Wyniki wyszukiwania - BazTech

1

A Host Based Autonomous Scheme for Seamless Vertical Handover

Hussain R., Malik S.A., Riaz R. A., Ahmed S., Shafiq G., Iqbal A., Abrar S., Khan S. A.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 9b

314-318

EN

In this paper we suggest a host based, end-to-end selfreliant scheme for handover in heterogeneous network environment. It directly involves the correspondent node in the handover process. The proposed scheme imitates the Network Address Translation. It maps a logical address to another logical address. It modifies the address information in the header of the packet while it is in transition. In principle the process is identical to the NAT box operation, but the goal is different. While NAT is primarily used in conjunction with masquerading to hide the private IP address space, HaMAT works in conjunction with MIH and serves to hide the IP address change of the mobile node encountered due to the vertical handover. HaMAT is a functional entity just like Media Independent Handover Function, and it resides inside the Mobile Node and Correspondent Node. By eliminating the need for rerouting, tunneling and route optimization as required in Mobile IP, HaMAT achieves high performance results in terms of handover delay, end to end packet latency, jitter and the overhead involved. The service disruption time for HaMAT is as low as 10 msec compared to reported handover delays of 260 msec and 1 sec for MIPv4 and MIPv6 respectively.

PL

W artykule zaproponowano bazujący na hoście schemat przełączania typu handover w niejednorodnym środowisku sieciowym. Schemat imituje Network Address Translation i mapuje logiczny adres orasz modyfikuje nagłówek w pakiecie.

2

Evolutionary paths in wireless communication systems

Michalski W.

Journal of Telecommunications and Information Technology

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2005

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nr 3

105-111

EN

The paper contains a review and analysis of evolutionary paths of seven most important, from network development strategy point of view, wireless communication systems, especially the WLAN operating according to the IEEE 802.11 standard. With respect to WLAN, trends related to evolution toward mobile network and self organizing network as well as toward integration of WLAN and GSM using GPRS are presented. Concerning WLAN architecture development, evolution paths toward distributed controlled network as well as centrally coordinated and controlled network are described. Moreover, analysis includes cellular mobile radio systems, wireless personal networks, wide area wireless packet data systems, satellite-based mobile systems, paging/messaging systems and cordless telephones. With respect to these systems, general evolution process and trends associated with this process are described.

3

Seamless roaming between UMTS and IEEE 802.11 networks

Matusz P., Machań P., Woźniak J.

Journal of Telecommunications and Information Technology

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2004

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nr 4

21-27

EN

Mobile Internet access is currently available mainly using 2G/3G cellular telecommunication networks and wireless local area networks. WLANs are perceived as a local complement to slower, but widely available cellular networks, such as existing GSM/GPRS or future UMTS networks. To benefit from the advantages offered by both radio access networks, a mobile user should be able to seamlessly roam between them without the need to terminate already established Internet connections. The goal of this paper is to present an overview of the profitability of performing vertical handovers between UMTS and IEEE 802.11b using Mobile IP. Several simulations have been carried out using NS-2, which prove that handovers from IEEE 802.11b to UMTS can, under certain circumstances, be profitable not only when there is no more IEEE 802.11b coverage. Simulation results show that a mobile user should be able to roam between these networks depending on the current available channel bandwidth and quality, generated traffic type and number of users in both of them.

4

Adaptive handover control in IP-based mobility networks

Park T., Dadej A.

Journal of Telecommunications and Information Technology

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2003

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nr 2

62-70

EN

In this paper, we propose framework for an adaptive handover control architecture (AHCA), which aims at enhancing overall IP handover performance while maximising utilisation of resources in wireless access networks. The IP handover procedures in the AHCA adapt dynamically to network conditions, as well as to a wide range of user profiles and application quality of service (QoS) requirements. To confirm our expectations that the AHCA will bring performance benefits in heterogeneous mobile IP networking environment, we have investigated basic performance characteristics of different handover mechanisms. The preliminary simulation results demonstrate that the AHCA will bring significant performance improvements as compared with non adaptive IP handovers.

5

Systemy komórkowe do roku 2010

Dąbrowski M.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2001

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nr 8-9

502-514

PL

Omówiono prognozy rynku systemów komórkowych 3G, problemy technologiczne i techniczne związane z opracowywaniem standardów i systemów, a także sprawy dostępnych częstotliwości i sprawy regulacji prawnych.

EN

Potential market demand for the 2G and 3G until 2010, standardization processes, available technology and changing role of the main mobile players are described.