A QoS-Aware Dynamic Bandwidth Allocation Algorithm for Passive Optical Networks with Non-Zero Laser Tuning Time

The deployment of new 5G services and future demands for 6G make it necessary to increase the performance of access networks. This challenge has prompted the development of new standardization proposals for Passive Optical access Networks (PONs) that offer greater bandwidth, greater reach and a higher rate of aggregation of users per fiber, being Time- and Wavelength-Division Multiplexing (TWDM) a promising technological solution for increasing the capacity by up to 40 Gbps by using several wavelengths. This solution introduces tunable transceivers into the Optical Network Units (ONUs) for switching from one wavelength to the other, thus addressing the ever-increasing bandwidth demands in residential broadband and mobile fronthaul networks based on Fiber to the Home (FTTH) technology. This adds complexity and sources of inefficiency, such as the laser tuning time (LTT) delay, which is often ignored when evaluating the performance of Dynamic Bandwidth Allocation (DBA) mechanisms. We present a novel DBA algorithm that dynamically handles the allocation of bandwidth and switches the ONUs’ lasers from one wavelength to the other while taking LTT into consideration. To optimize the packet delay, we introduce a scheduling mechanism that follows the Longest Processing Time first (LPT) scheduling discipline, which is implemented over the Interleaved Polling with Adaptive Cycle Time (IPACT) DBA. We also provide quality of service (QoS) differentiation by introducing the Max-Min Weighted Fair Share Queuing principle (WFQ) into the algorithm. The performance of our algorithm is evaluated through simulations against the original IPACT algorithm, which we have extended to support multi-wavelengths. With the introduction of LPT, we obtain an improved performance of up to 73% reduction in queue delay over IPACT while achieving QoS differentiation with WFQ.

Mobile Wi-Fi Based Scheduling of Cyber-Physical Systems in Healthcare

Wireless Body Area Networks (WBANs) and Wireless Local Area Networks (WLANs) have been widely regarded as solution providers for future Cyber-Physical Systems (CPS)-based ehealthcare amenities. The IEEE 802.11 standard specifies media access protocols in wireless networks, along with channel access methods. WBANs are expected to improve the existing healthcare services significantly, but several research challenges also have to be tackled for apt utilization of the technology. Guarantee of Quality-of-Service (QoS) differentiation between various health parameters, such as temperature and blood pressure, during mobility is a major challenge for the provision of ehealthcare services. The scheme proposed in this paper for the Mobile Wi-Fi based connectivity of WBANs is designed to provide QoS-based priorities for ehealthcare subscribers by altering the Contention Window (CW) for different applications of patient health monitoring. The relationship between CW and QoS is utilized to achieve efficient resource assignment. Three different health parameters, i.e., ECG (Electrocardiogram), BP (blood pressure) and temperature. are monitored using medical CPS in this work. The performance evaluation results, such as end-to-end packet delay and throughput for various data traffic classes reveal that the proposed scheme improves QoS provision.

Internet of Things, future networks, and the economics of virtual networks

The Internet of Things (IoT) gains momentum. Developments regarding smart grids, intelligent transportation systems, and low-power networks for smart cities constitute significant drivers in the evolution of network industries. IoT creates an array of new requirements for information and communications technology (ICT) data transmission: In addition to real-time and data geopositioning, new service characteristics result from the change of the traditional sender–receiver perspective of Transmission Control Protocol/Internet Protocol (TCP/IP) to content relevancy for many users (e.g. cloud computing) and dynamic changes of the state of devices. The future development and success of IoT hinges critically on the provision of heterogeneous quality of service (QoS) requirements which cannot be provided by best-effort TCP/IP Internet. It is thus not surprising that both in the US and the EU network neutrality regulations are currently being reconsidered. Alternative network logistics (virtual networks) dealing with heterogeneous QoS requirements of network traffic may require fundamental deviations from traditional Internet architectures. Corresponding logistics operating over joint physical infrastructures gain increasing attention under the heading of future networks (FNs). The goal of this article is to focus on the economic mechanisms of how the potentials of QoS differentiation in the context of FNs can be fully exploited and incentivized within innovative all-IP-based QoS traffic architectures.