WO2012060687A1 - Method for use in a wireless sensor network - Google Patents
Method for use in a wireless sensor network Download PDFInfo
- Publication number
- WO2012060687A1 WO2012060687A1 PCT/MY2011/000133 MY2011000133W WO2012060687A1 WO 2012060687 A1 WO2012060687 A1 WO 2012060687A1 MY 2011000133 W MY2011000133 W MY 2011000133W WO 2012060687 A1 WO2012060687 A1 WO 2012060687A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- active
- traffic
- sensor
- sensor nodes
- time
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/02—Details
- H04L12/12—Arrangements for remote connection or disconnection of substations or of equipment thereof
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/02—Power saving arrangements
- H04W52/0209—Power saving arrangements in terminal devices
- H04W52/0212—Power saving arrangements in terminal devices managed by the network, e.g. network or access point is master and terminal is slave
- H04W52/0216—Power saving arrangements in terminal devices managed by the network, e.g. network or access point is master and terminal is slave using a pre-established activity schedule, e.g. traffic indication frame
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/02—Power saving arrangements
- H04W52/0209—Power saving arrangements in terminal devices
- H04W52/0212—Power saving arrangements in terminal devices managed by the network, e.g. network or access point is master and terminal is slave
- H04W52/0219—Power saving arrangements in terminal devices managed by the network, e.g. network or access point is master and terminal is slave where the power saving management affects multiple terminals
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/50—Allocation or scheduling criteria for wireless resources
- H04W72/56—Allocation or scheduling criteria for wireless resources based on priority criteria
- H04W72/566—Allocation or scheduling criteria for wireless resources based on priority criteria of the information or information source or recipient
- H04W72/569—Allocation or scheduling criteria for wireless resources based on priority criteria of the information or information source or recipient of the traffic information
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W84/00—Network topologies
- H04W84/18—Self-organising networks, e.g. ad-hoc networks or sensor networks
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Definitions
- the preferred embodiments of the present invention direct to a method for use in a wireless sensor network, and more particularly to an energy saving method for managing the active and sleeping time of sensor nodes in a wireless sensor network.
- the sensor nodes would be equipped with conventional AA alkaline batteries as power source.
- the battery gradually drain out and in many cases changing of batteries may not be convenient for users.
- progressive advancements in sensor network systems has created the possibility to save power on sensor nodes, whereby one of the known solutions is allowing or putting the sensor nodes in sleep mode if they are not assigned with any task. This condition is shown in FIG 1.
- the timing however depends on the application of the wireless sensor network, whereby in some applications it might be required that the sensor nodes are active most of the time while in other cases the sensor nodes will be required to be put to sleep most of the times. Therefore, setting active and sleeping mode time may not be advantageous considering the diversity of applications nowadays.
- FIG 2 illustrates the situation of nodes in the event that the sensor nodes are not configured based on sleeping mode schedule. Accordingly, it is seen that if an active sensor node sends a message to a sleeping node, the sleeping node will miss the message, due to the fact the sensor nodes are not synchronized allowing some nodes to be in active mode and some in sleeping mode. As a result, re-transmitting the message has to take place. Further under another circumstance, an active node sends a message to a sleeping node, and a reply is anticipated. However, reply will be received in a much delayed time as the node is still in sleeping mode, and further actions will not be taken until the sleeping node is in active mode again.
- traffic is not the same for all sensor nodes, as it depends on the position of the sensor nodes. For instance, the sensor nodes which are closer to the base station or gateway would have higher traffic owing to the fact that they have to route messages from the other nodes within the network to the gateway. These sensor nodes therefore should stay active most of the times. If they are put to sleep because of the sleeping schedule timing, messages may be lost or missed. As opposed to these nodes, the nodes which are located at the corners of the network or within a place with reduced traffic would preferably by in sleeping mode most of the times. Conclusively, traffic varies for all sensor nodes within a network as seen in FIG 3 As discussed above, developing a system and method that is suitable to accommodate the drawbacks in conserving energy with respect to sensor networks has been difficult.
- the present invention has been accomplished to significantly improve the conventional methods and systems.
- a method for use in managing at least two sensor nodes in a wireless sensor network comprising the step of scheduling the active and sleeping time for the sensor node based on the type of traffic at said sensor nodes.
- a method comprising the step of determining the traffic based on active period in a current active period. In another aspect of the present invention, there is provided a method comprising the step of adjusting the next active period based on the current active period.
- the method further comprising the step of synchronizing the active state of all sensor nodes with a base station.
