27th September 2010
Optical fiber is the medium of choice for high capacity digital transmission systems and high speed local area network. Besides these applications, optical fiber also can be used to transmit microwave signals for cable television, cellular radio, WLAN and...
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10th February 2010
Cable Television (TV) networks deliver TV broadcasts from TV stations to cable TV subscriber homes. Digital TV broadcasts using VHF and UHF frequencies between 47 MHz to 862 MHz. Each TV channel occupies 6 MHz bandwidth and modulated using 64/128/256 QAM ...
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22nd December 2009
Satellite links are used to deliver long distance telecommunications voice/data services, broadband internet services, television broadcast and communications with remote and hard to reach locations. Satellite link consists of an uplink and a downlink. Up...
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30th November 2009
MIMO (Multiple Input Multiple Output) wireless system uses multiple antennas at the transmitter and receiver to transmit and receive multiple data streams to achieve higher data rate and improves performance of radio systems with increase spectral efficie...
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30th October 2009
Optical WDM (Wavelength Division Multiplexing) networks are networks that deploy optical WDM fiber links where each fiber link carries multiple wavelength channels. An All Optical Network (AON) is an optical WDM network which provides end-to-end optical p...
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22nd September 2009
The broadband networks of US telecommunications carriers are fiber optics networks using SONET (Synchronous Optical Network) and WDM (Wavelength Division Multiplexing) technologies. SONET uses TDM (Time Division Multiplexing) to multiplex data streams of ...
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25th August 2009
Radio wave propagation can be categorized as LOS (Line Of Sight) and non-LOS modes. LOS is direct point-to-point propagation with no obstructions in between. Non-LOS is indirect propagation in the absence of LOS path which consists of diffraction, reflect...
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23rd July 2009
Some 70 - 80% of mobile traffic originates from inside buildings. This is especially true in urban environments where the focus of the mobile user is on high data rates. For mobile 3G network, only serving macro base station within a few hundred meters of...
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05th July 2009
Mobile TV can be watched on a smart or 3G mobile phone, such as the LG Vu or Samsung SCH u620 smart phone. Both AT&T Wireless and Verizon Wireless offer mobile TV services. For Verizon, it is VCAST TV and for AT&T, it is AT&T Mobile TV. Both AT&T and Ver...
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Paul Ngai, P.E. is a telecom consultant specialized in RF and Fiber Optics Networks. He is also the principal of Network Systems Technologies LLC, a telecommunications consulting firm provides planning, analysis, design, testing and operation support services. Paul Ngai has over 20 years of experience in telecommunications, data network and satellite industry. He had held lead engineer positions in various industrial corporations such as Boeing, Lockheed Martin, Verizon, Bell Atlantics and Sprint PCS. Effective as a project manager, a lead engineer or a individual contributor in providing innovative solutions to complex and time constrained engineering problems. 
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