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Streaming Media

Streaming Media

Streaming media is audio and/or video images being sent from one computer to one or more other computers while simultaneously playing. This different than media that is downloaded, then played because the user must wait until the entire media file is downloaded before it begins to play. Typical streaming media players will buffer the content so that it can play partially downloaded content while continuing to download additional content.

Bandwidth Considerations

The primary concern in streaming media is the bandwidth capability of the network between the streaming media server and the end-user. For this reason streaming media content can be encoded in specific stream rates or in a format known has multi-rate. The specific rate will condition the content for the speed capability of the connection, therefore for a 56k modem connection you might have a 56k stream rate or 28.8k stream rate delivery. This will make the media stream uninterrupted, however the quality would have to be lowered to accomodate the slower rate. For example, in a streaming video you will notice a much smaller screen size for the 28.8k encoded video vs. a 300k encoded video.

A streaming media file encoded in a multi-rate format allows the streaming media client to sense the connectivity rate and request the stream at a speed rate to match the connectivity rate. While this seems like an optimal solution over providing multiple stream rates to choose from, it also is not as dependable as a fixed rate format. Multi-rate streams are more succeptible to packet loss.

Another issue to consider is unicast vs. mult-cast. Unicast means that the stream is being delivered from one system to another as one stream. So if you have 20 people wanting access to the same content, the streaming media server generates 20 separate streams thus consuming 20 times the stream rate. So if you are streaming 20 56k streams, you are consuming 1.12Mbps on your network. Unicast is also referred to as on-demand, because any user can request the stream at any time.

Multi-cast on the other hand generates a single stream and all the clients receive that stream at the same time. Regardless of whether you have 1 request or 2,000 requests the bandwidth consumption remains constant at the chosen stream rate. Unlike unicast, users cannot request the stream at any time, they must request the stream while the stream is already playing and will receive the stream as it is playing, not necessarily at the beginning. Also, networks must be conditioned to support multi-casting which is not typically the case in most default network configurations.

Streaming Media Applications

There are many applications for streaming media, from entertainment to learning. Consider an on-line learning event in which the instructor can be viewed through a multi-cast, or an asynchronous e-learning course that includes streaming video of an installation process. Even in medical e-learning programs you can include sounds of healthy hearts mixed in with irregular beats or heart mumurs to help medical students practice for examinations.

Corporate communication is another key application of streaming media. Conducting webcasts of corporate communications can reach almost the entire population of a company.

Costs and Return on Investment

The investment in streaming media is usually determined by the return on that investment. The metrics can be determined by whether streaming media is replacing a current method of communication, extending a current method, or creating a new method.

Replacing a Current Method

As an example of replacing a current method let's consider a current method of communication as satellite TV. There are costs associated with uplink time, hardware for satellite dishes, transmitting station(s), receiving stations, etc., and monthly maintenance of the hardware. Also consider that communication can only be realized during the actual time of a broadcast, not on-demand, and viewers will likely need to travel to a receiving location which will have limited seating.

Now consider that you would need to purchase hardware for content delivery engines, upgrading routers to multi-casting (for live events), and possibly expanding some network pipes to accomodate the minimal bandwidth for streaming and still leave room for normal network traffic.

Sounds daunting in regards to the investment, but one company was spending an average of $1.05M annually to reach 14% of its audience using a satellite system 2% of the time. That same company spent $500,000 for content delivery engines, upgrading of routers to multi-casting, and expansion of some network pipes in the first year. In that first year they reached 78% of their audience with 80% utilization, and expect to spend less than $100,000 per year on maintenance and additional lease line costs. This produced a realized ROI of 466%.

Extending a Current Method

Extending a current method is simply adding on streaming media to other forms of communications. For example, you may be considering extending e-learning with live remote instruction via streaming media. From this perspective you are incurring additional cost to deliver the same content you are already delivering by a different method, such as self-paced. The expense is justified when you discover that more people will attend training if there is a live remote instructor element included. This would make streaming media a particularly attractive investment if the students are paying students.

Creating a New Method

If you never have conducted corporate communications or distance learning, then the cost justification needs to come from the benefits realized by adding this new method. The primary one that comes to mind is savings on travel expenses, however consider that this justification usually exists only in the first year or two. Once the company has adjusted to the savings, it is no longer a savings, so you have to look towards the future as well.