1,304 research outputs found
60 GHz MAC Standardization: Progress and Way Forward
Communication at mmWave frequencies has been the focus in the recent years.
In this paper, we discuss standardization efforts in 60 GHz short range
communication and the progress therein. We compare the available standards in
terms of network architecture, medium access control mechanisms, physical layer
techniques and several other features. Comparative analysis indicates that IEEE
802.11ad is likely to lead the short-range indoor communication at 60 GHz. We
bring to the fore resolved and unresolved issues pertaining to robust WLAN
connectivity at 60 GHz. Further, we discuss the role of mmWave bands in 5G
communication scenarios and highlight the further efforts required in terms of
research and standardization
Topology Control in Heterogeneous Wireless Networks: Problems and Solutions
Previous work on topology control usually assumes homogeneous wireless nodes with uniform transmission ranges. In this paper, we propose two localized topology control algorithms for heterogeneous wireless multi-hop networks with nonuniform transmission ranges: Directed Relative Neighborhood Graph (DRNG) and Directed Local Spanning Subgraph (DLSS). In both algorithms, each node selects a set of neighbors based on the locally collected information. We prove that (1) the topologies derived under DRNG and DLSS preserve the network connectivity; (2) the out degree of any node in the resulting topology by DLSS is bounded, while the out degree cannot be bounded in DRNG; and (3) the topologies generated by DRNG and DLSS preserve the network bi-directionality
Exploiting Device-to-Device Communications to Enhance Spatial Reuse for Popular Content Downloading in Directional mmWave Small Cells
With the explosive growth of mobile demand, small cells in millimeter wave
(mmWave) bands underlying the macrocell networks have attracted intense
interest from both academia and industry. MmWave communications in the 60 GHz
band are able to utilize the huge unlicensed bandwidth to provide multiple Gbps
transmission rates. In this case, device-to-device (D2D) communications in
mmWave bands should be fully exploited due to no interference with the
macrocell networks and higher achievable transmission rates. In addition, due
to less interference by directional transmission, multiple links including D2D
links can be scheduled for concurrent transmissions (spatial reuse). With the
popularity of content-based mobile applications, popular content downloading in
the small cells needs to be optimized to improve network performance and
enhance user experience. In this paper, we develop an efficient scheduling
scheme for popular content downloading in mmWave small cells, termed PCDS
(popular content downloading scheduling), where both D2D communications in
close proximity and concurrent transmissions are exploited to improve
transmission efficiency. In PCDS, a transmission path selection algorithm is
designed to establish multi-hop transmission paths for users, aiming at better
utilization of D2D communications and concurrent transmissions. After
transmission path selection, a concurrent transmission scheduling algorithm is
designed to maximize the spatial reuse gain. Through extensive simulations
under various traffic patterns, we demonstrate PCDS achieves near-optimal
performance in terms of delay and throughput, and also superior performance
compared with other existing protocols, especially under heavy load.Comment: 12 pages, to appear in IEEE Transactions on Vehicular Technolog
Randomized neighbor discovery protocols with collision detection for static multi-hop wireless ad hoc networks
[EN] Neighbor discovery represents a first step after the deployment of wireless ad hoc networks, since the nodes that form them are equipped with limited-range radio transceivers, and they typically do not know their neighbors. In this paper two randomized neighbor discovery approaches, called CDH and CDPRR, based on collision detection for static multi-hop wireless ad hoc networks, are presented. Castalia 3.2 simulator has been used to compare our proposed protocols against two protocols chosen from the literature and used as reference: the PRR, and the Hello protocol. For the experiments, we chose five metrics: the neighbor discovery time, the number of discovered neighbors, the energy consumption, the throughput and the number of discovered neighbors versus packets sent ratio. According to the results obtained through simulation, we can conclude that our randomized proposals outperform both Hello and PRR protocols in the presence of collisions regarding all five metrics, for both one-hop and multi-hop scenarios. As novelty compared to the reference protocols, both proposals allow nodes to discover all their neighbors with probability 1, they are based on collision detection and know when to terminate the neighbor discovery process. Furthermore, qualitative comparisons of the existing protocols and the proposals are available in this paper. Moreover, CDPRR presents better results in terms of time, energy consumption and number of discovered neighbors versus packets sent ratio. We found that both proposals achieve to operate under more realistic assumptions. Furthermore, CDH does not need to know the number of nodes in the network.This work has been partially supported by the "Ministerio de Economia y Competitividad" in the "Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia, Subprograma Estatal de Generacion de Conocimiento" within the project under Grant TIN2017-84802-C2-1-P. This work has also been partially supported by European Union through the ERANETMED (Euromediterranean Cooperation through ERANET joint activities and beyond) project ERANETMED3-227 SMARTWATIR.Sorribes, JV.; Peñalver Herrero, ML.; Tavares De Araujo Cesariny Calafate, CM.; Lloret, J. (2021). Randomized neighbor discovery protocols with collision detection for static multi-hop wireless ad hoc networks. Telecommunication Systems. 77(3):577-596. https://doi.org/10.1007/s11235-021-00763-457759677
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