- FIG 1 shows the difference between a node which is always active and a node which has sleeping schedule
- FIG 2 shows a prior art system whereby it illustrates the nodes in the event that the sensor nodes are not configured based on sleeping mode schedule
- FIG 3 shows the traffic variety for all sensor nodes
- FIG 4 illustrates the change of active time of the sleeping schedule in the sensor nodes based on their traffic, in accordance with a preferred embodiment of the present invention.
- FIG 5 shows the low active time in accordance with a preferred embodiment of the present invention.
- FIG 6 shows the normal active time in accordance with a preferred embodiment of the present invention
- FIG 7 shows the high active time in accordance with a preferred embodiment of the present invention.
- FIG 8 shows the sleeping schedule for all sensor nodes in accordance with a preferred embodiment of the present invention
- FIG 9 shows the process involved for traffic based sleeping schedule for wireless sensor networks in accordance with a preferred embodiment of the present invention
- FIG 10 shows the sleeping and active time of the sensor nodes changing according to the average traffic at the sensor node.
- the present invention provides a method and system for use in managing the sensor nodes within a wireless sensor network, whereby there is provided a dynamic active and sleeping mode schedule for the nodes which is based on network traffic. Accordingly, each node is configured to monitor the inflow and outflow of traffic, and if the traffic reduces, the sensor node will reduce its active time.
- traffic in this context refers to messages that are either sent to the node or have been broadcasted and the node have received them, or the messages that the sensor node has sent out to the network.
- FIG 4 illustrates the change of active time of the sleeping schedule in the sensor nodes based on their traffic, in accordance with a preferred embodiment of the present invention.
- L T is the threshold for low traffic and ⁇ is the threshold for high traffics at the sensor node. It is preferred that the traffic ranges and so the active time types of the sensor nodes are as below:
- LA Low Active -
- each sensor node will count the number of messages that are either sent to its address or broadcasted or the messages that the sensor node has sent out to other nodes and calculate the traffic for each cycle. Accordingly, the node will check its traffic and define the active period for the next active time. This process is as shown in FIG 9.
- reducing and increasing the active time of the sensor node aids significantly to optimize the life time of the sensor nodes as shown in FIG 10, whereby there is shown the sleeping and active time of the sensor node which changes according to the average traffic at the sensor node.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
The present invention discloses a method for use in managing at least two sensor nodes within a wireless sensor network, whereby the method comprising the steps of scheduling the active and sleeping time for the sensor node based on the type of traffic at said sensor nodes, determining the traffic based on active period in a current active period, adjusting the next active period based on the current active period, and synchronizing the active state of all sensor nodes with a base station.
Description
METHOD FOR USE IN A WIRELESS SENSOR NETWORK
FIELD OF INVENTION The preferred embodiments of the present invention direct to a method for use in a wireless sensor network, and more particularly to an energy saving method for managing the active and sleeping time of sensor nodes in a wireless sensor network.
BACKGROUND
The need to improve power consumption, particularly to provide energy efficient sensing systems within a network has been progressively emerging and thus placed as a significant target among researchers of the relevant art when developing advanced wireless systems paradigm. The main challenges are to provide cost and energy efficient in addition to reliable sensing connections for future generation sensor networks.
Nowadays, in many cases related to wireless sensor-based applications, the sensor nodes would be equipped with conventional AA alkaline batteries as power source. In the event that the sensor nodes are deployed unattended in the subject environment for sensing purposes typically for a substantial period of time, the battery gradually drain out and in many cases changing of batteries may not be convenient for users.
In order to accommodate the limitation as described above, progressive advancements in sensor network systems has created the possibility to save power on sensor nodes, whereby one of the known solutions is allowing or putting the sensor nodes in sleep mode if they are not assigned with any task. This condition is shown in FIG 1.
By putting the sensor nodes in sleeping mode, it is observed that the power consumption can be reduced significantly. However, a trivial drawback in putting sensor nodes in sleeping mode is that in the case when another node sends a message to the particular sensor which is in sleeping mode, the message will not be received and thus not read by the sleeping node. In this case, the active node will then would have to re-transmit the message, which obviously a task that also consumes power. Therefore, in order to have an optimized power conservation technique, it should be ensured that the sensor nodes are in sleeping mode as much as possible however not missing the messages sent for them thus avoiding retransmissions.
Other drawbacks associated to current techniques in putting nodes into sleeping mode include losing messages and the latency in receiving reply messages due to delay from sensor node which has yet to be activated from sleeping mode.
