IEEE 802.11s - Wireless Mesh Network


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  • Now let’s talk about interference Previous slide covered non-bursty weak interference Make this not look like directional antennas (broadcasts, waves) Distance, trees attenuate signal Delivery probability depends in part on signal-to-noise ratio P(delivery) = f(S/N) Perhaps many Roofnet node pairs have S/N corresponding to intermediate delivery probabilities Mention S/N measurements calibrated in the lab Replace hypothesis slides w/ pictures Mention s/n reported by the card Don’t #2 make it sound so definite Qualify the second point Mention ‘textbook model of ber’
  • We’ve eliminated the possibility that we’re losing bursts of packets We’ve narrowed the possibilities enough that we know we’re losing packets individiually “ the important special case” Start the explanation of this hypothesis here Why two phases? Mention it’s all beacons, constant, 8 APs XXX Roofnet shares its 802.11 channel with the rest of Cambridge XXX Other 802.11 traffic could corrupt our traffic at a time-scale of individual packets, without affecting our S/N measurements (xxx what’s the experiment?)
  • IEEE 802.11s - Wireless Mesh Network

    1. 1. IEEE 802.11s implementation for multimedia campus networking Sikkim Manipal Institute Of Technology Jan 2008 – Jun 2008
    2. 2. Why, What ,How?
    3. 3. Wireless Mesh Networks IEEE 802.11s <ul><li>WMN is dynamically self-organized and self </li></ul><ul><li>configured. Researches have been going on </li></ul><ul><li>to establish protocol for mesh networking </li></ul><ul><li>using current technologies such as IEEE </li></ul><ul><li>802.11, IEEE 802.15 and 802.16 </li></ul>
    4. 4. Classical 802.11 WLAN
    5. 5. WLAN with mesh
    6. 6. Why Mesh? <ul><li>What’s so good about Mesh? </li></ul><ul><li>– Enables rapid deployment with lower-cost backhaul </li></ul><ul><li>– Easy to provide coverage in hard-to-wire areas </li></ul><ul><li>– Self-healing, resilient, extensible </li></ul><ul><li>– Under the right circumstances: </li></ul><ul><li>– Greater range due to multi-hop forwarding </li></ul><ul><li>– Higher bandwidth due to shorter hops </li></ul><ul><li>– Better battery life due to lower power transmission </li></ul>
    7. 7. Modes Of WMN <ul><li>Infrastructure/backbone WMN </li></ul><ul><li>Client WMN </li></ul><ul><li>Hybrid WMN </li></ul>
    8. 8. Infrastructure/Backbone WMNs
    9. 9. Client WMNs
    10. 10. Hybrid WMNs
    11. 11. Comparison with existing technologies
    12. 12. Mesh vs. Ad-Hoc Networks <ul><li>Multihop </li></ul><ul><li>Nodes are wireless, possibly mobile </li></ul><ul><li>May rely on infrastructure </li></ul><ul><li>Most traffic is user-to-user </li></ul>Ad-Hoc Networks WMN <ul><li>Multihop </li></ul><ul><li>Nodes are wireless, </li></ul><ul><li>some mobile, some fixed </li></ul><ul><li>It relies on infrastructure </li></ul><ul><li>Most traffic is user-to-gateway </li></ul>
    13. 13. Mesh vs. Sensor Networks <ul><li>Bandwidth is limited (tens of kbps) </li></ul><ul><li>In most applications, fixed nodes </li></ul><ul><li>Energy efficiency is an issue </li></ul><ul><li>Resource constrained </li></ul><ul><li>Most traffic is user-to-gateway </li></ul>Wireless Sensor Networks WMN <ul><li>Bandwidth is generous (>1Mbps) </li></ul><ul><li>Some nodes mobile, some fixed </li></ul><ul><li>Normally not energy limited </li></ul><ul><li>Resources are not an issue </li></ul><ul><li>Most traffic is user-to-gateway </li></ul>
    14. 14. WLAN Coverage 802.11 WMN Wiring Costs Low High Number of APs As needed Twice as many Cost of APs High Low Bandwidth Good Very Good
    15. 15. Mesh Implementation Model <ul><li>Different factors affecting a wireless transmission </li></ul><ul><li>rate for a mesh network. </li></ul><ul><li>1) Marginal S/N </li></ul><ul><li>2) Long bursts of interference due devices working in same </li></ul><ul><li>spectrum. eg microwave </li></ul><ul><li>3) Short bursts of interference due to concurrent sends from other routers </li></ul><ul><li>4) Multipath interference. </li></ul>
    16. 16. Marginal S/N <ul><li>Simplified model for packet loss: </li></ul><ul><ul><li>P(delivery) = f(signal/noise) </li></ul></ul><ul><ul><li>Signal strength reflects attenuation </li></ul></ul><ul><ul><li>Noise reflects interference </li></ul></ul><ul><li>Perhaps marginal S/N explains intermediate delivery probabilities </li></ul>
    17. 17. Long bursts of interference Bursty noise might corrupt packets without affecting S/N measurements A B
    18. 18. Short bursts of interference (802.11) A B Outcome depends on relative signal levels When a nearby AP sends a packet, we lose a packet.
