Home >> February 2013 Edition >> SatBroadcasting™— Viable Solutions For E-Learning
SatBroadcasting™— Viable Solutions For E-Learning
The Internet has changed the e-Learning paradigm by introducing interactivity and multiple communication threads.

The challenge is that delivery of video content to the classroom, or to video distribution to customers, is usually done with platforms that are based on broadcasts over the air that do not allow for interactivity. The trade-offs of low cost satellite DTH systems such as these is a lack of bi-directional functionality that is required for modern, distance-learning interaction, newsgathering activities, and content distribution networks.

NewcomFig1 The Internet has changed the e-Learning paradigm by introducing interactivity and multiple communication threads such as chat, video, audio, and desktop sharing into the educational realm. Likewise, video content delivery over existing Internet access networks has penetrated developed markets at an extremely fast pace.

These new applications require large amounts of bandwidth, which is quite costly in remote sites where no terrestrial infrastructure is readily available. Most Internet based applications like this are unicast; the application generates a single stream for each user, therefore, the number of streams increases with the number of users and the network can serve only as many users as bandwidth allows—this severely limits scalability.

A Solution Is @ Hand
IP multicast is an efficient mechanism for transmitting data from a single source to many receivers in a network. The destination address of a multicast packet is always a multicast group address. This address comes from the IANA block– A source transmits a multicast packet by using a multicast group address, while many receivers “listen” for traffic from that same group address.

NewcomFig2 Multicast is a scalable solution as it efficiently delivers content while conserving network resources. NewCom’s shared satellite networks are specially designed to support Multicast traffic for these types of applications. The combination of iDirect Multicast features in the network and several IP streaming and e-Learning platforms that support multicast solves the scalability limitations of unicast in shared satellite networks.

The primary advantage of multicast over unicast is that it replicates the video stream closest to users at the last possible point in the network, as opposed to unicast, which replicates a single video stream for each user at the source. Multicast uses network servers, routers, and switches more efficiently without the time delays inherent to unicast systems. The primary advantage of NewCom’s multicast over shared satellite networks is that it allows for fine granularity, and access restriction at the remote level, which facilitates conditional access mechanisms over a unified management infrastructure.

NewcomFig3 Specific Applications
— E-Learning networks
— Radio Broadcast Services
— Emergency Broadcast Services
— Live and pre-recorded occasional video multicast over iDirect Networks

Multicast Marvels
Typical e-Learning platforms require a minimum of 256Kbps per video stream received or sent per participant. In a multicast environment, the video stream is received by all participants and counted only once within the multicast domain, regardless of the number of participants.

Inexpensive IP video and audio streaming applications can multicast their media streams to multiple end points, using very little bandwidth compared to individual streams delivered to each remote end.

For additional information, head over to Newcom’s website