Wireless Networking Strategy

This document proposes a strategy for the use of wireless networking as a means of providing connectivity to the campus network.  It summarises the technical considerations that need to be taken into account and identifies potential applications and locations for its deployment.

The use of wireless to provide high bandwidth connectivity over long distances (e.g. between buildings) is a separate subject that is not addressed by this report


Wireless Networks and Cabled Networks compared

Wireless networking is a way of connecting personal computers or workstations to a network without the need for conventional data cabling.  The following table summarises the advantages and drawbacks of these two different approaches

Wireless and Cable Comparison
   Wireless network connection  Cabled network connection
 Flexibility  Laptops can be used to connect to the network from anywhere on campus in range of a wireless base station.  Staff are no longer restricted to their own offices; students can use their laptops from different locations around campus Laptops can only be used in proximity to network points, subject to the length of the network cable
 Security Data transmitted over a wireless network can be intercepted using appropriate receiver equipment (potentially remotely from outside a building containing a wireless base station) without users being aware Data transmissions are very rarely intercepted over a cabled network
 Performance Wireless networks offer lower bandwidth and less functionality (both now and for the foreseeable future).  They are therefore better suited to less demanding applications such as email and web access Cabled networks offer higher bandwidth and more advanced management functionality such as Quality of Service.  They are therefore more suitable for research systems and major corporate applications requiring consistent performance levels and/or involving significant data transmission
 Interference Wireless connectivity can be adversely affected by electronic equipment in the building or by the structure of the building itsel Cabling technology is designed to avoid this problem
 Connectivity New users can join an existing wireless network without delay (possibly subject to registration) New users may need to await the installation of additional network points if there are none spare
 Management Network incidents and performance issues are less easily traceable with wireless networks, making it harder to target remedial actions Network registration systems allow network incidents and performance issues to be pinpointed to specific network points and machines

Potential Applications for Wireless Networks

The features of Wireless Networks make them particularly suitable for the following categories of users and situations:

Research – Staff who find it inefficient to be tied to a desk and need to move around to conduct research in different locations or to work with colleagues.

Administration – Staff who need the flexibility to take their laptops to meetings outside of their office, for example, to demonstrate systems, take minutes or communicate by email

Teaching – Staff who would like to use the flexibility of wireless connected laptops to promote e-Learning – in lectures, tutorials or self-study facilities.

Students  who need to use their laptops as they travel around campus – in lectures, in libraries, or in recreational areas during breaks.

 

Technical Considerations for Wireless Networks

In the context of the University Network, a Wireless Network is an alternative way of establishing network connectivity to the Campus Network Core.  In a wireless environment, the client machine’s usual network interface card is replaced with a wireless network card, which communicates by radio with a nearby wireless base station, usually located in the ceiling.  Wireless base stations are connected to the Core Network with appropriate security through a distribution or edge switch.

As with cabled networks, there are certain technical considerations that need to be taken into account when designing a wireless network:

  • Location – The wireless base station needs to be carefully located to provide sufficient spatial coverage to reach all intended users. 
  • Capacity – Multiple base stations will need to be installed if the number of expected users exceeds the capacity of a single base station; otherwise performance may be significantly degraded
  • Interference – In locating a Wireless Network  account must be taken of potential interference from electronic equipment or the building infrastructure; likewise the risk that the Wireless Network itself may interfere with adjacent electronic equipment..
  • Security – Enforced authentication and data encryption should be implemented to control access to the network and protect data from interception.
  • Traceability – In the event of abuse it is necessary to be able to trace the offending machine; otherwise it may be necessary to disconnect the entire wireless network from the Campus Core

 

Recommended Strategy for Wireless Networks

The University Plan envisages the installation of Wireless Networks at diverse locations around campus to complement the new cabled network structure as an integral part of the University’s Network Upgrade Strategy. 

Information Services has recognised this as one of its key objectives and is planning to implement Wireless Network installations in the following locations:

1)  Access in public areas

Wireless Networks will be provided for general staff and student use in public areas, such as libraries, learning centres, eating and recreational venues.  Pilot facilities have already been installed in the Main Library, Arts Mason Lounge, Barnes and Harding Libraries and the Learning Centre.  These initial pilots are limited to laptops loaned from Information Services using simple authorisation by MAC address rather than full authentication and encryption.  These initial venues will ultimately be upgraded to the full standard described in 3) below and extended to other popular public areas of the campus

2)  Access in Schools and departments

Wireless Network facilities will be installed in Schools and administrative budget centres to meet the need for flexible working and itinerant student access. Locations will be selected in consultation with budget centres to reflect local requirements such as

in office areas where staff need the flexibility to work in alternative locations away from their own office

in and around lecture theatres to allow students to connect to the network from their own laptops  . 

3)  Standards

The following standards will be adopted for Wireless Network installations, to address the security and management issues identified in the first section of this report:

   Authentication against the University’s directory service (e-Directory) will be enforced before access is granted to the wireless base station, to prevent the possibility of unauthorised access and provide flexible instant access, normally without the need for prior registration

   The wireless LAN will be will be segregated from the cabled network behind its own firewall, to ensure that any illegal access or abuse cannot spread to infect the entire campus network

   Encryption of data transmissions across the Wireless LAN will be implemented to protect against interception by intruders using receiver equipment.

An initial installation to these standards is currently being developed in conjunction with the Business School for the their new University House accommodation.  Once implemented these standards will be adopted for all further Wireless Network installations across campus.  

4)  Restrictions

To protect the University against the security risks inherent in wireless networks, it is recommended that unapproved wireless networks installed by individual budget centres which do not conform with these minimum security standards (or an acceptable equivalent) should be prohibited as a matter of University policy.  Information Services will use monitoring equipment to identify the existence of such networks.

5)  Research and Development

Wireless Networks are a fast evolving area of C&IT and Information Services is keen to explore future developments through close collaboration with CETADL.  This may in future include possible network access from PDAs using G3 technology and the use of IPv6 to permit roaming network access across campus

 

Summary

Wireless networking is an exciting development in C&IT which offers considerable potential for more flexible and efficient working, complementing the advanced functionality offered by the new campus network.  These opportunities should be exploited for the benefit of teaching, learning, research and administration

As envisaged in the University Plan, Information Services should take the lead in the  implementation of wireless technology in a variety of selected locations across campus.  This will ensure that all installations are fully compatible with the University’s Network Upgrade Strategy and follow the necessary security standards to protect the University Network from illegal access and abuse.

 

R K Tier

11 November 2003