What are the deliverables to your customer after successfully implementing a WLAN infrastructure?

While planning for a VoWLAN deployment requiring 25 dB SNR, you measure the noise floor at -88 dBm. What is the minimum RSSI needed to meet the system's performance requirements?

After deploying a 5 GHz-only WLAN infrastructure in the USA, using 20 MHz channel-widths and all 25 available channels, one of the managers of the company brings his 802.11n tablet to the office to test the Guest SSID. While testing, there were several spots where we would get poor RSSI (below -80dBM) or none at all. You checked the WLAN infrastructure and all APs are up and running and you've validated coverage after deployment. What is causing this issue?

What is the minimum PoE budget required to power 6 APs using IEEE 802.3at with no additional details provided?

Which vertically polarized antenna is best suited for a WLAN infrastructure with access points mounted on a ceiling over 6 meters high, where all client stations operate from the floor level?