The wireless broadband (wibro) system for broadband wireless internet services

2006 ◽  
Vol 44 (7) ◽  
pp. 106-112 ◽  
Author(s):  
Seung-Que Lee ◽  
Namhun Park ◽  
Choongho Cho ◽  
Hyongwoo Lee ◽  
Seungwan Ryu
Author(s):  
Tamer Z. Emara

The voice-over-Internet protocol (VoIP) service is expected to be widely supported in wireless mobile networks. Mobile Broadband Wireless networks VoIP service to users with high mobility requirements, connecting via portable devices which rely on the use of batteries by necessity. Energy consumption significantly affects mobile subscriber stations in wireless broadband access networks. Efficient energy saving is an important and challenging issue because all mobile stations are powered by limited battery lifetimes. Therefore, the authors propose an adaptive mechanism suitable for VoIP service with silence suppression. The proposed mechanism was examined with a computer simulation. The simulation results demonstrate that the proposed mechanism reduces energy consumption.


2003 ◽  
Vol 29 (12) ◽  
pp. 1122-1134 ◽  
Author(s):  
A. Ocampo ◽  
D. Boggio ◽  
J. Munch ◽  
G. Palladino

Author(s):  
Balakrishnan K ◽  
Ritesh Kumar Kalle ◽  
Debabrata Das

The exponential growth in multimedia traffic (Cisco Visual Networking Index, 2010), predominantly on UDP transport, poses a threat to the TCP’s best effort throughput. This problem is more acute in last mile broadband wireless access networks (Bakshi, Krishna, Vaidya, & Pradhan, 1997). Most scheduling algorithms discuss improving the combined TCP and UDP throughput or improving the TCP throughput without studying the effects of inelastic traffic such as UDP. This chapter furthers the necessity for TCP throughput protection and proposes a novel dynamically adapting Weighted Fair Queue (WFQ) based scheduling mechanism that provides a higher degree of TCP protection. This is accomplished by differentiating between TCP and UDP flows, buffer provisioning for each flow, and prioritizing TCP ACK packets. The simulation results show that the proposed mechanism yields a relative improvement of up to 29% of TCP goodput and 7.5% of aggregate MAC throughput over the mechanism without the proposed improvements.


Author(s):  
Haymen Shams

There is a continuous demand for increasing wireless access broadband services to the end users, especially with widespread high quality mobile devices. The Internet mobile applications and multimedia services are constantly hungry for broadband wireless bandwidth. In order to overcome this bandwidth limitation, a frequency band (57-64 GHz) has recently been assigned for short range indoor wireless broadband signals due to the large available bandwidth. However, the transmission at this band is limited to a few meters due to the high atmospheric absorption loss. Radio over Fiber (RoF) technology was considered an efficient solution to extend the distribution range and wireless capacity services. This chapter presents an introduction to RoF technology and its basic required optical components for indoor short range wireless millimeter waves (mm-waves). The limiting factors of RoF and its impairments are also described. Moreover, optical mm-wave generation solutions are explained and followed by the recent optical 60GHz activities and upcoming research areas such as THz and optical wireless.


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