When there is provided wake up and sleep time for the sensor nodes, the timing however depends on the application of the wireless sensor network, whereby in some applications it might be required that the sensor nodes are active most of the time while in other cases the sensor nodes will be required to be put to sleep most of
the times. Therefore, setting active and sleeping mode time may not be advantageous considering the diversity of applications nowadays.
As described earlier, FIG 2 illustrates the situation of nodes in the event that the sensor nodes are not configured based on sleeping mode schedule. Accordingly, it is seen that if an active sensor node sends a message to a sleeping node, the sleeping node will miss the message, due to the fact the sensor nodes are not synchronized allowing some nodes to be in active mode and some in sleeping mode. As a result, re-transmitting the message has to take place. Further under another circumstance, an active node sends a message to a sleeping node, and a reply is anticipated. However, reply will be received in a much delayed time as the node is still in sleeping mode, and further actions will not be taken until the sleeping node is in active mode again.
In addition, within a wireless sensor network, traffic is not the same for all sensor nodes, as it depends on the position of the sensor nodes. For instance, the sensor nodes which are closer to the base station or gateway would have higher traffic owing to the fact that they have to route messages from the other nodes within the network to the gateway. These sensor nodes therefore should stay active most of the times. If they are put to sleep because of the sleeping schedule timing, messages may be lost or missed. As opposed to these nodes, the nodes which are located at the corners of the network or within a place with reduced traffic would preferably by in sleeping mode most of the times. Conclusively, traffic varies for all sensor nodes within a network as seen in FIG 3
As discussed above, developing a system and method that is suitable to accommodate the drawbacks in conserving energy with respect to sensor networks has been difficult.
Recognizing the aforementioned shortcomings, the present invention has been accomplished to significantly improve the conventional methods and systems.
Accordingly, it is a primary object of the method of the present invention to provide a method and system for use in managing sensor nodes within a sensor network.
It is therefore another object of the present invention to provide a method for use in providing a dynamic sleeping schedule for sensor nodes within a wireless sensor network.
It is further object of the present invention to provide a method for use in a wireless sensor network, wherein the sleeping schedule is based on the traffic of the network.
It is yet another object of the present invention to provide a method for use in a wireless sensor network, wherein the message loss in the network can be reduced by increasing the active period of the sensor node when traffic is increasing.
It is a further object of the present invention to provide a method for use in a wireless sensor network, wherein there is provided a time synchronization ability so to synchronize the sleeping schedules.
Further objects and advantages of the present invention will become apparent in the following description. SUMMARY OF INVENTION
In one aspect of the invention, there is provided a method for use in managing at least two sensor nodes in a wireless sensor network comprising the step of scheduling the active and sleeping time for the sensor node based on the type of traffic at said sensor nodes.
In another aspect of the present invention, there is provided a method comprising the step of determining the traffic based on active period in a current active period. In another aspect of the present invention, there is provided a method comprising the step of adjusting the next active period based on the current active period.
In yet another aspect of the present invention, the method further comprising the step of synchronizing the active state of all sensor nodes with a base station.
BRIEF DESCRIPTION OF THE FIGURES
FIG 1 shows the difference between a node which is always active and a node which has sleeping schedule;
FIG 2 shows a prior art system whereby it illustrates the nodes in the event that the sensor nodes are not configured based on sleeping mode schedule;
FIG 3 shows the traffic variety for all sensor nodes;
FIG 4 illustrates the change of active time of the sleeping schedule in the sensor nodes based on their traffic, in accordance with a preferred embodiment of the present invention. FIG 5 shows the low active time in accordance with a preferred embodiment of the present invention;
FIG 6 shows the normal active time in accordance with a preferred embodiment of the present invention;
FIG 7 shows the high active time in accordance with a preferred embodiment of the present invention;
FIG 8 shows the sleeping schedule for all sensor nodes in accordance with a preferred embodiment of the present invention;
FIG 9 shows the process involved for traffic based sleeping schedule for wireless sensor networks in accordance with a preferred embodiment of the present invention;
FIG 10 shows the sleeping and active time of the sensor nodes changing according to the average traffic at the sensor node.
The invention will be more understood by reference to the description below taken in conjunction with the accompanying drawings herein:
DETAILED DESCRIPTION
In addition to the drawings, further understanding of the object, construction, characteristics and functions of the invention, a detailed description with reference to the embodiments is given in the following.
