Operation Manual

Chapter 3 Wi-Fi 25

The Wi-Fi network design for high density is more complex, due to the higher density of

mobile devices. Because of the large number of devices in each classroom, one access point per

classroom might be required. Multiple access points should be considered for the common areas,

to provide adequate coverage and capacity. The number of access points for the common areas

may vary, depending on the density of Wi-Fi devices in those spaces.

Channel

157

Channel

161

Channel

Important: A pre-install site survey should always be performed to determine the exact number

of access points needed and where those access points should be mounted. A site survey also

determines the proper power settings for each radio. Once the installation of the Wi-Fi network

is complete, a post-install site survey should be performed to conrm the Wi-Fi environment.

For example, if designing a network to support a large number of people in a building it is best

to validate the design with people in the building. (Or, if classroom doors will be closed when the

network is in use, the door should be closed when validating the design as well.)

Sometimes it is desirable to create multiple SSIDs for dierent purposes. For example, a guest

network may be required. Care should be taken to avoid creating too many SSIDs, as the

additional SSIDs cause additional bandwidth usage.

Design for Applications

Apple products use multicast networking for services like AirPlay and AirPrint. Therefore,

multicast support should be part of the design plan. For information about how to prepare your

network for Bonjour, see Bonjour.

Wi-Fi standards in iOS devices

Wi-Fi specications for Apple iOS devices are detailed in the list that follows, which includes this

information:

•

802.11 compatibility: 802.11ac, 802.11n, 802.11a, 802.11b/g

•

Frequency band: 2.4 GHz or 5 GHz

•

Maximum Transmit Rate: This is the highest rate at which a client cant transmit data over Wi-Fi.

•

Spatial streams: Each radio can send independent data streams at the same time, each

containing dierent data, which can increase overall throughput. The number of these

independent data streams is dened as the number of spatial streams.

•

MCS index: The Modulation and Coding Scheme (MCS) index denes the maximum

transmission rate at which 802.11ac/n devices can communicate. 802.11ac uses Very High

Throughput (VHT) and 802.11n uses High Throughput (HT).

100% resize factor