    19. 19. Multi-path interference Reflection is a delayed and attenuated copy of the signal A B B
    22. 22. HORN ANTENNA
    23. 23. PARABOLIC REFLECTOR <ul><li>A parabolic reflector (or dish or mirror ) is a parabola-shaped reflective device, used to collect or distribute energy such as light, sound, or radio waves </li></ul>
    24. 24. CAT5 CABLE
    25. 25. i Pod Touch
    26. 26. Wireless Settings For iPod
    28. 28. What is a router? <ul><li>A router is a computer whose software and hardware are usually tailored to the tasks of routing and forwarding, generally containing a specialized operating system RAM, NVRAM, flash memory, and one or more processors. </li></ul>
    29. 29. LINKSYS WRT54G
    30. 31. WRT54G Series Router Specification
    31. 32. LINKSYS WRT54GL version 1.1 <ul><li>Linux Kernel 2.4 </li></ul><ul><li>Based on the Broadcom BCM5352E SoC </li></ul><ul><li>Hardware design is the WRT54G Version 4.0 </li></ul><ul><li>All-in-one Internet-sharing Router, 4-port Switch, and 54Mbps Wireless-G (802.11g) Access Point </li></ul><ul><li>Shares a single Internet connection and other resources with Ethernet wired and Wireless-G and -B devices </li></ul><ul><li>Push button setup feature makes wireless configuration secure and simple </li></ul>
    32. 34. Software Requirements <ul><li>1. MS WINDOWS </li></ul><ul><li>2. LINUX—UBUNTU GUTSY RIBBON </li></ul><ul><li>2.0 CONFIGURING UBUNTU </li></ul><ul><li>2.1 TCP DUMP </li></ul><ul><li>2.2 NDISWRAPPER </li></ul><ul><li>2.3 WI FI RADAR </li></ul><ul><li>2.4 WIRELESS TOOLS </li></ul><ul><li>MATLAB & SIMULINK </li></ul><ul><li>SOFTWARES : </li></ul><ul><li>-NETSTUMBLER </li></ul><ul><ul><li>NETMEETING </li></ul></ul><ul><ul><li>SKYPE </li></ul></ul><ul><ul><li>PRTG TRAFFIC MONITOR </li></ul></ul><ul><ul><li>NETSCAN </li></ul></ul><ul><ul><li>ANGRY IP </li></ul></ul>
    33. 35. MS WINDOWS
    35. 37. WI FI RADAR
    37. 39. What is VoIP? <ul><li>Voice over IP – Video over IP </li></ul><ul><li>– not limited to voice/video </li></ul><ul><li>– “ any data” over IP </li></ul><ul><li>How does it work: </li></ul><ul><li>– VoIP is the process of breaking up data into small chunks (packets), transmitting those chunks over an IP network and reassembling those chunks at the receiving end </li></ul><ul><li>Receiver handles packet loss, packet delay, and wrong order of packets </li></ul>
    38. 40. VoIP Protocols <ul><li>1 . Transport Protocols </li></ul><ul><li>RTP: Real-Time Protocolpayload can be any “multimedia” data defined by additional protocols and codecs </li></ul><ul><li> RTCP: Real-Time Control Protocol </li></ul><ul><li>2 . Call-Signalling Protocols </li></ul><ul><li>SIP: Session Initiation Protocol </li></ul><ul><li> H.323 </li></ul><ul><li>3 . Proprietary Protocols </li></ul><ul><li> Skype (P2P-based) </li></ul>
    39. 41. Why VoIP? <ul><li>• provides the opportunity to bring significant change in the way people communicate </li></ul><ul><li>• apart from email and Web, VoIP is the “killer application” for wireless networks </li></ul>
    40. 42. VoIP Services <ul><li>• Telephony </li></ul><ul><li>• Video Conferencing </li></ul><ul><li>• Instant Messaging </li></ul><ul><li>• Application Sharing </li></ul><ul><li>• Whiteboarding </li></ul><ul><li>• etc. </li></ul>
    41. 43. Microsoft Windows Netmeeting
    43. 48. PRTG Traffic Grapher <ul><li>It is an easy to use Windows software for monitoring and classifying bandwidth usage. It provides system administrators with live readings and long-term usage trends for their network devices. </li></ul>
    44. 49. <ul><li>The traffic monitoring system was also tested for wired LAN system existing in campus using PRTG network monitor software </li></ul>TRAFFIC MONITORING GRAPH-1
    47. 52. Network Traffic Table
    48. 53. Wireless Site Survey Netstumbler
