Wi-Fi

IIIT-B unwires itself

Indian Institute of Information Technology, Bangalore has built a WLAN in its campus to give its students and faculty the capability for better research and collaboration in an anytime-anywhere environment. A look at the strategies being used.

Professor S. Sadagopan

Going unwired has been a dream of IIIT-B from the very beginning. “Our overarching purpose in setting up a wireless network is to provide students with the mobility and ability to get information like classroom or instructor material, e-mail and collaborative data anywhere on the campus,” says Professor S Sadagopan, Director, IIIT-B.

The campus is spread across eight acres of land and has 270 students.

What began as a dream for the institute is now reality. The institute’s campus WLAN includes the main building, all the classrooms, faculty areas, lobby, theme-based labs, hardware labs, library, incubation centre, virtual classrooms and the lush green landscapes. “The institute has a floating population of students and faculty members, who need seamless connectivity from any part of the campus,” says Sadagopan.

First Step

The first step was when the institute offered notebooks to its students in 1999. It is now one of the most ‘unwired’ institutes in the country. Sadagopan explains, “We are preparing our students for ubiquitous computing and it is a step in the right direction.”

This was the driving factor for going wireless. And it saw the institute go live with 30 wireless access points in December 2003.

Designing the Wireless Architecture

A three-member team from the institute began work on designing the wireless architecture in June 2003, with some help from BNA Networks and two technical consultants from D-Link. The access points are designed in such a way that one access point works as a hub providing services for three to four access points in its proximity.

Out of the total space of eight acres, two acres are integrated with 30 D-Link access points located in the institute’s main building supporting 250 Wi-Fi clients. These are either notebooks with D-Link’s DWL 120 wireless USB adapter or Intel Centrino-based notebooks.

“We are using 30 access points shared equally by the entire campus. Access points have had to be shifted in some cases and some removed altogether due to HP (Hewlett-Packard) projects in the main academic building (a special security need),” says Sadagopan. The locations of the access points are optimised so that Wi-Fi clients do not lose the connection at any point.

Meanwhile, to provide connectivity between the fixed user, mobile user, server and application software, IIIT-B has connected each access point to three central Layer 3 switches from Cisco and D-Link that transform the campus into both wired and wireless networks. Changes with additional security system and Internet access is restricted by time slots.

Wireless as an Overlay Network

The campus network is hybrid in nature and has a four-km optical Gigabit backbone, which extends to the desktop using a star topology. “We have moved to the software technology park (STPI) with 4 Mbps bandwidth (2Mbps + 2Mbps = 4Mbps). One for Research Net and the other for Academic Net,” says Sadagopan.

As its wired infrastructure is highly reliable, the institute decided to use the 802.11b standard as an overlay network offering 11 Mbps of shared connectivity.

Inside the Campus

IIIT-B moved to a new campus in 2003, an Intel-approved WLL site. Intel is funding the entire wireless initiative of the institute as part of its vision to spread mobile computing with Centrino technology. Nortel is funding security systems such as VPN Router, Firewall, IDS/IPS, Application Switch and NMS.

“It took us two weeks of rigorous testing and fine-tuning the wireless network in September 2003, and the results were satisfactory. There were grey areas like frequency interference and signal strength, which we have solved. However, frequency range is limited and as it is the first generation of Wi-Fi products, we have upgraded the product so that we can allow access at the edges of the campus,” explains Sadagopan.

Network Devices

D-Link’s products were chosen due to its research engagement for testing interoperability and mobile IP with D-Link. There are 20 D-Link DWL-900AP+ (wireless access point with bridging function) and 10 DWL-1000AP+ devices in use.

D-Link is also supplying 150 DWL-120 wireless USB adapters for notebooks.

Security and Managing Wireless Access Points

For authentication, the institute uses a pre-configured default Service Set Identifier (SSID) and password. E-serve provides the wired and wireless security.

Only notebooks configured with an SSID are allowed to proceed to the next level of authentication. Next comes encryption of data transmission using Wired Equivalent Privacy (WEP). The access points use DHCP (Dynamic Host Configuration Protocol) to automatically assign IP addresses to connected wireless nodes. To maintain security, the system administrator will configure for any new user or visitor to the campus.

Redundancy and Failover

Dr Debabrata Das, HP Chair Professor at IIIT-B said, “Simply creating a wireless infrastructure is meaningless. We have built redundancy into our wireless network for the main campus by having enough Ethernet data and voice ports so that business continuity is maintained in case of an emergency. We have designed our wireless architecture in such a way that each classroom and faculty room has two data ports and a voice port, and each lab has 100 data ports. This adds up to 734 data ports, and over 100 voice ports at our campus.”

Early Mover

Sadagopan says, “Adopting new technology gives several early mover advantages. We are expecting dramatic improvements in the students’ group project work. The productivity is doubled and it had unbound them all from being glued to classrooms and labs. The students feel they have extended work time.”

The Next Step

The institute plans to upgrade to 802.11g in this financial year (2006-07). It plans to use the same technology for its hostel (with 290 rooms).

The institute has wireless-enabled hostels completely with 24 wireless access points except for a few rooms at the network edge. Also on the cards is the conversion of its entire car park into a Wi-Fi zone, with hotspots where users with notebooks can drive at their leisure to check e-mail and browse.

—With updates from Vinita Gupta