Home Rf


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Home Rf

  1. 1. HomeRF Bringing Wireless Connectivity Home
  2. 2. Contents <ul><li>Introduction to Wireless Home Networking </li></ul><ul><li>Brief History of HomeRF </li></ul><ul><li>HomeRF Technology- SWAP </li></ul><ul><li>Summary </li></ul>
  3. 3. Overview of HomeRF <ul><li>A next step wireless networking optimized for home/office environment </li></ul><ul><li>Provides Data and Voice communication between devices such as PC’s, Cordless Phones and DSL Modems etc. </li></ul><ul><li>Uses SWAP-CA Technology </li></ul>
  4. 4. What is Home Networking ? <ul><li>The distribution of information(Audio, Video, & Data) around the home and their interface with attached devices and external services. </li></ul><ul><li>The interconnection and interoperation of </li></ul><ul><li>- Home appliances </li></ul><ul><li>- Entertainment devices </li></ul><ul><li>PC hardware </li></ul><ul><li>Telecommunication devices </li></ul><ul><li>Security lighting and environmental control systems </li></ul>
  5. 5. Wireless Technology <ul><li>Infrared </li></ul><ul><li>-Line-of-Sight Technology </li></ul><ul><li>Radio Frequency </li></ul>
  6. 6. HomeRF WG(Working Group) <ul><li>Formed in 1997 with 85+ members </li></ul><ul><li>Enable existence of a broad range of interoperable consumer devices bringing information services to each part of the home </li></ul><ul><li>Establish an open industry specification for unlicensed RF digital communications for PCs and consumer devices anywhere in and around the house </li></ul><ul><li>Initiating members: Compaq, Ericsson, HP, IBM, Intel, Microsoft… </li></ul>
  7. 7. HomeRF Vision
  8. 8. HomeRF Technology <ul><li>SWAP </li></ul><ul><li>(Shared Wireless Access Protocol) </li></ul><ul><li>Derived from extension of existing cordless Telephone (Digital Enhanced Cordless Telephone) and wireless LAN technology </li></ul>
  9. 9. HomeRF Technical Goals <ul><li>Low cost and voice support of DECT </li></ul><ul><li>– Adapted to 2.4GHz band </li></ul><ul><li>– Client call services well defined </li></ul><ul><li>TCP/IP support of IEEE 802.11 </li></ul><ul><li>– Relaxed specs to lower cost </li></ul><ul><li>– Use existing 2.4GHz support (FH) </li></ul>
  10. 10. HomeRF Origins 802.11 Uses CSMA/CA Good for data DECT Uses TDMA Good for voice SWAP TDMA+CSMA/CA Good for voice and Data Optimized for small networks(in home) Simplified Radio & Protocol to reduce cost Both Data & Voice are important for HomeRF
  11. 11. SWAP <ul><li>HomeRF SWAP specification </li></ul><ul><li>– Designed for both data & voice wireless communication </li></ul><ul><li>– Defines interoperation of PSTN & Internet </li></ul><ul><li>Operates in the 2.4GHz band </li></ul><ul><li>– Uses digital frequency hopping spread spectrum radio </li></ul><ul><li>Derived from extensions of existing cordless telephone (DECT) & wireless LAN technology </li></ul><ul><li>– Enables new class of home cordless services </li></ul><ul><li>IP Data at up to 2 Mbps & support cordless telephony </li></ul>
  12. 12. SWAP supports <ul><li>TDMA </li></ul><ul><li>– Time Division Multiple Access </li></ul><ul><li>– Provides delivery of interactive voice & other time critical service </li></ul><ul><li>CSMA/CA </li></ul><ul><li>Carrier Sense Multiple Access/Collision Avoidance </li></ul><ul><li>– Service for delivery of high speed packet data </li></ul>
  13. 13. Capabilities of HomeRF <ul><li>Up to 150 foot range </li></ul><ul><li>Networks up to 50 PCs </li></ul><ul><li>Work with dial-up, DSL, and cable modems </li></ul><ul><li>Work through walls & floors </li></ul><ul><li>Data secured through unique network ID </li></ul><ul><li>Robust & reliable & minimizes the impact of radio frequencies </li></ul><ul><li>Includes support of near line quality voice & full telephony </li></ul>
  14. 14. Data Service Types <ul><li>Isochronous (I Node) </li></ul><ul><li>– Used mainly to carry interactive voice </li></ul><ul><li>Minimum latency </li></ul><ul><li>Requires the presence of a Connection Point </li></ul><ul><li>– Example: cordless telephones </li></ul><ul><li>Asynchronous (A Node) </li></ul><ul><li>– Used for data networking - TCP/IP traffic </li></ul><ul><li>– Example: fridge pad </li></ul><ul><li>I Nodes get priority on bandwidth </li></ul><ul><li>CP - connection point </li></ul><ul><li>– Can manage a network or act as an A node </li></ul><ul><li>– Can be USB, PCI, PC-Card, Device Bay </li></ul><ul><li>– CP can place calls even when PC is down </li></ul>
  15. 15. Frequency Hopping <ul><li>It works very much like its name implies </li></ul><ul><li>-Data signal is modulated with a narrowband carrier signal that hops from frequency to frequency as a function of time over a wide band of frequencies </li></ul><ul><li>-Hopping pattern is known to both transmitter & receiver </li></ul><ul><li> To properly receive the signal the receiver must be set to the same hopping code & listen to the incoming signal at the right time & correct frequency </li></ul><ul><li>Unintended receiver see FH to be short-duration impulse noise </li></ul>
  16. 16. Network Layers of HomeRF
  17. 17. Network Topology SWAP system supports <ul><li>Ad-Hoc Network </li></ul><ul><li>– Only data communication is supported </li></ul><ul><li>– All stations are equal </li></ul><ul><li>– Control of the network is distributed between the stations </li></ul><ul><li>Managed network under the control of a CP </li></ul><ul><li>– Ideal for isochronous data and power savings </li></ul><ul><li>– Such as time critical communications such as Interactive voice </li></ul><ul><li>– Provides gateway to PSTN </li></ul>
  18. 18. Uses <ul><li>PC Enhanced Cordless Telephony </li></ul><ul><li>Mobile Internet viewing </li></ul><ul><li>PC resource sharing </li></ul>
  19. 19. Comparative study
  20. 20. Technical Summary <ul><li>Hybrid TDMA/CSMA frame </li></ul><ul><li>Frequency Hopping: 50 hops/sec </li></ul><ul><li>Range up to 50 meters indoors </li></ul><ul><li>Speed: dual speed </li></ul><ul><li>– 1 or 2 Mb/sec </li></ul><ul><li>– Also supports TCP/IP voice </li></ul><ul><li>Voice: High quality voice channels with retransmission </li></ul><ul><li>– High quality cordless telephones </li></ul><ul><li>– Voice recognition </li></ul>
  21. 21. References <ul><li>XILINX HomeRF Tutorial </li></ul><ul><li>WPAN-HomRF Tutorial from Intel’s Lab </li></ul><ul><li>http://www.palowireless.com/homerf/about.asp </li></ul><ul><li>http://en.wikipedia.org/wiki/HomeRF </li></ul>