Comparative Analysis of Quality of Service Scheduling Classes in Mobile Ad-Hoc Networks

Quality of Service (QoS) is now regarded as a requirement for all networks in managing resources like bandwidth and avoidance of network impairments like packet loss, jitter, and delay. Media transfer or streaming would be virtually impossible if QoS parameters were not used even if the streaming protocols were perfectly designed. QoS Scheduling classes help in network traffic optimization and the priority management of packets. This paper presents an analysis of QoS scheduling classes using video traffic in a MANET. The main objective was to identify a scheduling class that provides better QoS for video streaming. A simulation was conducted using NetSim and results were analyzed according to throughput, jitter, and delay. The overall results showed that extended real-time Polling Service (ertPS) outperformed the other classes. ertPS has hybrid features of both real-time Polling Service (rtPS) and Unsolicited Grant Service(UGS) hence the enhanced performance. It is recommended that ertPS scheduling class should be used in MANET where QoS consideration is utmost particularly in multimedia streaming applications.

Multiple Power-Saving MSSs Scheduling Methods for IEEE802.16e Broadband Wireless Networks

This work proposes two enhanced multiple mobile subscriber stations (MSSs) power-saving scheduling methods for IEEE802.16e broadband wireless networks. The proposed methods are designed for the Unsolicited Grant Service (UGS) of IEEE802.16e. To reduce the active periods of all power-saving MSSs, the base station (BS) allocates each MSS fewest possible transmission frames to retrieve its data from the BS. The BS interlaces the active periods of each MSS to increase the amount of scheduled MSSs and splits the overflowing transmission frames to maximize the bandwidth utilization. Simulation results reveal that interlacing the active periods of MSSs can increase the number of scheduled MSSs to more than four times of that in the Direct scheduling method. The bandwidth utilization can thus be improved by 60%–70%. Splitting the overflowing transmission frames can improve bandwidth utilization by more than 10% over that achieved using the method of interlacing active periods, with a sacrifice of only 1% of the sleep periods in the interlacing active period method.

Available Data Packet Size Policy for Unsolicited Grant Service in the Power Saving Multi-Channel MAC Protocol

With Multi-channel MAC protocols, transmission pairs can send data packet simultaneously. Hence, higher network throughput can be achieved. The developing of 802.11s standard provides the power saving model multi-channel MAC protocol (PSM-MMAC) framework, which divides into negotiation phase and data phase. All the users select appropriate channels to transmit data in dedicated channel during negotiation phase, then the users will switch the transceivers to the selected channel to transfer data packet by RTS/CTS handshake. While taking the size of data window constraints, therefore how to design the data packet size is the key issue of PSM-MMAC in saturation network case. In this paper, we propose a new policy that can adjust the size of data packet based on the channel occupancy and the fairness of user access for unsolicited Grand Service, which has strict requirements on the delay jitter and maximum reserved traffic rate. We also develop the probabilistic statistical analysis model to compare the performance of previous policy and our proposed policy. Simulation results verify our analysis model, and show our policy has the superior performance of the PSM-MMAC to the previous scheme.

Optimal Packetization Interval for VoIP Applications Over IEEE 802.16 Networks

An analysis of the impact of the packetization interval for constant bit rate traffic has been done in the context of the IEEE 802.16 MAC layer. Bandwidth used for overheads which include lower layer headers as well as retransmissions at the MAC layer is considered. An optimal packetization interval selection method for delay sensitive applications such as VoIP is proposed. Enhancements to the Unsolicited Grant Service retransmission strategy are proposed to further improve delay and minimize packet loss while making efficient use of the limited bandwidth resource.