the preferred C-RAN technology from 2018 and beyond
• 33,86% CAGR - 2016-2030
Dedicated fiber is dropping off
Ethernet is starting to win traction around 2020
WDM is growing to be the preferred C-RAN technology
Source: SNS Research, 2016
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LTE attracts new applications and revenue streams
The low latency requirement in LTE networks attracts development of new applications requiring real-time treatment
• 4G/LTE is now about half lag time as HSDPA
• Government, healthcare and other markets and industries are attracted to mobile networks
• Examples: Real-time video surveillance, distance learning, expanded telemedicine, public safety
Source: Backhaul Forum 2014
Comparing lag timesof the mobile network standards
8 | © 2016 Infinera
Latency performance for LTE compared to latency for 5G
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5G technology requirements
Requirements are driven by the internet of things 1-10Gbps connections to end points in the field 1 millisecond end-to-end round trip delay (latency) 1000x bandwidth per unit area 10-100x number of connected devices (Perception of) 99.999% availability (Perception of) 100% coverage 90% reduction in network energy usage Up to ten year battery life for low power, machine-type devices
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With 5G It all becomes about latency and bandwidth
Source: Ericsson
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Mobile BackhaulKey Components
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Trends in mobile networks impact mobile backhaul
Strong need to enhance and improve existing mobile backhaul
To fulfill capacity requirements, new technologies are required
More stringent accuracy requirements needed to support new functionality, like LTE coordinated multipoint (CoMP) and enhanced inter-cell interference coordination (eICIC)
• Synchronization becoming one of the most important criteria
• Phase and time synchronization is required for LTE-Advanced
SLA assurance and end-to-end performanceis important
Support for multiple radio access architectures (RAA)
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Evolution to Fronthaul Architectures
Everything at the
Antenna
Move to BBU Hotels
BBU Collaboration
C-RAN
Virtualization
Radio Equipment Evolution
Network Architecture Evolution
C-RAN
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So What does the overall architecture look like?
RRH: Remote Radio HeadBBU: Base Band UnitD-RoF: Digital Radio over fiber (CPRI/OBSAI)
Cell sitecabinet
RRH
RRH
RRH
RRH
RRH
RRH
D-RoFFronthaul Backhaul IP MPLS Network
Stacking of BBUsin Central Office
CO
CO
CO
COBBU
Central Office
RRH
RRH
RRH
Fiber all the way from antenna to Central Office
Cell sitecabinet
Cell sitecabinet
BENEFITS: Increased security of CO
Saves space in the cell site
Lower total OPEX
Enables X2 optimization
Supports LTE-A evolution
Less interfaces to backhaul / core
CAPEX saving due to lower number of BBUs
Simplification of mobility management
Load
bal
anci
ng
Source: GSMA
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1. Distributed base station architecture
RRU: Remote Radio Unit RRH: Remote Radio Head
BBU: Base Band Unit D-RoF: Digital Radio over fiber (CPRI/OBSAI)
Remote Radio Head
(RRH) placed next to
antenna
Digital Radio over Fiber
(D-RoF) from antenna to
cell site cabinet
Copper connected antenna Fiber connected antenna
Remote Radio Unit
(RRU) placed in
cell site cabinet
RRH
RRH
RRH
BBU
D-RoF
RRU
RRU BBU
Cell site cabinet Cell site cabinet
COAX
Central
Office (CO)
RRU
Small cells would typically use a single RRU,
macro cell would use 3+ RRUs
Small cells would typically use a single RRH,
macro cell would use 3+ RRHs
Benefit: Saves energy!
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2. BBU centralization – Centralized-RAN (today)
Additional Benefits:
Saves even more energy!
Increased security of CO (no need for IPSec)
Saves space in the cell site
Lower total OPEX
Enables X2 optimization
Supports LTE-A evolution
RRU: Remote Radio Unit RRH: Remote Radio HeadBBU: Base Band UnitD-RoF: Digital Radio over fiber (CPRI/OBSAI)
RRH
RRH
RRH
D-RoFFronthaul Backhaul IP MPLS Network
Cell site cabinet
Cell site cabinet
Cell site cabinet
Fiber all the way from antenna to Central Office Stacking of BBUs in Central Office
CO
CO
CO
COBBU
BBU
Central Office
BBU
RRH
RRH
RRH
RRH
RRH
RRH
17 | © 2016 Infinera
3. BBU Consolidation – Cloud-RAN (Future)
RRH: Remote Radio HeadBBU: Base Band UnitD-RoF: Digital Radio over fiber (CPRI/OBSAI)
Cell sitecabinet
RRH
RRH
RRH
RRH
RRH
RRH
D-RoFFronthaul Backhaul IP MPLS Network
Stacking of BBUsin Central Office
CO
CO
CO
COBBU
Central Office
RRH
RRH
RRH
Fiber all the way from antenna to Central Office
Cell sitecabinet
Cell sitecabinet
BENEFITS: Saves even more energy!
