Applications with deterministic quality of service (QoS) requirements are becoming widespread, driving the evolution of wireless networks to meet strict performance demands. Wi-Fi 7, the latest generation of IEEE 802.11 standard, introduces Restricted Target Wake Time (R-TWT). It serves latency-sensitive traffic by providing contention-free channel access for certain devices and reducing their energy consumption. This paper evaluates the performance of R-TWT across diverse service types and network sizes in terms of worst-case latency, energy efficiency, collision rate, and throughput. The results, generated using the ns-3 simulator, show that R-TWT achieves bounded latency for sensitive traffic types, such as Internet of Things (IoT) and real-time (RT) applications. Moreover, R-TWT outperforms legacy mechanisms, i.e., Power Saving Mode (PSM) and Distributed Coordination Function (DCF), by achieving higher energy efficiency and a lower collision rate. Furthermore, R-TWT maintains stable and scalable performance as network size increases. This makes it a robust solution for latency-sensitive and energy-efficient wireless applications.

The IEEE 802.11 working group is currently finalizing the 802.11be amendment, which defines the features that will be supported by Wi-Fi 7 devices. A prominent new feature, termed Multi-Link Operations (MLO), is the ability for a device to operate on multiplelinks, i.e., on multiple frequency channels. Among the various MLO modes defined, Enhanced Multi-Link Single Radio (EMLSR) is attracting the interest of many vendors due to its potential for exploiting operations on multiple links through reduced hardware capabilities. In this paper, we first provide an overview of the standard specifications for EMLSR and describe the model underlying its implementation that we have contributed to the ns-3 simulator. The implemented model is rather flexible and enables to simulate various architectures differing for implementation cost, power consumption and performance. Then, we thoroughly evaluate several EMLSR configurations with the goal of shedding light on the possible alternatives that are available. We consider both a scenario of saturated conditions without interfering traffic and a scenario of non-saturated conditions with interfering traffic. Our study shows that the main differences in performance among the various EMLSR configurations are observed in the uplink direction and that EMLSR operations enable to reduce latency with respect to single-link devices at the cost of a slight increase in power consumption.

Wi-Fi 7, based on the IEEE 802.11be amendment, is designed to increase the maximum achievable throughput, expand the range of operating frequencies, and improve latency and jitter in worst-case scenario. In the context of the discussions to shape what Wi-Fi 8 will be, the IEEE 802.11 WG is evaluating multi-AP coordination as a strategy to further improve network performance in several aspects. MAC-driven multi-AP coordination strategies include coordinated Orthogonal Frequency Division Multiple Access (c-OFDMA), coordinated Time Division Multiple Access (c-TDMA), and coordinated Spatial Reuse (c-SR). In c-OFDMA, a set of APs transmit during a Transmission Opportunity on different channels, whereas in c-TDMA, the APs take turns transmitting on the same channel during a Transmission Opportunity. Instead, in c-SR, a set of APs transmit simultaneously on the same channel and during the same Transmission Opportunity. In this paper, we focus on c-SR. We introduce a c-SR interference model and present a strategy based on the proposed model for estimating groups of APs that can transmit successfully simultaneously. We implemented the proposed approach in the multi-AP coordination framework of ns-3 that we developed to analyze c-TDMA. We then thoroughly evaluate the performance of the proposed c-SR scheme via ns-3 simulations. The proposed scheme allows increasing the system throughput of a dense deployment up to 2.3 times as well as substantially reducing the Head of Line delay.

The Next Generation Networks (NGN) set its standard to provide very high data rates, Ultra-Reliable Low Latency Communications (URLLC), increased network capacity and significantly improved Quality of Service (QoS). Thus, it provides an infrastructure for the Internet of Things (IoT) to power billions of connected devices. With this upsurge in IoT devices, the need for adopting IPv6 over exhausting IPv4 addresses becomes more unavoidable. Hence, Internet Service Providers (ISP's) are adopting IPv6 along with IPv4 addresses using an address transition method called dual-stack. However, the Dual-Stack network causes relatively more connectivity overhead than the single stack network. For example, DNS lookup and TCP connection time are comparatively high in dual-stack mobile devices. This affects the page loading time of the application, thereby impacting the user experience significantly. In this paper, we analyzed all these connectivity overheads and propose a novel solution called NexGen Connectivity optimizer (NexGenCO), which provides better connectivity for the applications using network-aware concurrency and intelligent DNS caching. NexGenCO is prototyped and evaluated in Samsung devices with Android Pie. It significantly reduces connectivity overhead and improves page loading time up to 18% consistently.

In this work, we propose an innovative approach to contrast the bufferbloat, one of the primary sources of queueing latency, in 3GPP mobile networks. Our purpose is to validate an all-software, in-node traffic-control infrastructure, similar to what the Linux operating system already employs for Ethernet and WiFi networks. We introduce the IPtraffic-control infrastructure in the RAN part of an LTE network, for both UE and eNB, that can perform packet scheduling on flows directed to the same Data Radio Bearer. The effectiveness of such strategy leverages on a reduced usable size of the in-node RLC buffer, thanks to the BQL algorithm, which we evaluate for the first time in the context of LTE. By using BQL, we can create a backlog of packets that stays in the Traffic Control layer, on which it is possible to perform packet scheduling without bloating the RLC buffer. We compare the performance of BQL to another algorithm, called DynRLC, proposed to dynamically size the RLC buffer eNB side. The preliminary evaluation of the proposed approach is done on the ns-3 network simulator and it shows that the proposed approach with BQL significantly improves the flow delay, by controlling the queueing latency, as well as enhancing the flow isolation.

The problem of bufferbloat arises due to the presence of large unmanaged buffers and leads to high queuing delays and significant degradation in the performance of time-sensitive and interactive Internet applications. Recently, a new smart queue management system called Common Applications Kept Enhanced (CAKE) has been introduced in Linux 4.19 to tackle the problem of bufferbloat in home Internet gateways. One of the integral parts of CAKE system is COBALT (CoDel and BLUE Alternate), a queue discipline which is a combination of Controlled Delay (CoDel) and BLUE algorithms. Although CAKE is a part of the Linux kernel, a detailed discussion on the design of COBALT is missing. In this paper, we discuss the design of COBALT and compare its performance with CoDel. Additionally, we propose a simulation model for COBALT in ns-3 and test its correctness by comparing the results obtained from it to those obtained from the Linux model. Our evaluation shows that COBALT offers substantial benefits in terms of curtailing queue delays when unresponsive flows exist.