scholarly journals Reliable Multicast MAC Protocol for Spatial Reuse Efficiency assisted by Multicarrier DS-CDMA in WLAN Systems

2011 ◽  
Vol 3 (5) ◽  
pp. 119-133
Author(s):  
Jeonghun Kim ◽  
Junwoo Jung ◽  
Jaesung Lim
Keyword(s):  
Mac Protocol ◽  
Spatial Reuse ◽  
Reliable Multicast

ORCHESTRATING SPATIAL REUSE IN WIRELESS AD HOC NETWORKS USING SYNCHRONOUS COLLISION RESOLUTION (SCR)

2002 ◽  
Vol 03 (03n04) ◽  
pp. 167-195 ◽  
Author(s):  
JOHN A. STINE ◽  
GUSTAVO DE VECIANA ◽  
KEVIN H. GRACE ◽  
ROBERT C. DURST
Keyword(s):  
Access Control ◽  
Wireless Ad Hoc Networks ◽  
Ad Hoc ◽  
Mac Protocol ◽  
Medium Access Control Protocol ◽  
Control Mechanisms ◽  
Spatial Reuse ◽  
Medium Access ◽  
Signaling Mechanism ◽  
Key Factor

We propose a novel medium access control protocol for ad hoc wireless networks data to send can contend simultaneously for the channel. Nodes contend for access using a synchronous signaling mechanism that achieves two objectives: it arbitrates contentions locally and it selects a subset of nodes across the network that attempt to transmit simultaneously. The subset of nodes that survive the signaling mechanism can be viewed as an orchestrated set of transmissions that are spatially reusing the channel shared by the nodes. Thus the 'quality' of the subset of nodes selected by the signaling mechanism is a key factor in determining the spatial capacity of the system. In this paper, we propose a general model for such synchronous signaling mechanisms and recommend a preferred design. We then focus via both analysis and simulation on the spatial and capacity characteristics of these access control mechanisms. Our work is unique in that it specifically focuses on the spatial capacity aspects of a MAC protocol, as would be critical for ad hoc networking, and shows SCR is a promising solution. Specifically, it does not suffer from congestion collapse as the density of contending nodes grows, it does not suffer from hidden or exposed node effects, it achieves high capacities with a spatial usage exceeding 1 (i.e. more than one packet exchange in the area covered by a transmission), and it facilitates the integration of new physical layer capacity increasing technologies.

scholarly journals A Multichannel MAC Protocol for IoT-enabled Cognitive Radio Ad Hoc Networks

2020 ◽  
Vol 5 (1) ◽  
pp. 45-55
Author(s):  
Chien-Min Wu ◽  
Yen-Chun Kao ◽  
Kai-Fu Chang
Keyword(s):  
Cognitive Radio ◽  
Ad Hoc Networks ◽  
Ad Hoc ◽  
Mac Protocol ◽  
Cognitive Radios ◽  
Window Size ◽  
Spatial Reuse ◽  
Wireless Spectrum ◽  
Multichannel Mac ◽  
Hoc Networks

Cognitive radios have the ability to dynamically sense and access the wireless spectrum, and this ability is a key factor in successfully building Internet-of-Things (IoT)-enabled mobile ad hoc networks. This paper proposes a contention-free token-based multichannel MAC protocol for IoT-enabled Cognitive Radio Ad Hoc Networks (CRAHNs). In this, secondary users of CRAHNs detect activity on the wireless spectrum and then access idle channels licensed by primary users. CRAHNs are divided into clusters, and the channel to use for transmission is determined dynamically from the probability of finding idle primary-user channels. The token-based MAC window size is adaptive, with adjustment according to actual traffic, which reduces both end-to-end MAC contention delay and energy consumption. High throughput and spatial reuse of channels can also be achieved using a dynamic control channel and dynamic schemes for contention windows. We performed extensive simulations to verify that the proposed method can achieve better performance in mobile CRAHNs than other MAC schemes can.

scholarly journals GSR-TDMA: A Geometric Spatial Reuse-Time Division Multiple Access MAC Protocol for Multihop Underwater Acoustic Sensor Networks

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Changho Yun ◽  
Yong-Kon Lim
Keyword(s):  
Sensor Networks ◽  
Mac Protocol ◽  
Propagation Delay ◽  
Packet Transmission ◽  
Acoustic Sensor ◽  
Spatial Reuse ◽  
Underwater Acoustic Sensor Networks ◽  
Underwater Acoustic ◽  
Performance Improvements ◽  
Acoustic Sensor Networks

The nonnegligible propagation delay of acoustic signals causes spatiotemporal uncertainty that occasionally enables simultaneous, collision-free packet transmission among underwater nodes (UNs). These transmissions can be handled by efficiently managing the channel access of the UNs in the data-link layer. To this end, Geometric Spatial Reuse-TDMA (GSR-TDMA), a new TDMA-based MAC protocol, is designed for use in centralized, multihop underwater acoustic sensor networks (UASNs), and in this case all UNs are periodically scheduled after determining a geometric map according to the information on their location. The scheduling strategy increases the number of UNs that send packets coincidentally via two subscheduling configurations (i.e., interhop and intrahop scheduling). Extensive simulations are used to investigate the reception success rate (RSR) and the multihop delay (MHD) of GSR-TDMA, and the results are compared to those of previous approaches, including C-MAC and HSR-TDMA. GSR-TDMA outperforms C-MAC; the RSR of GSR-TDMA is 15% higher than that of C-MAC, and the MHD of GSR-TDMA is 30% lower than that of C-MAC at the most. In addition, GSR-TDMA provides even better performance improvements over HSR-TDMA; the RSR of GSR-TDMA is 50% higher than that of HSR-TDMA, and the MHD of GSR-TDMA is an order of102lower than that of HSR-TDMA at the most.

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