Probability and Measure

Millimeter wave (mmWave) communications have recently attracted large research interest, since the huge available bandwidth can potentially lead to the rates of multiple gigabit per second per user Though mmWave can be readily used in stationary scenarios, such as indoor hotspots or backhaul, it is challenging to use mmWave in mobile networks, where the transmitting/receiving nodes may be moving, channels may have a complicated structure, and the coordination among multiple nodes is difficult To fully exploit the high potential rates of mmWave in mobile networks, lots of technical problems must be addressed This paper presents a comprehensive survey of mmWave communications for future mobile networks (5G and beyond) We first summarize the recent channel measurement campaigns and modeling results Then, we discuss in detail recent progresses in multiple input multiple output transceiver design for mmWave communications After that, we provide an overview of the solution for multiple access and backhauling, followed by the analysis of coverage and connectivity Finally, the progresses in the standardization and deployment of mmWave for mobile networks are discussed

Millimeter Wave Communications for Future Mobile Networks

Diverse proprietary network appliances increase both the capital and operational expense of service providers, meanwhile causing problems of network ossification. Network function virtualization (NFV) is proposed to address these issues by implementing network functions as pure software on commodity and general hardware. NFV allows flexible provisioning, deployment, and centralized management of virtual network functions. Integrated with SDN, the software-defined NFV architecture further offers agile traffic steering and joint optimization of network functions and resources. This architecture benefits a wide range of applications (e.g., service chaining) and is becoming the dominant form of NFV. In this survey, we present a thorough investigation of the development of NFV under the software-defined NFV architecture, with an emphasis on service chaining as its application. We first introduce the software-defined NFV architecture as the state of the art of NFV and present relationships between NFV and SDN. Then, we provide a historic view of the involvement from middlebox to NFV. Finally, we introduce significant challenges and relevant solutions of NFV, and discuss its future research directions by different application domains.

Software-Defined Network Function Virtualization: A Survey

The fifth generation (5G) mobile communication systems will be in use around 2020. The aim of 5G systems is to provide anywhere and anytime connectivity for anyone and anything. Several new technologies are being researched for 5G systems, such as massive multiple-input multiple-output communications, vehicle-to-vehicle communications, high-speed train communications, and millimeter wave communications. Each of these technologies introduces new propagation properties and sets specific requirements on 5G channel modeling. Considering the fact that channel models are indispensable for system design and performance evaluation, accurate and efficient channel models covering various 5G technologies and scenarios are urgently needed. This paper first summarizes the requirements of the 5G channel modeling, and then provides an extensive review of the recent channel measurements and models. Finally, future research directions for channel measurements and modeling are provided.

A Survey of 5G Channel Measurements and Models

While celebrating the 21st year since the very first IEEE 802.11 “legacy” 2 Mbit/s wireless local area network standard, the latest Wi-Fi newborn is today reaching the finish line, topping the remarkable speed of 10 Gbit/s. IEEE 802.11ax was launched in May 2014 with the goal of enhancing throughput-per-area in high-density scenarios. The first 802.11ax draft versions, namely, D1.0 and D2.0, were released at the end of 2016 and 2017. Focusing on a more mature version D3.0, in this tutorial paper, we help the reader to smoothly enter into the several major 802.11ax breakthroughs, including a brand new orthogonal frequency-division multiple access-based random access approach as well as novel spatial frequency reuse techniques. In addition, this tutorial will highlight selected significant improvements (including physical layer enhancements, multi-user multiple input multiple output extensions, power saving advances, and so on) which make this standard a very significant step forward with respect to its predecessor 802.11ac.

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A Tutorial on IEEE 802.11ax High Efficiency WLANs

Aiming at the problem of slow neighbor discovery speed of sector antenna neighbor discovery (SAND) protocol based single token, an asynchronous sector antenna neighbor discovery protocol based double tokens (D-SAND) is proposed. The double tokens include one master token and one slave token. The master token holder (MTH) starts its neighbor nodes discovery process by sending hone-in message through beam scanning, and ends this process when each neighbor node is discovered. Then, MTH passes the master token to the next hop master token holder (nMTH). At the same time, MTH sends the location information of the nMTH node to its parent master token holder (MTP) from which it obtains its token. MTP determines whether to generate a slave token according to that if there exists a neighbor node with a distance greater than 2R from nMTH, where R represents the communication distance. If there exists one such neighbor, MTP generates a slave token and passes it to that neighbor node, who can begin the neighbor discovering process. The time conditions are theoretically derived when these two tokens begin their neighbor discovering process respectively and without interference to each other. Simulation results show that compared to Q-SAND(quick-SAND), the proposed D-SAND protocol reduces the network-wide neighbor discovery time about by 10%.

