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Even though network externality plays an important role in users’ motivations to use services or products, the implications of this are not clear because previous studies did not distinguish between the number of peers and the number of total users. Thus, the purpose of this paper is to demonstrate that there is a difference between the two network externalities, i.e., the number of peers and the total number of users. To accomplish this, the perception of quality of life is considered to have an impact on the effects of the two different network externalities.

Data were collected from a survey that covered 508 online game players in South Korea, and the two hypotheses of “player experience of need satisfaction” from self-determination theory as well as user gratification theory (UGT) were assessed using structural equation modeling.

The results indicate that people consider the total number of users and the number of peers differently. In addition, the effects of the total number of users and the number of peers vary according to respondents’ perceived life quality in four dimensions: loneliness, happiness, satisfaction with life (SWL), and escapism. In particular, people’s offline tendencies are reflected online in terms of loneliness, whereas online life compensates for a lack of enjoyment offline.

The authors verify that UGT can affect the network externality by considering perceived quality of life (loneliness, SWL, happiness, and escapism) as a moderating effect.

This paper aims to the increasing need for high-speed low-power data transmissions over frequency-selective fading channels has drawn attention to suggest dual-carrier modulation (DCM) for multiband orthogonal frequency division multiplexing (OFDM) transceivers for ultra wideband (UWB) wireless personal area network (WPAN).

Under frequency-selective fading channel conditions, the decoder is not sufficient enough to decode the transmission bits of severely attenuated data tones. Hence, the authors suggest DCM for a multiband OFDM transceiver because of its multiple capability of providing both frequency diversity and coding gain. It also resulted in low bit-error-rate (BER) at a given signal- to-noise ratio when compared to conventional multiband OFDM system. To achieve an optimised BER, DCM transforms four re-ordered bits into two quaternary phase shift keying symbols and further transforms to two 16-quadrature amplitude modulation-like (16-QAM) symbols with a suitable mapping technique, and at the receiver end, they are decoded with maximum likelihood decision rule. After performing the transformation, the outage probability and average BER expressions are derived to analyse the system performance.

DCM is suitable for high data rate transmission and is immune to frequency-selective fading. The outage and BER performance outstands over conventional multiband OFDM transceiver because of the inclusion of DCM mapping.

It is widely used in WPANs such as high definition multimedia interface and wireless universal serial bus.

This paper derives novel closed-form outage probability and a tight upper bound on average BER expressions for DCM-based multiband OFDM UWB transceiver over frequency-selective Nakagami-m fading channels for any arbitrary value of m. For this, moment-generating function of sum of squared, independent and identically distributed (i.i.d.) Nakagami-m random variables are used. Further, the system performance is also validated for the case of exponential decaying power delay profile, and the simulation results are provided to check the accuracy of the derived expressions.