Demand-assigned satellite communications system

• US 6,044,277 A
• Filed: 03/28/1997
• Issued: 03/28/2000
• Est. Priority Date: 03/28/1996
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Tsuda, Hiroki
• Primary Examiner(s): Trost, William G.
• Assistant Examiner(s): GELIN, JEAN ALLAND
• Application Number:
  US08/827,302
• Time in Patent Office: 1,096 Days
• Field of Search: 455/12.1, 455/13.4, 455/67.1, 455/67.6, 455/403, 455/430, 455/504, 455/505, 455/506, 455/507, 455/511, 455/522, 455/571, 455/423
• US Class Current: 455/522
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04B 17/382 for resource allocation, admission control or handover
• CPC Class Codes: H04B 7/2123 Variable assignment, e.g. demand assignment
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 52/0232 according to average transmission signal activity
• CPC Class Codes: H04W 52/0245 according to signal strength
• CPC Class Codes: H04W 74/00 Wireless channel access
• CPC Class Codes: H04W 84/06 Airborne or Satellite Networks space-based or airborne stations H04B7/185
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A mobile station comprises a power detector, an averaging circuit, and a signal fade detector. The power detector measures a channel signal power (receive signal power) of a receive signal received by a receiver. The averaging circuit averages the receive signal power measured by the power detector. The signal fade detector detects the fade of the channel signal power with the average of the receive signal power. When the fade of the receive signal is detected, while a call request or a call response is being transmitted, after the receive signal power is recovered, a control circuit of the mobile station re-transmits the call request or the call response. When the fade of the receive signal is detected just before a call request or a call response is to be transmitted, the control circuit of the mobile station stops transmitting the call request or the call response. After the receive signal power is recovered, the control circuit of the mobile station transmits the call request or the call response.

Claims

1. A satellite communication method based on demand network assignment access, the method comprising the steps of:

detecting a receive signal power of a channel control signal successively transmitted from a network control station at a mobile station; and

transmitting a call request for a call response from the mobile station,

detecting a decrease of the receive signal power of the channel control signal during transmission of the call request or call response, and after the receive signal power is recovered, re-transmitting the call request or the call response from the mobile station after the receive signal power is recovered.

2. The method as set forth in claim 1, further comprising:

measuring a carrier power to noise sower ratio at the mobile station; and

controlling an average amount of the receive signal power of the channel control signal corresponding to the measured carrier power to noise power ratio.

3. A communication method based on demand network assignment access, the method comprising the steps of:

detecting a receive signal power of a channel control signal successively transmitted from a network control station at a mobile station;

detecting a decrease of the receive signal power of the channel control signal just before a call request or a call response is to be transmitted from the mobile station, stopping transmitting of the call request or the call response and recovering the receive signal power and after the receive signal power s recovered, transmitting the call request or the call response from the mobile station.

4. The method as set forth in claim 3, further comprising:

measuring a carrier power to noise power ratio at the mobile station; and

controlling an average amount of the receive signal power of the channel control signal corresponding to the measured carrier power to noise power ratio.

5. A communication method based on demand network assignment access, the method comprising the steps of:

detecting a receive signal power of a channel control signal successively transmitted from a network control station at a mobile station;

transmitting a call request or a call response from the mobile station, detecting a decrease of the receive signal power of the network control signal during transmission of the call request or call response, recovering the receive signal power and after the receive signal power is recovered, re-transmitting the call request or the call response from the mobile station; and

detecting a decrease of the receive signal power of the channel control signal just before a call request or a call response is to be transmitted from the mobile station, recovering, the receive signal power and after the receive signal power is recovered, transmitting the call request or the call response from the mobile station.

6. The method as set forth in claim 5, further comprising:

measuring a carrier power to noise power ratio at the mobile station; and

controlling an average amount of the receive signal power of the channel control signal corresponding to the measured carrier power to noise power ratio.

7. A satellite communication system based on demand assignment access having a mobile station,

wherein the mobile station comprises:

detecting means for detecting a receive level of a channel control signal that is successively transmitted from a network control station; and

means for re-transmitting a call request or a call response, said detecting means comprising a detector for detecting, while the call request or the call response is being transmitted, when the receive level becomes less than a threshold value of the receive level, and said means for retransmitting retransmits the call request or call response after the receive level recovers to a value larger than the threshold value.

8. A communications apparatus for use with a demand assignment access satellite communications system, comprising:

detecting means for detecting a receive level of a channel control signal that is successively transmitted from a network control station; and

means for re-transmitting a call request or a call response, said detecting means comprising a detector for detecting, while the call request or the call response is being transmitted, when the receive level becomes less than a threshold value of the receive level, and said means for retransmitting retransmits the call request or call response after the receive level recovers to a value larger than the threshold value.