In one embodiment, the present invention provides a method and system for use in managing the sensor nodes within a wireless sensor network, whereby there is provided a dynamic active and sleeping mode schedule for the nodes which is based on network traffic. Accordingly, each node is configured to monitor the inflow and outflow of traffic, and if the traffic reduces, the sensor node will reduce its active time.
It should be noted that "traffic" in this context refers to messages that are either sent to the node or have been broadcasted and the node have received them, or the messages that the sensor node has sent out to the network.
FIG 4 illustrates the change of active time of the sleeping schedule in the sensor nodes based on their traffic, in accordance with a preferred embodiment of the present invention.
As seen in FIG 4, there is defined two thresholds of traffic and three active times for the sensor node. LT is the threshold for low traffic and Ητ is the threshold for high traffics at the sensor node. It is preferred that the traffic ranges and so the active time types of the sensor nodes are as below:
1. Low Active - (LA) : in the event that the traffic at the sensor node is less or equal to LT, the traffic is considered low and the active time of the sensor will be reduced by half of the normal time in the next active time as shown in FIG
5.
2. Normal Active - (NA): in the event that the traffic at the sensor node is more than LT and less than or equal to HT, then the traffic at the node is considered as normal traffic. Therefore the next active time of the sensor node will be normal active as shown in FIG 6. 3. High Active - (HA): in the event that the traffic at the sensor node is more than HT, the traffic at the sensor node is considered as high traffic and the sensor node will change its active time to high active for the next active time as suitably shown in FIG 7. In accordance with a preferred embodiment of the present invention, the sensor nodes are supposed to be synchronized with the gateway of base station. Therefore, when all the nodes are turned on or active, they will get time synchronized with the gateway and thus will have the same sleeping schedule as seen in FIG 8.
Subsequently, the nodes start their tasks, conduct readings based on the environment and reply to the requests coming from the respective gateway. In this method, each sensor node will count the number of messages that are either sent to its address or broadcasted or the messages that the sensor node has sent out to other nodes and calculate the traffic for each cycle. Accordingly, the node will check its traffic and define the active period for the next active time. This process is as shown in FIG 9.
In conclusion, reducing and increasing the active time of the sensor node aids significantly to optimize the life time of the sensor nodes as shown in FIG 10, whereby there is shown the sleeping and active time of the sensor node which changes according to the average traffic at the sensor node.
The present invention may be modified in light of the above teachings. It is therefore understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
Claims
1. A method for use in managing at least two sensor nodes in a wireless sensor network comprising the step of scheduling the active and sleeping time for the sensor node based on the type of traffic at said sensor nodes.
2. The method as claimed in Claim 1 wherein the method further comprising the step of determining the traffic based on active period in a current active period.
3. The method as claimed in Claim 1 wherein the method further comprising the step of adjusting the next active period based on the current active period.
4. The method as claimed in Claim 1 wherein the method further comprising the step of synchronizing the active state of all sensor nodes with a base station.
5. The method as claimed in Claim 3, wherein adjusting the next active period based on the current active period step further comprising the steps of comparing the traffic in the current active period with the traffic thresholds and adjusting the next active period based on said comparison.
6. The method as claimed in Claim 1 further comprising the steps of providing three active times for the sensor nodes, said active times are low active time, normal active time and high active time.
7. The method as claimed in Claim 6 wherein low active time is considered as low traffic therefore the active time of the sensor nodes are reduced.
8. The method as claimed in Claim 6 wherein the normal active time is considered as normal traffic therefore the sensor nodes active time in the next active time is normal.
