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Full-Text Articles in Computer and Systems Architecture
An Overview Of Using Directional Antennas In Wireless Networks, Hong-Ning Dai, Kam-Wing Ng, Min-You Wu
An Overview Of Using Directional Antennas In Wireless Networks, Hong-Ning Dai, Kam-Wing Ng, Min-You Wu
Hong-Ning Dai
Compared with omni-directional antennas, directional antennas have many merits, such as lower interference, better spatial reuse, longer transmission range and the improved network capacity. Directional antennas enable numerous emerging outdoor and indoor applications, which have been addressed in many recent studies. Despite the advances in wireless networks with directional antennas (DAWNs), there are many research challenges in all layers of DAWNs. This paper presents a detailed study on recent advances and open research issues on DAWNs. Firstly, we briefly introduce the classification of directional antennas, antenna radiation patterns, antenna modes as well as the challenges in the physical layer of …
Collision-Tolerant Transmission With Narrow-Beam Antennas, Hong-Ning Dai, Kam-Wing Ng, Min-You Wu, Bo Li
Collision-Tolerant Transmission With Narrow-Beam Antennas, Hong-Ning Dai, Kam-Wing Ng, Min-You Wu, Bo Li
Hong-Ning Dai
The application of directional antennas in wireless ad hoc networks brings numerous benefits, such as increased spatial reuse and mitigated interference. Most MAC protocols with directional antennas are based on the RTS/CTS mechanism which works well in wireless ad hoc networks using omni-directional antennas. However, RTS/CTS frames cannot mitigate the interference completely. Besides, they also contribute a lot to the performance overhead. This paper studies the problem from a new perspective. We have found that the transmission success probability under directional transmission and directional reception is quite high when the antenna beamwidth is quite narrow. Motivated by the analytical results, …
A Busy-Tone Based Mac Scheme For Wireless Ad Hoc Networks Using Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Min-You Wu
A Busy-Tone Based Mac Scheme For Wireless Ad Hoc Networks Using Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Min-You Wu
Hong-Ning Dai
Applying directional antennas in wireless ad hoc networks offers numerous benefits, such as extended communication range, increased spatial reuse, improved capacity and suppressed interference. However, directional antennas can cause new location-dependent carrier sensing problems, such as new hidden terminal and deafness problems, which can cause severe penalties to the performance. Recently, a few schemes have been proposed to tackle these problems. However, these methods can provide limited solutions on the hidden terminal and deafness problems. We propose a new MAC protocol, termed the busy-tone based directional medium access control (BT-DMAC) protocol. When the transmission is in progress, the sender and …
An Overview Of Mac Protocols With Directional Antennas In Wireless Ad Hoc Networks, Hong-Ning Dai, Kam-Wing Ng, Min-You Wu
An Overview Of Mac Protocols With Directional Antennas In Wireless Ad Hoc Networks, Hong-Ning Dai, Kam-Wing Ng, Min-You Wu
Hong-Ning Dai
Although directional antennas have been used in mobile communications systems for quite a long time, realistic applications of directional or smart antennas in wireless ad hoc network have emerged just in recent years. Directional antennas provide numerous benefits, such as higher gains, increased transmission range and low interferences. Wireless medium access schemes play a crucial role in ensuring the efficient and fair sharing of wireless resources. Therefore there are many research work on mechanisms at the wireless medium access layer by using directional antennas. The new features of MAC with directional antennas can cause not only location dependent carrier sensing …