Software Defined Modems for “The Internet of Things”
Software Defined Modems for “The Internet of Things” Dr. John Haine, IP Operations Manager www.cognovo.com What things? “20 billion connected devices” Manufactured for global markets Low cost Lifetimes from months to decades Different... Networks Frequencies Protocols Evolving networks & spectrum allocations Versatility & programmability required 2 Multiple systems and bands Cellular Conventional cellular GSM, HSPA, LTE(A), bands, 400 – 2600 MHz EVDO, WiMax,... License-exempt – 2400 & Short range 5800 MHz WiFi, Zigbee, UWB, “Digital Dividend” Bluetooth,... spectrum Emerging techniques “Shared” bands “WhiteSpace” Other systems Tetra & derivatives 3 Focus on the radio modem “Apps” IP packets Digital processing OS – Android etc. Modem – HSPA, LTE etc I/Q stream Radio “Photons” 4 Relative computational load for LTE Video decoder: ~500 MO/s DSP arithmetic: ~50 GO/s LTE Modem 5 Baseband Complexity 500 450 LTE-A 1Gbps 300GOp/s ...Arithmetic 400 350 300 250 LTE 200 50GOp/s Bitrate, Bitrate, Mbps 60 150 LTE-A HSPA+ LTE 100 20GOp/s 50 GPRS HSPA HSPA+ 200MOp/s 5GOp/s 50 GSM 0 40 1990 1995 2000 2005 2010 2015 HSPA 30 WCDMA 20 Bit shuffling... 10 GPRS GSM Cumulative, Modulation Cumulative, Modulation & Coding Schemes 0 1990 1995 2000 2005 2010 2015 6 Conventional Modem Architecture Applications Protocol Layer 1 Stack H/w Drivers Software Hardware DSP Protocol Dedicated Processor arithmetic System hardware RF 7 Conventional Modem Architecture Hardware is inflexible Different / upgraded / new protocols Multi-mode needs separate hardware engines – increases chip area & cost Distributed memory less efficient, increases area / cost Difficult development process FPGA prototyping cannot fully model final device Software development depends on chip availability Hardware bugs need software work-arounds which may not be ideal Cost of large chip developments rising exponentially Need to amortise over maximum number of applications 8 Product development – the software paradigm Processor System Application software Drivers “Real-world” interfaces My PC is a..
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