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Wireless Body Sensor Networks (WBSNs) are becoming increasing popular in a number of healthcare applications. A particular requirement of WBSNs in a healthcare system is the transmission of time-sensitive and critical data, captured by heterogeneous biosensors, to a base station while considering the constraints of reliability, throughput, delay and link quality. However, the simultaneous communication among various biosensors also raises the possibility of congestion on nodes or transmission links. Consequently, the likelihood of a number of untoward situations increases, such as disruption (high delays), packet losses, retransmissions, bandwidth exhaustion, and insufficient buffer space. The significant level of interference in the network leads to a higher number of collisions and retransmissions. The selection of an optimized route to cope with these issues and satisfy the QoS requirements of a WBSN has not been well-studied in the relevant literature. In this regard, we propose a multi-constraint, Intra-BAN, QoS-Aware Routing Protocol (referred to as MIQoS-RP) which introduces an improved, multi-facet routing metric to optimize the route selection while satisfying the aforementioned constraints. The performance of the proposed protocol is evaluated in terms of average end-to-end delay, throughput and packet drop ratio. The comparison of MIQoS-RP with the existing routing protocols demonstrates its efficacy in terms of the selected criteria. The results show that the MIQoS-RP achieves improved throughput by 22%, average end-to-end delay by 29% and packet drop ratio performance by 41% as compares to existing schemes.

Wireless Body Sensor Network (WBSN) is deployed in delay-sensitive application scenarios where providing Quality-of-Service (QoS) is utmost important. The QoS-aware routing protocol not only discovers a route from source to destination but also satisfies QoS requirements in heavily loaded wireless networks. Emergency / critical data packets must reach the intended destination without incurring significant delays and fulfill multiconstrained demands (reliability, delay, Packet Delivery Ratio (PDR)) of heterogeneous applications. Congestion occurs in heavy traffic situation when the incoming traffic load exceeds the capacity of transmission link, buffer overflows, packet collision, channel contention. Consequently, it impacts QoS in terms of packet loss, end-to-end delay and PDR. Moreover, the selection of poor links/routes may have detrimental impacts of the performance of WBSN and there can be significant variations in throughput, delay, network lifetime, route stability performance. Majority of the existing priority-aware routing protocols proposed for Medium Access Control (MAC) layer to solve the slot allocation problem by which data packets are classified into different categories. However, less attention has been given to traffic prioritization at network layer for data categorization. Furthermore, optimized traffic prioritization has been overlooked, thereby increases the data redundancy, queue/link delay, data loss and decreases the reliability of the network, and it does not satisfy the QoS requirements of WBSN and affects the critical data to be delivered in a less privileged manner. This work proposes the Low Latency Traffic Prioritization scheme for QoS-aware routing (LLTP-QoS). The LLTP-QoS is designed to enhance the transmission of critical data in a privileged manner (reliability) and avoids the end-to-end delay. The performance of proposed scheme is evaluated in terms of throughput, average end-to-end delay, PDR, normalized routing load, network lifetime through extensive simulations using Network Simulator-2 (NS2). The simulation results verified improved performance of proposed LLTP-QoS scheme as compared to existing routing protocols. INDEX TERMS Wireless body sensor networks, physiological data, QoS, data traffic, priority queue, packet delivery ratio, latency.

Abstrak Teknologi suara lewat protocol internet (VoIP) lebih murah dan tidak memerlukan infrastruktur baru karena sudah tersedia pada jaringan komputer global (IP). (voice, video and text). To justify the research of the improved PQ algorithm be compared against the algorithm existing.

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Software Defined Networks (SDN) is a new network paradigm that emerged to offer better network management through the separation of network control logic and data forwarding element. This separation speed up network innovation without the need to rely on the vendor-proprietary interface for network element configuration to forward packets. However, SDN is flow driven network, for each arrived flow, a feasible path is computed to forward the flow to its destination. Afterward, the SDN control logic process the corresponding routing and instruct the set of data forwarding elements to install them on their Flowtable to guide the routing process. Unfortunately, the network changes more frequently in dynamic large-scale networks and the Flowtable is a constraint with limited space. These challenges require the SDN controller to compute paths more often which may also need a large number of flow routing rules placement. In addition, the frequency of communication link failures increases lately. The successful deployment of SDN heavily depends on how it satisfies the reliability requirement with uninterrupted services. Several studies were conducted to compute the optimal path for data forward to meet their Quality of Service demand. Other studies focus on reducing the frequency of link failure. Some studies were conducted to manage the constraint Flowtable resources. This survey focuses on Routing rules placement, unoptimized routing, link, and switch load balancing, failure detection, and recovery. The paper extensively discusses each issue and analyzes the weakness of the current solutions. Finally, it highlights potential challenges that need future research attention.

Software Defined Networks (SDN) introduced better network management by decoupling control and data plane. However, communication reliability is the desired property in computer networks. The frequency of communication link failure degrades network performance, and service disruptions are likely to occur. Emerging network applications, such as delaysensitive applications, suffer packet loss with higher Round Trip Time (RTT). Several failure recovery schemes have been proposed to address link failure recovery issues in SDN. However, these schemes have various weaknesses, which may not always guarantee service availability. Communication paths differ in their roles; some paths are critical because of the higher frequency usage. Other paths frequently share links between primary and backup. Rerouting the affected flows after failure occurrences without investigating the path roles can lead to post-recovery congestion with packet loss and system throughput. Therefore, there is a lack of studies to incorporate path criticality and residual path capacity to reroute the affected flows in case of link failure. This paper proposed Reliable Failure Restoration with Congestion Aware for SDN to select the reliable backup path that decreases packet loss and RTT, increasing network throughput while minimizing post-recovery congestion. The affected flows are redirected through a path with minimal risk of failure, while Bayesian probability is used to predict post-recovery congestion. Both the former and latter path with a minimal score is chosen. The simulation results improved throughput by (45%), reduced packet losses (87%), and lowered RTT (89%) compared to benchmarking works.