METHOD AND APPARATUS FOR RETRANSMITTING PACKET FOR LOW-POWER WIRELESS SENSOR COMMUNICATIONS

• US 20150172031A1
• Filed: 12/16/2014
• Published: 06/18/2015
• Est. Priority Date: 12/17/2013
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: YEO, Geon-Min, KIM, Young-Il, RYU, Won
• Granted Patent: US 9,819,466 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 1/1614 using bitmaps
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method of retransmitting a packet for low-power wireless sensor communications of a coordinator in a sensor network is provided. The method includes receiving packets from a plurality of sensor devices during a plurality of guaranteed time slots (GTSs) of a Contention Free Period (CFP) which are allocated to the respective sensor devices; checking whether there is an error in each of the received packets; generating one GTS Bulk ACK frame that contains pieces of ACK information to be transmitted to the respective sensor devices, according to the error check results; and transmitting the generated GTS Bulk ACK frame to the plurality of sensor devices.

Claims

1. A method of retransmitting a packet for low-power wireless sensor communications, the method comprising:

receiving packets from a plurality of sensor devices during a plurality of guaranteed time slots (GTSs) of a Contention Free Period (CFP) which are allocated to the respective sensor devices;

checking whether there is an error in each of the received packets;

generating one GTS Bulk ACK frame that contains pieces of ACK information to be

transmitted to the respective sensor devices, according to the error check results; and

transmitting the generated GTS Bulk ACK frame to the plurality of sensor devices.

2. The method of claim 1, wherein the transmitting of the generated GTS Bulk ACK frame comprises broadcasting the generated GTS Bulk ACK frame to the plurality of sensor devices.

3. The method of claim 1, wherein the transmitting of the generated GTS Bulk ACK frame comprises transmitting the generated GTS Bulk ACK frame during a predetermined period within a Contention Access Period (CAP) offset, which is different from a beacon transmission period within the CAP offset.

4. The method of claim 1, wherein the transmitting of the generated GTS Bulk ACK frame comprises transmitting the GTS Bulk ACK frame included in a beacon.

5. The method of claim 1, wherein the GTS Bulk ACK frame comprises a GTS ACK Bitmap including bits, each of which represents ACK information with respect to each of the packets received during the plurality of GTSs.

6. The method of claim 5, wherein the GTS Bulk ACK frame further comprises Data Sequence Number (DSN) indicator and GTS Cumulative DSN, wherein the DSN indicator includes information whether Data Sequence Number (DSN) which has been successfully received from each of the plurality of sensor devices using each GTS is contained in the GTS Bulk ACK frame and the GTS Cumulative DSN indicates a final value of continuous DSNs that have been successfully received from each of the plurality of sensor devices.

7. A method of retransmitting a packet for low-power wireless sensor communications, the method comprising:

receiving one guaranteed time slot (GTS) Bulk ACK frame containing ACK information to be transmitted to each of a plurality of devices;

checking the received GTS Bulk ACK frame and determining whether packet retransmission is required; and

in response to a determination that the packet retransmission is required, retransmitting a corresponding packet during an allocated GTS within a Contention Free Period (CFP) offset.

8. The method of claim 7, wherein the determining of whether packet retransmission is required comprises, in a case where there is no new packet to be sent during the allocated GTS, checking the received GTS Bulk ACK frame.

9. The method of claim 7, further comprising:

in response to a determination that the packet retransmission is not required, removing the corresponding packet.

10. The method of claim 7, wherein the retransmitting of the corresponding packet comprises determining whether the corresponding packet has been transmitted less than a maximum allowed retransmission times, and only in response to a determination that the corresponding packet has been transmitted less than the maximum allowed retransmission times, retransmitting the corresponding packet during the allocated GTS.

11. An apparatus for retransmitting a packet for low-power wireless sensor communications, the apparatus comprising:

a packet receiver configured to receive packets transmitted from a plurality of sensor devices during guaranteed time slots (GTSs) of a Contention Free Period (CFP) offset which are allocated to each of the plurality of sensor devices;

an error checker configured to check whether there is an error in each of the received packets;

an ACK generator configured to, in response to an error check result, generate one GTS Bulk ACK frame containing ACK information to be transmitted to each of the plurality of sensor devices; and

an ACK transmitter configured to transmit the generated GTS Bulk ACK frame to the plurality of sensor devices.

12. The apparatus of claim 11, wherein the ACK transmitter is configured to broadcast the generated GTS Bulk ACK frame to the plurality of sensor devices.

13. The apparatus of claim 11, wherein the ACK transmitter is configured to transmit the GTS Bulk ACK frame during a predetermined period within a Contention Access Period (CAP) offset which is different from a beacon transmission period within the CAP offset.

14. The apparatus of claim 11, wherein the ACK transmitter is configured to transmit the GTS Bulk ACK frame included in a beacon.

15. The apparatus of claim 11, wherein the GTS Bulk ACK frame comprises a GTS ACK Bitmap including bits, each of which represents ACK information with respect to each of the packets received during the plurality of GTSs.

16. An apparatus for retransmitting a packet for low-power wireless sensor communications, the apparatus comprising:

an ACK receiver configured to receive one guaranteed time slot (GTS) Bulk ACK frame containing ACK information to be transmitted to each of a plurality of devices;

a checker configured to check the received GTS Bulk ACK frame and determine whether packet retransmission is required; and

a re-transmitter configured to, in response to a determination that the packet retransmission is required, retransmitting a corresponding packet during an allocated GTS within a Contention Free Period (CFP) offset.

17. The apparatus of claim 16, wherein the checker is configured to, in a case where there is no new packet to be transmitted during the allocated GTS, check the received GTS Bulk ACK frame.

18. The apparatus of claim 16, further comprising:

a packet storage;

wherein the checker is configured to, in response to a determination that the packet retransmission is not required, remove the corresponding packet from the packet storage.

19. The apparatus of claim 16, wherein the re-transmitter is configured to determine whether the corresponding packet has been transmitted less than a maximum allowed retransmission times, and only in response to a determination that the corresponding packet has been transmitted less than the maximum allowed retransmission times, retransmit the corresponding packet during the allocated GTS.