9. The method as claimed in Claim 6 wherein the high active time is considered for high traffic therefore the sensor nodes active time is increased.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
MYPI2010005200 | 2010-11-03 | ||
MYPI2010005200 | 2010-11-03 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2012060687A1 true WO2012060687A1 (en) | 2012-05-10 |
Family
ID=46024657
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/MY2011/000133 WO2012060687A1 (en) | 2010-11-03 | 2011-06-23 | Method for use in a wireless sensor network |
Country Status (1)
Country | Link |
---|---|
WO (1) | WO2012060687A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103002590A (en) * | 2012-11-23 | 2013-03-27 | 南京邮电大学 | Scheduling method of directed nodes in wireless sensor network |
CN103237337A (en) * | 2013-02-28 | 2013-08-07 | 山东省计算中心 | Adaptive network dormancy control method for wireless sensors |
JP2014216960A (en) * | 2013-04-26 | 2014-11-17 | 富士通株式会社 | Communication apparatus and timing adjustment method |
WO2015009138A3 (en) * | 2013-07-18 | 2015-04-09 | Mimos Berhad | A system and method for managing sleeping mode of wireless nodes in a wireless sensor network |
CN111586615A (en) * | 2020-05-13 | 2020-08-25 | 甘肃省农业工程技术研究院 | Sampling scheduling method and system for agricultural wireless sensor network |
-
2011
- 2011-06-23 WO PCT/MY2011/000133 patent/WO2012060687A1/en active Application Filing
Non-Patent Citations (2)
Title |
---|
CHIANG ET AL.: "Neighborhood-Aware Density Control in Wireless Sensor Networks", SUTC'08. IEEE INTERNATIONAL CONFERENCE ON SENSOR NETWORKS, UBIQUITOUS AND TRUSTWORTHY COMPUTING, 2008., TAICHUNG, pages 122 - 129 * |
LEE ET AL.: "Adaptive Duty-cycle based Congestion Control for Home Automation Networks", IEEE TRANSACTIONS ON CONSUMER ELECTRONICS, VOL. 56, NO. 1, SCH. OF ELECTRON. ENG. KWANGWOON UNIV., vol. 56, no. 1, February 2010 (2010-02-01), SEOUL, SOUTH KOREA, pages 42 - 47 * |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103002590A (en) * | 2012-11-23 | 2013-03-27 | 南京邮电大学 | Scheduling method of directed nodes in wireless sensor network |
CN103237337A (en) * | 2013-02-28 | 2013-08-07 | 山东省计算中心 | Adaptive network dormancy control method for wireless sensors |
JP2014216960A (en) * | 2013-04-26 | 2014-11-17 | 富士通株式会社 | Communication apparatus and timing adjustment method |
WO2015009138A3 (en) * | 2013-07-18 | 2015-04-09 | Mimos Berhad | A system and method for managing sleeping mode of wireless nodes in a wireless sensor network |
CN111586615A (en) * | 2020-05-13 | 2020-08-25 | 甘肃省农业工程技术研究院 | Sampling scheduling method and system for agricultural wireless sensor network |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US8611268B1 (en) | Access point power save mechanism for wireless communication systems | |
US7356561B2 (en) | Adaptive sleeping and awakening protocol for an energy-efficient adhoc network | |
US8588119B2 (en) | Asynchronous low-power multi-channel media access control | |
US9313275B2 (en) | Communication protocol for energy-harvesting devices | |
KR101614830B1 (en) | Wireless beacon reception | |
CN102685780B (en) | Wireless sensor network channel access and bulk data transmission method | |
KR101174406B1 (en) | A Low Power MAC Architecture for Wireless Sensor Network with Wireless Power Transfer | |
Ramezani et al. | Overview of MAC protocols for energy harvesting wireless sensor networks | |
CN101557408A (en) | Wireless sensor network active mode resting dispatching method | |
WO2012060687A1 (en) | Method for use in a wireless sensor network | |
Liu et al. | LEB-MAC: Load and energy balancing MAC protocol for energy harvesting powered wireless sensor networks | |
WO2016189995A1 (en) | Communication system, smart meter, gateway device, and communication program | |
Mazloum et al. | DCW-MAC: An energy efficient medium access scheme using duty-cycled low-power wake-up receivers | |
EP3171661A1 (en) | Wireless ad hoc network, center node, dynamic selection method and storage medium | |
Zhao et al. | An energy-efficient self-adaptive duty cycle MAC protocol for traffic-dynamic wireless sensor networks | |
WO2012064178A1 (en) | Method for use in providing an adaptable sensor nodes schedule in a wireless sensor network | |
CN104735756A (en) | Self-adaptive duty ratio adjusting method based on residual energy in sensor network | |
Shelke et al. | Energy management in wireless sensor network | |
CN102724741B (en) | Micro-cycle-based sleep method adapted to routing nodes in wireless sensor network | |
CN102917467B (en) | Asynchronous reservation channel access method of wireless sensor network | |
WO2015009138A2 (en) | A system and method for managing sleeping mode of wireless nodes in a wireless sensor network | |
CN105939537B (en) | Wireless sensor node module, system and method for reducing data transmission delay | |
CN104703257A (en) | Wireless sensor network distributed clustering and sleep scheduling method specific to target detection | |
Siddiqui et al. | ES-MAC: Energy efficient Sensor-MAC protocol for wireless sensor networks | |
Zhang et al. | An enhanced coverage control protocol for wireless sensor networks |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 11838287 Country of ref document: EP Kind code of ref document: A1 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 11838287 Country of ref document: EP Kind code of ref document: A1 |