Fig 3 - uploaded by Chin-Sean Sum
Content may be subject to copyright.
Source publication
In this paper, we propose a deflection routing scheme that improves effective throughput (defined as the successfully transmitted bits over the duration between two available sequential time slots) of millimeter-wave wireless personal area network (mmWave WPAN) systems. The upcoming mmWave WPAN is based on dynamic time division multiple access (TDM...
Similar publications
Millimeter-wave or 60 GHz communication is a promising technology that enables data rates in multigigabits. However, its tremendous propagation loss and signal blockage may severely affect the network throughput. In current data-centric device-to-device (D2D) communication networks, the devices with intended data communications usually lay in close...
Citations
... In this section, we discuss the state-of-the-art methods of blockage and link movement detection and discrimination. The authors in [12] proposed to detect blockage by a sudden drop of SINR in static HDTV signal links. In more recent work, Sur et al. [13] proposed a method to predict the quality of all the paths around a receiver by probing just one path. ...
To employ millimeter wave technology in 5G networks, two inherent challenges need to be addressed in dynamic outdoor environments. Firstly, different types of obstacles can easily block the links. Secondly, the link quality can drop significantly in a mobile environment. It is critical to discriminate between the two different situations to take appropriate actions. Existing work makes the distinction based on RSSI variation measured in a time window, which is very time-consuming, leading to a large volume of data loss to achieve high accuracy. This paper proposes a learning-based prediction framework to classify link blockage and link movement efficiently and quickly. A classifier is trained with data blockage instances using different learning methods. It is used to make a prediction based on diffraction values on different multipath components formed around a receiver. Simulation results for both blockage and link movement show that the prediction framework can predict blockage with close to 90% accuracy. The accuracy of detecting the blockage (not the link movement) is measured in the experiments as well to analyze the feasibility of the method. The prediction framework can eliminate the need for having time-consuming methods to discriminate between link movement and link blockage. The simulations show that our framework does not need a large amount of training data to achieve the desired prediction accuracy. The experiments using commodity millimeter wave radios demonstrate a very high prediction accuracy.
... assistance of RSs, more LoS links are expected and the network signal-to-noise ratio (SNR) or signal-to-interferencenoise ratio (SINR) performance can be improved significantly. Lan et al. [17] proposed a deflecting routing scheme to improve the effective throughput by sharing time slots for the direct path with the relay path in mmWave wireless personal area networks. Biswas et al. [18] investigated the coverage probability and transmission capacity of relay-assisted outdoor mmWave networks using stochastic geometry tools. ...
Due to short wavelength and weak diffraction ability, millimeter-wave (mmWave) signals are highly susceptible to blockage, which results in significant degradation in received signal power. As a possible solution for overcoming the blockage problem in millimeter-wave communication systems, the deployment of a relay station (RS) has been considered in recent years. In this paper, we discuss the problems to be considered in a relay-assisted mmWave cellular system based on orthogonal frequency division multiplexing. We describe a frame structure and a pilot-based training method to achieve efficient RS selection during blockage. In addition, a method designed to overcome the inter-symbol interference problem caused by different symbol time offsets of pilot signals received from adjacent RSs in the relay-assisted mmWave cellular system is discussed. Then, we propose two different types of pilot sequences that allow a mobile station to distinguish among the pilot sources in multi-cell multi-relay environments: pilot signals based on the Zadoff-Chu sequence (PS1) and pilot signals based on the m-sequence (PS2). The correlation property of PS2 is derived and compared with that of PS1 and another sequence (Gold sequence). Simulations are performed using a blockage model to verify the properties, constraints, and advantages and disadvantages of the proposed pilot sequences in RS-assisted mmWave cellular systems.
... The authors in [7] have proposed blockage detection by a sudden drop of SINR in static HDTV signal links. In more recent work, Sur et al. [8] have proposed a method to predict the quality of all the paths around a receiver by probing just one path. ...
... • Power control and handover where decision supposed to be built based on previous states or results and making a decision using reinforcement in the current stage such to execute a handover [93]. • Accurate channel models with dynamic behavior with mobility [94]. ...
Channel modeling is fundamental to design wireless communication systems. A common practice is to conduct tremendous amount of channel measurement data and then to derive appropriate channel models using statistical methods. For highly mobile communications, channel estimation on top of the channel modeling enables high bandwidth physical layer transmission in state-of-the-art mobile communications. For the coming 5G and diverse Internet of Things, many challenging application scenarios emerge and more efficient methodology for channel modeling and channel estimation is very much needed. In the mean time, machine learning has been successfully demonstrated efficient handling big data. In this paper, applying machine learning to assist channel modeling and channel estimation has been introduced with evidence of literature survey.
