Directional Neighbor Discovery Research Articles

Meet in the air: Distributed neighbor discovery in 3D networks with directional transceivers

We formulate and analyze a generic neighbor discovery problem in three-dimensional wireless networks with directional transceivers, where any pair of neighbor nodes in 3D Euclidean space need to steer their transceivers towards each other simultaneously to discover each other. This problem, termed as 3D directional neighbor discovery, arises in a variety of emerging networked systems such as flying ad hoc networks composed of drones and distributed space systems composed of spacecrafts. Compared to the omni-directional 2D neighbor discovery problem extensively investigated in the literature, the 3D directional neighbor discovery problem is intuitively more challenging. Motivated by this observation, we establish an algorithmic framework on the 3D directional neighbor discovery problem. We first mathematically formulate the problem and derive the worst-case discovery delay of any neighbor discovery algorithm. Guided by the performance limit, we then design distributed neighbor discovery algorithms achieving bounded and minimal worst-case discovery delay. We further demonstrate how our algorithmic framework can be generalized to solve generic multi-dimensional rendezvous problems. Extensive numerical analysis is then presented to empirically evaluate of our neighbor discovery algorithms.

Three‐dimensional scan‐based algorithm for directional neighbor discovery in ad hoc networks

SummaryIn recent years, neighbor discovery techniques using directional antennas have attracted widespread attention. Most currently available directional neighbor discovery techniques are designed based on two‐dimensional (2D) space. Although these algorithms can accomplish the discovery between nodes, the algorithm portability is poor for three‐dimensional (3D) platforms, and the application scenarios are limited since new communication scenarios such as unmanned aerial vehicle (UAV) groups and maritime fleets emerge where information needs to be delivered in real time and nodes are located in 3D space. This paper proposes a new deterministic directional neighbor discovery algorithm in 3D space named 3D scan‐based algorithm (3D‐SBA) to meet the needs of the line‐of‐sight (LOS) scenes. Four existing neighbor discovery algorithms, namely, SBA‐based random mode selection (SBA‐R), quorum, complete random algorithm (CRA), and SBA‐based leader election algorithm (LE), have been extended to our proposed 3D algorithm model for simulation and comparative analysis with 3D‐SBA. The simulation results show that the 3D‐SBA algorithm consumes 51.15%, 180.20%, 9.48%, and 17.49% of the time slots compared with the four existing algorithms mentioned above. However, the quorum algorithm has a very high node collision rate, up to 92.11%. Ultimately, the 3D‐SBA algorithm has the best performance considering the conflicts and the density of network nodes.

Cross-Layer Optimization Spatial Multi-Channel Directional Neighbor Discovery with Random Reply in mmWave FANET

MmWave FANETs play an increasingly important role in the development of UAVs technology. Fast neighbor discovery is a key bottleneck in mmWave FANETs. In this paper, we propose a two-way neighbor discovery algorithm based on a spatial multi-channel through cross-layer optimization. Firstly, we give two boundary conditions of the physical (PHY) layer and media access control (MAC) layer for successful link establishment of mmWave neighbor discovery and give the optimal pairing of antenna beamwidth in different stages and scenarios using cross-layer optimization. Then, a mmWave neighbor discovery algorithm based on a spatial multi-channel is proposed, which greatly reduces the convergence time by increasing the discovery probability of nodes in the network. Finally, a random reply algorithm is proposed based on dynamic reserved time slots. By adjusting the probability of reply and the number of reserved time slots, the neighbor discovery time can be further reduced when the number of nodes is larger. Simulations show that as the network scale is 100 to 500 nodes, the convergence time is 10 times higher than that of the single channel algorithm.

Directional neighbor discovery in mmWave wireless networks

The directional neighbor discovery problem, i.e., spatial rendezvous, is a fundamental problem in millimeter wave (mmWave) wireless networks, where directional transmissions are used to overcome the high attenuation. The challenge is how to let the transmitter and the receiver beams meet in space under deafness caused by directional transmission and reception, where no control channel, prior information, and coordination are available. In this paper, we present a Hunting-based Directional Neighbor Discovery (HDND) scheme for ad hoc mmWave networks, where a node follows a unique sequence to determine its transmission or reception mode, and continuously rotates its directional beam to scan the neighborhood for other mmWave nodes. Through a rigorous analysis, we derive the conditions for ensured neighbor discovery, as well as a bound for the worst-case discovery time and the impact of sidelobes. We validate the analysis with extensive simulations and demonstrate the superior performance of the proposed scheme over several baseline schemes.

Auxiliary beam pair enabled initial access for mmWave D2D networks

In this paper, we propose two auxiliary beam pair (ABP) schemes, i.e., auxiliary-half (AH) and auxiliary-full (AF) to improve the initial access (IA) mechanism in a millimeter wave (mmWave) device-to-device (D2D) network. In AH, a uniform linear array (ULA) is split equally to form two simultaneous beams at both transmitter (TX) and receiver (RX) for device detection. The detection process takes place through the generation of antenna scan sequences. On the other hand, AF utilizes the full antenna array to form one beam at a time at RX and TX and searches the same sector twice in a time division manner. We also employ beamforming (BF) technique in the already existing schemes in literature, i.e., oblivious directional neighbor discovery (ODND) and Polya’s Necklaces. We compare all the schemes and it is shown that both AH and AF exhibit a high dependence on the separation between the beam pair. We also prove the dependence of discovery delay (DD) on the signal-to-noise ratio (SNR) which is contrary to the worst-case DD upper-bound given by ODND. For a reasonable value of beam separation, high SNR threshold and high TX–RX separation, AH achieves a lower DD than all other schemes. Moreover, AF outperforms all other schemes in terms of probability of miss detection (PMD) and for a considerable beam separation, low SNR threshold and low RX–TX separation, it also achieves a lower DD than ODND, Polya’s Necklaces and AH.

