Building Link-Layer Protocols in a Lego-like Fashion André Puschmann FOSDEM’14 February 2nd, 2014 Integrated Communication Integrated Communication International Graduate School on International Graduate School on Systems Group Systems Group Mobile Communications Mobile Communications
Introduction State of the Art Architecture Practical Examples Summary Outline 1 Introduction State of the Art 2 Component-based Link Layer Protocols 3 4 Practical Examples 5 Summary André Puschmann FOSDEM’14 Integrated Communication Systems Group 2 February 2nd, 2014 http://www.tu-ilmenau.de/ics
Introduction State of the Art Architecture Practical Examples Summary Motivation PHY: Flexibility mostly here, e.g. Antennas Waveforms Spectrum sensing Higher layer: Mostly individual y c n and application specific, e.g. e u q e r F Power Energy-efficiency Delay tolerant networking Cognitive Radio (CR) Time Dynamic Spectrum Access Key question: Can higher layer components benefit from flexibility, too? André Puschmann FOSDEM’14 Integrated Communication Systems Group 3 February 2nd, 2014 http://www.tu-ilmenau.de/ics
Introduction State of the Art Architecture Practical Examples Summary The CR link layer: What remains? What changes? Requirements: Basic link layer functions Management of PHY resources CR 2 Application specific, e.g.: CR 1 CR 3 Link establishment Link maintenance Challenges: How to address heterogeneous system requirements? Data transfer vs management functions? How to facilitate reuse of existing protocols? André Puschmann FOSDEM’14 Integrated Communication Systems Group 4 February 2nd, 2014 http://www.tu-ilmenau.de/ics
Introduction State of the Art Architecture Practical Examples Summary State of the Art Approaches: Higher Layer Stand alone or extended protocols Rendezvous Link Layer Link Layer + MAC ⊖ Limited feature set Mobility ⊖ Monolithic design, tight integration PHY Flexible MACs with fine-grained components ⊖ Off-the-shelf 802.11 HW or FPGA-only Flexible MACs with coarse-grained components Conclusion: Protocols complex and difficult to implement/maintain Reduced re-usability due to tight integration Mix of data transmission and management functionality André Puschmann FOSDEM’14 Integrated Communication Systems Group 5 February 2nd, 2014 http://www.tu-ilmenau.de/ics
Introduction State of the Art Architecture Practical Examples Summary Lego-like Link Layer Architecture Logical components: Legacy Architecture: Higher Layer Core blocks: → Basic LL+MAC Link Layer Rendezvous Link Layer + MAC Optional apps: Mobility → Rendezvous PHY → Spectrum Mobility .. Component-based Architecture: Higher Layer Controller: Link Layer → Manage PHY capabilities Controller → FSM to model dynamics Rendezvous LL+MAC Mobility → Events to allow interactions PHY André Puschmann FOSDEM’14 Integrated Communication Systems Group 6 February 2nd, 2014 http://www.tu-ilmenau.de/ics
Introduction State of the Art Architecture Practical Examples Summary Details of Link-Layer Architecture User Applications Application specific Link Layer Rendezvous Same Interfaces EFCP Mobility EFCP EFCP Frame Mux Frame Mux Decoupled Controller Generic Media MAC MAC dependent PHY Capabilities PHY EFCP: Error- and Flow-Control Protocol Data Control André Puschmann FOSDEM’14 Integrated Communication Systems Group 7 February 2nd, 2014 http://www.tu-ilmenau.de/ics
Introduction State of the Art Architecture Practical Examples Summary Let’s Play Protocol Lego Rendezvous Basic Link Layer Mobility Blind Stop and Wait Individual (Random, JS, ..) Block Acks Coordinator- assisted Coordinator- Flow ID with prios assisted Cluster-based MAC Pure Aloha Soft/FPGA CSMA Simple TDMA André Puschmann FOSDEM’14 Integrated Communication Systems Group 8 February 2nd, 2014 http://www.tu-ilmenau.de/ics
Introduction State of the Art Architecture Practical Examples Summary How does the protocol interaction work? FSM C++ FllFsmBase FSM XML Model Code Generator Implementation Business Logic <state name="AgileReceiver"> <transition event="EvStop" nextState="End"/> <state name="Unconnected"> <transition event="EvStart" nextState="FindNextChannel"/> FllController <transition event="EvFrameReceived" nextState="Connected"/> Library <state name="FindNextChannel"> <onEntry> <action>fsm.FindNextChannel()</action> </onEntry> <transition event="EvChannelFound" nextState="ReconfigureRadio"> <action>fsm.reconfigureChannel(channel)</action> </transition> </state> <state name="ReconfigureRadio"> <transition event="EvReconfDone" nextState="WaitForFrame"/> </state> .. [1] StateBuilderCpp, http://www.stateforge.com/ <state/> André Puschmann FOSDEM’14 Integrated Communication Systems Group 9 February 2nd, 2014 http://www.tu-ilmenau.de/ics
Introduction State of the Art Architecture Practical Examples Summary Database-assisted Dynamic Spectrum Access Features: Spectrum opportunity detection Dynamic channel allocation Database for predictive PU modelling Link adaptation and PU resilience A. Puschmann, et al., “Database-assisted Coordinator-based Spectrum Mobility in Cognitive Radio Ad-hoc Networks"“, 10th International Symposium on Wireless Communication Systems (ISWCS) , Ilmenau, Germany, August 2013. André Puschmann FOSDEM’14 Integrated Communication Systems Group 10 February 2nd, 2014 http://www.tu-ilmenau.de/ics
Introduction State of the Art Architecture Practical Examples Summary Low-cost, Frequency-agile SDR Networking 2,09250 GHz 2,09450 GHz 2,09650 GHz Ubuntu Touch Iris Iris QML Python ZMQ LiquidDsp Video App AgileRx UDP Frame .. OFDM FSM Detector André Puschmann FOSDEM’14 Integrated Communication Systems Group 11 February 2nd, 2014 http://www.tu-ilmenau.de/ics
Introduction State of the Art Architecture Practical Examples Summary Summary Flexibility in higher layers? Problem specific Link Layer Apps Generic, extensible Core protocol(s) FSM Interaction Controller through Events Protocol Wide application Separation of reuse range Transfer/management André Puschmann FOSDEM’14 Integrated Communication Systems Group 12 February 2nd, 2014 http://www.tu-ilmenau.de/ics
Questions, comments? andre.puschmann@tu-ilmenau.de Ilmenau University of Technology, Germany Visit us: http://www.tu-ilmenau.de/ics André Puschmann FOSDEM’14 Integrated Communication Systems Group 13 February 2nd, 2014 http://www.tu-ilmenau.de/ics
Sources Rohde & Schwartz Spectrum Analyser image http://www.rohde-schwarz.de/product/FSVR.html Nexus 7 image http://en.wikipedia.org/wiki/File: Front_view_of_Nexus_7_(cropped).png RTL-SDR http://ecx.images-amazon.com/images/I/41-RmZAq7EL._SY300_.jpg BladeRF image http://www.nuand.com/ Thinkpad image http://en.wikipedia.org/wiki/File:Thinkpad-x61-tablet.jpg André Puschmann FOSDEM’14 Integrated Communication Systems Group 14 February 2nd, 2014 http://www.tu-ilmenau.de/ics
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