Cisco Cisco Aironet 3500p Access Point Libro blanco
© 2011 Cisco and/or its affiliates. All rights reserved. This document is Cisco Public Information.
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The effect of these personal area networks is constrained, largely because the transmit power tends to be lower
and there are relatively few applications that motivate their use, but a large number of PANs could have a
meaningful impact on the overall Wi-Fi capacity. One positive side effect of having a properly designed Wi-Fi
network is that there tends to be fewer PAN networks, because network users will generally join the available
public network rather than trying to create their own.
and there are relatively few applications that motivate their use, but a large number of PANs could have a
meaningful impact on the overall Wi-Fi capacity. One positive side effect of having a properly designed Wi-Fi
network is that there tends to be fewer PAN networks, because network users will generally join the available
public network rather than trying to create their own.
Wi-Fi capacity can also be reduced by other non-Wi-Fi transmissions in the same band, such as those caused by
cordless phones, Bluetooth devices, wireless video cameras, and microwave ovens. To help Wi-Fi administrators
to manage their Wi-Fi networks, it is important that the Wi-Fi infrastructure be capable of identifying the source of
interference and assessing its level of impact on Wi-Fi network performance. The Cisco CleanAir Technology
scans, classifies, and locates interfering devices, allowing network administrators to take appropriate action to
remove or replace devices that affect Wi-Fi network capacity. In addition, Cisco CleanAir Technology can take
action to reduce the impact of interference through automated interference mitigation technologies, including
persistent device avoidance and event-driven RRM, which updates an access point’s transmit channel and power
level.
cordless phones, Bluetooth devices, wireless video cameras, and microwave ovens. To help Wi-Fi administrators
to manage their Wi-Fi networks, it is important that the Wi-Fi infrastructure be capable of identifying the source of
interference and assessing its level of impact on Wi-Fi network performance. The Cisco CleanAir Technology
scans, classifies, and locates interfering devices, allowing network administrators to take appropriate action to
remove or replace devices that affect Wi-Fi network capacity. In addition, Cisco CleanAir Technology can take
action to reduce the impact of interference through automated interference mitigation technologies, including
persistent device avoidance and event-driven RRM, which updates an access point’s transmit channel and power
level.
In addition to monitoring for Wi-Fi and non-Wi-Fi interference, the Connected Stadium Wi-Fi solution provides a
comprehensive suite of Wi-Fi performance monitoring tools, including the total number of devices, data rates per
device, and cumulative throughput. The available statistics can identify trends and help ensure that the network is
operating at levels that meet customer expectations.
comprehensive suite of Wi-Fi performance monitoring tools, including the total number of devices, data rates per
device, and cumulative throughput. The available statistics can identify trends and help ensure that the network is
operating at levels that meet customer expectations.
The Future: Video Distribution to Mobile Devices
Sports teams and venue operators are aggressively pursuing technologies and solutions that increase the fan
experience at venues and induce fans to attend sporting events. For example, Cisco StadiumVision
experience at venues and induce fans to attend sporting events. For example, Cisco StadiumVision
®
has been
deployed over the past two years at a number of venues to enhance the fan experience. Cisco StadiumVision
distributes high-definition video and digital signage to flat-panel TVs mounted throughout the concourse, suite,
club, and concession areas. The video streams can include replays and highlights, views from multiple camera
angles, and games played elsewhere.
distributes high-definition video and digital signage to flat-panel TVs mounted throughout the concourse, suite,
club, and concession areas. The video streams can include replays and highlights, views from multiple camera
angles, and games played elsewhere.
There is a strong and growing demand from venue owners and fans to extend the enhanced video streaming
experience to fans’ mobile devices, from the parking lot through the concourse to the bowl. But live video streaming
in a live sports environment has three fundamental challenges.
experience to fans’ mobile devices, from the parking lot through the concourse to the bowl. But live video streaming
in a live sports environment has three fundamental challenges.
●
The video quality must be excellent.
●
The video displayed on the mobile device must be delayed less than 1 second from the real-time action.
●
The video stream must be available to all fans without exhausting the Wi-Fi network capacity.
Conventional video streaming is accomplished using unicast techniques, in which a video stream is sent to each
mobile device requesting the stream. The quality can be excellent as long as there is sufficient bandwidth
available. But there are two fundamental challenges with unicast streaming. First, video streams are typically
delayed by 20 to 30 seconds from real time, which limits their appeal when fans can also see or hear the live event.
The second and larger challenge with unicast streaming is scalability. Delivering the same stream to many mobile
devices is an efficient use of bandwidth, which is clearly limited by serving only a small fraction of the devices in the
access point’s coverage cell. The high delay and lack of scalability limit the use of unicast video streaming
techniques to applications that are low-demand and do not stream in real time.
mobile device requesting the stream. The quality can be excellent as long as there is sufficient bandwidth
available. But there are two fundamental challenges with unicast streaming. First, video streams are typically
delayed by 20 to 30 seconds from real time, which limits their appeal when fans can also see or hear the live event.
The second and larger challenge with unicast streaming is scalability. Delivering the same stream to many mobile
devices is an efficient use of bandwidth, which is clearly limited by serving only a small fraction of the devices in the
access point’s coverage cell. The high delay and lack of scalability limit the use of unicast video streaming
techniques to applications that are low-demand and do not stream in real time.