Europe
: Motorola 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. Inset is Raghu Ra, Motorola Networks quoted below.
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.
About HSDPA
HSDPA is a key enabling
technology for mobile broadband. As the next step in the evolution
of UMTS, it provides significant performance and commercial benefits.
The spectral efficiency of HSDPA means that UMTS capacity is freed
up to carry more voice traffic, while its greater capacity supports
more users at mobile broadband speeds. For example, with phase 2 peak
download speeds of up to 14 Mbps, an entire novel can be downloaded
in around 10 seconds. HSDPA can be shown to reduce the cost per bit
of data delivered by up to two thirds compared to UMTS.