This is a simulator written in Tcl to simulate a network node carrying GSM and GPRS traffics with qos mechanisms. The payload type including circuit-switched voice, VoIP and web traffic, and the performance including packet drop, delay can be analyzed. The implemented qos mechanism is DiffServ, with 4 RED queues for different services with different priorities.
This thesis is about wireless communication in shared radio spectrum. Its origin and
motivation is ideally represented by the two quotations from above. In this thesis, the
support of Quality-of-Service (qos) in cognitive radio networks is analyzed. New
approaches to distributed coordination of cognitive radios are developed in different
spectrum sharing scenarios. The Wireless Local Area Network (WLAN) 802.11 proto-
col of the Institute of Electrical and Electronics Engineers (IEEE) (IEEE, 2003) with
its enhancement for qos support (IEEE, 2005d) is taken as basis. The Medium Access
Control (MAC) of 801.11(e) is modified to realize flexible and dynamic spectrum
assignment within a liberalized regulation framework.
Providing qos while optimizing the LTE network in a cost efficient manner is
very challenging. Thus, radio scheduling is one of the most important functions
in mobile broadband networks. The design of a mobile network radio scheduler
holds several objectives that need to be satisfied, for example: the scheduler needs
to maximize the radio performance by efficiently distributing the limited radio re-
sources, since the operator’s revenue depends on it.
With the rapid growth in the number of wireless applications, services and devices,
using a single wireless technology such as a second generation (2G) and third gener-
ation (3G) wireless system would not be efficient to deliver high speed data rate and
quality-of-service (qos) support to mobile users in a seamless way. The next genera-
tion wireless systems (also sometimes referred to as Fourth generation (4G) systems)
are being devised with the vision of heterogeneity in which a mobile user/device will
be able to connect to multiple wireless networks (e.g., WLAN, cellular, WMAN)
simultaneously.
This book addresses two aspects of network operation quality; namely, resource
management and fault management.
Network operation quality is among the functions to be fulfilled in order to offer
quality of service, qos, to the end user. It is characterized by four parameters:
– packet loss;
– delay;
– jitter, or the variation of delay over time;
– availability.
Resource management employs mechanisms that enable the first three parameters
to be guaranteed or optimized. Fault management aims to ensure continuity of service.
Mobile radio communications are evolving from pure telephony systems to multimedia
platforms offering a variety of services ranging from simple file transfers and audio and
video streaming, to interactive applications and positioning tasks. Naturally, these services
have different constraints concerning data rate, delay, and reliability (quality-of-service
(qos)). Hence, future mobile radio systems have to provide a large flexibility and scal-
ability to match these heterogeneous requirements.
