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In order to provide ubiquitous access for the users, future generation network integrate a multitude of radio access technologies (RAT’S) which can interoperate between them. However, the most challenging problem is the selection of an optimal radio access network, in terms of quality of service anywhere at anytime. This paper proposes a novel ranking algorithm, which combines multi attribute decision making (MADM) and Mahalanobis distance. Firstly, a classification method is applied to build a classes which having the homogeneous criteria. Afterwards, the Fuzzy AHP, MADM method is applied to determine weights of inter-classes and intraclasses. Finally, Mahalanobis distance is used to rank the alternatives. The simulation results show that the proposed algorithm can effectively reduce the ranking abnormality and the number of handoffs

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The expected growth in radio access technologies (RAT's) such as wireless technologies (802.11a, 802.11b, 802.15, 802.16, etc.) and cellular networks (GPRS, UMTS, HSDPA, LTE, etc.) requires efficient vertical handoff algorithm. Variety of vertical handoff algorithms (VHA) have been proposed to help the user to select dynamically the best access network (BAN) in terms of quality of service. The objective of this paper is to provide an optimized network selection decision that allow mobile users to choose the BAN with seamless manner and to exploit a minimum of criteria for all traffic classes namely: background conversational, interactive and streaming. Our optimized algorithm combines two multi attribute decision making (MADM) methods such as analytic network process (ANP) method to weigh the criteria, and the novel method based on mahalanobis distance (NMMD) to rank the alternatives.

Constantly faster, mobile terminals are developing, as well as wireless networks, to satisfy the growth of “Always Best Connected” demand. Users nowadays want to access the best available wireless network, either from 3GPP or IEEE group technologies, wherever they are, without losing their sessions. Consequently, mobile terminals must seamlessly transfer the communications to another access technology (vertical handover) if needed, as they often move into heterogeneous wireless environments. This work aims to optimize the network selection step in the vertical handover process. Multiattribute Decision-Making methods naturally fit this context. Nevertheless, they make wrong handover decisions sometimes, due to imprecise data collected from the metrics. This manuscript presents the use of a hybrid method, combining the fuzzy technique for order preference by similarity to the ideal situation and fuzzy analytic network process, in the network selection, to improve the quality of service and avoid, as much as possible, unnecessary handovers. The results demonstrate that this combination is the best, compared to the other methods of the same type in the network selection context.

The most important issue in the fourth generation (4G) of wireless communications is how to select the most suitable access network to be used for communication when several access networks are available. To achieve this issue, network selection is intended to choose the most suitable network in terms of quality of service (QoS) for mobile users. This paper proposes a new technique for network selection decision. This technique combines two multi attribute decision making (MADM) methods such as diff-analytic hierarchy process (Diff-AHP) and the technique for order preference by similarity to an ideal solution (TOPSIS). The Diff-AHP method is extension of AHP method which be used to find the differentiate weights of available networks by considering each criterion and TOPSIS method is used to rank the alternatives.

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