Mobile Versus Internet Streaming: 5 Key Challenges
Today, more and more mobile network operators are deploying high-speed 3G and 3.5G networks to bring their subscribers more services and exciting feature-rich applications. Of these, multimedia applications are best suited to take advantage of the relatively high data speeds supported by these wireless networks.
Unlike the internet, where downloading still prevails as the most popular method for delivering content, the mobile world is increasingly turning toward streaming to bring multimedia to users, in particular for live events and TV-type content. Streaming in the mobile space poses perhaps more significant challenges than traditional internet streaming. These challenges include issues that relate to and affect quality and the overall user experience.
This article addresses five key problem areas inherent in mobile streaming and suggests approaches that can lead to more successful delivery of mobile multimedia services.
Wireless streaming is a relatively recent phenomenon, made possible by advances in mobile handset technology and the development of high-speed mobile networks. However, despite some encouraging success stories and growing popularity, there are still many challenges for the mobile operators, solution providers, and handset companies largely due to the inherent differences in technology in relation to the more established internet-based services.
This article highlights some of the key issues in turn.
1. Streaming Quality is Limited by the Wireless Data Rate
Mobile networks tend to provide a fairly limited data rate compared with typical internet connections. Universal Mobile Telephone System (UMTS, or "3G") networks typically provide a mobile user with 128Kbps downlink bandwidth and 384Kbps in some scenarios, though sometimes even as low as 64Kbps. General packet radio service (GPRS) can deliver around 60Kbps (approximately 16 times less than a basic 1Mbps ADSL line) and EDGE a little higher. Hence, bandwidth is a critical factor in delivering high-quality streaming, and compared to the internet world this bandwidth is a severe restriction.
New advances such as high-speed download packet access (HSDPA) aim to deliver higher data rates up to several Mbps, comparable to many home broadband connections, which will alleviate the bandwidth restrictions to some extent. However, the network operators must understand how to utilize these new technologies to support the products and services provided to their customers.
Because huge demands are placed on the network bandwidth, advanced techniques are required to compress or "squeeze" the bitrate of the original content prior to streaming (e.g. to convert a full size TV-quality video into a small-screen version) using standards-based codecs. Although internet streaming also uses compressed formats such as Real, Windows Media, and Flash, the mobile industry has adopted highly efficient new formats such as H.264 video and AAC+ audio, developed primarily with mobile devices in mind.
The operators and content providers face an important choice in the initial stages of content creation, as the video and audio quality depends mainly on the codec selected, and also the implementation of the software that encodes the content into the mobile format, ready to be streamed by a server to the handset.