caa a22 4500 606189947 CHVBK 20210128100853.0 cr unu---uuuuu 210128e20150301xx s 000 0 eng 10.1007/s10776-015-0261-4 doi (NATIONALLICENCE)springer-10.1007/s10776-015-0261-4 Modeling and Performance Analysis of an Improved Data Channel Assignment (DCA) Scheme for 3G/WLAN Mixed Cells [Elektronische Daten] [S. Nandakumar, Sibaram Khara] In this paper, we present an efficient data channel assignment (DCA) scheme for a mixed cell (i.e., a 3G cell with embedded WLANs). Our effort is essential to increase the data request (i.e., a call) handling capacity in 3G systems, with a ‘low request dropping probability'. In UMTS-first DCA scheme prefers 3G channel in dual coverage and reduces vertical handoffs from 3G to WLAN. But it deprives some users of high speed service of WLAN even when WLAN facility is available. On the contrary, a WLAN-first DCA scheme overcomes this problem by preferring WLAN system. But the overall call request dropping probability increases with increasing WLAN traffic and at some point, the benefit of WLAN cannot be achieved in a mixed cell. Further, most of the existing models do not consider the reality of non-identical WLAN-hotspots and bidirectional vertical handoffs, restricting the free mobility of the users across 3G and WLAN systems. We propose an improved DCA scheme based on WLAN-first access technique to maximize the usage of WLAN. The proposed model considers the reality of non-identical WLAN-hotspots and allows free mobility between 3G and WLAN. A proposed DCA scheme improves the dropping probability as blocked call request of WLAN are transferred to 3G. Our DCA scheme drops a request only when all the channels of both 3G and WLAN systems are busy. We derive an analytical model for proposed scheme and validate the same with a set of simulation results. We provide an extensive number of numerical results to show that our scheme performs far better than the existing models. The DCA modeling approach can be quite conveniently used for better planning of WLAN hotspots in the mixed cell. Springer Science+Business Media New York, 2015 Data channel assignment (DCA) nationallicence 3G/WLAN integration nationallicence Embedded WLAN nationallicence Handoff request nationallicence Vertical handoff nationallicence Nandakumar S. School of Electronics Engineering, VIT University, Vellore, Tamil Nadu, India aut Khara Sibaram School of Electrical, Electronics and Communication Engineering, Galgotias University, Greater Noida, U.P., India aut International Journal of Wireless Information Networks Springer US; http://www.springer-ny.com 22/1(2015-03-01), 10-28 1068-9605 22:1<10 2015 22 10776 https://doi.org/10.1007/s10776-015-0261-4 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10776-015-0261-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Nandakumar S. School of Electronics Engineering, VIT University, Vellore, Tamil Nadu, India aut NATIONALLICENCE 700 1- Khara Sibaram School of Electrical, Electronics and Communication Engineering, Galgotias University, Greater Noida, U.P., India aut NATIONALLICENCE 773 0- International Journal of Wireless Information Networks Springer US; http://www.springer-ny.com 22/1(2015-03-01), 10-28 1068-9605 22:1<10 2015 22 10776