1. WME

2. 802.11 ABC ’ s LayerDescription aPHY 54 Mb/s in 5 GHz bands bPHY 11 Mb/s direct sequence in 2.4 GHz band cMAC Bridging operation dPHY International domains eMAC Quality of service (QoS) (late ’ 04) fboth Access point interoperability gPHY 54 Mb/s at 2.4 GHz (802.11b compatible) hboth Coordination with European HiperLAN2 standards iMAC Security (mid ’ 04)

3. 2004 QoS/WME WPA 802.11i/WPA2 802.11i 802.11e Wi-Fi Certifications IEEE Standardization QoS/WSM 2005 2003 Technology Roadmap

4. QoS Considerations for Voice Admission Control is required Admission Control is required Streaming applications need priority service Streaming applications need priority service Bandwidth management required to maximize capacity and minimize contention Bandwidth management required to maximize capacity and minimize contention Battery life must be maximized Battery life must be maximized Traffic is predictable Traffic is predictable Schedule periods of “ sleep ” are possible Schedule periods of “ sleep ” are possible

5. IEEE 802.11e New medium access mechanism – Hybrid coordination function (HCF) Priority classes Priority classes Enhanced Distributed Coordination Access (EDCA) Enhanced Distributed Coordination Access (EDCA) Polled access Polled access HCF Coordinated Channel Access (HCCA) HCF Coordinated Channel Access (HCCA) Automatic Power Save Delivery (APSD) Automatic Power Save Delivery (APSD) APSD requires the Access Point to maintain a schedule for the intervals it will send packets APSD requires the Access Point to maintain a schedule for the intervals it will send packets This allows device to predict when traffic will arrive and schedule periods of ‘ sleep ’ This allows device to predict when traffic will arrive and schedule periods of ‘ sleep ’

6. Wi-Fi Alliance QoS Activities Defined by the Wi-Fi Alliance, optional for Wi-Fi certification Two profiles Wi-Fi [Wireless] Multimedia Extensions (WME) Wi-Fi [Wireless] Multimedia Extensions (WME) Based on EDCA priority service Based on EDCA priority service Wi-Fi [Wireless] Scheduled Multimedia (WSM) Wi-Fi [Wireless] Scheduled Multimedia (WSM) Based on HCCA polled access, includes EDCA Based on HCCA polled access, includes EDCA

7. WME vs. WSM WMEWSM Based on 802.11e Based on 802.11e, includes WME Based on EDCA (Enhanced Distributed Coordination Access) Based on HCCA (HCF Coordinated Channel Access) EDCA provides priority classes of service HCCA ‘ reserves ’ bandwidth based on traffic specifications from client devices Best suited for one way audio applications Best suited for two way streaming media (voice, video) Triggered APSD Optional Uses Scheduled APSD- suitable for power save

8. A Hybrid Approach

9. Enhanced distributed channel access (EDCA) Enhancement for 802.11 Distributed Coordination Function EDCA supports 8 priority values (traffic classes) Priority values (0 to 7) identical to the IEEE 802.1D priorities It does not guarantee that low priority frames will always wait until all higher priority frames are transmitted Provides statistical traffic class differentiation Mapping between 802.1D priorities and EDCA access categories. Background Spare Best Effort Excellent Effort Controlled Load Video Voice Network Control

11. HCF Controlled Channel Access (HCCA) QoS-aware centralized coordinator (Hybrid Coordinator HC) ▪ Has higher priority than EDCA ▪ Polls terminals ▪ Provides o Negotiated connections between an access point and terminals o Specifically assigned transmit times for every frame Close to strict QoS guarantees => Support for Voice over wireless LAN

13. WME 802.11 access point

14. Summary Wireless LAN (WLAN) and Voice over IP (VoIP) are no longer considered emerging technologies. Wireless LAN (WLAN) and Voice over IP (VoIP) are no longer considered emerging technologies. All we have to do is reference the WLAN phones that offer voice services to understand that wireless IP phones are now as real as wired IP phones. All we have to do is reference the WLAN phones that offer voice services to understand that wireless IP phones are now as real as wired IP phones.