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802.11 Wireless Support
Special Hardware Requirements
Ensure that all computers are using the latest NIC (Network Interface Connector) drivers available
from the NIC vendor.
ere are two basic types of access points: residential and enterprise. A residential access point works
fine in a home environment where several computers share an Internet link.
An enterprise access point is designed to support 50 or more clients at the same time. If there are less
than five student computers in the class, a residential class access point may be suitable.
Installation
It is assumed that all student and teacher machines will use 802.11 wireless NIC’s. (Mixed environments
don’t work as well.) Also, it is assumed that all wireless computers are associated to the same access
point. Other than this, there are no other special installation concerns. Run the Teacher.msi/Student.
msi program on the teacher or student computers, as specified earlier in this guide.
Performance
e speed of the teacher’s screen broadcasts to student computers is not as good over a wireless network
when compared to the performance over a wired network. ere is no way to overcome this.
A typical wired network can send broadcast and multicast data at 100Mbits per second. An 802.11
wireless network may only send broadcast and multicast data at 1MBit per second (a mere 1% of the
wired speed).
In addition to the drastic bandwidth reduction of wireless networks, the access point architecture of
802.11 will quite oen add significant propagation delays to broadcast and multicast data. (is is due
to the power save architecture of the 802.11 world.)
However, the Insight Teacher Broadcast feature will still work reasonably well. Even complex teacher
screens should appear on student screens within three seconds. Simple teacher screen changes should
appear almost immediately.
Wireless Performance Tweaks
To improve performance, configure the teacher access point. Since this differs from vendor to vendor,
we can only give general guidelines. Consult the access point’s manual to see how to actually make the
change on the particular access point.
1. Drop the Beacon Interval as low as possible. (is can go down to 50ms.)
2. Set the DTIM to ZERO. (is allows broadcast and multicast packets to be sent aer every
beacon packet.)
3. Increase the Broadcast or Multicast speed. (Not all access points allow this to be set.)
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