Refer to Exhibit. What two items need to be supported on the VoWLAN phones in order to take full advantage of this WLAN configuration? (Choose two.)

APSD (Automatic Power Save Delivery) is a power-saving sub-feature within 802.11e/WMM but is not the primary QoS mechanism needed to benefit from voice traffic prioritization.

802.11a defines the 5 GHz PHY layer standard and has no bearing on QoS capabilities for voice traffic.

802.11e is the IEEE amendment that defines QoS mechanisms for wireless LANs, including Enhanced Distributed Channel Access (EDCA), which provides the traffic access categories required for voice prioritization.

WMM (Wi-Fi Multimedia) is the Wi-Fi Alliance certification based on 802.11e that defines four access categories - Voice, Video, Best Effort, and Background - and is the practical client-side implementation required to take advantage of wireless QoS on the WLAN.

802.11r (Fast BSS Transition) improves roaming handoff speed but is not required to utilize QoS traffic prioritization on the WLAN.

SIFS (Short Inter-Frame Space) is a medium access timing mechanism built into the 802.11 standard and is not a configurable client feature.