... Although decodeand-forward relays can extend the limited coverage and deal with blockage for mmWave communications, it decreases the effective throughput (defined as the successfully transmitted bits over the duration between two available sequential time slots), which will affect the data-greedy applications. Owing to the good space isolation brought by significant path-loss, Lan et al. [67] proposed a deflection routing scheme, in which time slots can be shared between direct path and relay path to improve effective throughput for mmWave WPAN networks. A sub-exhaustive search based best fit deflection routing algorithm was proposed to find a relay path which can maximize the effective throughput while bringing in the least interference. ...
Millimeter-wave (mmWave) with large spectrum available is considered as the most promising frequency band for future wireless communications. The IEEE 802.11ad and IEEE 802.11ay operating on 60 GHz mmWave are the two most expected wireless local area network (WLAN) technologies for ultra-high-speed communications. For the IEEE 802.11ay standard still under development, there are plenty of proposals from companies and researchers who are involved with the IEEE 802.11ay task group. In this survey, we conduct a comprehensive review on the medium access control layer (MAC) related issues for the IEEE 802.11ay, some cross-layer between physical layer (PHY) and MAC technologies are also included. We start with MAC related technologies in the IEEE 802.11ad and discuss design challenges on mmWave communications, leading to some MAC related technologies for the IEEE 802.11ay. We then elaborate on important design issues for IEEE 802.11ay. Specifically, we review the channel bonding and aggregation for the IEEE 802.11ay, and point out the major differences between the two technologies. Then, we describe channel access and channel allocation in the IEEE 802.11ay, including spatial sharing and interference mitigation technologies. After that, we present an in-depth survey on beamforming training (BFT), beam tracking, single-user multiple-input-multiple-output (SU-MIMO) beamforming and multi-user multiple-input-multiple-output (MU-MIMO) beamforming. Finally, we discuss some open design issues and future research directions for mmWave WLANs. We hope that this paper provides a good introduction to this exciting research area for future wireless systems.
... A heuristic algorithm is used to solve the formulated NP-hard problem in [18]. The second one (termed Benchmark 2) is proposed in [17], where relay paths are determined for multiple SD pairs with a heuristic to maximize the total throughput under static channel conditions. Throughput fairness among multiple SD pairs is not considered in this scheme. ...
... However, the algorithm is heuristic and lacks consideration of multiple coexisting links. The time slot allocation problem in multihop 60 GHz networks is investigated in [17], where the direct path shares time slots with the relay path. Different time slot allocation schemes may result in different system throughput, and the effective system throughput is optimized with time slot allocation. ...
... For multi-hop LOS transmissions, an optimal geographic routing protocol is proposed in [23] and a link scheduling scheme for 60 GHz multi-channel wireless mesh networks is investigated in [24]. A routing algorithm is developed in [25] to find the optimal relay path with the least interference to maximize the throughput. With high directional antennas, a multi-hop LOS relaying protocol proposed in [16] achieves high network utilization with low overhead despite high link blockage probability in a 60 GHz indoor WPAN. ...
... • The routing schemes in [23]- [25], [28], [29] do not consider the link blockage, while the main objective of our study is to develop a routing algorithm for the network with link blockage; ...
Indoor communications in the 60 GHz band is capable to support multi-gigabit wireless access thanks to the abundant spectrum and the possibility of using dense antenna arrays. However, the high directivity and penetration loss make it vulnerable to blockage events which can be frequent in indoor environments. Given network topology information in sufficient precision, we investigate the average throughput and outage probability when the connection between any two nodes can be established either via the line-of-sight (LOS) link, through a reflection link, or by a half-duplex relay node. We model the reflection link as an LOS with extra power loss and derive the closed-form expression for the relative reflection loss. For networks with a central coordinator and multiple relays, we also propose a generic algorithm, maximum throughput path selection (MTPS), to select the optimal path that maximizes the throughput. The complexity of the MTPS algorithm is O(n 2) for networks equipped with n relays, whereas a brute-forced algorithm has complexity of O(n · n!). Numerical results show that increasing the number of relays can significantly increase the average throughput and decrease the outage probability, and resorting to reflection paths provides significant gains when the probability of link blockage is high.
... Smaller wavelength (5mm) results in blockage of links by obstacles such as humans and furniture. Such blockage results in more than 40dB of attenuation in addition to the path loss [7]. One of the solutions to overcome signal blocking is the beamforming (BF) technology [4], [5], which improves the antenna gain. ...
... However, the simulation results are provided on the basis of grid topology and fixed relays, mostly positioned on ceiling. Centralized relay selection approach is proposed in [7], where each sender DEV knows two paths to the destination, direct and relay-path. The relay path is discovered in advance and in case of blockage, the data would 'deflect' through relay node. ...
