Frame formats and timing parameters in sub-1 GHz networks

• US 9,055,468 B2
• Filed: 03/01/2013
• Issued: 06/09/2015
• Est. Priority Date: 04/02/2012
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Vermani, Sameer, Baik, Eugene J
• Primary Examiner(s): Thompson, Jr., Otis L
• Application Number:
  US13/782,451
• Publication Number:
  US 20130315262A1
• Time in Patent Office: 830 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04L 27/26 Systems using multi-frequency codes H04L27/32 takes precedence
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2607 Cyclic extensions
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/0091 Signaling for the administration of the divided path
• CPC Class Codes: H04W 28/0273 adapting protocols for flow control or congestion control to wireless environment, e.g. adapting transmission control protocol [TCP] wireless network protocols or protocol adaptations to wireless operation, e.g. wireless application protocol H04W80/00

Abstract

Systems and methods of controlling characteristics of messages in sub-1 GHz networks (e.g., IEEE 802.11ah networks) are disclosed. One or more data structures indicating available frame formats and/or timing parameters may be stored at or accessible to transmitters and receivers. The data structures may be organized based on a frame format, a wireless network bandwidth, and/or the number of spatial streams in use at the wireless network. Information stored in the data structures may be used in generation and processing of messages communicated via the sub-1 GHz network.

Claims

1. A method comprising:

selecting, at a transmitter, a frame format for use in communicating a packet via a sub-one gigahertz wireless network operating at a particular bandwidth, wherein the frame format is selected based at least in part on the particular bandwidth;

determining one or more timing parameters based on the selected frame format and the particular bandwidth;

generating the packet in accordance with the selected frame format and the one or more timing parameters; and

sending the packet from the transmitter to a receiver,

wherein the selected frame format is a first frame format when the particular bandwidth is one megahertz,

wherein the selected frame format is the first frame format or a second frame format when the particular bandwidth is greater than one megahertz, wherein the second frame format comprises a first portion and a second portion, wherein the first portion comprises an omni portion comprising a short training field (STF), a first long training field (LTF), and a signal A field (SIG-A), and wherein the second portion comprises a data portion comprising a second STF, one or more signal B fields (SIG-Bs), and a data field.

2. The method of claim 1, wherein the sub-one gigahertz wireless network operates in accordance with an Institute of Electrical and Electronics Engineers (IEEE) 802.11ah protocol.

3. The method of claim 1, wherein the first frame format comprises a short training field (STF), a long training field (LTF), a signal field (SIG), and a data portion.

4. The method of claim 3, wherein when more than one spatial stream is in use, the first frame format further comprises one or more additional LTFs.

5. The method of claim 1, wherein when more than one spatial stream is in use, the second frame format further comprises one or more additional LTFs.

6. The method of claim 1, wherein the particular bandwidth comprises 1 megahertz (MHz), 2 MHz, 4 MHz, 8 MHz, or 16 MHz.

7. The method of claim 1, wherein the one or more timing parameters include:

a number of complex data subcarriers;

a number of pilot subcarriers;

a number of total subcarriers excluding guards;

a highest data subcarrier index;

a subcarrier frequency spacing;

a discrete Fourier transform (DFT) period;

an inverse DFT (IDFT) period;

a guard interval duration;

a double guard interval duration;

a short guard interval duration;

an orthogonal frequency-division multiplexing (OFDM) symbol duration with long guard intervals;

an OFDM symbol duration with short guard intervals;

an OFDM symbol duration;

a number of bits in a SERVICE field;

a number of tail bits per binary convolution code encoder;

a short training field (STF) duration;

a long training field (LTF) duration;

a signal field (SIG) duration;

a signal A field (SIG-A) duration;

a multiple-input multiple-output LTF (MIMO-LTF) duration;

a long format STF duration;

a signal B field (SIG-B) duration;

or any combination thereof.

8. The method of claim 7, wherein the STF duration, the LTF duration, and one of the SIG duration and the SIG-A duration are each longer when the particular bandwidth is one megahertz than when the particular bandwidth is greater than one megahertz.

9. The method of claim 7, wherein:

the subcarrier frequency spacing is 31.25 kilohertz (KHz);

the DFT period is 32 microseconds (μ

s);

the IDFT period is 32 μ

s;

the guard interval duration is 8 μ

s;

a double guard interval duration is 16 μ

s;

a short guard interval duration is 4 μ

s;

the OFDM symbol duration with long guard intervals is 40 μ

s;

an OFDM symbol duration with short guard intervals is 36 μ

s;

the OFDM symbol duration is 40 μ

s or 36 μ

s;

the number of bits in the SERVICE field is 16;

the number of tail bits per binary convolution code encoder is 6; and

the MIMO-LTF duration is 40 μ

s.

10. The method of claim 7, wherein when the particular bandwidth is 1 megahertz (MHz):

the number of complex data subcarriers is 24;

the number of pilot subcarriers is 2;

the number of total subcarriers excluding guards is 26;

the highest data subcarrier index is 13;

the STF duration is 160 microseconds (μ

s);

the LTF duration is 160 μ

s; and

the SIG duration is 240 μ

s or 200 μ

s.

