To enhance the Quality of service (QoS) communications over mobile ad hoc networks (MANETs), this paper proposes QoS-Aware Multipath Routing Protocol (QMRP). Delay is the most crucial factor for multimedia applications which can be minimized by providing more than one path between source-destination pair as well as choosing the path based on the quality in terms of reliability and stability of the link. To the best of our knowledge no one before included projected load; load introduced by the node requesting a path to a destination into the delay computation for a path between source-destination pair as well as maintaining loop freedom through the neighbor hop list of the source. The originality of the proposed protocol comes from the fact that it introduces this new parameter into route quality computation which makes QMRP unlike its precursors providing more accurate measure of the realistic delay as well as maintaining loop freedom of multiple node disjoint paths using neighbor hop list.

Cross layer communications between physical (PHY), MAC and routing layers interact to achieve QoS against the network and channel dynamics by minimizing delay and choosing more reliable and stable paths without requiring any additional resources. Performance evaluation of the proposed protocol against a single path AODV routing protocol using OPNET has been conducted. Results show that QMRP outperforms AODV in terms of E2E delay, packet delivery fraction (PDF) and route discovery frequency. However, routing overhead for QMRP is more than that of AODV due to the discovery of more one path in each route discovery process.

This paper proposes a novel multipath routing protocol for MANETs. The proposed protocol is a variant of the single path AODV routing protocol. The proposed multipath routing protocol establishes nodedisjoint paths that have the lowest delays based on the interaction of many factors from different layers. Other delay aware MANETs routing protocols don't consider the projected contribution of the source node that is requesting a path into the total network load. The implication is that end to end delay obtained through the RREQ is not accurate any more. On the contrary of its predecessors, the proposed protocol takes into consideration the projected contribution of the source node into the computation of end to end delay. To obtain an accurate estimate of path delay, the proposed multipath routing protocol employs cross-layer communications across three layers; PHY, MAC and Routing layers to achieve link and channel-awareness and creates an update packet to keep the up to date status of the paths in terms of lowest delay. The performance of the proposed protocol investigated and compared against the single path AODV and multipath AOMDV protocols through simulation using OPNET. Results have shown that our multipath routing protocol outperforms both protocols in terms of average throughput, end to end delay and packet dropped.

Scheduling is a fundamental component in resource (bandwidth and power) management in NG wireless networks and plays the main role in providing QoS requirements such as delay, throughput and packet loss for different classes of service in 802.16d networks. In this paper we propose a novel scheduling algorithm Strict Priority Based Adaptive modulation and Coding (SP_AMC_Based) that can grantee QoS between different connections belong to different users by the means of cross layer design between MAC and PHY layers in the process of bandwidth allocation to the contrary of most existing protocols that are base solely on MAC layer. Without loss of generality, the protocol serves a number of users with different connections (flows) that have different QoS requirements. The scheduler considers user current channel condition, connection QoS requirement and packet delay to select a user to be scheduled .The proposed scheduling algorithm is investigated through simulation and performance comparison with WFQ[l]scheduler. The results show a better performance of the proposed scheduler compared with WFQ algorithm.