Increased security of CO (no need for IPSec)
Saves space in the cell site
Lower total OPEX
Enables X2 optimization
Supports LTE-A evolution
Less interfaces to backhaul / core
CAPEX saving due to lower number of BBUs
Simplification of mobility management
Load
bal
anci
ng
RRHRRH
RRH
18 | © 2016 Infinera
Evolution of mobile transport networks
Today’s mobile networks are based on multi-layer technology
Quality of the end user’s experience will rely on all underlying technologies
Mobile networks are evolving
• Technology shift paves way for more efficient transport
A traditional mobile backhaul network deployed for 3G/4G. Based on IP/MPLS routers and Ethernet switches for last mile access.
Backhaul
IP MPLS Core
RRH
RRH
RRH
RRHRRH
RRH
RRH
RRH
RRH
CSR
CSR
OSS 1 OSS 2
WDM, IP/MPLS
Cell site router
Cell site router
1
The evolution of mobile networks, centralization of radio basebands, introduction of small cells requires a more efficient transport. Mobile fronthaul and mobile backhaul are separated.
2
Backhaul IP MPLS Network
Cell site cabinet
Cell site cabinet
CO
CO
Central Office
RRH
RRH
RRH
BBU
BBU
BBU
Fronthaul
Small cells
RRHRRH
RRH
RRH
RRH
RRH
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Key Components and Interfaces of an LTE Network
ENodeB - Base Station - Smarter than a NodeB in 3G architecture, eliminates the need for a RNC
S1 Interface – User plane and control pane data
X2 Interface – Communication and coordination between eNodeBs. (3-5% of S1 Interface)
UE - Handset
MME – Main Control Node. Plays a role in user authentication, handoffs, and initial connection setup (PGW and SGW), Location, Bearer Management
SGW – Serving Gateway. Terminates the EUTRAN – Each UE has 1. Responsible for handovers, packet routing and forwarding, accounting
PGW – Packet Gateway Node. UE has 1 per PDN connection. Provides UE IP address allocation (DHCP), QOS, , packet filtering per UE, etc.
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What are some of those cool technologies and why do carriers want them?
Coordinated Multipoint (CoMP) advanced cell and handset cooperation allowing better use of
spectrum
Cell 1
Cell 5
Cell 4
Cell 2
Cell 7
Cell 3
Cell 6
Enhanced Inter-Cell Interference Coordination (E-ICIC) advanced cell cooperation helping prevent
interference and allowing for better use of Spectrum
Major Short Term Objective – Making better use of Spectrum
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Coordinated Multi-Point and EICIC using the X2 interface
X2 interface connections are much more difficult operationallyLatency is difficult to manageLatency is not as good no matter what Latency of the first switch alone will be in the microseconds
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For LTE X2 is critical and requires very low latency
Mobility Management
MobilePacket Core
X2fast
X2slow
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Sync?
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FDD and TDD
Most LTE is FDD today but TDD is being used more
Depending on the spectrum allocated
Timing and Synchronization Requirements
TDD FramesFDD Frames
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Latency Requirements in an LTE Network
10ms Round Trip Required for user plane
Requirement for S1 Interface
X2 is 10ms, 5ms recommended
Y.1731 Used to measure this result- Used for SLA for wholesale providers
Software vs. Firmware implementations of Y.1731• Software implementations not reliable• Include latency of the software itsself
26 | © 2016 Infinera
Phase and time is required in LTE-A
SyncE (frequency)
Provided by network
IEEE1588v2 PTP (phase and time)
Provided in base station
Assisted by network• By having low jitter (reduces 1588 error)
• By supplying SyncE (allows 1588 hybrid mode)
• By 1588 onpath support (T-TC and T-BC)
Poor sync results in
Less efficient radio interface
Poor performance on data traffic
Dropped calls and poor voice quality
Improved 1588v2 PTPperformance is required
Application Frequency Phase
GSM / UMTS / W-CDMA 16 ppb / 50 ppb None
UMTS / W-CDMA Femtocells n/a / 250 ppb None
CDMA2000 16 / 50 ppb ± 3 to 10 µs
TD-SCDMA 16 / 50 ppb ± 1.5 µs
LTE (FDD) 16 / 50 ppb None
LTE (TDD) 16 / 50 ppb ± 1.5 µs
LTE-A MBSFN 16 / 50 ppb ± 1.5 to 32 µs
LTE-A Hetnet Co-ordination 16 / 50 ppb ± 5 µs
LTE-A CoMP (Network MIMO) 16 / 50 ppb ± 1.5 µs to ± 500 ns
