radiovisor - a slicing plane for radio access networks
TRANSCRIPT
RadioVisor A Slicing Plane for Radio Access Networks
ONS 2014 Research Track
Li Erran Li (Bell Labs)
Joint work with Sachin Katti (Stanford)
Carrier’s Dilemma
2
0
2
4
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12
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
0.0 0.0 0.1 0.2 0.5 0.9 1.6
2.8
4.7
7.4
11.2 Exabyte
Annual Growth 83%
0
2
4
6
8
-15
-12.5
-10 -5
-2.5 0
2.5 5
7.5 10
12.5 15
17.5 20
Shannon
Shannon (3dB)
4G
Exponential Traffic Growth Limited Capacity Gain
• Poor wireless connectivity if left unaddressed
Dense and Chaotic Deployments
• Dense: high SNR per user leads to higher capacity
o Small cells, femto cells, repeaters, etc
3
Problems
• Current LTE distributed control plane is ill-suited
o Hard to manage inter-cell interference
o Hard to optimize for variable load of cells
• Dense deployment is costly
o Need to share cost among operators
o Maintain direct control of radio resources
o Lacking in current 3gpp RAN sharing standards
4
SoftRAN: SDN Approach to RAN
BS1
BS2
BS3
BS4
BS5
PHY & MAC Control Algo
Coordination :
X2 Interface
5
PHY & MAC Control Algo
PHY & MAC Control Algo
PHY & MAC Control Algo
PHY & MAC Control Algo
SoftRAN: SDN Approach to RAN
RE1
RE2
RE3
RE4
RE5
Network OS
Control Algo Operator Inputs
PHY & MAC
6
RadioVisor
PHY & MAC
PHY & MAC
PHY & MAC
PHY & MAC
Radio Element (RE)
RadioVisor Design
• Slice manager
o Slice configuration, creation,
modification, deletion and multi-
slice operations
• Traffic to slice mapping at
RadioVisor and radio elements
• 3D resource grid allocation and
isolation
o Considers traffic demand,
interference graph and policy
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RadioVisor
Slice
Manager
3D Resource Grid
Allocation &
Isolation
Traffic to Slice
Mapping
Slice Manager
• Slice definition
o Predicates on operator, device, subscriber, app attributes
o A slice can be all M2M traffic of operator 1
• Slice configuration at data plane and control plane
o PHY and scheduler: narrow band PHY for M2M slice
o Interference management algorithm
• Slice algebra to support flexible slice operations
o Slice merge, split, (un)nest, duplicate 8
Resource Grid Allocation and Isolation
• Slices present resource
demands every time window
• Max min fair allocation
• Example
o Red slice entitles 2/3 and
demands 2/3 RE1 only
o Blue slice entitles 1/3 and
demand 1/3 RE2 and 1 RE3
Radio
Element 1
Radio
Element 2
Radio
Element 3
Interference Edge
Fre
qu
en
cy
9
Conclusion
• Deployment costs motivate RAN Sharing
• We present the design of RadioVisor
o Enables direct control of per slice radio resources
o Configures per slice PHY and MAC, and
interference management algorithm
o Supports flexible slice definitions and operations