Transcript Management and Control of Heterogeneous Multi

A Brief Tutorial on WiMAX setup
using OMF
Joint Work: WINLAB, NECLA, NICTA
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Overview
•
•
•
•
System architecture
Control API
Use of the VM Grid service to setup an experiment
Example scenario
WINLAB
Prototype Architecture
Outside
World
Cons-wm-02
eth2
10.0.102.2
Outdoor
Network
Internal
Network
Outside Bus (Trunk)
vBTS Substrate
eth1
VM Bus (Trunk)
Cons-wm-03
eth2
eth0
10.0.102.3
Original
Components
Of the BTS
eth0
ASN Substrate
10.3.0.73
eth1
Instrumentation
Network
Base Station (BTS)
eth1
10.3.0.61
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API Architecture
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Baseline Experiment Setup Steps
• Admin Functions
• User commands:
– (1) Create/Destroy Slice
– (2) Start/Stop Slice
– (3) Add Client
• RF API
– Discussed in detail on the Wiki
WINLAB
Baseline Admin. Functions
• Initialize the grid service:
– wget http://wm-asngw-02:5012/wimaxvm/initvms
• Initializes the VM grid service
• Checks for running VMs and initializes datapath on the machine
• List all running slices in XML format:
– wget http://wm-asngw-02:5012/wimaxvm/vmlist
• Allows the administrator to have a detailed view of the running VMs
• Shows VM statistics in XML format
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Start and Stop Slice
• Functionality:
– Starts/Stops VM instance
– Configures VLANs on VM substrate
• wget http://wm-asngw-02:5012/wimaxvm/start?vmname = vm1
• wget http://wm-asngw-02:5012/wimaxvm/stop?vmname = vm1
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Add Mobile
• Functionality:
– Registers a client with the slice
– Currently adds default service flow settings for the
client
– Adds mapping to the datapath controller on ASNGW
• Call:
– wget http://wm-asngw-02:5012/wimaxvm/addclient?vmname =
vm1\& clientmac = 84:22:10.14.2b.9a
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Mock Experiment Sequence
• Mobile associates, gets added to default slice, starts UL traffic
• Slice user starts a new slice, adds the mobile to its slice
• Datapath switch from (Mobile – VM0)  (Mobile – VM1)
Default Slice (VM-0)
Air
Interface
ASN-GW
Physical
BTS
User Slice (VM-1)
WINLAB
Thanks.
WINLAB
Appendix
WINLAB
Project Overview
• The project leverages a commercial 802.16e base
station from NEC.
• We build an open software controller around a
standard WiMAX BTS for allowing integration and use
as a part of the GENI framework.
• The setup should support sharing of the BTS and
provide layer 2/3 programmability.
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BTS Virtualization
• Virtualization
– Abstraction
Each user sees
an independent BTS
User A
• Provide the illusion of
owning the entire hardware
to each slice
Isolation
– Programmability
• Sufficient degree of freedom
to every experimenter
– Isolation
• Control and prevent the
impact of one slice on the
other
Physical
BTS
User B
Terminology
•
Slice – refers to the share of
the resources owned by a
particular user.
WINLAB
Challenges In Sharing The BTS
• BTS framework should be time shared in such a way
that every experimenter/slice :
– Has the illusion of using the entire BTS
• Similar or scaled delay/throughput characteristics
• Similar access interface
– Has similar control to the BTS
• Adding its own set of clients, custom service flows
• Can run an IP independent protocol stack
– Has minimum coupling with experiments from
other slices
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Why have an ``Open” Basestation?
• Capabilities of an open basestation:
– Access to the experimenter community
– Measurement and data collection from the framework
– Control over some BTS parameters
• Driven by the NSF GENI* initiative
– A large federated testbed infrastructure with wireless
edges
• Allows shift of research: Simulation  Prototyping
* http://www.geni.net
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Range of experiments
• Longer range for a control channel
– Outdoor mobility: Vehicular, and or walking.
