Method and apparatus for adjusting data rate in a synchronous communication system

• US 5,974,032 A
• Filed: 05/19/1997
• Issued: 10/26/1999
• Est. Priority Date: 05/19/1997
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Gorday, Robert Mark, Snowden, Gregory O.
• Primary Examiner(s): Patel, Ajit
• Assistant Examiner(s): Pizarro, Ricardo M.
• Application Number:
  US08/861,308
• Time in Patent Office: 890 Days
• Field of Search: 370/311, 370/465, 370/468, 370/315, 370/316, 370/321, 370/328, 370/329, 370/324, 370/341, 370/347, 340/825.44, 340/825.47, 340/825.49, 455/12.1, 455/13.2, 455/38, 455/427, 455/422, 455/426
• US Class Current: 370/316
• CPC Class Codes: H04B 7/18532 Arrangements for managing transmission, i.e. for transporting data or a signalling message

Abstract

A method and apparatus are for receiving a portion of a message by a call receiver (2). A radio signal is intercepted (910) which is modulated with a hierarchical signalling protocol having variable bit rate protocol divisions (443). A particular variable bit rate protocol division (443) includes the portion of the paging message and a bit rate indicator (460). An optimum bit rate that is being used in the particular variable bit rate protocol division is determined (930) from the bit rate indicator (460). Words (450, 455) in the particular variable bit rate protocol division (443) are decoded (940) using the optimum bit rate. The portion of the paging message is obtained (950) from the words.

Claims

1. A method for receiving a portion of a message by a call receiver, comprising the steps of:

intercepting radio signal which is modulated with a hierarchical signalling protocol having variable bit rate protocol divisions that each include a bit rate indicator and encoded information wherein the encoded information comprises information bits in a plurality of words that are interleaved with each other;

determining a bit rate and an associated interleaving mode the determination made from the bit rate indicator included in a particular variable bit rate protocol division

generating a set of information by decoding the encoded information included in the particular variable bit rate protocol division using the optimum bit rate and the associated interleaving mode; and

obtaining from the set of information the portion of the message,

wherein the bit rate and associated interleaving mode are either a first bit rate 25,000 bps and an associated interleaving using 13 sequential pairs of 26 thirty two bit words or a second bit rate of 50,000 bps and an associated interleaving using a sequential triplet of thirty two bit words plus 5 sequential pairs of thirty two bit words.

2. The method according to claim 1, wherein each of the variable bit rate protocol divisions includes only one set of dispersed information.

3. The method according to claim 1, wherein the radio signal is transmitted by a satellite communication system, and wherein each of the variable bit rate protocol divisions, including the particular variable bit rate protocol division, is a simplex time slot.

4. A method for generating hierarchical signalling protocol for use in a sattelite communication system comprising the steps of:

determining an optimum bit rate having an associated interleaving mode to use for transmitting a portion of a paging message to call receiver;

including the portion of the paging message in a set of information;

generating a set of encoded information by using the associated interleaving mode;

including the set of encoded information in a particular variable bit rate protocol division;

setting a bit rate indicator within the particular variable bit rate protocol division, but not within the set of encoded information, wherein the bit rate indicator indicates the optimum bit rate and the associated interleaving mode;

setting an indicator in an activity table included in a battery saving protocol division to indicate that the caller receiver should monitor the parlicular variable bit rate protocol division; and

transmitting the particular variable bit rate protocol divisions using the optimum bit rate to transmit the set of encoded information and transmitting the battery saving protocol division, wherein the battery saving protocol division is transmitted at periodic intervals that have been predetermined at which the call receiver can monitor for determining when information is being transmitted imminently for the call receiver,

wherein the optimum bit rate and associated interleaving mode are either a first bit rate 25,000 bps and an associated interleaaving using 13 sequential pairs of 26 thirty two bit words or a second bit rate of 50,000 bps and an associated interleaving using a sequential triplet of thirty two bit words plus 5 sequential pairs of thirty two bit words.

5. A call receiver comprising:

a receiver section for intercepting a radio signal which is modulated with a hierarchical signalling protocol having variable bit rate protocol divisions that each include a bit rate indicator and encoded information, wherein a particular variable bit rate protocol division includes a portion of a message;

a processor, coupled to said receiver section, which controls the call receiver; and

a memory, coupled to said processor, for storing computer programs which control the processor, comprising

a first segment for determining from the bit rate indicator a bit rate having an associated interleaving mode that is being used in the particular variable bit rate protocol division;

a second segment for generating a set of information by decoding encoded infomation in the particular variable bit rate protocol divisions using the bit rate and the associated interleaving mode; and

a third segment for obtaining from the set of information the portion of the message,

wherin the bit rate and associated interleaving mode are either a first bit rate 25,000 bps and an associated interleaving using 13 sequential pairs of 26 thirty two bit words or a second bit rate of 50,000 bps and an associated interleaving using a sequential triplet of thirty two bit words plus 5 sequential pairs of thirty two bit words.