1 QoS depends on Transmitter Power Control depends on Transmitter - PDF document

The Last Issue The Last Issue � Power Consumption Issues 無線網路多媒體系統 • Standy/PowerON • Processing Power Consumption Wireless Multimedia System • Transmitting Power Consumption • Routing Power Consumptions Dr. Eric Wu Dr. Eric Wu Lecture 1 Lecture 11 Power Issues & Energy Efficient Power Issues & Energy Efficient Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory Wireless & Multimedia Network Laboratory Reading list for This Lecture Reading list for This Lecture Power- Power -Sensitive Network Architectures Sensitive Network Architectures � Required Reading (August 2001 Communication Magazine) in Wireless Communications in Wireless Communications • [Bambus98] Bambus, “Power Sensitive Architecture in Wireless Network, Concepts, Issues and Design Aspects, IEEE Personal Communications Magazine, 1998 • [Jones2001] C. E. Jones, K. M. Stvalingam, P. Agrawal, J. C. Chen, “A Survey of Energy Efficient Network Protocols for Wireless Networks”, Journal of Wireless Networks 2001 • [Gomez2001]J. Gomez, A.T. Campbell, M. Naghshineh, C. Bisdikian, “Conserving Transmission Power in Wireless Ad Hoc Networks” • [Chen2001]B. Chen, K. Jamieson, H. Balakrishnan, R. Morris, “Span: An Energy-Efficient Coordination Algorithm for Topology Maintenance in Ad Hoc Wireless Network” Concepts, Issues, and Design Aspects Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory Wireless & Multimedia Network Laboratory Agenda Agenda Power Control Concept and Its Practical Power Control Concept and Its Practical � Sensitive Power Control Wireless Network Significance Significance � Energy Efficient Network Protocols for Wireless Network Higher Bandwidth (150 Mega) Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory Wireless & Multimedia Network Laboratory 1

QoS depends on Transmitter Power Control depends on Transmitter Power Control QoS Related Issues Related Issues (PC) (PC) � System Point of View • Transmitter power minimization, network capacity maximization, optimal resource allocation � Individual Connection Point of View • Online link QoS monitoring • Adaptation to changes due to mobility and channel impairments Adjust the power WLAN Feedback Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory Wireless & Multimedia Network Laboratory Basic Requirements for PC dynamics Basic Requirements for PC dynamics Research Background in PC Research Background in PC � Distributed � Packet Radio (’80) • Allowing autonomous execution at the node or link level • Point to Point Wireless Communication � Simple • Packet-Switch datagram Traffic • Dynamically allocate slits/codes to various communication links • Suitable for real time implementation • Power Control in packet radio was mainly used for adjusting the � Agile transmission range to reach various receivers • For fast tracking of channel changes and adaptation � Cellular Networks (’90) � Robust • PC is used for improving spatial channel reuse and increasing network • To gracefully adapt to diverse stressful contingencies capacity � Scalable • SIR (Signal-to-interference ratios): lowering them while congested • Satisfy a required SIR threshold using the least possible power • To maintain high performance at various network scales of interest Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory Wireless & Multimedia Network Laboratory Three Fundamental goals Three Fundamental goals Adaptive Power Control Adaptive Power Control � To Minimize Power Consumption � The Wireless Network as a Collection of Power-Controlled Interfering and Prolog Battery Life of Mobile links Nodes � Distributed Power Control: The concept of Active Link Protection � To mitigate interference and � Autonomous Online Admission Control: The Voluntary/Forced increase network capacity � To maintain link QoS by adapting to Dropped Concept � Quick Noninvasive Channel Proving and Monitoring: The Probing node movements and channel impairments Concept � Autonomously probe: admission control, channel selection, switching, handoff Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory Wireless & Multimedia Network Laboratory 2

Associated Research Issues Associated Research Issues � Online Adaptation of DPC/ALP to Congestion � The Multi-channel Case: Channel Selection and Switching A Survey of Energy Efficient Energy Efficient Network Network A Survey of � The Minimum-Power Routing Problem in Multi-hop Wireless Protocols for Wireless Networks Protocols for Wireless Networks Networking � Node Mobility, Network Stretching and Reconfiguration, and Probing- Based Handoffs � The Stochastic Basis for Power Control and Quick Online Estimation of Link Quality � The Power Manager’s Dilemma: To Transmit or Wait? � Error-Driven Power Management Wireless Network 2001 � Power-Sensitive Wireless Network Architectures? Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory Wireless & Multimedia Network Laboratory Abstract Abstract Introduction Introduction � As wireless networks become an integral component of the modern � Wireless devices have maximum utility when they can be used communication infrastructure, energy efficiency will be an important “anywhere at anytime”. One of the greatest limitations to that goal, design consideration due to the limited battery life of mobile terminals. however, is finite power supplies. � This paper presents a comprehensive summary of recent work � Studies show that the significant consumers of power in a typical addressing energy efficient and low-power design within all layers of laptop are the microprocessor (CPU), liquid crystal display (LCD), the wireless network protocol stack. hard disk, system memory (DRAM), keyboard/mouse, CDROM drive, floppy drive, I/O subsystem, and the wireless network interface card Application [55,62]. OS, MiddleWare Energy Efficient RTP, TCP, UDP RSVP � A typical example from a Toshiba 410 CDT mobile computer IP, Mobile IP Wireless Network Layer demonstrates that nearly 36% of power consumed is by the Low-power Clustering(optional) display,21% by the CPU/ memory, 18% by the wireless interface, and Data Link MAC 18% by the hard drive. Radio Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory Wireless & Multimedia Network Laboratory Introduction(cont.) Introduction(cont.) Background Background � Consequently, energy conservation � Infrastructure wireless network architecture: has been largely considered in the • Wireless networks often extend, hardware design of the mobile rather than replace, wired networks terminal [10] and in components • A hierarchy of wide area and such as CPU,disks, displays, etc. local area wired networks is used as the backbone network . � Significant additional power • BS are responsible for coordinating access to one or more transmission savings may result by incorporating channel(s) for mobiles located within low-power strategies into the the coverage cell. design of network protocols used • Transmission channels may be FDMA , for data communication. TDMA ,CDMA Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory ™ ™ Wireless & Multimedia Network Laboratory Wireless & Multimedia Network Laboratory 3