1. Best Practices for Voice Deployment with Cisco WLAN Infrastructure
  2. Network Settings and Device RF Characteristics
  3. Recommended Environment
  • Best Practices for Voice Deployment with Cisco WLAN Infrastructure
Recommended Environment

Recommended Environment

  • Perform a Voice Grade Site Survey to ensure the requirements in Table 4 are met.
  • Signal to Noise Ratio (SNR), measured in dB, is the delta between the noise in dBm and the coverage RSSI in dBm. The minimum SNR value is shown in Table 4. Ideally, the raw noise floor should be -90 dBm or lower.
  • In floor level, Same-Channel Separation refers to two or more APs with the same channel are in RF sight of a scanning device in a given location. Table 4 specifies the minimum received signal strength indicator (RSSI) delta between these APs.
Network Recommendations
Setting
Value
Latency
< 100 msec end-to-end
Jitter
< 100 msec
Packet Loss
< 1%
Minimum AP Coverage
-65 dBm
Minimum SNR
25 dB
Minimum Same-Channel Separation
19 dB
Radio Channel Utilization
< 50%
Coverage Overlap
20% in critical environments
Channel Plan
2.4 GHz: 1, 6, 11
  • No adjacent channels (overlapping)
  • Overlapping APs must be on different channels
5 GHz: 36, 40, 44, 48, 149, 153, 157, 161, 165
  • If you are using DFS channels, broadcast the SSID in beacons.
  • Unlicensed National Information Infrastructure-2 (U-NII-2) (DFS channels 52 to 140) and U-NII-3 (channels 149 to 165) are subject to local regulatory rules.