    49. 54. <ul><li>The program is commonly used for: </li></ul><ul><li>Wardriving </li></ul><ul><li>Verifying network configurations </li></ul><ul><li>Finding locations with poor coverage in a WLAN </li></ul><ul><li>Detecting causes of wireless interference </li></ul><ul><li>Detecting unauthorized (&quot;rogue&quot;) access points </li></ul><ul><li>Aiming directional antennas for long-haul WLAN links </li></ul>
    50. 55. Graph- SNR vs Time
    51. 56. Netstumbler Window Showing network details
    52. 57. FIRMWARE <ul><li>OPEN WRT </li></ul><ul><li>FREIFUNK </li></ul><ul><li>MAD WIFI </li></ul><ul><li>TOMATO </li></ul>
    54. 59. OPEN WRT FIRMWARE <ul><li>OpenWrt is a Linux-based firmware program for embedded devices such as residential gateways. </li></ul><ul><li>The most popular routers seem to be the Linksys WRT54G series and the Asus WL500G. </li></ul><ul><li>OpenWrt primarily uses a command-line interface, but also features an optional web-based GUI </li></ul>
    56. 64. FREIFUNK FIRMWARE <ul><li> (German for: &quot;Free radio&quot;) is a non commercial open initiative to support free radio networks in the German region. </li></ul><ul><li> is part of the international movement for free and wireless radio networks. </li></ul><ul><li>To support the fast deployment of free radio networks, Freifunk uses a specialized firmware for WRT54G devices.. </li></ul>
    58. 66. FREIFUNK FIRMWARE LAN Settings
    59. 67. System Settings
    60. 68. MAD WI FI FIRMWARE
    61. 69. MAD WIFI FIRMWARE <ul><li>MadWifi is WLAN drivers available for Linux today. </li></ul><ul><li>It is stable and has an established userbase. </li></ul><ul><li>The driver is open source </li></ul><ul><li>We tested the wireless mesh network for using Madwifi firmware, but we faced some glitches with the deployment of the driver. </li></ul><ul><li>First the madwifi being Linux based worked only on Linux and we were having difficulties getting the drivers for various routers. Yet we were able to run Linksys WRT54USBG card under Ubuntu 7.04 </li></ul>
    63. 71. TOMATO FIRMWARE <ul><li>Tomato Firmware is a free HyperWRT + tofu based, Linux core firmware for several wireless routers, most notably the Linksys WRT54G , Buffalo AirStation and Asus Routers. </li></ul><ul><li>Tomato is open source software </li></ul><ul><li>Asynchronous Java & XML(AJAX) as well as an Scalable Vector Graphics(SVG)-based graphical bandwidth monitor. </li></ul>
    64. 72. Supported Devices <ul><li>WRT54G </li></ul><ul><li>WRT54GS </li></ul><ul><li>WRT54GL </li></ul>
    65. 73. Upgrading The Firmware <ul><li>Open the GUI in your browser. The default URL is </li></ul><ul><li>Click Administration, then Upgrade. </li></ul><ul><li>Select any of the files and click the Upgrade button. </li></ul><ul><li>Wait for about 2 minutes while the firmware is uploaded & flashed. </li></ul>
    66. 74. Menus in Tomato <ul><li>Status </li></ul><ul><li>Overview </li></ul><ul><li>System </li></ul><ul><li>Gives current overall system status, like the amount of time the router has been running, CPU load, and memory usage. </li></ul><ul><li>WAN </li></ul><ul><li>Gives information on the Wide Area Network (Internet) connection. </li></ul><ul><li>LAN </li></ul><ul><li>Gives a summary of the settings related to the Local Area Network, and the MAC Address for the wired portion of the network. </li></ul>
    67. 75. <ul><li>Wireless </li></ul><ul><li>Gives information on the wireless portion of the Local Area Network. </li></ul><ul><li>Device List </li></ul><ul><li>Provides a list of the current devices that have been assigned an IP address by the DHCP server. Devices are listed by Interface, which indicates where on the router they are connected: </li></ul><ul><li>br0 refers to Wired Ethernet (LAN) devices. In other words, devices that are connected to the router on the four Ethernet ports (either directly or via a hub or switch). </li></ul><ul><li>eth1 refers to Wireless Ethernet (WLAN) devices. In other words, devices that are connected to the router via the wireless radio. </li></ul><ul><li>vlan1 refers to your WAN (Internet) connection. In other words, the connection to your Internet modem (Cable modem, DSL modem, or upstream router). </li></ul><ul><li>Logs </li></ul><ul><li>Allows you to view the Internal system logs </li></ul>
