Campus WLAN

IIIT-B unwires itself

Indian Institute of Information Technology, Bangalore is building a WLAN in its campus to give its students and faculty the ability to perform better research and collaboration in an anytime-anywhere environment. Let's look at the strategies it is using. by Akhtar Pasha

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, said Professor S. Sadagopan, Director, IIIT-B.

Established in 1999, Indian Institute of Information Technology, Bangalore (IIIT-B) is a premier IT institute located at the outskirts of Bangalore. The campus is spread across eight acres of land and has 250 students.

What began as a dream for the institute will now become reality. The institute's campus WLAN will include the main building, all the classrooms, faculty areas, lobby, theme-based labs, hardware labs, library, incubation center, 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," said Prof. Sadagopan.

Stepping stone

The stepping stone was when the institute offered notebooks to its students in 1999. Four years later, it is now one of the most 'unwired' institutes in the country. Prof. Sadagopan said, "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 is 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.

Of the 30 access points, 22 are in use and the remaining eight will be utilized shortly. The access points' locations are optimized in a way that Wi-Fi clients should 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.

Venkatesh Kamath, General Manager-Sales South, D-Link (India) Ltd said, "We conducted a systems study in June 2003. The implementation began in September and took only five days to complete including commissioning and testing with the help of our system integrator, Orva Networks."

Wireless as an overlay network

VSNL has offered 2 Mbps of international bandwidth. The campus network is hybrid in nature and has a four km optical Gigabit backbone which extends to the desktop using a star-topology. As its wired infrastructure is highly reliable, the institute has 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, which is 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. Wireless computing is accessible across the campus up to the main gate of Infosys whose facility faces the institute. Almost all students and professors have notebooks. Around 300 notebooks are in use, 150 of which incorporate Centrino technology.

"It took us two weeks of rigorous testing and fine-tuning the wireless network in September 2003, and the results were satisfactory. But there are gray areas like frequency

interference and signal strength, which we wanted to iron out in the second fine-tuning process in December 2003, but were not able to do so due to vacations," said Professor Asoke K Talukder, DaimlerChrysler Chair at IIIT-B. These issues are expected to be resolved in the first quarter of 2004.

Challenges ahead

Professor Talukder said, "Designing a wireless network and implementing it was not a big deal. But the larger part of challenges lies ahead when the institute starts operating with its full capacity of students in 2004, and when the user density increases as the hostels get unwired with an additional 24 access points."

When you have 250 mobile users in a WLAN spread over two acres of land, there's bound to be frequency interference that will reduce the channels, and weaken the signal strength.

"When we expand our WLAN to the yet-to-open student hostels, we need to take a fresh look at the architecture to avoid frequency interference, and instances of frequency percolating into another floor and through walls," added Prof. Talukder.

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 units of DWL-120 wireless USB adapters for notebooks. The institute is also planning to use Cisco access points for its new hostel facility.

Security and managing wireless access points

For authentication, the institute uses a pre-configured default Service Set Identifier (SSID) and password. 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.

Redundancy and failover

Dr. Debabrata Das, HP Chair Professor at IIIT-B said, "Simply creating a wireless infrastructure is meaningless. We have to build redundancy in our wireless network by having sufficient number of Ethernet data and voice ports so that business continuity is maintained in case of an emergency.

So 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 hundred data ports. This adds up to 734 data ports, and over 100 voice ports at our campus."

Early mover

Prof. Sadagopan says, "Adopting new technology gives several early mover advantages. We are expecting dramatic improvements in the students' group project work. Their productivity will double and it will unbound them all from getting glued to classrooms and labs."

The next step

The institute plans to upgrade to 802.11g in 2004. It plans to use the same technology for its hostel (with 290 rooms), that will be partially ready with 100 rooms by March 2004, and fully functional by May 2004. The institute is planning to wirelessly enable the entire hostel, with 24 wireless access points. 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 during their leisure time to check e-mail and browse.

Akhtar Pasha can be reached at akhtar@expresscomputeronline.com