– Collection of GPS traces, sensor measurement, …
• Allows evaluation of end – to – end links
– Used in conjunction with a wired experimentation backbone
such as PlanetLAB or VINI
• With enough Basestations:
– Evaluate a service with ``real” traffic
– Comparing Handoff mechanisms
• Optimization and evaluation of transport mechanism for
performance over cellular wireless
• Performance evaluation of a wide area network
• Security
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Envisioned Architecture
Virtual GENI Router (at PoP)
GENI Backbone
Network
GENI Compliant
WIMAX Base
Station
Controller
GENI Access
Network
(Ethernet SW &
Routers)
WiMAX Base Station
(GBSN)
GENI terminals
(WiMAX phone/PDA
running GENI/Linux)
• Experimenters include the BTS as a part of their
experiments
• Backbone is time shared ..so.. How do we share the
BTS?
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Design & Implementation
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BTS Hardware
Basestation
(IDU) Unit
RF (ODU)
Amplifier
Roof mounted Antenna
• Operational with an educational license
• Inherently IP based
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Major additions and changes
• All packet forwarding is now L2
– Eliminated all IP routing from the datapath
• Provided API within each virtual machine to interact
with the BTS
– Similar features to that provided on the raw BTS
(Add client, remove client, setup service flows …)
• Mechanism for isolation between slices
– VNTS traffic shaping mechanism
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vBTS Architecture
Virtual
machine
instances
Dynamically
created
VLANs
vBTS Substrate
ASN Substrate
Base Station (BTS)
• Redirect all traffic from VLANs to individual slices
• Similar redirection from slices to outbound VLAN interfaces
• Grid services for creation, destruction, maintenance of slices,
adding clients, slice allocation control …
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ASN Packet Forwarding
vBTS Substrate
ASN Substrate
Base Station (BTS)
• Removed all default IP routing, simplified ASN controller*
• All switching purely based on MAC addresses
• Implemented the VNTS shaping mechanism in click for slice
isolation
* Work done at NEC
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BTS
vBTS Substrate
Data
And
Control
Pipes
Un-modified WiMAX
BTS
ASN Substrate
(Black box)
Base Station (BTS)
• The BTS itself is a black box
• Hence, the slice isolation mechanism and control framework
is outside of this box
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Baseline Measurement
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Measured
RSSI
Coverage map of the WiMAX BaseStation
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Demo Setup at GEC6
• Goal:
– Show the effectiveness
of our shaping
mechanism for providing
isolation across slices
• Setup:
– 2 Clients (1 per slice)
– Stationary client in
control room (CINR =31)
Mobile
Client
Mobile
Slice
Stationary
Slice
Open WiMAX BTS
Stationary
Client
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Path For The Mobile
• UDP CBR traffic: 1024bytes,
10Mbps/Slice
• Mobile client moves as
shown
• Measured RSSI along the
mobile client’s path
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Observed UDP Throughput
DL Throughput Vs Time – no shaping
• No isolation among clients without VNTS
• BTS is throughput fair
– But, air-time fairness is voilated
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With VNTS
Good
aggregate
throughput
Isolation
improves
DL Throughput Vs Time – VNTS
• Performance improves significantly
– Good overall throughput performance
– Improvement in isolation
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Future Steps
• Tighter integration of the control framework
• Better algorithms to adaptively shape client traffic
• Similar control mechanism for UL slice traffic
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BTS Specification
PHY
MAC
Networking
Access mode
SOFDMA/TDD
Frequency
2535 ~ 2605 MHz
DL:UL ratio
35:12, 26:21, 29:18
Channel BW
10 MHz , 8.75 MHz
FFT size
1024, 512
Frame duration
5ms
TX output Power
35dBm (max)
# of sectors
3
Head compression
PHS
ARQ
HARQ/CC, ARQ
MBS support
Single BS, multiple BS-MBS
Resource
management
Power control, mode control
(idle, sleep etc.)
IP protocols
IPv4, IPv6
Bridging/Routing
Packet handling
rtPS
real-time polling service
ertPS
enhanced real-time polling service
nrtPS
non real-time polling service
Transparent L2 switch,
Bridging
UGS
unsolicited grant service
802.1Q VLAN, PHS**)
BE
best effort
Base Station Features
Supported Service Classes
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VNTS Mechanism
• Baseline algorithm for evaluating the shaping rate at the BTS
• Modifications which account for retries are not included here
– Work in progress
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Outdoor Measurements
2
3
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Performance comparison
Fairness Index
Coupling Coefficient
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