11. The method of claim 7, wherein when the particular bandwidth is greater than 1 megahertz (MHz):

the STF duration is 80 microseconds (μ

s);

the LTF duration is 8 μ

s;

the SIG duration is 80 μ

s;

the SIG-A duration is 80 μ

s;

the long format STF duration is 40 μ

s; and

the SIG-B duration is 40 μ

s.

12. The method of claim 7, wherein when the particular bandwidth is 2 megahertz (MHz):

the number of complex data subcarriers is 52;

the number of pilot subcarriers is 4;

the number of total subcarriers excluding guards is 56; and

the highest data subcarrier index is 28.

13. The method of claim 7, wherein when the particular bandwidth is 4 megahertz (MHz):

the number of complex data subcarriers is 108;

the number of pilot subcarriers is 6;

the number of total subcarriers excluding guards is 114; and

the highest data subcarrier index is 58.

14. The method of claim 7, wherein when the particular bandwidth is 8 megahertz (MHz):

the number of complex data subcarriers is 234;

the number of pilot subcarriers is 8;

the number of total subcarriers excluding guards is 242; and

the highest data subcarrier index is 122.

15. The method of claim 7, wherein when the particular bandwidth is 16 megahertz (MHz):

the number of complex data subcarriers is 468;

the number of pilot subcarriers is 16;

the number of total subcarriers excluding guards is 484; and

the highest data subcarrier index is 250.

16. A non-transitory processor-readable medium storing:

one or more data structures, the one or more data structures indicating timing parameters for a first frame format and a second frame format of a sub-one gigahertz wireless network for each of a plurality of operating bandwidths of the sub-one gigahertz wireless network, wherein a first operating bandwidth of one megahertz is associated with the first frame format, wherein a second operating bandwidth that is greater than one megahertz is associated with the first frame format or the second frame format, wherein the second frame format comprises a first portion and a second portion, wherein the first portion comprises an omni portion comprising a short training field (STF), a first long training field (LTF), and a signal A field (SIG-A), and wherein the second portion comprises a data portion comprising a second STF, one or more signal B fields (SIG-Bs), and a data field;

wherein the timing parameters include;

a number of complex data subcarriers;

a number of pilot subcarriers;

a number of total subcarriers excluding guards;

a highest data subcarrier index;

a subcarrier frequency spacing;

an inverse discrete Fourier transform period;

a discrete Fourier transform period;

a guard interval duration;

a double guard interval duration;

a short guard interval duration;

an orthogonal frequency-division multiplexing (OFDM) symbol duration with long guard intervals;

an OFDM symbol duration with short guard intervals;

an OFDM symbol duration;

a number of bits in a SERVICE field;

a number of tail bits per binary convolution code encoder;

a short training field (STF) duration;

a long training field (LTF) duration;

a signal field (SIG) duration;

a signal A field (SIG-A) duration;

a multiple-input multiple-output LTF (MIMO-LTF) duration;

a long format STF duration;

a signal B field (SIG-B) duration;

or any combination thereof.

17. An apparatus comprising:

a memory storing one or more data structures, the one or more data structures indicating timing parameters for a plurality of frame formats and a plurality of bandwidths of a sub-one gigahertz wireless network; and

a processor coupled to the memory, the processor configured to;

select a frame format for use in communicating a packet via the sub-one gigahertz wireless network operating at a particular bandwidth, wherein the frame format is selected based at least in part on the particular bandwidth;

determine one or more timing parameters based on the selected frame format and the particular bandwidth; and

generate the packet in accordance with the selected frame format and the one or more timing parameters,

wherein the selected frame format is a first frame format when the particular bandwidth is one megahertz, and

wherein the selected frame format is the first frame format or a second frame format when the particular bandwidth is greater than one megahertz, wherein the second frame format comprises a first portion and a second portion, wherein the first portion comprises an omni portion comprising a short training field (STF), a first long training field (LTF), and a signal A field (SIG-A), and wherein the second portion comprises a data portion comprising a second STF, one or more signal B fields (SIG-Bs), and a data field.

18. The apparatus of claim 17, wherein the sub-one gigahertz wireless network operates in accordance with an Institute of Electrical and Electronics Engineers (IEEE) 802.11ah protocol.

19. An apparatus comprising:

means for storing one or more data structures, the one or more data structures indicating timing parameters for a plurality of frame formats and a plurality of bandwidths of a sub-one gigahertz wireless network;

means for selecting a frame format for use in communicating a packet via the sub-one gigahertz wireless network operating at a particular bandwidth, wherein the frame format is selected based at least in part on the particular bandwidth;

means for determining one or more timing parameters based on the selected frame format and the particular bandwidth; and

means for generating the packet in accordance with the selected frame format and the one or more timing parameters,

wherein the selected frame format is a first frame format when the particular bandwidth is one megahertz,

wherein the selected frame format is the first frame format or a second frame format when the particular bandwidth is greater than one megahertz, wherein the second frame format comprises a first portion and a second portion, wherein the first portion comprises an omni portion comprising a short training field (STF), a first long training field (LTF), and a signal A field (SIG-A), and wherein the second portion comprises a data portion comprising a second STF, one or more signal B fields (SIG-Bs), and a data field.