Paul Ngai - Articles

 

Paul Ngai, P.E. is an engineering consultant specialized in Telecommunications Network and Systems. He is also the principal of Network Systems Technologies LLC (http://www.nstecs.net), 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.

Satellite Link Design Considerations

Satellite links are widely used in telecommunications and television broadcast. The factors affecting a satellite link are earth station characteristics, link BER, rain attenuation and antenna pointing errors. Read

By: Paul Ngai | 22/12/2009 | Communication

Maximize Wireless Reach with Multi-Antenna MIMO

MIMO wireless system uses multiple antennas at the transmitter and receiver to send and receive data. Examples of MIMO systems are IEEE 802.11n WLAN and 4G cellular networks such as WiMAX and LTE. MIMO techniques can significantly increase the capacity and range of wireless systems. Read

By: Paul Ngai | 28/11/2009 | Communication

Wavelength Service in Optical Transport Networks

An optical transport network (OTN) is an All Optical Network (AON) where optical connections, known as lightpaths, are used for data transmission. Lightpaths are used to provide wavelength services such as low latency broadband data service, dedicated private lines and virtual private networks. Read

By: Paul Ngai | 26/10/2009 | Communication

Carrier Ethernet Over SONET/WDM Networks

Traditional SONET networks are incompatible with Ethernet traffic. New technology standards, Generic Framing Procedure (GFP) and Virtual Concatenation, are introduced to adapt the SONET network to carry Ethernet traffic. This enables the Telcos to offer Carrier Ethernet services such as E-LINE and E-LAN. Read

By: Paul Ngai | 19/09/2009 | Communication

Radio Wave Propagation Models Used in RF Coverage Analysis

Radio wave propagation models are statistical models of how radio waves propagate in different conditions, terrains and environments. These propagation models are used in RF coverage analysis to determine the performance of a wireless system. The most commonly used propagation models are Longley-Rice, Okumura, Cost 231, Egli and ITU terrain model. Read

By: Paul Ngai | 22/08/2009 | Communication

Distributed Antenna Systems for Indoor Cellular Network

High speed data services constitutes a significant portion of indoor cellular traffic. Active and passive Distributed Antenna Systems (DAS) are used indoor to increase the performance of the 3G mobile network (EVDO, UMTS) inside buildings. For HSPA (High Speed Packet Access) mobile data service, indoor DAS is essential to provide sufficient RF coverage for the high data rate inside a building. Read

By: Paul Ngai | 21/07/2009 | Communication

Why Mobile TV Does Not Use IPTV

This article describes the mobile TV services and technology of AT&T Wireless and Verizon Wireless. It also explains why the current mobile TV services does not use IPTV technology. Read

By: Paul Ngai | 20/06/2009 | Communication