    71. 79. <ul><li>Subnet Mask: </li></ul><ul><li>The default of means that anything starting in the first three numbers as the router (default 192.168.1.x) is assumed to be on the Local Network. </li></ul><ul><li>Static DNS: </li></ul><ul><li>Allows you to list a series of DNS servers manually (as opposed to getting them from your Internet Service Provider). </li></ul><ul><li>DHCP Server </li></ul><ul><li>Dynamic Host Configuration Protocol (DHCP) is a protocol used by networked computers (clients) to obtain IP addresses. To control the IP addresses that your router hands out to computers connected to Network. </li></ul><ul><li>Customize the amount of time before computers on the LAN will renew their IP addresses (the Lease Time) </li></ul><ul><li>Specify a Windows Internet Name Service (WINS) server if you use WINS. </li></ul>
    72. 80. Wireless <ul><li>Wireless </li></ul><ul><li>Controls the connection over the Wireless Local Area Network. </li></ul><ul><li>Enable Wireless: </li></ul><ul><li>If checked, Wireless access will be allowed. </li></ul><ul><li>MAC Address: </li></ul><ul><li>Displays the MAC address assigned to the Wireless radio on the router. </li></ul><ul><li>Wireless Mode: The normal setting for this is Access Point, which allows clients to connect to this router. The router can also be used in Wireless Distribution System (WDS) mode, </li></ul><ul><li>Another possible mode is Wireless Ethernet Bridge mode. This allows it to connect to another gateway router while still keeping all computers connected to both routers in the same subnet. Note: If the router is used as a wireless client or Wireless Ethernet Bridge, it cannot be used as an access point at the same time. </li></ul><ul><li>B/G Mode: </li></ul><ul><li>This may be Mixed (B+G), B-Only (restricted to 802.11b), or G-Only (restricted to 802.11g). If you set this to B-Only or G-Only, connection attempts from the other protocol may be seen as interference. Recommend leaving this set to &quot;Mixed&quot;. </li></ul>
    73. 81. Wireless( continued) <ul><li>SSID: </li></ul><ul><li>Wireless router identifier. Allows you to uniquely identify your router and differentiate it from other routers in range. </li></ul><ul><li>Broadcast: </li></ul><ul><li>If checked, the SSID will be broadcast, allowing the router to be found more easily. Disabling this is a very limited security measure. Casual scans will not be able to find the router, but anyone running sniffing software can easily find it. </li></ul><ul><li>Channel: </li></ul><ul><li>The 2.4Ghz range channel used by the router. Generally, it is best to use the Wireless Survey under Tools to find any other access points in range, and use the frequency that is the furthest from any other frequency in use. </li></ul><ul><li>Security: </li></ul><ul><li>Allows you to secure your wireless connections. WPA and/or WPA2 personal are the most secure protocols. Disabled means all connections are unencrypted and anyone can access the router. WEP is an older encryption protocol. While better than nothing, it is easily broken. </li></ul>