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SyncE assisted 1588 PTP
SyncE in mobile backhaul network assists LTE-A bases stations to fulfill phase and time requirements
Superior network performance significantly improves phase stability with SyncE network assisting 1588v2 PTP
SyncE
Red line shows 1588 Slave clock phase error, blue shows Infinera SyncE assisted 1588 Slave clock phase error
RAASyncE
1588 PTP
SyncE assisted1588 Slave Clock
1588 SlaveClock
SyncE network between grand master and slave clock
28 | © 2016 Infinera
1588 T-TC onpath support required
T-SC
Each hop contributing with traffic generating PDV in each output
GbE GbEGbE GbE GbE GbE GbE GbE GbE GbE
10G 10G 10G 10G 10G 10G 10G 10G 10G
GM
Measurement of packet delay variation (PDV) with and without T-TC:
Network with T-TC onpath support
0.2 us PDV
Slave clock (SC) keeps phase well within requirements
Network without T-TC onpath support
16 usPDV
Impossible for slave clock (SC) to keep phase accuracy
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Full onpath support using 1588 Transparent Clock
Without T-TC onpath support:
Phase ~50 us
With T-TC support:
Phase ~80 ns
Reduces packet delay variation (PDV) significantly
No configuration required
Fast setup times Handles asymmetry
Advantages with Transparent Clock (T-TC)
30 | © 2016 Infinera
Solve the nanosecond challenge
Solutions Tools
1 Bring a PRC clock to the cell site SyncE Hybrid mode
2 Completely remove impact of PTP packets from packet scheduling Transparent Clock
3 Onpath support using G.8271.1 Telecom Boundary Clock iSync concept
SyncE
T-BC
T-TC
T-TC
T-TCT-TC T-TC
T-TC
T-TC
IP MPLS Network
PRC / GM
HybridMode SC
T-BCT-BC
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Mobile Fronthaul
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Mobile Fronthaul“The connection between the
two main parts of a cellular base station; the baseband unit and radio unit.”
Mobile Backhaul“The network between
the core network and the sub networks at the edge.”
Mobile Fronthaul vs. Mobile Backhaul
Applicable to both small cells and micro cells
RRH
RRH
RRH
IP MPLSNetwork
CO
CO
CO
CO
BBU
BBU
Central Office
BBU
Mobile Fronthaul Mobile Backhaul
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Why do Operators want to deploy fronthaul networks?
1. Spectrum: Move to LTE-A, take advantage of Coordinated Multi-Point and EICIC
2. Low Latency for 5G Applications
3. They are Cheaper to build
4. Operational Cost Savings
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Industry challenges
OPEX (power consumption, OAM and space) represents 60% of TCO
TCO Analysis of cell site
OPEX over 7 years
CAPEX
40%TCO
60%TCO
Electricity
O&M
Site Rent
Transmission
Civil Work
Site Support
Site Acquisition & Planning
BTS
A cell site’s power consumption representsthe majority of a mobile operator’s
total power consumption
Transmission 15%
ManagementOffice, 7%
Channel6%
Cell Site 72%
Major Equipment
51%Air
Conditioners 46%
Other Support Equipment, 3%
35 | © 2016 Infinera
Mobile Backhaul 2.0 and Mobile Fronthaul – details
Scalable interfaces 100M –10GE Ethernet
CE2.0 compliant Ethernet services
Multi-CoS and flexible QoS
Service OAM
Mobile Backhaul 2.0Small Cells
BBU
BBU
WiFi
Radio Access Architectures (RAA)
BBU
RRHRRH
RRH
Macro Cells
Mobile Fronthaul
Small Cells Interoperable protection schemes
Precise delivery of synchronization (frequency, phase and time-of-day)
Multi-layer management
IEEE 1588 SyncE
36 | © 2016 Infinera
Mobile Fronthaul Solution
Supports challenging CPRI v6.1/OBSAI requirements
− Superior sync performance
− Ultra low latency performance
Multiple options
− Passive / Semi-passive (wavelength monitoring)
− Active
• Transparent WDM Transponder
• Transponder/Muxponder with delay compensation
• Framed WDM Muxponder
Leading low power and high density capabilities
Integrated fronthaul and backhaul in the same network optimizes fiber use
Backhaul
CO
CO
CO
CO
Central Office
Passive / Semi Passive Fronthaul
Active Fronthaul
Central Office
37 | © 2016 Infinera
Unique optical capabilities – supports Centralized and Cloud-RAN networking models
Ultra low latency design and superior sync performance
Low power and high density capabilities
Integrated fronthaul and backhaul, also supporting small cells
Infinera Mobile Fronthaul - Key benefits
38 | © 2016 Infinera