WiMAX CS441 Dr. Kemal Akkaya 12/8/2011 By: Chun-Cheng Chuang

Contents  What is WiMax  Why WiMax  WiFi vs. WiMax  WiMax PHY/MAC layer  Challenges  Conclusion 2

What is WiMAX  Worldwide Interoperability for Microwave Access  Wireless MAN (Wireless Metropolitan Access Network)  Broadband wireless networks  based on the IEEE standard. 3

What is WiMAX  Offers data transfer rates of up to 75 Mbit/s  A range of up to 30 miles to make broadband network access widely available  Without wires  Last Mile access 4

Why WiMax  End-user are used to high bandwidth from fixed sources  Speed  higher range and speeds compared to  Wireless  Easier to extend to suburban and rural areas  Broad Coverage  Much wider coverage that WiFi 5

WPAN vs. WLAN vs. MAN StandardTransmission distance Max rate WPANBluetooth ( ) Zigbee ( ) 1~10 M 20 to 250 (Kbps)/ ~700 (kbps) WLANWi-Fi( a/b/g)50~100 M 11~54 (mpbs) MANWiMAX (802.16)30 miles 75 (mbps) 6

WiMax PHY layer  OFDM (orthogonal frequency division multiplex)  More advanced: MIMO (multiple-input and multiple-output) 7

WiMax MAC layer  Connection-oriented  A fundamental premise of the MAC architecture is quality of service (QoS)  QoS provided via service flows  Applies to both downlink (DL) and uplink (UL) 8

WiMax MAC layer Interface to higher layer protocols, classifies incoming data, etc. Core MAC functions (i.e., scheduling, connection maintenance,fragmentation), QoS control Encryption, authentication, secure key exchange Service Specific Convergence Sublayer MAC Common Part Sublayer Privacy Sublayer 9

Applyciation  Metro Area Networks  High-Speed Internet  Clustered wifi hotspot  Wireless VoIP  Video-on-demand, video surveillance  Education (rural schools & government orgs.) 10

Source : B08BADAA987F/wimax_and_wifi_together.pdf 11

Challenges  Security issues  Eavesdrop  Masquerade  Instead of sending packet to server, client send it to Hacker.  (Hacker takes identity of server.) 12

Challenges  Denial of Service  Attackers make resources (server, bandwidth) unavailable to client by overwhelming resource.  Jamming  Block the service by sending out radio waves along the same frequencies that WiMax use. 13

Conclusions  WiMax may becomes the dominant standard for Wireless MAN in the realistic market.  WiMax connect you faster and from much longer ranges  An intrusion detection system approach and firewall can be used to address some of the threats.  More research is needed. 14

References  Ppt  downloads/Finneran.pdf 15

Thank you! 16