Multiband Directional Neighbor Discovery in Self-Organized mmWave Ad Hoc Networks

A 60-GHz radio is an attractive technology in wireless home networks because it can provide high data rate up to a few gigabits per second. A 60-GHz network generally uses directional antennas and has a problem of neighbor discovery (ND), although it has an advantage of high data transmissions. In particular, if a directional antenna is used in self-organized wireless ad hoc networks, the ND time and energy consumption can be significantly increased. To solve this problem, we propose a multiband directional ND (MDND) scheme, in which management procedures are carried out by using the 2.4-GHz band with the omnidirectional antennas, whereas data transmissions are performed by using the 60-GHz band with directional antennas. Analytical models on the ND time and energy consumption are also derived by considering assisted and beamforming periods in the ND procedure through the omnidirectional and directional antennas. Performance evaluation results demonstrate that the proposed scheme outperforms comparative schemes that use only directional beamforming in terms of the average ND time and energy consumption.

IEEE 802.15.3c 기반에서 지향성 안테나를 사용했을 때의 이웃장치 탐지과정 분석

밀리미터파 대역에서의 이웃장치 탐지는 이 대역의 통신에서의 필수 선제조건이므로 아주 중요하고 또한 긴급한 문제이다. 본 논문에서는 모든 장치에 지향성 안테나가 탑재되어 있는 경우 밀리미터파 대역 개인영역 무선네트워크에서 지향성 안테나의 효과를 기반으로 한 동기식, direct, two-way 지향성 이웃장치 탐지과정을 분석한다. 주어진 시간동안 발견되는 장치의 비율과 한 방향에서 머무르는 최적의 시간 등과 같은 측도를 수학적으로 표현하였다. IEEE 802.15.3c 표준을 기반으로 한 분석결과는 지향성 안테나를 사용하는 경우의 이웃장치 탐지의 효율성을 보여준다. 본 연구는 밀리미터파 대역에서 이웃장치 탐지에 관한 이론적 기반을 제공할 것으로 보인다. The neighbor discovery using directional antennas in mmWave band is a prerequisite for communications and this issue is crucial and urgent. In this paper, the synchronized, direct, two-way directional neighbor discovery process is analyzed mathematically for mmWave WPANs. The analysis is based on the values which are derived from the effect of using directional antennas. The neighbor discovery probability for a given amount of time is considered and several performance measures such as the optimal sojourn time are derived in closed forms. Numerical results are obtained using parameters based on the IEEE 802.15.3c. The mathematical analysis provides the theoretical basis for the directional neighbor discovery process.

Impact of Antenna Pattern and Link Model on Directional Neighbor Discovery in 60 GHz Networks

60 GHz radio is a very attractive technology for short-range wireless communication due to its capability to provide Gbps data rate. To address the neighbor discovery (ND) problem in 60 GHz networks, we propose a novel analytical framework to investigate the ND performance. The main difficulty in modeling the ND process in a 60 GHz network is the involvement of the directional antennas with gain differences between the antenna's main lobe and side lobes. Different antenna modes - directional or omni-directional - coupled with different ND mechanisms make the analytical study demanding. In this article, we propose a comprehensive theoretical model to demonstrate the performance of ND processes using one-way ND and handshake-based ND mechanisms. Moreover, we combine them with different antenna modes, i.e., directional transmitting with omni-directional listening (DO) and directional transmitting with directional listening (DD) modes. The impact of antenna modes on the ND process is analyzed. Since 60 GHz radio is prone to co-channel interference, we examine a realistic interference-aware link model and antenna pattern via simulation studies. Our work is specifically beneficial to provide guidelines for applying directional neighbor discovery process within 60 GHz wireless networks.

Directional neighbor discovery in 60 GHz indoor wireless networks

Signal propagation in the 60 GHz band significantly differs from that in the 2.4 and 5 GHz bands. In particular, the signals are often reflected in indoor settings in this band. Directional antennas can help limit the impact of reflection, but make the process of neighbor discovery complex. We consider this problem in this paper. We examine two approaches (a) direct discovery where each node explicitly discovers its neighbors, and (b) gossip-based discovery where nodes exchange information about their already discovered neighbors. We analyze the two approaches and validate our models via simulations. We examine the impact of system parameters such as varying beamwidth and node density.

Neighbor discovery in wireless networks with sectored antennas

Directional antennas offer many potential advantages for wireless networks such as increased network capacity, extended transmission range and reduced energy consumption. Exploiting these advantages requires new protocols and mechanisms at various communication layers to intelligently control the directional antenna system. With directional antennas, many trivial mechanisms, such as neighbor discovery, become challenging since communicating parties must agree on where and when to point their directional beams to communicate. In this paper, we propose a fully directional neighbor discovery protocol called Sectored-Antenna Neighbor Discovery (SAND) protocol. SAND is designed for sectored-antennas, a low-cost and simple realization of directional antennas, that utilize multiple limited beamwidth antennas. Unlike many proposed directional neighbor discovery protocols, SAND depends neither on omnidirectional antennas nor on time synchronization. SAND performs neighbor discovery in a serialized fashion allowing individual nodes to discover all potential neighbors within a predetermined time. SAND guarantees the discovery of the best sector combination at both ends of a link, resulting in more robust and higher quality links between nodes. Finally, SAND reliably gathers the neighborhood information in a centralized location, if needed, to be used by centralized networking protocols. The effectiveness of SAND has been assessed via simulation studies and real hardware implementation.