Method for indicating padding in a digital mobile radio system

• US 7,489,675 B2
• Filed: 09/11/2006
• Issued: 02/10/2009
• Est. Priority Date: 09/12/2005
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Wiatrowski, David G., Chowdhary, Dipendra M.
• Primary Examiner(s): Kizou; Hassan
• Assistant Examiner(s): Rutkowski; Jeffrey M
• Application Number:
  US11/530,660
• Publication Number:
  US 20070058565A1
• Time in Patent Office: 883 Days
• Field of Search: 370/395.1, 370/464, 370/465, 370/470, 370/471, 370/474, 370/476, 370/310.1, 370/349, 370/466, 370/469, 370/473, 370/505, 370/252, 714/755
• US Class Current: 370/349
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00

Abstract

A method for indicating padding in a digital mobile radio is disclosed. The method comprises receiving a packet comprising a header and a defined length blocks portion. The defined length blocks portion comprises payload and a padding portion. The padding portion comprises padding and a payload pad count field. The method further indicates by a pad field in the header to examine the payload pad count field to determine an amount of padding for the padding portion of the defined length blocks portion. The method further indicates an amount of padding for the padding portion in the payload pad count field.

Claims

1. A method for indicating padding in a digital mobile radio system, wherein the method comprises:

creating a packet comprising a header and a defined length blocks portion, wherein the defined length blocks portion comprises payload and a padding portion, and wherein the padding portion comprises padding and a payload pad count field;

comparing an amount of padding for the padding portion to a threshold that is determined based on a format of the payload;

when the amount of padding exceeds the threshold, indicating by a pad field in the header to examine the payload pad count field to determine the amount of padding for the padding portion;

indicating an amount of padding for the padding portion in the payload pad count field; and

transmitting the packet.

2. The method of claim 1 wherein the payload pad count field comprises the last octet preceding a cyclic redundancy check field of the defined length blocks portion.

3. The method of claim 1 wherein a minimum padding portion of the pad field indicates to examine the payload pad count field.

4. The method of claim 3 wherein a minimum padding portion indicates to examine the payload pad count field by a value of binary ones.

5. The method of claim 1 wherein the amount of padding is a number of pad bits that are required to bring the defined length blocks portion to become a predetermined length.

6. The method of claim 1 further comprising:

creating a second packet comprising a header and a defined length blocks portion, wherein the defined length blocks portion comprises payload and a padding portion;

when an amount of padding for the padding portion is less than or equal to the threshold, indicating by a pad field in the header the amount of padding for the padding portion for the second packet; and

transmitting the second packet.

7. The method of claim 6 wherein the pad field further indicates the format of the payload in the defined length blocks portion.

8. The method of claim 6 wherein the amount indicates a number of pad words for padding the padding portion of the defined length blocks portion.

9. A method for indicating padding in a digital mobile radio system, wherein the method comprises:

receiving a defined length data message comprising at least a short data header and a defined length blocks portion, wherein the short data header has at least a format field and a pad field, wherein the format field indicates a type of service, and wherein the pad field has a data format field and a minimum padding field for the padding of the defined length blocks portion, wherein the minimum padding field provides an indication to examine a payload pad count field of the defined length block portion when an amount of padding in the defined length blocks portion exceeds a threshold, wherein the threshold is based on a data format indicated in the data format field of the pad field;

examining the payload pad count field of the defined length blocks portion for the amount of padding in the defined length blocks portion, if the minimum padding field indicates that the defined length blocks portion comprises the payload pad count field.

10. The method of claim 9 wherein the minimum padding field is a variable length field.

11. The method of claim 9 wherein the short data header is one defined block in length.

12. The method of claim 9 wherein a last defined length block of the defined length blocks portion comprises a cyclic redundancy check that serves as a check over the defined length blocks portion.

13. The method of claim 9 wherein the pad field is at least one of 5 bits in length and 8 bits in length.

14. The method of claim 9 wherein the format field identifies data in the defined length blocks portion having at least one of a binary data format, a BCD data format, a 7 bit character data format, an 8 bit character data format, a 16 bit character data format, and a 24 bit character data format.

15. The method of claim 14 wherein the 8 bit character data format adheres to an international standard.

16. The method of claim 9 wherein the format field indicates a short data service.

17. A method for indicating padding in a defined length blocks portion of a packet in a digital mobile radio system, wherein the method comprises:

computing a number of blocks of payload for a packet, wherein the packet is to be sent to a receiver in the digital mobile radio system;

computing an amount of padding for the number of blocks of payload so that the packet is of a defined length to create a packet of the defined length by adding the amount of padding to a padding portion of the packet;

comparing the amount of padding to a threshold that is based on a format for the payload;

when the amount of padding exceeds the threshold indicating the amount of padding by a payload pad count field in the padding portion of the packet; and

indicating by a pad field in a header of the packet to examine the payload pad count field of the padding portion to determine the amount of padding in the padding portion of the packet.

18. The method of claim 17 wherein the amount of padding is computed with reference to the following equation:

19. The method of claim 18 wherein the N_bits/CRC is set to 32.

20. The method of claim 17 wherein the step of computing the number of blocks of payload further comprises considering at least one of a) the format of the payload to compute the blocks of the payload, b) a number of bits in a cyclic redundancy check field, a forward error correction coding, and a delivery type.