• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.4
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• pp.247-256
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• 2013

According to the complete standard document for PHY/MAC layer of visible light communication through the IEEE 802.15.7 WG on Sept. 2011, visible light communication lays a good foundation for developing a variety of application services. Thus, visible light communication moves to the advanced research period for developing application services, but most of applications are limited only to PtP service model. However, PtMP communication environment for VLC is required to accommodate more various applications. In this paper, we analyze an effect of key parameters on network performance in the star topology based visible personal area network system. We implement a simulator with considering attributes of PHY and MAC layer which are defined by IEEE 802.15.7 standard documents, and analyze the VLC performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.8
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• pp.719-724
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• 2013

Visible light communication based wireless personal area network (WPAN) has recently remained in the center of attention, as it shows a lot of promise to a be a perfect replacement for the contemporary Radio frequency (RF) communication at least in the indoor environment. A commercially deployable VLC based WPAN must support diverse traffic requirement for different kinds of service. In this paper, we have proposed an innovative bandwidth allocation scheme for VLC based WPAN. We wish to allocate bandwidth adaptively for users in a network where bandwidth for each user is allocated scalably. Our aim is to allow maximum number of users in a VLC based WPAN where each user is guaranteed their required QoS. The simulation results justify that the proposed scheme is better than the conventional scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.3C
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• pp.224-232
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• 2012

Priority MAC is an important issue in every communication system when we consider differentiated service applications. In this paper, we propose a mechanism to support priority MAC based on multi-parameters for IEEE 802.15.7 visible light communication (VLC). By using three parameters such as number of backoff times (NB), backoff exponent (BE) and contention window (CW), we provide priority for multi-level differentiated service applications. We consider beacon-enabled VLC personal area network (VPAN) mode with slotted version for random access algorithm in this paper. Based on a discrete-time Markov chain, we analyze the performance of proposed mechanism under non-saturation environments. By building a Markov chain model for multi-parameters, this paper presents the throughput and transmission delay time for VLC system. Numerical results show that we can apply three parameters to control the priority for VLC MAC protocol.

• International journal of advanced smart convergence
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• v.1 no.1
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• pp.14-18
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• 2012

This paper presents a fair MAC protocol based on the CSMA/CA algorithm in visible light communication (VLC) networks. The problem of bandwidth sharing among differentiated priority in VLC networks can be solved by using number of backoff time and backoff exponent parameters with AIFS. The proposed algorithm can achieve fair allocation of the bandwidth resource among differentiated priority. The two dimension Markov chain is assisted for analyzing the proposed mechanism about throughput and delay metrics. Numerical results show that our proposed algorithm improves the fairness among different traffic flows.