a brief tutorial on wimax setup using omf
DESCRIPTION
Joint Work: WINLAB, NECLA, NICTA. A Brief Tutorial on WiMAX setup using OMF. Overview. System architecture Control API Use of the VM Grid service to setup an experiment Example scenario. Prototype Architecture. vBTS Substrate. ASN Substrate. Outdoor Network. Outside World. - PowerPoint PPT PresentationTRANSCRIPT
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Joint Work: WINLAB, NECLA, NICTA
A Brief Tutorial on WiMAX setup using OMF
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Overview• System architecture• Control API• Use of the VM Grid service to setup an experiment• Example scenario
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Prototype Architecture
ASN Substrate
vBTS SubstrateCo
ns-
wm
-02
eth
2
Co
ns-
wm
-03
eth
2
Outdoor Network
eth0
eth1
InstrumentationNetwork
InternalNetwork
Base Station (BTS)eth1
eth1
eth0
OutsideWorld
10.3.0.61
10.3.0.73
Outside Bus (Trunk)
10
.0.1
02
.31
0.0
.10
2.2
VM Bus (Trunk)
Original ComponentsOf the BTS
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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
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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 ASN-
GW
• 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)
PhysicalBTS
ASN-GW
Default Slice (VM-0)
User Slice (VM-1)
AirInterface
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Thanks.
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Appendix
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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• Provide the illusion of
owning the entire hardware to each slice
– Programmability• Sufficient degree of freedom
to every experimenter
– Isolation• Control and prevent the
impact of one slice on the other
PhysicalBTS
Each user sees an independent BTS
Isolation
• Slice – refers to the share of the resources owned by a particular user.
User A
User B
Terminology
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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
• Experimenters include the BTS as a part of their experiments
• Backbone is time shared ..so.. How do we share the BTS?
GENI terminals(WiMAX phone/PDA running GENI/Linux)
Virtual GENI Router (at PoP)
GENI BackboneNetwork
GENI Access Network
(Ethernet SW &Routers)
GENI Compliant WIMAX Base
StationController
WiMAX Base Station (GBSN)
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Design & Implementation
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BTS Hardware
Roof mounted Antenna
• Operational with an educational license• Inherently IP based
Basestation (IDU) Unit
RF (ODU)Amplifier
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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
• 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 …
Virtual machine instances
Dynamicallycreated VLANs
ASN Substrate
vBTS Substrate
Base Station (BTS)
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ASN Packet Forwarding
• 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
ASN Substrate
vBTS Substrate
Base Station (BTS)
* Work done at NEC
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BTS
• The BTS itself is a black box• Hence, the slice isolation mechanism and control framework
is outside of this box
ASN Substrate
vBTS Substrate
Base Station (BTS)
Un-modified WiMAXBTS
(Black box)
DataAndControlPipes
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Baseline Measurement
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Coverage map of the WiMAX BaseStation
MeasuredRSSI
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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)
MobileSlice
StationarySlice
Open WiMAX BTS
MobileClient
StationaryClient
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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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DL Throughput Vs Time – no shaping
Observed UDP Throughput
• No isolation among clients without VNTS• BTS is throughput fair
– But, air-time fairness is voilated
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With VNTS
• Performance improves significantly– Good overall throughput performance– Improvement in isolation
DL Throughput Vs Time – VNTS
Good aggregate throughput
Isolationimproves
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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
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
MAC
Head compression PHS
ARQ HARQ/CC, ARQ
MBS support Single BS, multiple BS-MBS
Resource management
Power control, mode control (idle, sleep etc.)
Networking
IP protocols IPv4, IPv6
Bridging/Routing Transparent L2 switch, Bridging
Packet handling 802.1Q VLAN, PHS**)
rtPS real-time polling service
ertPS enhanced real-time polling service
nrtPS non real-time polling service
UGS unsolicited grant service
BE best effort
Base Station FeaturesSupported 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