Networks based on 60-GHz promise data rates in gigabits and show least tolerance towards signal blockage. In addition to severe propagation loss, signal blockage may result in an attenuation upto 40dB. Distributed relay selection scheme is proposed in this paper to cater for signal attenuation. By maintaining a table containing details about interference measurements and neighboring devices, a receiver device determines an optimal relay for its active transmission. Furthermore, outage probability analysis is provided and is utilized to compare our proposed scheme with direct transmission and fixed node relay scheme. Simulation results show that our proposed scheme significantly improves outage probability and system throughput.
... Directive antennas are employed to cater for propagation loss and attaining data rates in multigigabits. However, directive antennas result in another nuisance, a signal blockage which may result in signal attenuation up to 40 dB [7]. The network capacity in 60 GHz networks is severely affected by signal blockage and propagation loss. ...
... Relay selection and scheduling algorithm for 60 GHz have generated sizable literature [7,11,[14][15][16][17][18][19][20][21][22] in recent years. Both efforts are made to achieve one goal: capacity enhancement, either directly or indirectly. ...
... However, the simulation results are provided on the basis of grid topology and fixed relays, mostly positioned on ceiling. Centralized relay selection approach is proposed in [7], where each sender DEV knows two paths to the destination, direct and relay path. The relay path is discovered in advance and in case of blockage, the data would "deflect" through relay node. ...
Millimeter-wave or 60 GHz communication is a promising technology that enables data rates in multigigabits. However, its tremendous propagation loss and signal blockage may severely affect the network throughput. In current data-centric device-to-device (D2D) communication networks, the devices with intended data communications usually lay in close proximity, unlike the case in voice-centric networks. So the network can be visualized as a naturally formed groups of devices. In this paper, we jointly consider resource scheduling and relay selection to improve network capacity in 60 GHz based D2D networks. Two types of transmission scenarios are considered in wireless personal area networks (WPANs), intra and intergroup. A distributed receiver based relay selection scheme is proposed for intragroup transmission, while a distance based relay selection scheme is proposed for intergroup transmission. The outage analysis of our proposed relay selection scheme is provided along with the numerical results. We then propose a concurrent transmission scheduling algorithm based on vertex coloring technique. The proposed scheduling algorithm employs time and space division in mmWave WPANs. Using vertex multicoloring, we allow transmitter-receiver () communication pairs to span over more colors, enabling better time slot utilization. We evaluate our scheduling algorithm in single-hop and multihop scenarios and discover that it outperforms other schemes by significantly improving network throughput.
... However, only two links are scheduled for concurrent transmissions in this scheme, and the spatial reuse is not fully exploited. Lan et al. [87] also proposed a deflection routing scheme to improve the effective throughput by sharing time slots for direct path with relay path. It includes a routing algorithm, the best fit deflection routing (BFDR), to find the relay path with the least interference that maximizes the system throughput. ...
... Park et al. [132] proposed a multi-band directional neighbor discovery scheme, where management procedures are carried out in the 2.4 GHz band with the omni-directional antennas while data transmissions are performed in the 60 GHz band with directional antennas, to reduce the neighbor discovery time and energy consumption. Chen et al. [ Reflection or NLOS transmission [80], [81], [82], [83], [84] PHY/MAC Relaying [34], [85], [86], [87], [89] MAC Multi-AP diversity [88] MAC multipath routing [90] Routing Fig. 8. Heterogeneous networks consisting of macrocells, microcells, WLANs, and picocells in the 60 GHz band forming training results among clients that can be established at the AP. ...
With the explosive growth of mobile data demand, the fifth generation (5G)
mobile network would exploit the enormous amount of spectrum in the millimeter
wave (mmWave) bands to greatly increase communication capacity. There are
fundamental differences between mmWave communications and existing other
communication systems, in terms of high propagation loss, directivity, and
sensitivity to blockage. These characteristics of mmWave communications pose
several challenges to fully exploit the potential of mmWave communications,
including integrated circuits and system design, interference management,
spatial reuse, anti-blockage, and dynamics control. To address these
challenges, we carry out a survey of existing solutions and standards, and
propose design guidelines in architectures and protocols for mmWave
communications. We also discuss the potential applications of mmWave
communications in the 5G network, including the small cell access, the cellular
access, and the wireless backhaul. Finally, we discuss relevant open research
issues including the new physical layer technology, software-defined network
architecture, measurements of network state information, efficient control
mechanisms, and heterogeneous networking, which should be further investigated
to facilitate the deployment of mmWave communication systems in the future 5G
networks.
