Multimedia video applications on mobile devices become pervasive and basically crept into every part of our life. Historically, the wireless standards tend to make the LAN faster and now we have the latest version 11 ac with new advanced features like multi-user (MU) transmission on downlinks. Basically, the LAN standards extend in two different directions. First, increasing performance while reducing the power consumption. Second, as the wireless LAN has become so successful, new concepts, such as Internet of Things, lead to the problem of the interference since many devices use the same frequency spectrum at the same time. While downlink MU feature tries to reduce the interference problem, setting up the LAN for the devices to have a fair opportunities within the network is of high importance. As the IEEE 802.11 ac standard left the fairness to the implementation, in this paper, we present practical schemes to deal with this issue in video streaming applications. The proposed schemes are mathematically modeled and their tractable optimal solutions are presented and verified. The simulation studies show that the proposed schemes meet the fairness criteria while guaranteeing the required quality and performance.

The inherent characteristics of the wireless channel, such as broadcast communication and high variability in channel quality, make it difficult to achieve high throughput in wireless mesh networks (WMNs). However, some innovative techniques like wireless inter-flow network coding and opportunistic routing leverage the broadcast nature of the wireless channel to improve the throughput. In addition, in order to cope with channel quality variation, the transmission rate can be adjusted using a rate adaptation algorithm. In this paper, we study how these fundamental techniques collaborate and how they can be combined into an integrated solution. We suggest Multi Rate Opportunistic Routing-aware Network Coding (MRORNC) as an integrated cross-layer approach that jointly determines the coded packet, potential next hops, and transmission rate using a novel metric. The simulation results demonstrate that the suggested approach can achieve higher throughput compared to the rate-oblivious opportunistic routing-aware network coding solutions.

According to the current IEEE 802.11e HCCA standard, if more than three video sessions are to be in service in a WSTA, some of them must share the TXOP because the number of TSIDs assigned to video transmission is two. In order to resolve the problem, we devise a method in which up to 15 video sessions can be accommodated by slightly modifying the frame structure while maintaining the compatibility with the current standard. Experimental results show that our method guarantees the transmission bandwidth requested by each video session.

An analysis is provided of queuing models in virtual route networks for which a pacing window flow control mechanism is used. An input queue is introduced to describe the waiting system where messages prevented from entering the network are stored in first-come, first-served manner. Both finite and infinite capacity are considered. The model leads to a Markovian queuing system, which is fully solved by matrix-geometric methods. The analytical results show that the optimal window size which maximizes the power criterion including the admission delay is nearly twice the number of hops (nodes of the network) for the model with infinite input-queue capacity. This rule of thumb also applies to the finite-capacity model with certain restrictions. Simulations are presented to verify the analytical results.>