Due to copyright restrictions, the access to the full text of this article is only available via subscription.Visible light communications (VLC) is a high-speed wireless communication technology that has recently emerged. VLC uses the illumination infrastructure to meet broadband needs of bandwidth-hungry devices. Its high data rate, immunity to electromagnetic interference, ability to operate in an unlicensed band and high reuse factor position VLC as a strong alternative to existing communication technologies. The physical and medium access control (MAC) layers of VLC have been standardised in IEEE 802.15.7. Yet, theoretical performance bounds of the MAC layer have not been explored in detail so far. In this paper, we derive Markov-based performance bounds for the MAC layer of IEEE 802.15.7. We provide a thorough study of throughput, delay, power consumption, collision probability, transmission probability, access probability and packet discard probability using analytical analysis and simulations.Istanbul Development Agenc

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Due to copyright restrictions, the access to the full text of this article is only available via subscription.Visible light communication (VLC) uses the illumination infrastructure to provide high speed wireless connectivity. VLC has recently emerged as a promising alternative/complementary technology to conventional radio-frequency wireless access and has been standardized in IEEE 802.15.7. In this paper, we model the multiple access mechanism of IEEE 802.15.7 standard with a Markov chain and present simulation results for the network performance metrics including throughput, delay, and packet delivery.Qatar National Research Fun

Mobile Internet Protocol v6 (MIPv6) is a protocol that allows a mobile node (MN) to transparently maintain connections while moving from one subnet to another. Using the route optimization (RO) method in MIPv6 gives optimized routing and helps avoid triangular routing. In real-time applications such as video conference applications, quality of service (QoS) issues will increase especially in the handover process between subnets. This study investigates the performance of MIPv6 handover in IEEE802.11e standard in wireless environments. The investigation considers that handover for the MN moves between 2 home agents (HA). The system model’s fundamental performance limits are measured by packet delay variation, HA binding delay, and wireless local area network (WLAN) media access delay analysis metrics in video conference applications. According to the results of real-time simulations, network performance during the handover process can be effectively improved as the packet lost during handover decreased significantly from 43% in IEEE802.11b distributed coordination function (DCF) to 36% in IEEE802.11e hybrid coordination function (HCF). Furthermore, experimental results prove that IEEE802.11e connects to new HA roughly 20% quicker than IEEE802.11b, and IEEE802.11b has 100 times more time delay than IEEE802.11e. In addition to this, the WLAN media access delay of IEEE802.11b often reaches 0.00011 s as compared to 0.000005 s of IEEE802.11e. Thus, it is evident that the performance of IEEE802.11e in terms of packet delay variation, HA binding delay, and WLAN media access delay is better than IEEE802.11b. Likewise, it is noted that network speed during the handover process in IEEE802.11e can be considerably improved in a MIPv6 scenario.

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