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A Brief Tutorial on WiMAX setup using OMF Joint Work: WINLAB, NECLA, NICTA WINLAB 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 WINLAB API Architecture WINLAB 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 WINLAB 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 WINLAB 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 WINLAB 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. WINLAB 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 WINLAB 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 WINLAB 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 WINLAB 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? WINLAB Design & Implementation WINLAB BTS Hardware Basestation (IDU) Unit RF (ODU) Amplifier Roof mounted Antenna • Operational with an educational license • Inherently IP based WINLAB 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 WINLAB 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 … WINLAB 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 WINLAB 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 WINLAB Baseline Measurement WINLAB Measured RSSI Coverage map of the WiMAX BaseStation WINLAB 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 WINLAB Path For The Mobile • UDP CBR traffic: 1024bytes, 10Mbps/Slice • Mobile client moves as shown • Measured RSSI along the mobile client’s path WINLAB 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 WINLAB With VNTS Good aggregate throughput Isolation improves DL Throughput Vs Time – VNTS • Performance improves significantly – Good overall throughput performance – Improvement in isolation WINLAB Future Steps • Tighter integration of the control framework • Better algorithms to adaptively shape client traffic • Similar control mechanism for UL slice traffic WINLAB 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 WINLAB VNTS Mechanism • Baseline algorithm for evaluating the shaping rate at the BTS • Modifications which account for retries are not included here – Work in progress WINLAB Outdoor Measurements 2 3 WINLAB Performance comparison Fairness Index Coupling Coefficient WINLAB