Wireless Network Computing in CityU

Tsui Siu Ki

Introduction

A wireless local area network (WLAN) is a flexible data communication system using radio frequency (RF) technology to transmit and receive data over the air. It can be integrated with the existing wired network seamlessly and easily so that users can enjoy network computing without the need to plug in. Over the last several years, WLANs have grown rapidly in the health-care, retail, manufacturing, warehousing, and academic arenas.

Why use wireless LAN?

In the past, we can only conduct computer training courses or hands-on sessions in terminal rooms or laboratories. With WLANs, we can now conduct such courses in ordinary classrooms by turning the latter into terminal rooms instantly with ease. As space is very limited in the CityU, this will undoubtedly relax the growing demand for well-equipped PC teaching studios. Apart from classroom teaching, WLAN also provides the mobility to users with open access to real-time information anywhere inside the campus.

In certain cases, we may need temporary network points in some locations for specific functions where wiring is not appropriate. With WLAN, network installation can be easy and instant without the need to physically lay cables through floors and ceilings.

The Pilot Scheme

The WLAN service has been incorporated in Room Neptune of the CSC Terminal Area and is now in the final testing stage. If everything runs smoothly, a proper pilot scheme will be implemented at the start of Semester B. The following are the three areas in which the technology will be tested:

1. Teaching

   There will be trial runs for using WLAN to conduct scheduled lectures held in the classrooms on the 4th floor. Hopefully, with the co-operation of lecturers from other departments, we can have students, say those working on a particular project, split into 2 to 3 groups each with a sample size of up to 40. Laptops will be on loan to the students attending these scheduled classes. By employing such method, we will be able to discover the real potential of WLAN.

2. Open Access

   Currently, the WLAN service covers areas like Room Neptune of the CSC Terminal Area, Multimedia Room (MMR) on the 4th floor and public areas outside Heng Sang Bank and FMO Service Counter. More locations such as the Library, late reading room and student canteen will be covered for network connections as more access points (transceivers) are installed in Semester B.

3. Lecturer's workstation

   Starting Semester B, WLAN and a LCD/Barcographics projector will be installed in some classrooms on the 5th floor, but this is confined to the lecturer's workstation only. The teaching staff in question simply power on the laptop and he/she will have instant access to the network to facilitate teaching provided that his/her laptop has the appropriate interface card installed.

During the course of the aforesaid pilot testing scheme, the CSC will closely monitor its progress. If it is successful, WLAN will be extended to cover all locations within the entire campus.

At the moment, there are about 70 Pentium II notebooks with wireless network interface cards available for loan from the CSC, some of which have already been used in the MMR and for conducting staff short courses and computer literacy courses in Room Neptune. The employed WLAN product can offer 10 Mbps transfer speed and should satisfy the bandwidth requirement of general network applications such as Internet browsing, e-mail and Information Services for more than 10 clients. For bandwidth demanding applications such as video applications, a transfer speed of 10 Mbps is only good for 2 to 3 clients. To support more clients, more transceivers are needed to increase the bandwidth.

Finally

Needless to say, flexibility and mobility make wireless networks superior to wired networks, but at the expense of higher initial setup cost and slower network transfer speed. Indeed, a faster WLAN configuration is required in order to provide better support for multimedia applications. Fortunately, faster WLAN products at similar cost will be available next year.

Computing Services Centre City University of Hong Kong ccnetcom@cityu.edu.hk