ENHANCED WIRELESS PACKET DATA COMMUNICATION SYSTEM, METHOD, AND APPARATUS APPLICABLE TO BOTH WIDE AREA NETWORKS AND LOCAL AREA NETWORKS

• US 20070071114A1
• Filed: 11/22/2006
• Published: 03/29/2007
• Est. Priority Date: 03/30/2001
• Status: Active Grant

• Current Assignee: Sensus Spectrum, LLC (Xylem, Inc.)
• Original Assignee: Advanced Metering Data Systems Incorporated (Xylem, Inc.)
• Inventors: Naden, Gary, Brown, Michael, Rouquette, Robert, SANDERFORD, H. BRITTON, Reed, Marc, Boudreaux, Gordon
• Granted Patent: US 7,705,777 B2
• Time in Patent Office: Days
• US Class Current: 375/259
• CPC Class Codes: H03B 21/00 Generation of oscillations by combining unmodulated signals of different frequencies H03B19/00 takes precedence; frequency changing circuits in general H03D
• CPC Class Codes: H03L 7/08 Details of the phase-locked loop
• CPC Class Codes: H04L 25/061 providing hard decisions only; arrangements for tracking or suppressing unwanted low frequency components, e.g. removal of dc offset removal of dc offset in coupling arrangements H04L25/029, H04L25/0296
• CPC Class Codes: H04L 25/4902 Pulse width modulation; Pulse position modulation
• CPC Class Codes: H04L 25/4921 using quadrature encoding, e.g. carrierless amplitude-phase coding
• CPC Class Codes: H04L 27/12 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04L 27/2331 wherein the received signal is demodulated using one or more delayed versions of itself
• CPC Class Codes: H04L 27/32 Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
• CPC Class Codes: H04L 27/34 Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
• CPC Class Codes: H04L 27/3433 using an underlying square constellation
• CPC Class Codes: H04L 27/3483 using a modulation of the constellation points
• CPC Class Codes: H04L 27/364 Arrangements for overcoming imperfections in the modulator, e.g. quadrature error or unbalanced I and Q levels
• CPC Class Codes: H04L 27/38 Demodulator circuits; Receiver circuits
• CPC Class Codes: H04L 27/3845 using non - coherent demodulation, i.e. not using a phase synchronous carrier
• CPC Class Codes: H04L 5/06 the signals being represented by different frequencies combined with time-division multiplexing H04L5/26
• CPC Class Codes: H04L 5/16 Half-duplex systems; Simplex/duplex switching; Transmission of break signals non-automatically inverting the direction of transmission
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/083 wherein at least one of the access points is a moving node
• CPC Class Codes: H04W 72/27 between access points

Abstract

A cellular wireless packet data communication system containing transmit-only endpoint devices which transmit to receive-only base stations. The system is configured to allow for large area coverage (e.g., a metropolitan area) with far fewer number base stations than are required with conventional two-way cellular systems. The base station coverage areas are configured to overlap, allowing for reception of packets at multiple base stations. A data concentrator resolves redundantly received messages. The network is configurable as a WAN, a LAN, or a combination of the two. Novel modulation techniques (e.g., a 16QAM submodulation together with a 7FSK modulation) are used such that low cost components can be used in the transmitters and receivers while achieving outstanding probability of success performance. The endpoint devices are battery operated and accordingly, are designed for low power consumption and multi-year battery life. The system is used in a variety of applications including remote monitoring and mobile communications.

Claims

1. A system, comprising:

a plurality of receiver systems; and

a multifrequency transmitter having a Global Positioning System receiver,

wherein the multifrequency transmitter is configured to communicate with the plurality of receiver systems and to receive a present location from a Global Positioning System satellite, and to transmit on a first predetermined frequency when the present location is within a first predetermined geographic area, and on a second predetermined frequency when the present location is within a second predetermined geographic area.