Cisco Cisco Aironet 350 Mini-PCI Wireless LAN Client Adapter Guia Do Desenho
9-10
Enterprise Mobility 4.1 Design Guide
OL-14435-01
Chapter 9 VoWLAN Design Recommendations
Call Capacity
Figure 9-10
Sample VoWLAN Capture
When multipath interference is present at a location where signal level measurements are being taken, it
is quite likely that the reported values will fluctuate from packet to packet. A packet may be as much as
5 dB higher or lower than the previous packet. It may take several minutes to obtain an average value for
a given measurement location.
is quite likely that the reported values will fluctuate from packet to packet. A packet may be as much as
5 dB higher or lower than the previous packet. It may take several minutes to obtain an average value for
a given measurement location.
AP Call Capacity
A key part of the planning process for a VoWLAN deployment is to plan the number of simultaneous
voice streams per AP. When planning the voice stream capacity of the AP, consider the following points:
voice streams per AP. When planning the voice stream capacity of the AP, consider the following points:
Note
A call between two phones associated to the same AP counts as two active voice streams.
•
The utilization of an unlicensed (shared) 802.11 channel is the real determinant for the number of
simultaneous voice streams an AP may carry.
simultaneous voice streams an AP may carry.
•
Because the channel utilization and AP performance determine the number of voice streams, same
channel and next channel separation are very important. Two APs in the same location, operating on
the same channel do not provide double the number of voice streams. In fact, there can be fewer
voice streams than one AP would provide.
channel and next channel separation are very important. Two APs in the same location, operating on
the same channel do not provide double the number of voice streams. In fact, there can be fewer
voice streams than one AP would provide.
•
Cell capacity or bandwidth determines the number of voice streams that can be simultaneously
conducted.
conducted.
•
The handset QoS features supported in the handsets and VoWLAN deployment should be
considered.
considered.