Cisco Cisco Aironet 350 Mini-PCI Wireless LAN Client Adapter Guia Do Desenho
9-8
Enterprise Mobility 4.1 Design Guide
OL-14435-01
Chapter 9 VoWLAN Design Recommendations
Call Capacity
Therefore, the clients send their management, control, multicast, and broadcast packets at the “required”
data rates as advertised by the AP. The clients can send their unicast packets at any of the data rates
advertised by the AP. Generally, those unicast packets are sent at a data rate that provides the highest
reliable data rate for the link between the AP and client. The AP is capable of sending unicast packets
at a data rate that is unique to each client link.
data rates as advertised by the AP. The clients can send their unicast packets at any of the data rates
advertised by the AP. Generally, those unicast packets are sent at a data rate that provides the highest
reliable data rate for the link between the AP and client. The AP is capable of sending unicast packets
at a data rate that is unique to each client link.
SNR is an important consideration for packet reception. The receiving radio is either the AP radio or the
phone radio. The SNR is not likely to be the same at both radios of the link. SNR and multipath
interference must be considered at the AP and at the coverage area edge. Path loss can be assumed to be
the same at both ends of the link.
phone radio. The SNR is not likely to be the same at both radios of the link. SNR and multipath
interference must be considered at the AP and at the coverage area edge. Path loss can be assumed to be
the same at both ends of the link.
Cisco recommends for voice applications that the cell edge be determined by using the actual phone at
the desired data rate. The voice packets sent between the AP and the phone in Wi-Fi applications are
generally unicast RTP G711 packets with a typical size of 236 bytes. The Real-Time Transport Protocol
(RTP) packet is based on UDP and IP protocols, and therefore RTP is connectionless. The signal
strength, SNR, data rate, and error rates of the phone call can be seen from the AP statistics, either on
the standalone AP or the Lightweight Access Point Protocol (LWAPP) controller. A sample of a phone
client’s cell edge dBm values for 802.11g and 802.11a are shown in
the desired data rate. The voice packets sent between the AP and the phone in Wi-Fi applications are
generally unicast RTP G711 packets with a typical size of 236 bytes. The Real-Time Transport Protocol
(RTP) packet is based on UDP and IP protocols, and therefore RTP is connectionless. The signal
strength, SNR, data rate, and error rates of the phone call can be seen from the AP statistics, either on
the standalone AP or the Lightweight Access Point Protocol (LWAPP) controller. A sample of a phone
client’s cell edge dBm values for 802.11g and 802.11a are shown in
and
. The call
stream statistics are shown in
. The stream metrics can be viewed on the WCS after the voice
metrics are enabled. The path to enable the metrics is Configure > Controller > ipaddress > 802.11bg >
Voice Parameters > Enable Voice Metrics.
Voice Parameters > Enable Voice Metrics.
Figure 9-7
11g Client Statistics