Motorola today released three latest findings from its HSDPA (High Speed Downlink Packet Access) trial results in Europe. The findings will help operators determine how to best deploy HSDPA and are taken from the first known global study which includes both multiple users and outdoor performance.
Motorola's HSDPA trials focused on user experience and how to ensure high customer satisfaction at the launch. Initial user perception in the adoption of mobile broadband is critical, and the aim for many operators is to provide a performance similar to fixed broadband. A video of Motorola's HSDPA trials is now available from http://www.motorola.com/content/0,,2033-8202,00.html
The latest outcomes from the various trials reveal three guidelines that operators should take into account when implementing high speed services across an HSDPA network:
1. Sufficient processing power needed to reduce latency
HSDPA will provide high speed but can be prone to delays when using applications such as web browsing. These delays can be attributed to a mechanism known as "state switching". This effectively moves a user from a high to a low speed state based on user activity without the user being aware. When the user requests data, such as clicking a hyperlink for a web page, there can be delays of seconds as the radio network transitions back from a slow to a fast state. Users will not expect such delays for services marketed as "Mobile Broadband".
There is a solution - avoid switching users down from a high to a low speed state regardless of user activity. As HSDPA enables radio resources to be dynamically shared between users (known as scheduling), the necessity to state switch should be reduced. However, scheduling requires intensive computer processing capabilities at the base station. Network operators should ensure that they have sufficient processing power at the base stations to schedule the highest possible number of calls at launch of the HSDPA service.
2. Adopt key handset functionality for improved mobile performance
The performance of HSDPA is heavily dependent on device or handset capability. A signal processing function known as an equaliser enhances performance when the user is moving. Initial trial results demonstrate an increase in data rates of as much as 40 percent for devices that support equalisation. Today only a few device manufacturers claim to have equaliser functionality.
3. Video services need priority
The trials have shown that video streaming performance degrades when a relatively modest number of users are active. As little as four active users are sufficient to cause video streaming to freeze if scheduling priorities are not set properly. To compensate for this, operators must actively prioritise video over other services or provide more capacity. Operators could defer video services on HSDPA to a later stage, but as video services consume a large amount of UMTS capacity they should be moved to HSDPA for improved efficiency. This will reduce the cost to deliver video services.
To ensure a mobile broadband user experience Motorola recommends early introduction of Quality of Services features for video.
"Motorola's HSDPA experience is industry leading and through the identification of these three guidelines, a result of the real-life trials, we can help operators significantly enhance the consumer experience of HSDPA at launch," said Raghu Rau, senior vice president, global marketing and strategy, Motorola Networks. "The trials are specifically designed to help build optimal performance HSDPA-enabled networks and to effectively deploy services on those networks."
HSDPA data transmission speeds to the end user will be similar to today's fixed broadband services and should enable operators to both realise greater margins from existing offerings while launching new data rich products at competitive prices. It also promises to smooth the transition of services like video streaming and music downloads from 'high potential' to commercially viable.