by John Shay

Contributing Editor - WIIE

Technology can sometimes be counterintuitive. Things that you’d expect to be easy can be surprisingly difficult, while things that should be exceedingly difficult can happen with surprising ease. Such is the case for streaming media on the Internet versus 3G cellular networks. When compared to the labyrinth of the Internet, one would think that tightly controlled proprietary 3G networks touting tens of millions of subscribers would provide the ideal platform for streaming media. However, the fact that a global live streaming media broadcast has never taken place on a cellular network reflects technology’s fickle nature.

With the Beijing Olympics wrapping up, it’s interesting to note that Internet streaming media history was made by China on July 1, 1997. China was reassuming authority over Hong Kong and the world’s first large-scale streaming media cybercast was delivering the event live to countless Internet users across the globe. As the creator and executive producer of the Hong Kong Handover Cybercast (HKHC), I had flown to Hong Kong two days earlier to oversee the cybercast and to problem solve any technical glitches. The fact that I spent very little time addressing technical issues over the course of the three day event is a testament to the technical prowess of the software developers I worked with at RealNetworks, my employer at the time. Founded in 1994 by Rob Glaser, RealNetworks is widely credited with introducing real-time streaming media to the Internet in the form of RealAudio. However, the fact that the HKHC was heard live by millions of people worldwide when streaming media was still in its infancy reveals a great deal about the nature of the Internet as well as the challenges faced by cellular network operators deploying streaming media services.

Four factors contributing to the early success of Internet streaming media and which continue to challenge cellular network operators include: bandwidth, network topology, standards, and content discovery.

Bandwidth

In 1997, Internet bandwidth was far from the broadband experience most of us enjoy today. With the vast majority of Internet users still using dial-up connections, the HKHC was encoded using the low bit-rate RealAudio 14.4 kbps codec. In hindsight, the limited encoding choice simplified the broadcast logistics while supporting a larger audience in the bandwidth constrained Internet of 1997.

For cellular network operators bandwidth utilization and optimization is a continuous struggle. From maximizing real-time caller access to a single cell to balancing network load for real-time and non-real-time data, bandwidth optimization is a complex and formidable challenge. In the case of streaming media, network operators must design capacity that balances real-time services demands with non-real-time data requirements. The bandwidth struggle is compounded by the growing demand for data hungry video services.

Network Topology

If the HKHC had taken place a few months earlier its “global audience” would have effectively been limited to the city of Hong Kong. Fortunately, RealNetworks had recently introduced stream splitting technology that allowed single streams to be sent to remote servers across the globe for replication and distribution. The ability to service large audiences using a limited number of origin streams allows Internet broadcasts to scale to tens of thousands of simultaneous listeners.

For cellular network operators the critical topologic struggle for streaming media is managing subscriber movement between cells. To limit the disruption of streaming media presentations as subscribers move from cell to cell, network operators are experimenting with technologies that allow streams to be forward buffered onto memory-restricted handsets or be quickly restarted at points of interruption. The splitting of real-time live streams across a cellular network remains an enormous challenge.

Standards

Internet streaming media encoding, transmission and playback were still largely proprietary technologies in 1997. This meant that anyone wanting to listen to the HKHC had to have the RealAudio player application installed on their PC. Fortunately, RealAudio was an Internet darling in the spring of 1997 and millions of Internet users had already adopted the technology. Today, the transmission of streaming media across IP based networks is done using the open standard, Real Time Streaming Protocol (RTSP). Although proprietary encoding remains an issue, most Internet videos can be played using free player applications from Microsoft, RealNetworks, Apple, and Adobe (flash). Systems supporting all of these formats are not uncommon since users who consume Internet streaming media tend to have computers with an abundance of memory and processing power (both of which are severely limited on mobile handsets).

Since RTSP is also the 3GPP sanctioned transmission standard for streaming media on cellular networks, the struggle for cellular network operators lies primarily on the playback side of content delivery. Since handsets vary greatly in their ability to playback different media, operators are devising technologies that either map different versions of the same content to handset capability or transcode the content from one media type to one supported by the receiving handset.

Content Discovery

The number one factor that drove the success of the HKHC was the fact that anyone wishing to listen to the broadcast could do so by clicking on a single sharable Uniform Record Locator (URL). The content was easy to find, easy to join, and easy to share with others across the globe. Ease of discovery and sharing is what drives YouTube and every other successful Internet media site today.

The ability to easily discover and share content universally within and across cellular networks is perhaps the greatest challenge facing cellular network operators.