Cellular Phones as Embedded Systems EEL 6935 Embedded

Cellular Phones as Embedded Systems EEL 6935 - Embedded Systems Dept. of Electrical and Computer Engineering University of Florida Liza Rodriguez Aurelio Morales

Outline • Introduction • Today’s Cellular Phone • Architecture Challenges for Wireless Access • Memory, OS, and Power Challenges • Conclusions EEL 6935 Cellular Phones as Embedded Systems 2 of 33

Outline • Introduction • Today’s Cellular Phone • Architecture Challenges for Wireless Access • Memory, OS, and Power Challenges • Conclusions EEL 6935 Cellular Phones as Embedded Systems 3 of 33

Cellular Generations o Analog Cellular Technology (1 G) § Early 1980’s § NMT, AMPS (FDMA) § Susceptible to noise and interference. No protection. o Digital Mobile Communication (2 G, 2. 5 G) § § Early 1990’s GSM (TDMA), IS-95 (CDMA), IS-136 (D-AMPS, TDMA), PDC (TDMA) Data services: SMS Digital encryption of conversations. Enhanced privacy. o Wide Band Mobile Communication (3 G, 3. 5 G) § § Early 2000’s EDGE (TDMA), CDMA 2000, UMTS (CDMA) Data transfer rates >= 2 Mbit/s Data & Voice convergence, Internet access. o Broadband Mobile Communication (4 G) § LTE Advanced, IEEE 802. 16 (Wi. MAX) § Data transfer rates >= 100 Mbits/s § Mobile IPTV, Wireless Vo. IP. EEL 6935 Cellular Phones as Embedded Systems 4 of 33

Introduction (cont. ) Evolution of Radio Systems, Mobility, Data Rates EEL 6935 Cellular Phones as Embedded Systems 5 of 33

Introduction (cont. ) Digital Convergence • Convergence enables people to create, share and consume digital content, using interoperable devices • Cellular phones evolve from traditional cost-optimized handhelds to multifunctional terminals • Cellular phones: key platform for mobile convergence applications (web browsing, video streaming, etc. ) EEL 6935 Cellular Phones as Embedded Systems 6 of 33

Agenda • Introduction • Today’s Cellular Phone • Architecture Challenges for Wireless Access • Memory, OS, and Power Challenges • Conclusions EEL 6935 Cellular Phones as Embedded Systems 7 of 33

Today’s Cellular Phone • Extremely complex embedded system • Functional blocks are custom-made for mobility • Chips are either proprietary designs or based on available chips. • Miniaturization and functionality EEL 6935 Cellular Phones as Embedded Systems 8 of 33

Block diagram of triple-band cellular phone EEL 6935 Cellular Phones as Embedded Systems 9 of 33

Example: Blackberry Bold EEL 6935 Cellular Phones as Embedded Systems 10 of 33

Example: Blackberry Bold EEL 6935 Cellular Phones as Embedded Systems 11 of 33

Example: Blackberry Bold EEL 6935 Cellular Phones as Embedded Systems 12 of 33

Example: Blackberry Bold EEL 6935 Cellular Phones as Embedded Systems 13 of 33

Example: Nokia N 95 EEL 6935 Cellular Phones as Embedded Systems 14 of 33

Example: Nokia N 95 EEL 6935 Cellular Phones as Embedded Systems 15 of 33

Example: Nokia N 95 EEL 6935 Cellular Phones as Embedded Systems 16 of 33

Example: Nokia N 95 EEL 6935 Cellular Phones as Embedded Systems 17 of 33

Agenda • Introduction • Today’s Cellular Phone • Architecture Challenges for Wireless Access • Memory, OS, and Power Challenges • Conclusions EEL 6935 Cellular Phones as Embedded Systems 18 of 33

Development of Cellular phones • Miniaturization • Functionality EEL 6935 Cellular Phones as Embedded Systems 19 of 33

Baseband RF domains challenges Challenge Possible solution New Challenges Baseband ASICs are limited in performance by computational power, onchip communication and clock distribution Decentralized architectures: small distributed controller processors running at lower frequencies Management of processing power resources Baseband flexibility and support for multiple radio systems Use configurable logic, configurable processors, or processor generators Design methodology, verification and testability RF Cost and size of Bi. CMOS chips RF on digital CMOS technology Substrate-coupling effects, device models RF design portability RF on digital CMOS technology New RF circuits and architectures based on fast sampling and time-discrete signal processing needed EEL 6935 Cellular Phones as Embedded Systems 20 of 33

