Programmable Wireless Networking Overview

Transcription

1 Programmable Wireless Networking Overview Dr. Joseph B. Evans Program Director Computer and Network Systems Computer & Information Science & Engineering National Science Foundation NSF Programmable Wireless Networking Informational Meeting 5 February 2004 Arlington, Virginia

2 Outline Themes and problems Research issues Needs and focus Impact of innovations 5 February 2004 Programmable Wireless Networking 2

3 Recent Wireless Themes Applications End-user interest in mobile access to information Requirements of national defense & homeland security Recognition that spectrum is woefully under-utilized Proposals to dramatically re-architect the modes & mechanisms for using radio frequencies Policy Opportunity - Wireless Networks That Exploit Flexibility Advances in radio system engineering flexible radios are just becoming available Technology 5 February 2004 Programmable Wireless Networking 3

4 State of Wireless Networking Wireless systems today Inflexible, wasteful static spectrum allocations Fixed radio functions Limited network and systems coordination Implications Proliferation of standards, such as Wi-Fi/802.11, Bluetooth, 3G, 4G, CDMA, GSM Encourages stovepipe architectures and services Discourages innovation and growth Source: FCC Source: Cisco Source: Linksys 5 February 2004 Programmable Wireless Networking 4

5 Critical Problems Interference in unlicensed bands Underutilization in many other bands Source: B. Becker Source: M. McHenry 5 February 2004 Programmable Wireless Networking 5

6 Evolution of Wireless Systems Receive Transmit Capture radio waves Generate radio waves Extract information from radio waves Implant information into radio waves Present information to user Accept information from user Circa 1900 Vacuum Tube Analog Processing Circuits Today s Systems Analog Processing Circuits Digitizer Digital Signal Processing Software Tomorrow Analog Processing Circuits Digitizer Digital Signal Processing Software Derived from version by R. Sternowski 5 February 2004 Programmable Wireless Networking 6

7 Advances in Radios Software radio attributes and capabilities Wide operational frequency supports novel use of multiple bands Multiple waveforms in a single hardware unit provides interoperability Impact Dynamic spectrum management helps prevent interference Adaptable to local & current situation; flexible frequency use provides opportunities for quality of service Rapid deployment and service creation Enables new network architectures through flexible & dynamic connectivity Microphone Video Fax Data Narrowband A/D-D/A (Optional Integral Source Coding) N-/RT Software Programmable Processor(s)? Wideband A/D-D/A? Antenna Tightly Integrated Host Hardware Systems and networking issues remain unexplored and unexploited! 5 February 2004 Programmable Wireless Networking 7

8 Spectrum Resources The spectrum resource space consists of Frequency the radio frequencies used to carry a signal Time the time duration a signal is transmitted Space the volume over which the signal transmission is effectively communicated or causes interference Signal format the manner in which information is encoded on the radio frequency signal Frequency TDMA Space Time CDMA TV FM Source: G. Minden RF resources illustrating a few signals in time, frequency, and space 5 February 2004 Programmable Wireless Networking 8

9 Programmable Wireless Networks Route messages through network and interoperate with larger Internet Dynamically and cooperatively manage spectrum resources Self-organize with rapid initial configuration Provide for mobility Support variety of network services Use adaptation to assure quality of service Support multiple users & domains 5 February 2004 Programmable Wireless Networking 9

10 Research Area Evolution Programmable Wireless Networking Research Focus Deployed Infrastructure Applications Commercial Solutions Architectures, algorithms, & protocols for auto-configuration, topology, routing, management Reusable Systems & Science Required for accelerated progress Programmable wireless systems that provide improved and more efficient connectivity & services Foundations Research Experimental Systems Programmable wireless systems with radio & software capabilities for research in networking, management, and control Close coupling required 5 February 2004 Programmable Wireless Networking 10

11 Programmable Wireless Focus Research Area Dynamic spectrum management architectures and techniques Topology discovery, optimization and network self-configuration Spectrum Coordinated Networks or SCN Changes Needs Architectures that are secure & robust, with quality of service and policy enforcement How to choose among possible topologies, and evaluate novel network architectures Interaction between routing, topology, and administration Source: H. Rajan Which approaches for diverse applications, communication modes, security & policy domains 5 February 2004 Programmable Wireless Networking 11

12 Some Desirable Radio Attributes Flexible in RF carrier frequency (~0-6 GHz) Flexible in bandwidth (several 10 s MHz) Flexible in waveform Generally A/D and D/A driven Generated/processed by programmable DSP and/or FPGAs DoD s Joint Tactical Radio System (JTRS) is an example Waveforms and network control all in software Significant general and signal processing In the prototype and experimentation stage 5 February 2004 Programmable Wireless Networking 12

13 Impact of Programmable Wireless Networks Vastly improved connectivity Remote areas use more power and better frequencies where utilization relatively low Urban areas provide more capacity where utilization is relatively high More opportunities for networking devices such as sensors and controllers by providing capacity & adaptability More efficient use of a shared national resource 5 February 2004 Programmable Wireless Networking 13

14 NSF Programmable Wireless Networking