Article,
Delivery of Broadcast Services in 3G Networks
IEEE TRANSACTIONS ON BROADCASTING, 53 (1): 188-199 (March 2007)
Abstract
TV is regarded as a key service for mobile devices.
In the past, Mobile TV was often associated with broadcast transmission.
However, unicast technology is sufficient in many cases,
especially since mobile users prefer to access content on-demand,
rather than following a fixed schedule. In this paper we will focus
on 3G mobile networks, which have been primarily optimized
for unicast services. Based on a traffic model we will discuss the
capacity limits of 3G networks for unicast distribution of Mobile
TV. From the results it can be concluded that the capacity is sufficient
for many scenarios. In order to address scenarios in which
broadcast is a more appropriate technology, 3GPP has defined a
broadcast extension, called Multimedia Broadcast Multicast Service
(MBMS). MBMS introduces shared radio broadcast bearers
and has thus the capabilities of a real broadcasting technology.
We will give a short overview about MBMS including a discussion
on MBMS capacity. Since MBMS is primarily a new transport
technology, additional application and service layer technologies
are required, like electronic service guide and service protection.
These mechanisms are standardized by the Open Mobile Alliance
(OMA) and are favorably combined with MBMS or 3G unicast
distribution in order to create complete end-to-end solutions. In
order to optimize a system for delivery of broadcast services over
3G networks, the advantages of broadcast and unicast should be
combined.We argue that hybrid unicast-broadcast delivery offers
the best system resource usage and also the best user experience,
and is thus favorable not only for broadcast delivery in 3G networks,
but actually also for non-cellular broadcast systems like
DVB-H or DMB.