RF challenges: Multiradio o Wide variety of radio systems o Combination of systems at reasonable cost and size o Interference o Miniaturization challenges § Antennas § Filters EEL 6935 Cellular Phones as Embedded Systems 21 of 33

Outline • Introduction • Today’s Cellular Phone • Architecture Challenges for Wireless Access • Memory, OS, and Power Challenges • Conclusions EEL 6935 Cellular Phones as Embedded Systems 22 of 33

Memory Challenge • Total memory requirement is increasing rapidly • Mass Memories – interactive games, high quality video • Large memories are required to support data downloading and local storage • Supported by external memory cards: MMC or SD • Small Memories – processing and small applications • Memory chips and their interconnections consume large areas on PCBs and are accessed frequently • New types of NVRAM may challenge memory chips to provide smaller and more cost effective memory solutions EEL 6935 Cellular Phones as Embedded Systems 23 of 33

NVRAM – Alternatives to Flash Memory • Ferroelectric RAM (Fe. RAM) • DRAM cell with ferroelectric dielectric in the storage capacitor • Advantages: low power, faster reads and writes (single word vs. entire block erase), greater number of write-erase cycles (1016 vs. 106) • Disadvantages: lower storage density, higher cost • Phase Change Memory • Glass cells that become crystalline or amorphous by cooling • Advantages: faster reads and writes, greater number of write-erase cycles (108 vs. 106), longer hold times • Disadvantages: temp sensitivity, no pre-programming EEL 6935 Cellular Phones as Embedded Systems 24 of 33

Application Platform • Mobile internet – web browsing, video calls and high bit rate streaming • Java ME – provides flexible user interfaces, built in network protocols, multimedia support • Fact: 2. 1 Billion mobile phones use Java platforms • 3 rd Party Mobile Applications – if developed in Java, are portable enough to run on almost all cell phones EEL 6935 Cellular Phones as Embedded Systems 25 of 33

Java – Hardware or Software? • Hardware – an additional small processor dedicated for running Java • Improves performance, minimizes memory requirements • Software becomes dependent on inflexible hardware implementation • Software – Java is run on baseband processor • Virtual machine – Java commands are interpreted as equivalent microprocessor commands -- slow! • Just In Time – compiler that would translate Java classes into processor instructions --- fast! EEL 6935 Cellular Phones as Embedded Systems 26 of 33

Power Challenge • Recent evolution of communication and application functions have substantially increased power consumption • Constant annual growth of 10% in battery capacity has enabled battery volume shrinkage while having m. Ah level constant • However, when 3 G or WLAN communication is run simultaneously with multimedia applications, power consumption must be reduced EEL 6935 Cellular Phones as Embedded Systems 27 of 33

Power consumption and Battery Capacity EEL 6935 Cellular Phones as Embedded Systems 28 of 33

Solutions to Power Gap • 10% increase in battery capacity will continue forever • Reduce power hungry components: • Antennas – Bluetooth, Wi-Fi, RF • Digital displays • Dynamic voltage and frequency scaling (DVFS) • Reconfigurable RF components to reduce the number of ICs. EEL 6935 Cellular Phones as Embedded Systems 29 of 33

Outline • Introduction • Today’s Cellular Phone • Architecture Challenges for Wireless Access • Memory, OS, and Power Challenges • Conclusions EEL 6935 Cellular Phones as Embedded Systems 30 of 33

Conclusions • Cellular phones have come a long way from analog communication devices to digital mobile computers. • Today, a cellular phone is a paradigm of an embedded system having highly optimized cost, size, efficiency and performance. • Challenges in RF circuits, implementation architecture, memory, and power consumption are still affecting the development and growth of mobile devices. • New technologies such as decentralized architectures, reconfigurable circuits, advanced memories, and low power designs will help overcome challenges. EEL 6935 Cellular Phones as Embedded Systems 31 of 33

References • http: //ieeexplore. ieee. org/xpl/freeabs_all. jsp? arnumber=1332581 • http: //en. wikipedia. org/wiki/Mobile_phone • http: //www. portioresearch. com/resources. html • http: //www. phonewreck. com/wiki/index. php? title=Black. Berry_Bold • http: //www. phonewreck. com/wiki/index. php? title=Nokia_N 95 EEL 6935 Cellular Phones as Embedded Systems 32 of 33

Questions? EEL 6935 Cellular Phones as Embedded Systems 33 of 33