80 research outputs found
Analysis of GPRS Limitations
The General Packet Radio Service (GPRS) is a new standard for mobile
data communications, which is implemented under the existing
infrastructure of Global System for Mobile Communications (GSM). The
promise capability of handling Internet Protocol traffic enables instant
and constant connection to global network regardless of location and
time. With its packet-based nature, the new technology facilitates new
applications in wireless communications that have not been available
previously. Nonetheless, there are numbers of limitations that have to be
taken into consideration b~fore this technology can be implemented
commercially. Despite all arguments and challenges, the GPRS system is
here to stay and evolving towards the third generation mobile
communications. This report covers the background of the GPRS and
discusses the issues involved in implementing this current technology
besides considering the deployment of third generation networks beyond
GPRS
Cross-layer signalling and middleware: a survey for inelastic soft real-time applications in MANETs
This paper provides a review of the different cross-layer design and protocol tuning approaches that may be used to meet a growing need to support inelastic soft real-time streams in MANETs. These streams are characterised by critical timing and throughput requirements and low packet loss tolerance levels. Many cross-layer approaches exist either for provision of QoS to soft real-time streams in static wireless networks or to improve the performance of real and non-real-time transmissions in MANETs. The common ground and lessons learned from these approaches, with a view to the potential provision of much needed support to real-time applications in MANETs, is therefore discussed
Scalable Multiple Description Coding and Distributed Video Streaming over 3G Mobile Networks
In this thesis, a novel Scalable Multiple Description Coding (SMDC) framework is proposed. To address the bandwidth fluctuation, packet loss and heterogeneity problems in the wireless networks and further enhance the error resilience tools in Moving Pictures Experts Group 4 (MPEG-4), the joint design of layered coding (LC) and multiple description coding (MDC) is explored. It leverages a proposed distributed multimedia delivery mobile network (D-MDMN) to provide path diversity to combat streaming video outage due to handoff in Universal Mobile Telecommunications System (UMTS). The corresponding intra-RAN (Radio Access Network) handoff and inter-RAN handoff procedures in D-MDMN are studied in details, which employ the principle of video stream re-establishing to replace the principle of data forwarding in UMTS. Furthermore, a new IP (Internet Protocol) Differentiated Services (DiffServ) video marking algorithm is proposed to support the unequal error protection (UEP) of LC components of SMDC. Performance evaluation is carried through simulation using OPNET Modeler 9. 0. Simulation results show that the proposed handoff procedures in D-MDMN have better performance in terms of handoff latency, end-to-end delay and handoff scalability than that in UMTS. Performance evaluation of our proposed IP DiffServ video marking algorithm is also undertaken, which shows that it is more suitable for video streaming in IP mobile networks compared with the previously proposed DiffServ video marking algorithm (DVMA)
End-to-end admission control of multiclass traffic in WCDMA mobile network and wireline differentiated services
Master'sMASTER OF ENGINEERIN
Satellite Communications
This study is motivated by the need to give the reader a broad view of the developments, key concepts, and technologies related to information society evolution, with a focus on the wireless communications and geoinformation technologies and their role in the environment. Giving perspective, it aims at assisting people active in the industry, the public sector, and Earth science fields as well, by providing a base for their continued work and thinking
Design and analysis of optimal resource allocation policies in wireless networks
Ph.DDOCTOR OF PHILOSOPH
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