Today, increasing demands and expectations are being placed on GPS systems. Assisted GPS (A-GPS) has been developed to provide greatly improved capabilities, helping GPS work better and faster in almost any location. Offering a detailed look at all the technical aspects and underpinnings of A-GPS, this unique book places emphasis on practical implementation. The book reviews standard GPS design, helping professionals understand why GPS requires assistance in the first place. Readers discover how A-GPS enables the computing of a position from navigation satellites in the absence of precise time - a topic not covered in any other book. Moreover, engineers learn how to design and analyze a high sensitivity GPS receiver and determine the achievable sensitivity of a GPS receiver.