Wireless network access
General
Early childhood education services use image intensive applications and are likely to want to conduct image intensive transactions by wireless access. Typically, one wireless access point will provide sufficient coverage for each ECE Service.
Suppliers are entitled to assume that network cabling and the active network components, such as routers and switches, have already been installed to meet or exceed the Ministry’s minimum ICT infrastructure standards.
In summary, the minimum infrastructure requirements for new installations and significant upgrade projects are as follows:
- Category 6 Class E performance certified cabling
- 100Mbps switch ports
- Non-blocking switching architecture
Wireless access to the network shall support IEEE 802.11g (54Mbps, 2.4GHz) and be backwards compatible with IEEE 802.11b (11Mbps, 2.4GHz) shared access and must be capable of securing network usage.
Hardware vendors claim particular bandwidth capacities for wireless networks. In general, higher bandwidth is always better but actual data transfer rates are much lower. For example, 802.11b wireless networks claim 11Mbps but typically achieve less than 3 Mbps, which might not be enough to take full advantage of the broadband internet connection. IEEE 802.11g wireless access claims 54Mbps but typically achieve less than 18 Mbps of throughput.
Access Point Installation and Warranty
Wireless systems shall be installed only by properly qualified personnel accredited by the manufacturer to install their system and associated software.
All equipment shall be installed in full accordance with the manufacturer’s recommendations and instructions.
The Supplier shall warrant that the equipment will operate to the standards and specifications claimed by the manufacturer and that the product is free from any defects in materials or workmanship.
All equipment shall be supplied with a minimum 3 years repair or replacement “return to base” warranty included in the price.
Potential Problems
While connecting a single wireless access point and providing wireless service to a few laptops is a relatively simple task requiring few technical skills, properly qualified personnel should be engaged to install and setup the access point because of the sensitive nature of the environment.
Together with the ease of installation, the decreasing cost of components presents a compelling argument to “go wireless”. However, because wireless LAN technologies operate in the unlicenced portion of the radio spectrum there is no formal process for preventing interference caused by other wireless network installations or from the multitude of other wireless devices designed to operate in the same frequency band. Well known conflicts include 2.4GHz cordless phones and microwave ovens. Providing these potential conflicts are understood and equipment sited accordingly, interference can be avoided in most cases.
Encryption
All current systems offer WEP and WPA PSK (preshared key) encryption. 64-bit WEP (Wired Equivalent Protection) is now outdated and 128-bit WEP, an updated, more secure version is the recommended minimum level of encryption.
WPA-PSK is a more secure alternative to WEP and is supported by Microsoft Windows XP with Service Pack 2. This type of encryption is to be preferred for connecting XP computers to the wireless network.
WPA2 is the newest type of wireless encryption. WPA2 provides the highest level of encryption available and should be the first choice if the wireless router, computers, and all other wireless devices support it.
Emerging Technologies
The IEEE’s Task Group “n” committee is working on a new standard which aims to lift transfer rates to more than 100 Mbps. The IEEE 802.11n specification should also provide better coverage and still be interoperable with the current 802.11a/b/g wireless standards.
A second draft of the Wireless 802.11n standard has been approved by the 802.11 working group and some companies are now actively selling equipment labelled as wireless ‘n’. The standards which define 802.11n are now a little closer to final approval and any products certified against the second draft of 802.11n standards are guaranteed to be compliant with the final 802.11n specs.
The third draft is expected to be approved in 2008. Final 802.11n standards are likely to be published in April 2009.
Analysts advise not to deploy 802.11n hardware until the standard is ratified. Laptop manufacturers will start to include wireless interfaces complying with the new standard when it is ratified.
Product Selection
Most wireless access points and wireless interface cards provide similar features. Pick brand leaders and the top providers, especially those recognised as providing good product support. Until the new 802.11n standards are ratified by the IEEE, it would be considered unusual to select other than 802.11g (54Mbps) products.
To ensure interoperability, select equipment certified by the Wi-Fi Alliance as products which meets the recognised IEEE standards for 802.11g.
The Ministry web site lists suppliers recognised as meeting high standards of product performance, interoperability, and warranty.