    74. 82. STATUS OVERVIEW <ul><li>Network </li></ul><ul><li>Allows you to set up the Internet / Wide Area Network (WAN) connection that the router uses, and the basic parameters of the Local Area Network (LAN). </li></ul><ul><li>WAN / Internet </li></ul><ul><li>Specifies how your router should connect to the Internet. Normally, this is done via an Ethernet cable connected from the WAN/Internet port to a Cable or DSL Modem. </li></ul><ul><li>Type: Specifies the type of connection used. </li></ul><ul><li>The rest of the parameters are variable, and based on the type of connection. </li></ul><ul><li>The default for most Cable modems is &quot;DHCP&quot;, meaning that the router simply talks to your cable modem and is automatically assigned an IP address and other connection data. </li></ul><ul><li>LAN </li></ul><ul><li>Controls setup of the Local area Network (LAN) which includes settings for wired and wireless clients connected to the router. </li></ul><ul><li>Router IP Address: </li></ul><ul><li>The IP address assigned to the router on the LAN. Default is </li></ul>
    75. 83. Bandwidth Monitoring <ul><li>Following BW monitoring options are available with graphs: </li></ul><ul><li>Real time </li></ul><ul><li>Last 24 hours </li></ul><ul><li>Daily </li></ul><ul><li>Weekly </li></ul><ul><li>Monthly </li></ul>
    77. 85. TOOLS <ul><li>Ping </li></ul><ul><li>Allows you to ping computers on the Internet to verify connectivity. Simply enter the URL or IP address (Internet only) to ping, customize the number of retries or packet size if you wish, and press [PING]. Results will be displayed when the ping is complete. </li></ul><ul><li>Trace </li></ul><ul><li>Allows you to perform a TRACERT (Trace Route) from your router to any Internet server. Enter the URL or IP address to trace to, and optionally the maximum hops and/or wait times, and press [TRACE]. Results are displayed when the trace is complete. </li></ul><ul><li>Wireless Survey </li></ul><ul><li>Scans the local area for other Wireless Access Points, and gives received signal strength information and other data. </li></ul><ul><li>WOL </li></ul><ul><li>Allows you to send Wake-on-LAN (WOL) packets to computers on your network. </li></ul>
    78. 86. TOOLS-PING
    79. 87. TOOLS-TRACE
    81. 89. QoS( Quality Of Service) <ul><li>QoS, or Quality of Service, allows you to prioritize data, slowing down less important data to allow more important data to get through first. </li></ul><ul><li>Useful for outbound data. </li></ul><ul><li>Inbound data cannot be prioritized effectively </li></ul><ul><li>QoS in Tomato has ten levels of priority. </li></ul><ul><ul><li>-HIGHEST -the very highest priority (use sparingly) </li></ul></ul><ul><li> -CLASS-E (labeled as E) is the lowest-priority class . </li></ul>
    82. 90. Access Restriction <ul><li>Set time, computer, and protocol based bans on Internet access. </li></ul>
    83. 92. ADMINISTRATION <ul><li>Admin access </li></ul><ul><li>Bandwidth monitoring </li></ul><ul><li>Buttons/Led </li></ul><ul><li>Configuration </li></ul><ul><li>Scheduler </li></ul><ul><li>Scripts </li></ul><ul><li>Upgrade </li></ul>
    84. 93. <ul><li>It also has an option of </li></ul><ul><li>Reboot </li></ul><ul><li>Shut Down </li></ul>
    85. 94. CONCLUSION <ul><li>The capability of self-organization in WMNs reduces the complexity of network deployment and maintenance, and thus, requires minimal upfront investment. </li></ul><ul><li>In order to establish we just require mesh routers and configure them and mesh network is deployed. A user has to select the firmware that he himself founds comfortable with out of range of firmwares available.While testing the wireless mesh network for various applications the mesh network worked fairly well. The established mesh network was tested for </li></ul><ul><li>(1) Internet Services </li></ul><ul><li>(2) VOIP </li></ul><ul><li>(3) Broadcasting </li></ul><ul><li>(4) Multicasting </li></ul><ul><li>(5) Audio/Video Chat </li></ul><ul><li>(6) Internet Radio </li></ul>
    86. 95. Conclusion <ul><li>WMN- IEEE 802.11S- A disruptive technology?? </li></ul>
    87. 96. Thank You