Technological Delivery Options 

In order to understand the technological aspects of the various delivery options, it would be pertinent to understand the nature of the content that is to be delivered over these channels. The content provided by VITU would be in the form of multimedia content and rich web-based content.  

Multimedia content would include conventional audio-video content, which could be a simple introduction of a course by a Professor; a video clip explaining some point; or even a full-motion video of a Professor delivering a lecture, live or recorded. Other multimedia content could be streaming video and hypermedia processed video clips. 

Rich web-based content would be HTML based with graphics, hyperlinks and animations, sometimes with embedded video clips. The VITU Web server would also maintain Frequently Asked Questions (FAQ’s) as well as exercises, reading material and other reference material. 

The content delivery channels can be broadly classified into two main areas: Internet Protocol (IP) based delivery and interaction, and Television based delivery with Internet based interaction. IP based delivery and interaction can take place over fiber terrestrial networks or via two-way satellite communications. TV delivery can be via satellite using analog or digital broadcast, with a modest bandwidth requirement for reverse interaction over normal dial-up or dedicated lines. 

Pakistan Academic Intranet 

The setting up of a nationwide academic network is part of the IT Policy of the government. This network would connect all major universities and educational institutions together through a high bandwidth nationwide network. The suggested bandwidth for the network is 155Mbps. Several designs are under consideration but the one that makes the most logical sense from an economic as well as a management perspective is to develop city rings (metropolitan area networks) connecting all educational centres within the city. These rings would then be connected over the national fiber backbone to form the Pakistan Academic Intranet. The Academic Intranet will be connected to the Internet at one or more points, thereby providing Internet connectivity to all institutions connected to the Academic Network. 

VITU should give high priority to delivering content over the Academic Intranet. The content producing institutions would be connected to this network, as would be the majority of consuming universities. This would allow for full Internet Protocol (IP) based delivery of contents and interactivity between the various centers. 

Content servers would be housed at the VITU headquarters and mirror servers would be maintained at each city ring. The mirror servers would be synchronized every day during a low activity period, preferably the early morning hours. The distributed servers would help alleviate bandwidth congestion over the national backbone, provide faster response times for local users, and also make the VITU content network more resilient to single point failures. 

As shown in Figures 1 and 2 in Chapter 6, Pakistan already possesses an impressive terrestrial optical fiber network, which is further proposed to cover the major population centers by year 2004. This would provide the requisite bandwidth for the backbone of the Pakistan Academic Intranet. By creating city rings, VITU would be able to use pure IP based delivery and interaction and both obtain and deliver content effectively over this intranet.

TV Based delivery with reverse Internet based interaction 

The Academic Intranet can potentially link the major cities within Pakistan in a short time. However, more extensive coverage will gradually be achieved over the next four years. As such, in the short term, VITU would be restricted in coverage unless alternate channels are employed. The logical choice is television with its complete nation-wide coverage. Currently there are two main broadcast methods available. Pakistan Television (PTV) uplinks via digital channels to the Thaicom 3 satellite, which is then used to downlink to terrestrial broadcast stations which provide local area coverage using ordinary antennas. PTV2 uses conventional satellite broadcast to cover the region and requires analog satellite receiving equipment to view the broadcasts. 

SIIT in any case would require satellite based delivery and interaction to deliver content to the region. Using the experience of the network currently used in South Africa, deploying IP over DVB Satellite broadcast technology is currently quite feasible. The setup deployed in South Africa is shown below.

With current advances in technology, the analog video cameras with composite audio-video outputs and the IP Stream encoder can be replaced with low-cost digital cameras with IEEE 1394 ports supplying direct digital output in MPEG format. This further lowers the cost of the broadcast site and also allows for multiple broadcast centers as envisaged for VITU. The Academic Intranet may further reduce the requirements for satellite-based delivery by providing direct connections between provider and consumer sites.

The content originating sites for VITU are anticipated to be major education institutions with quality faculty available. These institutions would be linked over the Academic Intranet. However, if IP over DVB broadcasts are used for delivery of content to all learning sites, the Academic Intranet would only need to provide an E1 (2Mbps) link from the originating institution to the satellite uplink station, thereby saving on valuable bandwidth and also allowing multiple institutions to assume the role of the broadcast center as and when needed. The interaction would be obtained over the Academic Intranet as well as over regular dial-up lines from remote stations.

Two-way satellite connectivity

The above solution would work for Pakistan as well as other countries of the South, which have the facility of reverse connectivity via the Internet. For extremely remote areas, as well as regions where the Internet has not yet obtained a foothold, a newly emerging technology provides the solution. This is two-way IP based interaction via satellite.

Two-way access to the Internet is already being provided via satellite by at least one company in the United States. Many more are expected to follow in year 2001. The technology is based around a low cost ($600) card installed in a personal computer allowing for bandwidth up to 500kbps for the downlink with the uplink being slightly slower at about 150kbps. The downlink speed is adequate for reasonable delivery of rich content. Small aperture satellite dishes are requires for this connection.

This option could easily be adapted for use by SIIT/VITU. The coverage possibilities are nearly global and by utilizing the concept of learning centers instead of individuals at home, thereby spreading the cost over many users, the economics seem very favorable. This may be the path for the future and may also become the fastest method for bringing new centers online.

Last mile issues  

As would be clear from the above discussion, the Academic Intranet forms the heart of the VITU vision. Hence, connectivity of the various educational institutions around the country becomes a critical component. Whereas there is an extensive and excellent fiber network across Pakistan, last mile connectivity remains an issue.

Setting up fiber-based city rings will require considerable investment and can only be achieved over a period of time. Using the Digital Cross Connects (DXX) already in place provides the fastest path towards the goal, but may not have the broadest coverage as many in-city institutions may be prohibitively far from the nearest DXX equipped exchange. Remote areas, of course, do not have access to DXX connectivity.

An alternative would be to use spread-spectrum radio connectivity to set up the city rings. This can be achieved in a short period of time and the cost scales linearly with the number of institutions. Bandwidths up to 10Mbps can be achieved over 15-20km distances using this technique. The problem with this technique is the congestion in the frequency bands used by the radio modems. Special frequency allocation may be required if this technique is to be used by the Academic Intranet.

PTCL has also requested letters of interest from companies desiring to provide Digital Subscriber Loop (DSL) connectivity. DSL, in association with cable-modems may also compete for providing last-mile connectivity in the major urban centers.