Systems and method for use in a dual mode satellite communications system

• US 6,198,730 B1
• Filed: 10/13/1998
• Issued: 03/06/2001
• Est. Priority Date: 10/13/1998
• Status: Expired due to Term

• Current Assignee: CDC Propriete Intellectuelle
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Smith, Robert H., Emmons, Thomas Peter Jr., Hogberg, Shawn Wesley
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): HYUN, SOON D
• Application Number:
  US09/170,257
• Time in Patent Office: 875 Days
• Field of Search: 370/316, 370/319, 370/320, 370/321, 370/323, 370/326, 370/329, 370/335, 370/336, 370/337, 370/342, 370/465, 370/466, 370/467, 370/341, 370/345, 370/347, 370/441, 370/442
• US Class Current: 370/320
• CPC Class Codes: H04B 7/18563 Arrangements for interconnecting multiple systems data switching networks H04L12/00
• CPC Class Codes: H04B 7/2618 using hybrid code-time division multiple access [CDMA-TDMA]
• CPC Class Codes: H04W 4/18 Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 84/06 Airborne or Satellite Networks space-based or airborne stations H04B7/185
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A communications network is capable of using time division multiple access (TDMA) techniques, code division multiple access (CDMA) techniques, or a combination of both. A subscriber unit (30) makes a request for a traffic channel over a CDMA pilot channel or a TDMA broadcast channel. A satellite (20) or a base station (40) receives the request and determines whether to assign a TDMA or CDMA traffic channel. The downlink and uplink can have the same access scheme (e.g., TDMA) or different access schemes (e.g., TDMA on the uplink and CDMA on the downlink).

Claims

1. A method for use in a dual mode satellite communications network, comprising the steps of:

a) finding either a code division multiple access (CDMA) pilot channel or a time division multiple access (TDMA) broadcast channel; and

b) determining whether to use a CDMA traffic channel or a TDMA traffic channel between a subscriber unit and a satellite,

wherein step (b) further comprises the steps of;

determining whether the subscriber unit can operate in TDMA, CDMA or both;

calculating a traffic load on the satellite and a reuse area; and

selecting whether to use CDMA or TDMA or a combination for an uplink and a downlink based on the traffic load on the satellite and the reuse area.

2. A method as recited in claim 1, further comprising the steps of:

determining if spectrum is available in the selected CDMA or TDMA traffic channel; and

sending the selected CDMA or TDMA traffic channel to the subscriber unit if the spectrum is available.