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Wireless Networks & Interactive Whiteboards

Updated 29/06/07

This material looks at the health and safety issues involved in using computers in general, in the classroom and in the ICT suite.

http://www.hse.gov.uk/radiation/nonionising/whiteboards.htm

http://schools.becta.org.uk/index.php?section=lv&catcode=ss_lv_saf_hs_03&rid=2348

Updated 23/05/07

Please note:

A recent television programme highlighted some potential risks in the use of wireless networks in schools.

Please refer to the following: -

Health Protection Agency website: -

http://www.hpa.org.uk/radiation/default.htm

http://www.hpa.org.uk/radiation/understand/radiation_topics/emf/wlans.htm

BECTA website: -

http://news.becta.org.uk/display.cfm?resID=33517

http://foi.becta.org.uk/display.cfm?resID=15824

Please also consider the following advice offered by Broadband Sandwell for schools considering the implementation of Wireless networking:

General Information about wireless networks in schools

Wireless networks are sometimes regarded as an easy and cheap way to increase the availability of network resources in a school. This is not always the case, schools should be aware of these considerations:

1. Costs are not always apparent

In order to connect a computer system (whether laptop, desktop or PDA) to the network resources, you will need a wireless base station or Access Point (AP).

These access points should be located in the vicinity of the computer's usual work area, the signal will be blocked if there are walls between the AP and the computer (the signal will usually get through one wall, but this will depend upon the materials in use and distances; it is always adviseable to get a survey before installing).

The APs should be installed at height, usually just below the ceiling of the classroom. If you install the APs at bench height, the signal may have to negotiate childrens' bodies that come between the AP and the computer. As well as the health risks (see 3 below) this will reduce the signal's ability to travel between the two devices. When installed higher, a part of the signal will travel over the childrens' heads.

The APs will need to connect to the network; this will be achieved by installing extra network wiring. The APs will also need an electrical supply which will often means that extra mains has to be installed, although this can be reduced if the AP is capable of being powered using its network connection (Power Over Ethernet, or PoE). Whichever method is used, you will need to install extra network wiring between the AP and the school's network cabinets.

Implementing this extra technology between the network and the computer increases the technical understanding required by the school's technical support, and maybe the class teacher. We have been called on to fix wireless problems on a number of occasions where the AP was either turned off, plugged in incorrectly or unplugged. This will have led to the teacher being unable to use the ICT tools effectively until the problem was resolved, reducing the impact the ICT was able to make in the classroom.

In such cases it may be better to simply connect the computer directly to the network, and reduce the reliance on the wireless AP.

Alternatively, you may be considering using wireless technology to connect multiple computers (such as a trolley containing a number of laptops). In this case, consideration must be given to the required and available bandwidth: consider the connection available to a single desktop PC with a wired network connection. It is common that these will operate at 10Mbit per second, it is also possible to get connection speeds of up to 100Mbit/s or even 1000Mbit/s (1Gbit/s). The wireless connection will be limited to the maximum connection speed of the AP, commonly 11Mbit/s or 54Mbit/s.

This will then be shared by each extra laptop that connects and this will slow down access speeds, sometimes making the system unusable. This can be reduced by increasing the number of APs and by increasing the specification of the AP, these options will cost and may require extra support.

2. There is a security overhead

If you drive around a housing estate with a suitable laptop in your car you may be surprised to find a number of open wireless connections become available (you should not try this while driving). These invariably relate to unsecured home wireless systems. While some unscrupulous people use such connections illegally, what is more worrying for schools is that their wireless networks may be prone to such abuse. If your network is not properly secured, it may be possible to park close to the school and to wirelessly attach a laptop to the school's network, and to use that connection to attempt to "hack" the school's computer systems, accessing, changing or deleting information and thereby causing problems for the school later on.

To reduce this risk, schools should ensure that all wireless systems use an appropriate security system. These are built in to modern APs. Broadband Sandwell currently suggest that schools use 128 bit WEP encryption and use a pass key that is difficult to remember (i.e. consists of numbers and letters). The pass key must be entered on each AP and to each computer that needs to connect. Furthermore, the pass key should be changed on a regular basis to further reduce the possibility that it may become known. The school should also ensure that the key is removed from any computer when the computer is disposed of. If possible, APs could also be turned off when not in use to further reduce the potential to misuse them.

4. There may be health and safety implications

Wireless RF sources are becoming a public health concern in the press, where there was previously objection to mobile phone masts.

More recently, concern was raised over the use of wireless connections in classrooms over the possible future health impact of wireless RF on young people, following which a report warned against children using portable computers “on their laps”. There is undoubtedly a link between distance from source and "dosage", governed by the Inverse Square law (see http://en.wikipedia.org/wiki/Inverse-square_law).

We would always advise schools to follow such guidance, although “experts” sometimes offer conflicting advice.

Please see the following links to articles in this area:

Health Protection Agency website: -

http://www.hpa.org.uk/radiation/default.htm

http://www.hpa.org.uk/radiation/understand/radiation_topics/emf/wlans.htm

BECTA website: -

http://foi.becta.org.uk/display.cfm?resID=15824