Contents Introduction Steps done Where we are Next steps Data structure description

1. MobileMANHardware development for the MAC module: current state and outlookbyRalph Bernasconi, Ivan Defilippis, Silvia Giordano, Alessandro Puiatti SUPSI Manno Cambridge, March 23 2004 MobileMAN meeting, Cambridge

2. Contents • Introduction • Steps done • Where we are • Next steps • Data structure description • Cross-layering questions MobileMAN meeting, Cambridge

3. IntroductionProject’s SUPSI-DIE goals (reminder) • Provide flexible development- and test-bed for enhanced WLAN protocol (CNR) • Bursty responsive MAC • Better contention scheme (backoff); avoid collisions even for dense and active networks • Ensure compatibility with 802.11x • Provide few samples to partners • Provide inputs for new standard MobileMAN meeting, Cambridge

4. Steps Done (1/5) • Analysis of the Market for the 802.11 implementations • Which kind of solutions were present • Which solution best suited our needs • Cost • Reliability • Flexibility • Access to the software code • Access to the firmware • Easy development environment • Secure and prompt technical support MobileMAN meeting, Cambridge

5. Steps Done (2/5) • Analysis of the implementation starting point in relation with the market analysis • Starting from scratch: • Implementation fo all the chain: MAC - BB - RF • Starting from a “middle point“: • Implementation of the MAC only • Starting from an already implemented solution: • Change software and firmware for our pourpose MobileMAN meeting, Cambridge

6. Steps Done (3/5) • Choosed solution • Starting from a “middle point“ • BB and RF already developed by Elektrobit AG: • DT20 Modem • Ourselv MAC implementation on Texass Instrument DSP: • TI C6713 board MobileMAN meeting, Cambridge

7. Steps Done (4/5) • Analysis of 802.11 standard in deep • Procedures and flowchart for the TX/RX farther implementation • Implementations on a single board • CRC on FPGA • TX/RX between MAC and BB • Channel Sensig machanism on MAC, (MAC – RF) • MAC TX mechanism on DSP • MAC RX mechanism on DSP • Standard Backoff mechanism • Regular 802.11 frame generation • Fragmented frame generation MobileMAN meeting, Cambridge

8. Steps Done (5/5) • Duplicate above steps in a second board • Stress tests in TX between boards connected by cable • Stress tests in RX between boards connected by cable • Stress tests in TX/RX between boards connected by cable • Stress tests in TX/RX between boards in wireless mode MobileMAN meeting, Cambridge

9. Where we are • TX/RX of regular 802.11 frames OK • Backoff mechanism implemented • TX/RX of fragmented frame OK • RTS/CTS/DATA/AK handshake not yet implemented DT20 - Modems Level-Switch interfaces JTAG interface TI C6713 boards MobileMAN meeting, Cambridge

10. MobileMAN meeting, Cambridge

11. MobileMAN meeting, Cambridge

12. Next Steps • RTS/CTS/DATA/AK handshake • Test of Backoff standard • Implementation on a third board • Communication tests with three cards • Implementation of new Backoff algorithm • Communication between board and PC through FireWire interface • Implementation of Data structure MobileMAN meeting, Cambridge

13. Data Structure description (1/4) • Memory slotted in parameterized slot length (default frame max length) • Descriptor mechanism for handling data • Different queues for managing data transfer: • From MAC to PHY and from PHY to MAC • From MAC to Host and from Host to MAC • Implementation of priority mechanisms for each queue • Control flags in descriptor in which: • DATA = Frame • DATA = parameters for/from cross-layering MobileMAN meeting, Cambridge

14. Host to MAC Queue Begin End MPQ Descriptor x Host to MAC Queue Begin Descriptor x+1 Descriptor x+n+1 End HMQ End HMQ MAC h. y+n Frame body y+n End MPQ FCS y+n Data Structure description (2/4) Memory Data Area Descriptor y+n+1 MAC header x MAC h. y+n+1 Frame body x Frame body y+n+1 FCS x FCS y+n+1 Frame body x+1 Descriptor x+n MAC to PHY Queue MAC (DSP) Frame body x+n Frame body x+n+1 Descriptor y+n-1 Descriptor y+n MAC h. y+n-1 Frame body y+n-1 FCS y+n-1 Frame MobileMAN meeting, Cambridge

15. MAC to Host Queue Begin Descriptor x Descriptor x+1 PHY to MAC Queue PHY to MAC Queue End MHQ End MHQ MAC h. y+2 Frame body y+2 End PMQ FCS y+2 Data Structure description (3/4) Memory Data Area Frame body x Frame body x+1 Descriptor x+n MAC (DSP) Begin Frame body x+n Descriptor x+n+1 Descriptor y MAC header y Frame body x+n+1 Frame body y Descriptor y+1 Begin FCS y MAC h. y+1 Descriptor y+2 Frame body y+1 FCS y+1 Frame MobileMAN meeting, Cambridge

16. Descriptor 4 Pn Descriptor 2 Pn-1 Descriptor k Pn Descriptor g P0 Descriptor 3 Pn Descriptor h Pn-1 Descriptor 1 Pn Descriptor 2 P0 Descriptor 3 P0 Descriptor 2 Pn End Q-Pn Descriptor 1 Pn-1 End Q-Pn-1 Descriptor P0 End Q End Q-P0 Data Structure description (4/4) Management of queues with different levels of priority MobileMAN meeting, Cambridge

17. Cross-Layering Questions • How we think to implement the cross-layering: • A shared memory area in the host? • A s.m.a made in two blocks: one in the host and one in the MAC? • Other? • Who is the manager of the cross-layering data flow? • In which way the layers access the cross-layer area? • Which parameters we have to put in the cross-layer area? MobileMAN meeting, Cambridge

18. Questions? • Thanks for your attention! MobileMAN meeting, Cambridge