A Configurable Architecture for High-Speed Communication Systems

1. A Configurable Architecture for High-Speed Communication Systems Visvanathan Subramanian, Joseph G Tront, Charles W Bostian, Scott F Midkiff, Center for Wireless Telecommunications, Virginia Tech, Blacksburg, VA V Subramanian, JG Tront, CW Bostian, SF Midkiff

2. Outline • Motivation • Prototype Network Overview • Gateway Architecture • Conclusion V Subramanian, JG Tront, CW Bostian, SF Midkiff

3. Outline • Motivation • Prototype Network Overview • Gateway Architecture • Conclusion V Subramanian, JG Tront, CW Bostian, SF Midkiff

4. Motivation • Design Challenges Wireless Communication Systems • Need to address difficult and interesting issues related to access mechanisms, error rates, transmission speed and bandwidth. • Need to convert high level protocol descriptions rapidly into hardware and software that implement the system • Develop a thorough verification process and minimize costly redesigns within shrinking time to market windows V Subramanian, JG Tront, CW Bostian, SF Midkiff

5. Motivation (2) • Modern Design Approaches • System speed and complexity require breaking away from traditional DSP or processor based architecture. • Must take advantage of new technology and resources • Must be flexible enough to adapt to late changes in protocols or standards • Reuse IP to reduce design time and effort V Subramanian, JG Tront, CW Bostian, SF Midkiff

6. Outline • Motivation • System Overview • Gateway Architecture • Conclusion V Subramanian, JG Tront, CW Bostian, SF Midkiff

7. Emergency Response Communications • A disaster area of several miles with all communications wiped out. • Landline connections exist at the perimeter of disaster area • Solution: LMDS “fixed” Broadband Wireless for Disaster Recovery and Emergency Response Networks • Support of Internet Access, Audio/Video Conferencing, GIS Applications etc. for field response personnel can make a big difference in rescue and emergency management operations ! V Subramanian, JG Tront, CW Bostian, SF Midkiff

8. Prototype Network Existing NetworkInfrastructure Remote GISand other services High Data Rate Cable/Wireless Connection “Virtual Ethernet” Hub LMDS Remote Remote RemoteLAN RemoteLAN IEEE802.11b 10/100Base T V Subramanian, JG Tront, CW Bostian, SF Midkiff

9. System Overview WirelessLink Antenna Antenna Sounder(Channel Assessment) Radio Radio Radio Gateway Router/Switch MonitorComputer ... • GIS • Other applications Host Host V Subramanian, JG Tront, CW Bostian, SF Midkiff

10. Gateway Salient Features • High Data Rates • Fast Ethernet 100 Mbps wire line interface • 120 Mbps QPSK symbol mapped wireless radio interface • Implements TDMA MAC scheme for deployment of up to eight remotes • Implements adaptive FEC and ARQ scheme to minimize end-to-end retransmissions • Uses Reed Solomon and Turbo Product Codecs for multiple FEC coding levels • ARQ used based on channel/application requirements V Subramanian, JG Tront, CW Bostian, SF Midkiff

11. Outline • Motivation • System Overview • Gateway Architecture • Conclusion V Subramanian, JG Tront, CW Bostian, SF Midkiff

12. Architecture Design Space • ASIC vs. DSP vs. FPGA for Communication Systems • Why FPGA ? • Excellent alternative to low efficiency of DSP based designs and low flexibility of ASIC based designs • Availability of high performance FPGAs and configurable IP Cores. • New FPGAs provide high density, embedded memory, advanced routing, multiple I/O standard support V Subramanian, JG Tront, CW Bostian, SF Midkiff

13. Architecture consists of Specialized Motorola PowerQuicc II™ 8255 Communication Processor 64- bit, 200MHz Power PC Core provides high performance, 32-bit 133 MHz Communication Processor simplifies network interfaces : Built in Standards-based interfaces support for Fast Ethernet, ATM , T1 / HDLC , UART 16 KB of Instruction and 16 KB of Data Cache Xilinx Virtex™ XCV600 FPGA Co-processor High Density : Up to 1M+ gates, 512 I/Os High Performance : System frequencies up to 200MHz Embedded Memory : Up to 16 KB of Internal Single/Dual Port SRAM support Configurable Architecture V Subramanian, JG Tront, CW Bostian, SF Midkiff

14. Configurable Architecture (2) • The data path elements consist of • “Functional Units” (FU) which modify or transform data, • multiple scattered DMA-like “Processing Elements” (PE) that move data • embedded and external “Memory Units” (MU) to store data between stages. V Subramanian, JG Tront, CW Bostian, SF Midkiff

15. Configurable Architecture (2) Transmit Path Receive Path V Subramanian, JG Tront, CW Bostian, SF Midkiff

16. Gateway Prototype Architecture V Subramanian, JG Tront, CW Bostian, SF Midkiff

17. Outline • Motivation • Prototype Network Overview • Gateway Architecture • Conclusion V Subramanian, JG Tront, CW Bostian, SF Midkiff

18. Conclusion • TDMA MAC protocol was designed for simultaneous operation of up to eight remotes. • Initial testing of concept was performed using existing commercial point-to-point LMDS modems. • The configurable architecture provides a highly flexible architecture allowing for evolving or changing standards and protocols. V Subramanian, JG Tront, CW Bostian, SF Midkiff

19. Conclusion (2) • The mapping of functional units was based on performance tradeoffs as well as cost considerations. • The architecture has been simulated successfully and is found to be suitable for design of mid-range systems that still retain a high level of complexity. • Hardware will be available by November 2002 V Subramanian, JG Tront, CW Bostian, SF Midkiff