1 / 32

Indoor Communications

Indoor Communications. Rex Chen rex@ics.uci.edu. Outline. Overview Technologies Challenges Paper Discussion Research Progress Conclusion. Overview of Indoor Communication. Lots of electronic gadgets Need for connectivity Usually in proximity e.g. 1 to 30 meters Characteristics

Melvin
Download Presentation

Indoor Communications

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Indoor Communications Rex Chen rex@ics.uci.edu

  2. Outline • Overview • Technologies • Challenges • Paper Discussion • Research Progress • Conclusion

  3. Overview of Indoor Communication • Lots of electronic gadgets • Need for connectivity • Usually in proximity • e.g. 1 to 30 meters • Characteristics • Residential Homes • Corporate Offices • Public Facilities

  4. Wired vs. Wireless Indoor Communications?

  5. Indoor Wireless Communication Technologies • IEEE 802.11a/b/g • Bluetooth • IrDA • ZigBee • Powerline

  6. Electronic Gadgets

  7. A Closer look at 802.11 WLAN • Actual vs. theoretical bandwidth a major gap • CSMA/CA overhead (contention-based access) • Spectrum Regulations • 2.4 to 2.5 GHz unlicensed spectrum for open usage • Interferences with microwave and cordless telephony

  8. 802.11 Logistics • Standardization • IEEE 802.11 Specification • Many revisions • Involve multiple parties • Companies, governments • Wi-Fi Alliance • 260+ member companies

  9. 802.11 Technicalities • Signal Strength • Depend on signal-to-noise ratio • Receive power ~ to 1/d2 (distance square) • Handoff Decision • RSSI indicator

  10. Bluetooth • Characteristics • Short-range, 2.4 GHz RF • Peak rates up to 1 Mbit/sec • Line-of-sight not required • Low power, cost, size • Applications • Personal Computers • Keyboard, mouse, printer • Communication Devices • Cell phone and wireless headset

  11. Bluetooth Topology • Piconet Formation • Comprise of master, slave (active), parked (ready), and stand-by nodes • Synchronization of hopping pattern required

  12. Bluetooth Transmission • Scatternet – joining of multiple piconets • Frequency Selection

  13. IrDA • Characteristics • Short-range communications with infrared light • Requires line-of-sight • Low power, cost, size • Getting replaced by Bluetooth

  14. ZigBee • Characteristics • Low data rate, very low power consumption • Cheaper than Bluetooth ($1 transceiver) • Device Types: • ZigBee coordinator(ZC) • ZigBee Router (ZR) • ZigBee End Device (ZED) • Organized nodes in ad-hoc networks

  15. ZigBee in Home Automation

  16. Power line communications • Characteristics • Use electrical power wiring as transmission medium • Power plugs are ubiquitous • Several competing standards • Not widely adopted • Interference with outside signals • Applications • Home lighting and appliances

  17. The Challenge for Indoor Wireless Communications • Lack of standard or regulation • No protection against signal interferences • Interoperability issue in power line communications • Network planning problems in 802.11 WLAN • Dynamic building configurations • Physical object obstruction (e.g. walls, windows) • Dead spots

  18. The Challenge for Indoor Wireless Communications (2) • Security Problems • Encryption turn off in many access points WEP failure, can be cracked within a few days • Detecting unintended signals • Unauthorized network access • e.g. Using neighbor wireless access point while surfing for child porn • Intensive data traffic download of “pirated” data using P2P applications (e.g. music, software) • Usability • Setting up the wireless links can be difficult

  19. Seidel – On Path Loss Prediction Models for Indoor Communication • Goal • Understand implications of indoor wireless communication with respect to physical surroundings • Measurement Sample • Grocery store, retail store, two office buildings • Model • Mean path loss increases exponentially with distance • Path Loss (d) ~ (d/d0)n(solve for n)

  20. Seidel – Mean path loss exponent and standard deviation

  21. Seidel - Analysis

  22. Indoor Communication Tools – specifically for IEEE 802.11 • Access Point Detection • NetStumbler, Kismet • Wireless Packet Data Capture • OmniPeek (aka, Ethereal) • Network Topology Management • Ekahau

  23. Indoor Comm Tools - NetStumbler • Demo

  24. Indoor Comm Tools – Ekahau

  25. Indoor Comm Tools – Ekahau (2)

  26. Indoor Comm Tools – Ekahau (3)

  27. Relevant Projects withIndoor Communications • Ambient Networks • Integration of device communications • e.g. PDA-> (IrDA) -> Laptop-> (Bluetooth) -> Mobile -> (GPS) -> Mobile phone network • PlaceLab • Indoor location positioning • 802.11 access point using beacon frames

  28. The Future of Indoor Communications • Everything Wi-Fi enabled?

  29. The Future of Indoor Communications (2) • Extending coverage reach • Wi-Fi interface with WiMAX • Mesh routing • Higher throughput • 802.11n, 10x more bandwidth than 802.11a/g • Market Demand? • Multi-networked gaming • Wireless IPTV streaming

  30. Concluding Remarks • Many interested parties on indoor communications • Telephony and Cellular carriers • Dual-mode Wi-Fi and 3G handset • Wireless Internet Service Providers (WISP) • Inter-network from outdoor to indoor communication • Cable Operators • Set-top boxes streaming video contents to multiple indoor clients

  31. The FONERA Movement • http://www.fon.com

  32. Open Discussion

More Related