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An asynchronous neighbor discovery protocol based on double tokens in directional ad hoc networks

The full-duplex technology with the same frequency and the same time has developed rapidly in the wireless communication field. Compared with the traditional half-duplex technology, full-duplex technology can obtain the double spectral efficiency and throughput. However, in low-frequency asymmetric full-duplex communication, AP has full-duplex, and STA only has half duplex. And the interference between STAs results that we still cannot reach the theoretical multiple throughput. In this paper, we use the feature of directional propagation of mm wave to eliminate the interference between STAs in asymmetric full-duplex communication, and the full-duplex is applied to the WIFI high-frequency field for the first time. This paper introduces the BI frame of MAC architecture of IEEE 802.11 ay protocol in mmWave WIFI network, and designs the SP period of BI frame. So in SP period, the AP has full-duplex function and STAs still are half-duplex. We use Matlab to simulate, and get the theoretical multiple throughput.

Full Duplex Enabled Next Generation mmWave WiFi Network

This paper proposes an Open Shortest Path First (OSPF) based Backhaul Protocol for 5th Generation (5G) mobile communication millimeter wave network (OBPG). This protocol includes the establishment stage and the transmission stage of the millimeter wave backhaul network. During the establishment stage, all millimeter wave micro base stations use fixed time division. The method is based on the OSPF protocol to establish the backhaul path between millimeter wave micro base stations. In the transmission stage, based on the network topology formed by millimeter wave micro base stations, the coloring method is used to allocate data transmission time slots. After that, the micro base station polls and schedules users for data transmission in the allocated data transmission time slot. The simulation results show that when the blocking probability of the millimeter-wave directional link is 30\(\%\), and along with the number of multiple associations between users and millimeter-wave micro base stations increases, the network throughput performance is about 20\(\%\) higher than the performance of the number which is one less.

An OSPF Based Backhaul Protocol for 5G Millimeter Wave Network

Wireless Local Area Network (WLAN) has been greatly developed for the last twenty years. Quality of Service (QoS) and Quality of Experience (QoE) in high-dense deployment scenario greatly challenges the next-generation WLAN [1]. To address this challenge, researchers proposed channel reservation mechanism for WLAN, but the premise of channel reservation mechanism is to know the next packets exact arrival time. This assumption is impractical since the next packets arrival time is a stochastic process. In order to solve the above problem, this paper proposes an arrival prediction based channel reservation media access control (MAC) for the next generation WLAN. Simulations show that the protocol can reduce the network collisions generated by concurrency to a certain extent and improve network throughput.

Arrival Prediction Based Reservation MAC for the Next Generation WLAN

The application of wireless local area network (WLAN) technology can make devices connected to the network move. On this basis, the millimeter wave WLAN protocol and beamforming (BF) technology enables wireless communication to support the transmission of services with ultra-high data rates. But the problem of conflict when station (STA) nodes perform BF training during the associated beamforming training (A-BFT) period is still unsolved. Therefore, this paper proposes a grouping based BF training scheme for the next generation millimeter wave WLAN to reduce conflict. The simulation results show that this scheme can effectively reduce the collision probability of STAs during BF training. Finally, it can improve the efficiency of information transmission and can be used in future improvements for the millimeter wave WLAN protocol.

Zhongjiang Yan

Papers

An asynchronous neighbor discovery protocol based on double tokens in directional ad hoc networks

Full Duplex Enabled Next Generation mmWave WiFi Network

An OSPF Based Backhaul Protocol for 5G Millimeter Wave Network

Arrival Prediction Based Reservation MAC for the Next Generation WLAN

Grouping Based Beamform Training Scheme for the Next Generation Millimeter Wave WLAN