Cisco Cisco Service Application Module for IP 白皮書
Wireless LAN Design Guide for High Density
Client Environments in Higher Education
4 © 2011 Cisco and/or its affiliates. All rights reserved.
Introduction
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• Plan: Determine application and device requirements such as bandwidth, protocols, frequencies,
service level agreement (SLA), etc.
• Design: Determine density, cell sizing, antennas, coverage, site survey, etc.
• Implement: Install, test, tune, establish baseline, etc.
• Optimize: Monitor, report, adjust, review baseline for SLA
• Operate: Cisco Wireless Control System (WCS) monitoring, troubleshooting tools, capacity monitoring and reporting tools, etc.
The general concepts underlying high density Wi-Fi design remain true for many environments. But it is important to note that
the content and solutions presented here will not fit every WLAN design scenario. Rather, the intent of the guide is to explain
the challenges in WLAN design for high density client environments and to offer successful strategies so that engineers and
administrators understand them and are able to articulate the impact design decisions will have.
• Implement: Install, test, tune, establish baseline, etc.
• Optimize: Monitor, report, adjust, review baseline for SLA
• Operate: Cisco Wireless Control System (WCS) monitoring, troubleshooting tools, capacity monitoring and reporting tools, etc.
The general concepts underlying high density Wi-Fi design remain true for many environments. But it is important to note that
the content and solutions presented here will not fit every WLAN design scenario. Rather, the intent of the guide is to explain
the challenges in WLAN design for high density client environments and to offer successful strategies so that engineers and
administrators understand them and are able to articulate the impact design decisions will have.
Target Environmental Characteristics for WLANs in Higher Education Environments
High-density WLAN design refers to any environment where client devices will be positioned in densities greater than coverage
expectations of a normal enterprise deployment, in this case a traditional, carpeted office. For reference, a typical office
environment has indoor propagation characteristics for signal attenuation. User density is the critical factor in the design.
Aggregate available bandwidth is delivered per radio cell, and the number of users and their connection characteristics (such as
speed, duty cycle, radio type, band, signal, and SNR) occupying that cell determines the overall bandwidth available per user.
expectations of a normal enterprise deployment, in this case a traditional, carpeted office. For reference, a typical office
environment has indoor propagation characteristics for signal attenuation. User density is the critical factor in the design.
Aggregate available bandwidth is delivered per radio cell, and the number of users and their connection characteristics (such as
speed, duty cycle, radio type, band, signal, and SNR) occupying that cell determines the overall bandwidth available per user.
A typical office environment, Figure 1, may have APs deployed for 2500 to 5000 square feet with a signal of -67 decibels in
millowatts (dBm) coverage and a maximum of 20 to 30 users per cell. That is a density of one user every 120 square foot
(sq. ft.) and yields a minimum signal of -67 dBm.
millowatts (dBm) coverage and a maximum of 20 to 30 users per cell. That is a density of one user every 120 square foot
(sq. ft.) and yields a minimum signal of -67 dBm.
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In planning and deploying such a WLAN, an AP is typically placed in an area expected to have a higher user density, such as in a
conference room, while common areas are left with less coverage. In this way, pre-planning for high density areas is anticipated.
Conference rooms are often placed in clusters, so it is best to design for the maximum capacity of the area. For example,
maximum occupancy for the three rooms is 32, so user density would be one user per 28 square feet, Figure 2.
conference room, while common areas are left with less coverage. In this way, pre-planning for high density areas is anticipated.
Conference rooms are often placed in clusters, so it is best to design for the maximum capacity of the area. For example,
maximum occupancy for the three rooms is 32, so user density would be one user per 28 square feet, Figure 2.