A significant proportion of the traffic on the 4th generation of mobile networks (4G) will be interactive multimedia traffic. This chapter presents the development and evaluation of an edge device model for the lu interface of a 4G network for mapping the Quality of Service (QoS) requirements and traffic characteristics of aggregated IP traffic flows belonging to multiple classes of continuous media (Audio and Video) sources and data classes from the core network onto a single ATM Virtual Channel (VC) at the access network. This model was developed as part of a wider range of research activity focused on supporting QoS in future mobile networks.
Traditionally, multimedia services over the Internet have been restricted to the wireline environment and accessed primarily via desktop and laptop computers. However, the current trend of ubiquitous and pervasive computing is to provide mobile users with the same level of multimedia experience as available over a wireline infrastructure adhered specifically for the mobile computing environment. This includes services such as smart mobile phones, mobile TV, and audio and video sharing applications (e.g., iTunes, Napster, YouTube, Skype, etc.) that have become increasingly popular among a large population of users.
According to 3G, NTT DoCoMo plans to develop next generation phones which will be equipped with the latest version of Microsoft Windows Mobile operating system (“NTT DoCoMo”, 2007). Such phones will enable user’s interaction with PC through applications such as Outlook Mobile and Internet Explorer Mobile. In addition to accessing wireless LAN networks for IP telephony, these phones will provide users with touch screen facilities for operating innovative functions. For example, users will be able to access YouTube Mobile content and Mobile TV channels through streaming media software. Further the recent mobile phone provides facilities for music, 3D games, video, and high-speed Internet access. It comes with high resolution colour screen to facilitate enhanced-quality multimedia.
These multimedia services and applications require adequate level of QoS guarantees from the network in terms of the key QoS parameters, viz. delay, jitter, bandwidth, loss, and so forth, to maintain the perceptual quality and the integrity of the content. Over the years, the wireline Internet infrastructure has evolved from a passive, best-effort, QoS-less data transfer pipe to a real-time, QoS-sensitive, multiservice delivery platform capable of servicing the QoS requirements of different types of medias. During this transformation phase, the two very inherent and powerful characteristics of the Internet: its packet switching architecture and the uncomplicated IP protocol as its delivery protocol data unit (PDU) have been preserved.
Key Terms in this Chapter
Quality of Service (QoS): The level of service required by an application expressed in terms of certain parameters (e.g., bandwidth, maximum delay, loss, etc.).
Heterogeneous Sources: A class of traffic consisting of a number of flows of the same traffic category (e.g., video or voice) but different QoS parameters (e.g., inter-arrival time, packet length distribution, etc.).
Virtual Circuit: A logical circuit in an ATM network with its own set of QoS parameters (characteristics)
Queuing Model: Abstraction of a real queuing system where queueing theory could be applied to estimate the performance of the system.
Vacation Period: In queuing system, the duration of time a particular queue is not served by the server.
Streaming Media: Flow based medias such as video and audio that is generally continuous in nature and have strong QoS characteristics such as delay and jitter.
lu Interface: Interface between the core network and access network of 3G and 4G mobile networks.
4G: Fourth generation of mobile networks.
Edge Device: A type of packet forwarding device used in the network and located at the edges between two subnets.